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      1 /*
      2  * Copyright (C) 2011 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #include "runtime.h"
     18 
     19 // sys/mount.h has to come before linux/fs.h due to redefinition of MS_RDONLY, MS_BIND, etc
     20 #include <sys/mount.h>
     21 #ifdef __linux__
     22 #include <linux/fs.h>
     23 #include <sys/prctl.h>
     24 #endif
     25 
     26 #include <signal.h>
     27 #include <sys/syscall.h>
     28 #include "base/memory_tool.h"
     29 #if defined(__APPLE__)
     30 #include <crt_externs.h>  // for _NSGetEnviron
     31 #endif
     32 
     33 #include <cstdio>
     34 #include <cstdlib>
     35 #include <limits>
     36 #include <memory_representation.h>
     37 #include <vector>
     38 #include <fcntl.h>
     39 
     40 #include "JniConstants.h"
     41 #include "ScopedLocalRef.h"
     42 #include "arch/arm/quick_method_frame_info_arm.h"
     43 #include "arch/arm/registers_arm.h"
     44 #include "arch/arm64/quick_method_frame_info_arm64.h"
     45 #include "arch/arm64/registers_arm64.h"
     46 #include "arch/instruction_set_features.h"
     47 #include "arch/mips/quick_method_frame_info_mips.h"
     48 #include "arch/mips/registers_mips.h"
     49 #include "arch/mips64/quick_method_frame_info_mips64.h"
     50 #include "arch/mips64/registers_mips64.h"
     51 #include "arch/x86/quick_method_frame_info_x86.h"
     52 #include "arch/x86/registers_x86.h"
     53 #include "arch/x86_64/quick_method_frame_info_x86_64.h"
     54 #include "arch/x86_64/registers_x86_64.h"
     55 #include "art_field-inl.h"
     56 #include "art_method-inl.h"
     57 #include "asm_support.h"
     58 #include "atomic.h"
     59 #include "base/arena_allocator.h"
     60 #include "base/dumpable.h"
     61 #include "base/stl_util.h"
     62 #include "base/systrace.h"
     63 #include "base/unix_file/fd_file.h"
     64 #include "class_linker-inl.h"
     65 #include "compiler_callbacks.h"
     66 #include "compiler_filter.h"
     67 #include "debugger.h"
     68 #include "elf_file.h"
     69 #include "entrypoints/runtime_asm_entrypoints.h"
     70 #include "experimental_flags.h"
     71 #include "fault_handler.h"
     72 #include "gc/accounting/card_table-inl.h"
     73 #include "gc/heap.h"
     74 #include "gc/space/image_space.h"
     75 #include "gc/space/space-inl.h"
     76 #include "handle_scope-inl.h"
     77 #include "image-inl.h"
     78 #include "instrumentation.h"
     79 #include "intern_table.h"
     80 #include "interpreter/interpreter.h"
     81 #include "jit/jit.h"
     82 #include "jni_internal.h"
     83 #include "linear_alloc.h"
     84 #include "lambda/box_table.h"
     85 #include "mirror/array.h"
     86 #include "mirror/class-inl.h"
     87 #include "mirror/class_loader.h"
     88 #include "mirror/field.h"
     89 #include "mirror/method.h"
     90 #include "mirror/stack_trace_element.h"
     91 #include "mirror/throwable.h"
     92 #include "monitor.h"
     93 #include "native/dalvik_system_DexFile.h"
     94 #include "native/dalvik_system_VMDebug.h"
     95 #include "native/dalvik_system_VMRuntime.h"
     96 #include "native/dalvik_system_VMStack.h"
     97 #include "native/dalvik_system_ZygoteHooks.h"
     98 #include "native/java_lang_Class.h"
     99 #include "native/java_lang_DexCache.h"
    100 #include "native/java_lang_Object.h"
    101 #include "native/java_lang_String.h"
    102 #include "native/java_lang_StringFactory.h"
    103 #include "native/java_lang_System.h"
    104 #include "native/java_lang_Thread.h"
    105 #include "native/java_lang_Throwable.h"
    106 #include "native/java_lang_VMClassLoader.h"
    107 #include "native/java_lang_ref_FinalizerReference.h"
    108 #include "native/java_lang_ref_Reference.h"
    109 #include "native/java_lang_reflect_AbstractMethod.h"
    110 #include "native/java_lang_reflect_Array.h"
    111 #include "native/java_lang_reflect_Constructor.h"
    112 #include "native/java_lang_reflect_Field.h"
    113 #include "native/java_lang_reflect_Method.h"
    114 #include "native/java_lang_reflect_Proxy.h"
    115 #include "native/java_util_concurrent_atomic_AtomicLong.h"
    116 #include "native/libcore_util_CharsetUtils.h"
    117 #include "native/org_apache_harmony_dalvik_ddmc_DdmServer.h"
    118 #include "native/org_apache_harmony_dalvik_ddmc_DdmVmInternal.h"
    119 #include "native/sun_misc_Unsafe.h"
    120 #include "native_bridge_art_interface.h"
    121 #include "oat_file.h"
    122 #include "oat_file_manager.h"
    123 #include "os.h"
    124 #include "parsed_options.h"
    125 #include "profiler.h"
    126 #include "jit/profile_saver.h"
    127 #include "quick/quick_method_frame_info.h"
    128 #include "reflection.h"
    129 #include "runtime_options.h"
    130 #include "ScopedLocalRef.h"
    131 #include "scoped_thread_state_change.h"
    132 #include "sigchain.h"
    133 #include "signal_catcher.h"
    134 #include "signal_set.h"
    135 #include "thread.h"
    136 #include "thread_list.h"
    137 #include "trace.h"
    138 #include "transaction.h"
    139 #include "utils.h"
    140 #include "verifier/method_verifier.h"
    141 #include "well_known_classes.h"
    142 
    143 namespace art {
    144 
    145 // If a signal isn't handled properly, enable a handler that attempts to dump the Java stack.
    146 static constexpr bool kEnableJavaStackTraceHandler = false;
    147 // Tuned by compiling GmsCore under perf and measuring time spent in DescriptorEquals for class
    148 // linking.
    149 static constexpr double kLowMemoryMinLoadFactor = 0.5;
    150 static constexpr double kLowMemoryMaxLoadFactor = 0.8;
    151 static constexpr double kNormalMinLoadFactor = 0.4;
    152 static constexpr double kNormalMaxLoadFactor = 0.7;
    153 Runtime* Runtime::instance_ = nullptr;
    154 
    155 struct TraceConfig {
    156   Trace::TraceMode trace_mode;
    157   Trace::TraceOutputMode trace_output_mode;
    158   std::string trace_file;
    159   size_t trace_file_size;
    160 };
    161 
    162 namespace {
    163 #ifdef __APPLE__
    164 inline char** GetEnviron() {
    165   // When Google Test is built as a framework on MacOS X, the environ variable
    166   // is unavailable. Apple's documentation (man environ) recommends using
    167   // _NSGetEnviron() instead.
    168   return *_NSGetEnviron();
    169 }
    170 #else
    171 // Some POSIX platforms expect you to declare environ. extern "C" makes
    172 // it reside in the global namespace.
    173 extern "C" char** environ;
    174 inline char** GetEnviron() { return environ; }
    175 #endif
    176 }  // namespace
    177 
    178 Runtime::Runtime()
    179     : resolution_method_(nullptr),
    180       imt_conflict_method_(nullptr),
    181       imt_unimplemented_method_(nullptr),
    182       instruction_set_(kNone),
    183       compiler_callbacks_(nullptr),
    184       is_zygote_(false),
    185       must_relocate_(false),
    186       is_concurrent_gc_enabled_(true),
    187       is_explicit_gc_disabled_(false),
    188       dex2oat_enabled_(true),
    189       image_dex2oat_enabled_(true),
    190       default_stack_size_(0),
    191       heap_(nullptr),
    192       max_spins_before_thin_lock_inflation_(Monitor::kDefaultMaxSpinsBeforeThinLockInflation),
    193       monitor_list_(nullptr),
    194       monitor_pool_(nullptr),
    195       thread_list_(nullptr),
    196       intern_table_(nullptr),
    197       class_linker_(nullptr),
    198       signal_catcher_(nullptr),
    199       java_vm_(nullptr),
    200       fault_message_lock_("Fault message lock"),
    201       fault_message_(""),
    202       threads_being_born_(0),
    203       shutdown_cond_(new ConditionVariable("Runtime shutdown", *Locks::runtime_shutdown_lock_)),
    204       shutting_down_(false),
    205       shutting_down_started_(false),
    206       started_(false),
    207       finished_starting_(false),
    208       vfprintf_(nullptr),
    209       exit_(nullptr),
    210       abort_(nullptr),
    211       stats_enabled_(false),
    212       is_running_on_memory_tool_(RUNNING_ON_MEMORY_TOOL),
    213       instrumentation_(),
    214       main_thread_group_(nullptr),
    215       system_thread_group_(nullptr),
    216       system_class_loader_(nullptr),
    217       dump_gc_performance_on_shutdown_(false),
    218       preinitialization_transaction_(nullptr),
    219       verify_(verifier::VerifyMode::kNone),
    220       allow_dex_file_fallback_(true),
    221       target_sdk_version_(0),
    222       implicit_null_checks_(false),
    223       implicit_so_checks_(false),
    224       implicit_suspend_checks_(false),
    225       no_sig_chain_(false),
    226       force_native_bridge_(false),
    227       is_native_bridge_loaded_(false),
    228       is_native_debuggable_(false),
    229       zygote_max_failed_boots_(0),
    230       experimental_flags_(ExperimentalFlags::kNone),
    231       oat_file_manager_(nullptr),
    232       is_low_memory_mode_(false),
    233       safe_mode_(false),
    234       dump_native_stack_on_sig_quit_(true),
    235       pruned_dalvik_cache_(false),
    236       // Initially assume we perceive jank in case the process state is never updated.
    237       process_state_(kProcessStateJankPerceptible),
    238       zygote_no_threads_(false) {
    239   CheckAsmSupportOffsetsAndSizes();
    240   std::fill(callee_save_methods_, callee_save_methods_ + arraysize(callee_save_methods_), 0u);
    241   interpreter::CheckInterpreterAsmConstants();
    242 }
    243 
    244 Runtime::~Runtime() {
    245   ScopedTrace trace("Runtime shutdown");
    246   if (is_native_bridge_loaded_) {
    247     UnloadNativeBridge();
    248   }
    249 
    250   if (dump_gc_performance_on_shutdown_) {
    251     // This can't be called from the Heap destructor below because it
    252     // could call RosAlloc::InspectAll() which needs the thread_list
    253     // to be still alive.
    254     heap_->DumpGcPerformanceInfo(LOG(INFO));
    255   }
    256 
    257   Thread* self = Thread::Current();
    258   const bool attach_shutdown_thread = self == nullptr;
    259   if (attach_shutdown_thread) {
    260     CHECK(AttachCurrentThread("Shutdown thread", false, nullptr, false));
    261     self = Thread::Current();
    262   } else {
    263     LOG(WARNING) << "Current thread not detached in Runtime shutdown";
    264   }
    265 
    266   {
    267     ScopedTrace trace2("Wait for shutdown cond");
    268     MutexLock mu(self, *Locks::runtime_shutdown_lock_);
    269     shutting_down_started_ = true;
    270     while (threads_being_born_ > 0) {
    271       shutdown_cond_->Wait(self);
    272     }
    273     shutting_down_ = true;
    274   }
    275   // Shutdown and wait for the daemons.
    276   CHECK(self != nullptr);
    277   if (IsFinishedStarting()) {
    278     ScopedTrace trace2("Waiting for Daemons");
    279     self->ClearException();
    280     self->GetJniEnv()->CallStaticVoidMethod(WellKnownClasses::java_lang_Daemons,
    281                                             WellKnownClasses::java_lang_Daemons_stop);
    282   }
    283 
    284   Trace::Shutdown();
    285 
    286   if (attach_shutdown_thread) {
    287     DetachCurrentThread();
    288     self = nullptr;
    289   }
    290 
    291   // Make sure to let the GC complete if it is running.
    292   heap_->WaitForGcToComplete(gc::kGcCauseBackground, self);
    293   heap_->DeleteThreadPool();
    294   if (jit_ != nullptr) {
    295     ScopedTrace trace2("Delete jit");
    296     VLOG(jit) << "Deleting jit thread pool";
    297     // Delete thread pool before the thread list since we don't want to wait forever on the
    298     // JIT compiler threads.
    299     jit_->DeleteThreadPool();
    300     // Similarly, stop the profile saver thread before deleting the thread list.
    301     jit_->StopProfileSaver();
    302   }
    303 
    304   // Make sure our internal threads are dead before we start tearing down things they're using.
    305   Dbg::StopJdwp();
    306   delete signal_catcher_;
    307 
    308   // Make sure all other non-daemon threads have terminated, and all daemon threads are suspended.
    309   {
    310     ScopedTrace trace2("Delete thread list");
    311     delete thread_list_;
    312   }
    313   // Delete the JIT after thread list to ensure that there is no remaining threads which could be
    314   // accessing the instrumentation when we delete it.
    315   if (jit_ != nullptr) {
    316     VLOG(jit) << "Deleting jit";
    317     jit_.reset(nullptr);
    318   }
    319 
    320   // Shutdown the fault manager if it was initialized.
    321   fault_manager.Shutdown();
    322 
    323   ScopedTrace trace2("Delete state");
    324   delete monitor_list_;
    325   delete monitor_pool_;
    326   delete class_linker_;
    327   delete heap_;
    328   delete intern_table_;
    329   delete java_vm_;
    330   delete oat_file_manager_;
    331   Thread::Shutdown();
    332   QuasiAtomic::Shutdown();
    333   verifier::MethodVerifier::Shutdown();
    334 
    335   // Destroy allocators before shutting down the MemMap because they may use it.
    336   linear_alloc_.reset();
    337   low_4gb_arena_pool_.reset();
    338   arena_pool_.reset();
    339   jit_arena_pool_.reset();
    340   MemMap::Shutdown();
    341 
    342   // TODO: acquire a static mutex on Runtime to avoid racing.
    343   CHECK(instance_ == nullptr || instance_ == this);
    344   instance_ = nullptr;
    345 }
    346 
    347 struct AbortState {
    348   void Dump(std::ostream& os) const {
    349     if (gAborting > 1) {
    350       os << "Runtime aborting --- recursively, so no thread-specific detail!\n";
    351       return;
    352     }
    353     gAborting++;
    354     os << "Runtime aborting...\n";
    355     if (Runtime::Current() == nullptr) {
    356       os << "(Runtime does not yet exist!)\n";
    357       DumpNativeStack(os, GetTid(), nullptr, "  native: ", nullptr);
    358       return;
    359     }
    360     Thread* self = Thread::Current();
    361     if (self == nullptr) {
    362       os << "(Aborting thread was not attached to runtime!)\n";
    363       DumpKernelStack(os, GetTid(), "  kernel: ", false);
    364       DumpNativeStack(os, GetTid(), nullptr, "  native: ", nullptr);
    365     } else {
    366       os << "Aborting thread:\n";
    367       if (Locks::mutator_lock_->IsExclusiveHeld(self) || Locks::mutator_lock_->IsSharedHeld(self)) {
    368         DumpThread(os, self);
    369       } else {
    370         if (Locks::mutator_lock_->SharedTryLock(self)) {
    371           DumpThread(os, self);
    372           Locks::mutator_lock_->SharedUnlock(self);
    373         }
    374       }
    375     }
    376     DumpAllThreads(os, self);
    377   }
    378 
    379   // No thread-safety analysis as we do explicitly test for holding the mutator lock.
    380   void DumpThread(std::ostream& os, Thread* self) const NO_THREAD_SAFETY_ANALYSIS {
    381     DCHECK(Locks::mutator_lock_->IsExclusiveHeld(self) || Locks::mutator_lock_->IsSharedHeld(self));
    382     self->Dump(os);
    383     if (self->IsExceptionPending()) {
    384       mirror::Throwable* exception = self->GetException();
    385       os << "Pending exception " << exception->Dump();
    386     }
    387   }
    388 
    389   void DumpAllThreads(std::ostream& os, Thread* self) const {
    390     Runtime* runtime = Runtime::Current();
    391     if (runtime != nullptr) {
    392       ThreadList* thread_list = runtime->GetThreadList();
    393       if (thread_list != nullptr) {
    394         bool tll_already_held = Locks::thread_list_lock_->IsExclusiveHeld(self);
    395         bool ml_already_held = Locks::mutator_lock_->IsSharedHeld(self);
    396         if (!tll_already_held || !ml_already_held) {
    397           os << "Dumping all threads without appropriate locks held:"
    398               << (!tll_already_held ? " thread list lock" : "")
    399               << (!ml_already_held ? " mutator lock" : "")
    400               << "\n";
    401         }
    402         os << "All threads:\n";
    403         thread_list->Dump(os);
    404       }
    405     }
    406   }
    407 };
    408 
    409 void Runtime::Abort(const char* msg) {
    410   gAborting++;  // set before taking any locks
    411 
    412   // Ensure that we don't have multiple threads trying to abort at once,
    413   // which would result in significantly worse diagnostics.
    414   MutexLock mu(Thread::Current(), *Locks::abort_lock_);
    415 
    416   // Get any pending output out of the way.
    417   fflush(nullptr);
    418 
    419   // Many people have difficulty distinguish aborts from crashes,
    420   // so be explicit.
    421   AbortState state;
    422   LOG(INTERNAL_FATAL) << Dumpable<AbortState>(state);
    423 
    424   // Sometimes we dump long messages, and the Android abort message only retains the first line.
    425   // In those cases, just log the message again, to avoid logcat limits.
    426   if (msg != nullptr && strchr(msg, '\n') != nullptr) {
    427     LOG(INTERNAL_FATAL) << msg;
    428   }
    429 
    430   // Call the abort hook if we have one.
    431   if (Runtime::Current() != nullptr && Runtime::Current()->abort_ != nullptr) {
    432     LOG(INTERNAL_FATAL) << "Calling abort hook...";
    433     Runtime::Current()->abort_();
    434     // notreached
    435     LOG(INTERNAL_FATAL) << "Unexpectedly returned from abort hook!";
    436   }
    437 
    438 #if defined(__GLIBC__)
    439   // TODO: we ought to be able to use pthread_kill(3) here (or abort(3),
    440   // which POSIX defines in terms of raise(3), which POSIX defines in terms
    441   // of pthread_kill(3)). On Linux, though, libcorkscrew can't unwind through
    442   // libpthread, which means the stacks we dump would be useless. Calling
    443   // tgkill(2) directly avoids that.
    444   syscall(__NR_tgkill, getpid(), GetTid(), SIGABRT);
    445   // TODO: LLVM installs it's own SIGABRT handler so exit to be safe... Can we disable that in LLVM?
    446   // If not, we could use sigaction(3) before calling tgkill(2) and lose this call to exit(3).
    447   exit(1);
    448 #else
    449   abort();
    450 #endif
    451   // notreached
    452 }
    453 
    454 void Runtime::PreZygoteFork() {
    455   heap_->PreZygoteFork();
    456 }
    457 
    458 void Runtime::CallExitHook(jint status) {
    459   if (exit_ != nullptr) {
    460     ScopedThreadStateChange tsc(Thread::Current(), kNative);
    461     exit_(status);
    462     LOG(WARNING) << "Exit hook returned instead of exiting!";
    463   }
    464 }
    465 
    466 void Runtime::SweepSystemWeaks(IsMarkedVisitor* visitor) {
    467   GetInternTable()->SweepInternTableWeaks(visitor);
    468   GetMonitorList()->SweepMonitorList(visitor);
    469   GetJavaVM()->SweepJniWeakGlobals(visitor);
    470   GetHeap()->SweepAllocationRecords(visitor);
    471   GetLambdaBoxTable()->SweepWeakBoxedLambdas(visitor);
    472 }
    473 
    474 bool Runtime::ParseOptions(const RuntimeOptions& raw_options,
    475                            bool ignore_unrecognized,
    476                            RuntimeArgumentMap* runtime_options) {
    477   InitLogging(/* argv */ nullptr);  // Calls Locks::Init() as a side effect.
    478   bool parsed = ParsedOptions::Parse(raw_options, ignore_unrecognized, runtime_options);
    479   if (!parsed) {
    480     LOG(ERROR) << "Failed to parse options";
    481     return false;
    482   }
    483   return true;
    484 }
    485 
    486 bool Runtime::Create(RuntimeArgumentMap&& runtime_options) {
    487   // TODO: acquire a static mutex on Runtime to avoid racing.
    488   if (Runtime::instance_ != nullptr) {
    489     return false;
    490   }
    491   instance_ = new Runtime;
    492   if (!instance_->Init(std::move(runtime_options))) {
    493     // TODO: Currently deleting the instance will abort the runtime on destruction. Now This will
    494     // leak memory, instead. Fix the destructor. b/19100793.
    495     // delete instance_;
    496     instance_ = nullptr;
    497     return false;
    498   }
    499   return true;
    500 }
    501 
    502 bool Runtime::Create(const RuntimeOptions& raw_options, bool ignore_unrecognized) {
    503   RuntimeArgumentMap runtime_options;
    504   return ParseOptions(raw_options, ignore_unrecognized, &runtime_options) &&
    505       Create(std::move(runtime_options));
    506 }
    507 
    508 static jobject CreateSystemClassLoader(Runtime* runtime) {
    509   if (runtime->IsAotCompiler() && !runtime->GetCompilerCallbacks()->IsBootImage()) {
    510     return nullptr;
    511   }
    512 
    513   ScopedObjectAccess soa(Thread::Current());
    514   ClassLinker* cl = Runtime::Current()->GetClassLinker();
    515   auto pointer_size = cl->GetImagePointerSize();
    516 
    517   StackHandleScope<2> hs(soa.Self());
    518   Handle<mirror::Class> class_loader_class(
    519       hs.NewHandle(soa.Decode<mirror::Class*>(WellKnownClasses::java_lang_ClassLoader)));
    520   CHECK(cl->EnsureInitialized(soa.Self(), class_loader_class, true, true));
    521 
    522   ArtMethod* getSystemClassLoader = class_loader_class->FindDirectMethod(
    523       "getSystemClassLoader", "()Ljava/lang/ClassLoader;", pointer_size);
    524   CHECK(getSystemClassLoader != nullptr);
    525 
    526   JValue result = InvokeWithJValues(soa, nullptr, soa.EncodeMethod(getSystemClassLoader), nullptr);
    527   JNIEnv* env = soa.Self()->GetJniEnv();
    528   ScopedLocalRef<jobject> system_class_loader(env, soa.AddLocalReference<jobject>(result.GetL()));
    529   CHECK(system_class_loader.get() != nullptr);
    530 
    531   soa.Self()->SetClassLoaderOverride(system_class_loader.get());
    532 
    533   Handle<mirror::Class> thread_class(
    534       hs.NewHandle(soa.Decode<mirror::Class*>(WellKnownClasses::java_lang_Thread)));
    535   CHECK(cl->EnsureInitialized(soa.Self(), thread_class, true, true));
    536 
    537   ArtField* contextClassLoader =
    538       thread_class->FindDeclaredInstanceField("contextClassLoader", "Ljava/lang/ClassLoader;");
    539   CHECK(contextClassLoader != nullptr);
    540 
    541   // We can't run in a transaction yet.
    542   contextClassLoader->SetObject<false>(soa.Self()->GetPeer(),
    543                                        soa.Decode<mirror::ClassLoader*>(system_class_loader.get()));
    544 
    545   return env->NewGlobalRef(system_class_loader.get());
    546 }
    547 
    548 std::string Runtime::GetPatchoatExecutable() const {
    549   if (!patchoat_executable_.empty()) {
    550     return patchoat_executable_;
    551   }
    552   std::string patchoat_executable(GetAndroidRoot());
    553   patchoat_executable += (kIsDebugBuild ? "/bin/patchoatd" : "/bin/patchoat");
    554   return patchoat_executable;
    555 }
    556 
    557 std::string Runtime::GetCompilerExecutable() const {
    558   if (!compiler_executable_.empty()) {
    559     return compiler_executable_;
    560   }
    561   std::string compiler_executable(GetAndroidRoot());
    562   compiler_executable += (kIsDebugBuild ? "/bin/dex2oatd" : "/bin/dex2oat");
    563   return compiler_executable;
    564 }
    565 
    566 bool Runtime::Start() {
    567   VLOG(startup) << "Runtime::Start entering";
    568 
    569   CHECK(!no_sig_chain_) << "A started runtime should have sig chain enabled";
    570 
    571   // If a debug host build, disable ptrace restriction for debugging and test timeout thread dump.
    572   // Only 64-bit as prctl() may fail in 32 bit userspace on a 64-bit kernel.
    573 #if defined(__linux__) && !defined(__ANDROID__) && defined(__x86_64__)
    574   if (kIsDebugBuild) {
    575     CHECK_EQ(prctl(PR_SET_PTRACER, PR_SET_PTRACER_ANY), 0);
    576   }
    577 #endif
    578 
    579   // Restore main thread state to kNative as expected by native code.
    580   Thread* self = Thread::Current();
    581 
    582   self->TransitionFromRunnableToSuspended(kNative);
    583 
    584   started_ = true;
    585 
    586   // Create the JIT either if we have to use JIT compilation or save profiling info.
    587   // TODO(calin): We use the JIT class as a proxy for JIT compilation and for
    588   // recoding profiles. Maybe we should consider changing the name to be more clear it's
    589   // not only about compiling. b/28295073.
    590   if (jit_options_->UseJitCompilation() || jit_options_->GetSaveProfilingInfo()) {
    591     std::string error_msg;
    592     if (!IsZygote()) {
    593     // If we are the zygote then we need to wait until after forking to create the code cache
    594     // due to SELinux restrictions on r/w/x memory regions.
    595       CreateJit();
    596     } else if (jit_options_->UseJitCompilation()) {
    597       if (!jit::Jit::LoadCompilerLibrary(&error_msg)) {
    598         // Try to load compiler pre zygote to reduce PSS. b/27744947
    599         LOG(WARNING) << "Failed to load JIT compiler with error " << error_msg;
    600       }
    601     }
    602   }
    603 
    604   if (!IsImageDex2OatEnabled() || !GetHeap()->HasBootImageSpace()) {
    605     ScopedObjectAccess soa(self);
    606     StackHandleScope<2> hs(soa.Self());
    607 
    608     auto class_class(hs.NewHandle<mirror::Class>(mirror::Class::GetJavaLangClass()));
    609     auto field_class(hs.NewHandle<mirror::Class>(mirror::Field::StaticClass()));
    610 
    611     class_linker_->EnsureInitialized(soa.Self(), class_class, true, true);
    612     // Field class is needed for register_java_net_InetAddress in libcore, b/28153851.
    613     class_linker_->EnsureInitialized(soa.Self(), field_class, true, true);
    614   }
    615 
    616   // InitNativeMethods needs to be after started_ so that the classes
    617   // it touches will have methods linked to the oat file if necessary.
    618   {
    619     ScopedTrace trace2("InitNativeMethods");
    620     InitNativeMethods();
    621   }
    622 
    623   // Initialize well known thread group values that may be accessed threads while attaching.
    624   InitThreadGroups(self);
    625 
    626   Thread::FinishStartup();
    627 
    628   system_class_loader_ = CreateSystemClassLoader(this);
    629 
    630   if (is_zygote_) {
    631     if (!InitZygote()) {
    632       return false;
    633     }
    634   } else {
    635     if (is_native_bridge_loaded_) {
    636       PreInitializeNativeBridge(".");
    637     }
    638     NativeBridgeAction action = force_native_bridge_
    639         ? NativeBridgeAction::kInitialize
    640         : NativeBridgeAction::kUnload;
    641     InitNonZygoteOrPostFork(self->GetJniEnv(),
    642                             /* is_system_server */ false,
    643                             action,
    644                             GetInstructionSetString(kRuntimeISA));
    645   }
    646 
    647   StartDaemonThreads();
    648 
    649   {
    650     ScopedObjectAccess soa(self);
    651     self->GetJniEnv()->locals.AssertEmpty();
    652   }
    653 
    654   VLOG(startup) << "Runtime::Start exiting";
    655   finished_starting_ = true;
    656 
    657   if (profiler_options_.IsEnabled() && !profile_output_filename_.empty()) {
    658     // User has asked for a profile using -Xenable-profiler.
    659     // Create the profile file if it doesn't exist.
    660     int fd = open(profile_output_filename_.c_str(), O_RDWR|O_CREAT|O_EXCL, 0660);
    661     if (fd >= 0) {
    662       close(fd);
    663     } else if (errno != EEXIST) {
    664       LOG(WARNING) << "Failed to access the profile file. Profiler disabled.";
    665     }
    666   }
    667 
    668   if (trace_config_.get() != nullptr && trace_config_->trace_file != "") {
    669     ScopedThreadStateChange tsc(self, kWaitingForMethodTracingStart);
    670     Trace::Start(trace_config_->trace_file.c_str(),
    671                  -1,
    672                  static_cast<int>(trace_config_->trace_file_size),
    673                  0,
    674                  trace_config_->trace_output_mode,
    675                  trace_config_->trace_mode,
    676                  0);
    677   }
    678 
    679   return true;
    680 }
    681 
    682 void Runtime::EndThreadBirth() REQUIRES(Locks::runtime_shutdown_lock_) {
    683   DCHECK_GT(threads_being_born_, 0U);
    684   threads_being_born_--;
    685   if (shutting_down_started_ && threads_being_born_ == 0) {
    686     shutdown_cond_->Broadcast(Thread::Current());
    687   }
    688 }
    689 
    690 // Do zygote-mode-only initialization.
    691 bool Runtime::InitZygote() {
    692 #ifdef __linux__
    693   // zygote goes into its own process group
    694   setpgid(0, 0);
    695 
    696   // See storage config details at http://source.android.com/tech/storage/
    697   // Create private mount namespace shared by all children
    698   if (unshare(CLONE_NEWNS) == -1) {
    699     PLOG(ERROR) << "Failed to unshare()";
    700     return false;
    701   }
    702 
    703   // Mark rootfs as being a slave so that changes from default
    704   // namespace only flow into our children.
    705   if (mount("rootfs", "/", nullptr, (MS_SLAVE | MS_REC), nullptr) == -1) {
    706     PLOG(ERROR) << "Failed to mount() rootfs as MS_SLAVE";
    707     return false;
    708   }
    709 
    710   // Create a staging tmpfs that is shared by our children; they will
    711   // bind mount storage into their respective private namespaces, which
    712   // are isolated from each other.
    713   const char* target_base = getenv("EMULATED_STORAGE_TARGET");
    714   if (target_base != nullptr) {
    715     if (mount("tmpfs", target_base, "tmpfs", MS_NOSUID | MS_NODEV,
    716               "uid=0,gid=1028,mode=0751") == -1) {
    717       PLOG(ERROR) << "Failed to mount tmpfs to " << target_base;
    718       return false;
    719     }
    720   }
    721 
    722   return true;
    723 #else
    724   UNIMPLEMENTED(FATAL);
    725   return false;
    726 #endif
    727 }
    728 
    729 void Runtime::InitNonZygoteOrPostFork(
    730     JNIEnv* env, bool is_system_server, NativeBridgeAction action, const char* isa) {
    731   is_zygote_ = false;
    732 
    733   if (is_native_bridge_loaded_) {
    734     switch (action) {
    735       case NativeBridgeAction::kUnload:
    736         UnloadNativeBridge();
    737         is_native_bridge_loaded_ = false;
    738         break;
    739 
    740       case NativeBridgeAction::kInitialize:
    741         InitializeNativeBridge(env, isa);
    742         break;
    743     }
    744   }
    745 
    746   // Create the thread pools.
    747   heap_->CreateThreadPool();
    748   // Reset the gc performance data at zygote fork so that the GCs
    749   // before fork aren't attributed to an app.
    750   heap_->ResetGcPerformanceInfo();
    751 
    752 
    753   if (!is_system_server &&
    754       !safe_mode_ &&
    755       (jit_options_->UseJitCompilation() || jit_options_->GetSaveProfilingInfo()) &&
    756       jit_.get() == nullptr) {
    757     // Note that when running ART standalone (not zygote, nor zygote fork),
    758     // the jit may have already been created.
    759     CreateJit();
    760   }
    761 
    762   StartSignalCatcher();
    763 
    764   // Start the JDWP thread. If the command-line debugger flags specified "suspend=y",
    765   // this will pause the runtime, so we probably want this to come last.
    766   Dbg::StartJdwp();
    767 }
    768 
    769 void Runtime::StartSignalCatcher() {
    770   if (!is_zygote_) {
    771     signal_catcher_ = new SignalCatcher(stack_trace_file_);
    772   }
    773 }
    774 
    775 bool Runtime::IsShuttingDown(Thread* self) {
    776   MutexLock mu(self, *Locks::runtime_shutdown_lock_);
    777   return IsShuttingDownLocked();
    778 }
    779 
    780 bool Runtime::IsDebuggable() const {
    781   const OatFile* oat_file = GetOatFileManager().GetPrimaryOatFile();
    782   return oat_file != nullptr && oat_file->IsDebuggable();
    783 }
    784 
    785 void Runtime::StartDaemonThreads() {
    786   ScopedTrace trace(__FUNCTION__);
    787   VLOG(startup) << "Runtime::StartDaemonThreads entering";
    788 
    789   Thread* self = Thread::Current();
    790 
    791   // Must be in the kNative state for calling native methods.
    792   CHECK_EQ(self->GetState(), kNative);
    793 
    794   JNIEnv* env = self->GetJniEnv();
    795   env->CallStaticVoidMethod(WellKnownClasses::java_lang_Daemons,
    796                             WellKnownClasses::java_lang_Daemons_start);
    797   if (env->ExceptionCheck()) {
    798     env->ExceptionDescribe();
    799     LOG(FATAL) << "Error starting java.lang.Daemons";
    800   }
    801 
    802   VLOG(startup) << "Runtime::StartDaemonThreads exiting";
    803 }
    804 
    805 // Attempts to open dex files from image(s). Given the image location, try to find the oat file
    806 // and open it to get the stored dex file. If the image is the first for a multi-image boot
    807 // classpath, go on and also open the other images.
    808 static bool OpenDexFilesFromImage(const std::string& image_location,
    809                                   std::vector<std::unique_ptr<const DexFile>>* dex_files,
    810                                   size_t* failures) {
    811   DCHECK(dex_files != nullptr) << "OpenDexFilesFromImage: out-param is nullptr";
    812 
    813   // Use a work-list approach, so that we can easily reuse the opening code.
    814   std::vector<std::string> image_locations;
    815   image_locations.push_back(image_location);
    816 
    817   for (size_t index = 0; index < image_locations.size(); ++index) {
    818     std::string system_filename;
    819     bool has_system = false;
    820     std::string cache_filename_unused;
    821     bool dalvik_cache_exists_unused;
    822     bool has_cache_unused;
    823     bool is_global_cache_unused;
    824     bool found_image = gc::space::ImageSpace::FindImageFilename(image_locations[index].c_str(),
    825                                                                 kRuntimeISA,
    826                                                                 &system_filename,
    827                                                                 &has_system,
    828                                                                 &cache_filename_unused,
    829                                                                 &dalvik_cache_exists_unused,
    830                                                                 &has_cache_unused,
    831                                                                 &is_global_cache_unused);
    832 
    833     if (!found_image || !has_system) {
    834       return false;
    835     }
    836 
    837     // We are falling back to non-executable use of the oat file because patching failed, presumably
    838     // due to lack of space.
    839     std::string oat_filename =
    840         ImageHeader::GetOatLocationFromImageLocation(system_filename.c_str());
    841     std::string oat_location =
    842         ImageHeader::GetOatLocationFromImageLocation(image_locations[index].c_str());
    843     // Note: in the multi-image case, the image location may end in ".jar," and not ".art." Handle
    844     //       that here.
    845     if (EndsWith(oat_location, ".jar")) {
    846       oat_location.replace(oat_location.length() - 3, 3, "oat");
    847     }
    848 
    849     std::unique_ptr<File> file(OS::OpenFileForReading(oat_filename.c_str()));
    850     if (file.get() == nullptr) {
    851       return false;
    852     }
    853     std::string error_msg;
    854     std::unique_ptr<ElfFile> elf_file(ElfFile::Open(file.get(),
    855                                                     false,
    856                                                     false,
    857                                                     /*low_4gb*/false,
    858                                                     &error_msg));
    859     if (elf_file.get() == nullptr) {
    860       return false;
    861     }
    862     std::unique_ptr<const OatFile> oat_file(
    863         OatFile::OpenWithElfFile(elf_file.release(), oat_location, nullptr, &error_msg));
    864     if (oat_file == nullptr) {
    865       LOG(WARNING) << "Unable to use '" << oat_filename << "' because " << error_msg;
    866       return false;
    867     }
    868 
    869     for (const OatFile::OatDexFile* oat_dex_file : oat_file->GetOatDexFiles()) {
    870       if (oat_dex_file == nullptr) {
    871         *failures += 1;
    872         continue;
    873       }
    874       std::unique_ptr<const DexFile> dex_file = oat_dex_file->OpenDexFile(&error_msg);
    875       if (dex_file.get() == nullptr) {
    876         *failures += 1;
    877       } else {
    878         dex_files->push_back(std::move(dex_file));
    879       }
    880     }
    881 
    882     if (index == 0) {
    883       // First file. See if this is a multi-image environment, and if so, enqueue the other images.
    884       const OatHeader& boot_oat_header = oat_file->GetOatHeader();
    885       const char* boot_cp = boot_oat_header.GetStoreValueByKey(OatHeader::kBootClassPathKey);
    886       if (boot_cp != nullptr) {
    887         gc::space::ImageSpace::ExtractMultiImageLocations(image_locations[0],
    888                                                           boot_cp,
    889                                                           &image_locations);
    890       }
    891     }
    892 
    893     Runtime::Current()->GetOatFileManager().RegisterOatFile(std::move(oat_file));
    894   }
    895   return true;
    896 }
    897 
    898 
    899 static size_t OpenDexFiles(const std::vector<std::string>& dex_filenames,
    900                            const std::vector<std::string>& dex_locations,
    901                            const std::string& image_location,
    902                            std::vector<std::unique_ptr<const DexFile>>* dex_files) {
    903   DCHECK(dex_files != nullptr) << "OpenDexFiles: out-param is nullptr";
    904   size_t failure_count = 0;
    905   if (!image_location.empty() && OpenDexFilesFromImage(image_location, dex_files, &failure_count)) {
    906     return failure_count;
    907   }
    908   failure_count = 0;
    909   for (size_t i = 0; i < dex_filenames.size(); i++) {
    910     const char* dex_filename = dex_filenames[i].c_str();
    911     const char* dex_location = dex_locations[i].c_str();
    912     std::string error_msg;
    913     if (!OS::FileExists(dex_filename)) {
    914       LOG(WARNING) << "Skipping non-existent dex file '" << dex_filename << "'";
    915       continue;
    916     }
    917     if (!DexFile::Open(dex_filename, dex_location, &error_msg, dex_files)) {
    918       LOG(WARNING) << "Failed to open .dex from file '" << dex_filename << "': " << error_msg;
    919       ++failure_count;
    920     }
    921   }
    922   return failure_count;
    923 }
    924 
    925 void Runtime::SetSentinel(mirror::Object* sentinel) {
    926   CHECK(sentinel_.Read() == nullptr);
    927   CHECK(sentinel != nullptr);
    928   CHECK(!heap_->IsMovableObject(sentinel));
    929   sentinel_ = GcRoot<mirror::Object>(sentinel);
    930 }
    931 
    932 bool Runtime::Init(RuntimeArgumentMap&& runtime_options_in) {
    933   // (b/30160149): protect subprocesses from modifications to LD_LIBRARY_PATH, etc.
    934   // Take a snapshot of the environment at the time the runtime was created, for use by Exec, etc.
    935   env_snapshot_.TakeSnapshot();
    936 
    937   RuntimeArgumentMap runtime_options(std::move(runtime_options_in));
    938   ScopedTrace trace(__FUNCTION__);
    939   CHECK_EQ(sysconf(_SC_PAGE_SIZE), kPageSize);
    940 
    941   MemMap::Init();
    942 
    943   using Opt = RuntimeArgumentMap;
    944   VLOG(startup) << "Runtime::Init -verbose:startup enabled";
    945 
    946   QuasiAtomic::Startup();
    947 
    948   oat_file_manager_ = new OatFileManager;
    949 
    950   Thread::SetSensitiveThreadHook(runtime_options.GetOrDefault(Opt::HookIsSensitiveThread));
    951   Monitor::Init(runtime_options.GetOrDefault(Opt::LockProfThreshold));
    952 
    953   boot_class_path_string_ = runtime_options.ReleaseOrDefault(Opt::BootClassPath);
    954   class_path_string_ = runtime_options.ReleaseOrDefault(Opt::ClassPath);
    955   properties_ = runtime_options.ReleaseOrDefault(Opt::PropertiesList);
    956 
    957   compiler_callbacks_ = runtime_options.GetOrDefault(Opt::CompilerCallbacksPtr);
    958   patchoat_executable_ = runtime_options.ReleaseOrDefault(Opt::PatchOat);
    959   must_relocate_ = runtime_options.GetOrDefault(Opt::Relocate);
    960   is_zygote_ = runtime_options.Exists(Opt::Zygote);
    961   is_explicit_gc_disabled_ = runtime_options.Exists(Opt::DisableExplicitGC);
    962   dex2oat_enabled_ = runtime_options.GetOrDefault(Opt::Dex2Oat);
    963   image_dex2oat_enabled_ = runtime_options.GetOrDefault(Opt::ImageDex2Oat);
    964   dump_native_stack_on_sig_quit_ = runtime_options.GetOrDefault(Opt::DumpNativeStackOnSigQuit);
    965 
    966   vfprintf_ = runtime_options.GetOrDefault(Opt::HookVfprintf);
    967   exit_ = runtime_options.GetOrDefault(Opt::HookExit);
    968   abort_ = runtime_options.GetOrDefault(Opt::HookAbort);
    969 
    970   default_stack_size_ = runtime_options.GetOrDefault(Opt::StackSize);
    971   stack_trace_file_ = runtime_options.ReleaseOrDefault(Opt::StackTraceFile);
    972 
    973   compiler_executable_ = runtime_options.ReleaseOrDefault(Opt::Compiler);
    974   compiler_options_ = runtime_options.ReleaseOrDefault(Opt::CompilerOptions);
    975   image_compiler_options_ = runtime_options.ReleaseOrDefault(Opt::ImageCompilerOptions);
    976   image_location_ = runtime_options.GetOrDefault(Opt::Image);
    977 
    978   max_spins_before_thin_lock_inflation_ =
    979       runtime_options.GetOrDefault(Opt::MaxSpinsBeforeThinLockInflation);
    980 
    981   monitor_list_ = new MonitorList;
    982   monitor_pool_ = MonitorPool::Create();
    983   thread_list_ = new ThreadList;
    984   intern_table_ = new InternTable;
    985 
    986   verify_ = runtime_options.GetOrDefault(Opt::Verify);
    987   allow_dex_file_fallback_ = !runtime_options.Exists(Opt::NoDexFileFallback);
    988 
    989   no_sig_chain_ = runtime_options.Exists(Opt::NoSigChain);
    990   force_native_bridge_ = runtime_options.Exists(Opt::ForceNativeBridge);
    991 
    992   Split(runtime_options.GetOrDefault(Opt::CpuAbiList), ',', &cpu_abilist_);
    993 
    994   fingerprint_ = runtime_options.ReleaseOrDefault(Opt::Fingerprint);
    995 
    996   if (runtime_options.GetOrDefault(Opt::Interpret)) {
    997     GetInstrumentation()->ForceInterpretOnly();
    998   }
    999 
   1000   zygote_max_failed_boots_ = runtime_options.GetOrDefault(Opt::ZygoteMaxFailedBoots);
   1001   experimental_flags_ = runtime_options.GetOrDefault(Opt::Experimental);
   1002   is_low_memory_mode_ = runtime_options.Exists(Opt::LowMemoryMode);
   1003 
   1004   {
   1005     CompilerFilter::Filter filter;
   1006     std::string filter_str = runtime_options.GetOrDefault(Opt::OatFileManagerCompilerFilter);
   1007     if (!CompilerFilter::ParseCompilerFilter(filter_str.c_str(), &filter)) {
   1008       LOG(ERROR) << "Cannot parse compiler filter " << filter_str;
   1009       return false;
   1010     }
   1011     OatFileManager::SetCompilerFilter(filter);
   1012   }
   1013 
   1014   XGcOption xgc_option = runtime_options.GetOrDefault(Opt::GcOption);
   1015   heap_ = new gc::Heap(runtime_options.GetOrDefault(Opt::MemoryInitialSize),
   1016                        runtime_options.GetOrDefault(Opt::HeapGrowthLimit),
   1017                        runtime_options.GetOrDefault(Opt::HeapMinFree),
   1018                        runtime_options.GetOrDefault(Opt::HeapMaxFree),
   1019                        runtime_options.GetOrDefault(Opt::HeapTargetUtilization),
   1020                        runtime_options.GetOrDefault(Opt::ForegroundHeapGrowthMultiplier),
   1021                        runtime_options.GetOrDefault(Opt::MemoryMaximumSize),
   1022                        runtime_options.GetOrDefault(Opt::NonMovingSpaceCapacity),
   1023                        runtime_options.GetOrDefault(Opt::Image),
   1024                        runtime_options.GetOrDefault(Opt::ImageInstructionSet),
   1025                        xgc_option.collector_type_,
   1026                        runtime_options.GetOrDefault(Opt::BackgroundGc),
   1027                        runtime_options.GetOrDefault(Opt::LargeObjectSpace),
   1028                        runtime_options.GetOrDefault(Opt::LargeObjectThreshold),
   1029                        runtime_options.GetOrDefault(Opt::ParallelGCThreads),
   1030                        runtime_options.GetOrDefault(Opt::ConcGCThreads),
   1031                        runtime_options.Exists(Opt::LowMemoryMode),
   1032                        runtime_options.GetOrDefault(Opt::LongPauseLogThreshold),
   1033                        runtime_options.GetOrDefault(Opt::LongGCLogThreshold),
   1034                        runtime_options.Exists(Opt::IgnoreMaxFootprint),
   1035                        runtime_options.GetOrDefault(Opt::UseTLAB),
   1036                        xgc_option.verify_pre_gc_heap_,
   1037                        xgc_option.verify_pre_sweeping_heap_,
   1038                        xgc_option.verify_post_gc_heap_,
   1039                        xgc_option.verify_pre_gc_rosalloc_,
   1040                        xgc_option.verify_pre_sweeping_rosalloc_,
   1041                        xgc_option.verify_post_gc_rosalloc_,
   1042                        xgc_option.gcstress_,
   1043                        runtime_options.GetOrDefault(Opt::EnableHSpaceCompactForOOM),
   1044                        runtime_options.GetOrDefault(Opt::HSpaceCompactForOOMMinIntervalsMs));
   1045 
   1046   if (!heap_->HasBootImageSpace() && !allow_dex_file_fallback_) {
   1047     LOG(ERROR) << "Dex file fallback disabled, cannot continue without image.";
   1048     return false;
   1049   }
   1050 
   1051   dump_gc_performance_on_shutdown_ = runtime_options.Exists(Opt::DumpGCPerformanceOnShutdown);
   1052 
   1053   if (runtime_options.Exists(Opt::JdwpOptions)) {
   1054     Dbg::ConfigureJdwp(runtime_options.GetOrDefault(Opt::JdwpOptions));
   1055   }
   1056 
   1057   jit_options_.reset(jit::JitOptions::CreateFromRuntimeArguments(runtime_options));
   1058   if (IsAotCompiler()) {
   1059     // If we are already the compiler at this point, we must be dex2oat. Don't create the jit in
   1060     // this case.
   1061     // If runtime_options doesn't have UseJIT set to true then CreateFromRuntimeArguments returns
   1062     // null and we don't create the jit.
   1063     jit_options_->SetUseJitCompilation(false);
   1064     jit_options_->SetSaveProfilingInfo(false);
   1065   }
   1066 
   1067   // Allocate a global table of boxed lambda objects <-> closures.
   1068   lambda_box_table_ = MakeUnique<lambda::BoxTable>();
   1069 
   1070   // Use MemMap arena pool for jit, malloc otherwise. Malloc arenas are faster to allocate but
   1071   // can't be trimmed as easily.
   1072   const bool use_malloc = IsAotCompiler();
   1073   arena_pool_.reset(new ArenaPool(use_malloc, /* low_4gb */ false));
   1074   jit_arena_pool_.reset(
   1075       new ArenaPool(/* use_malloc */ false, /* low_4gb */ false, "CompilerMetadata"));
   1076 
   1077   if (IsAotCompiler() && Is64BitInstructionSet(kRuntimeISA)) {
   1078     // 4gb, no malloc. Explanation in header.
   1079     low_4gb_arena_pool_.reset(new ArenaPool(/* use_malloc */ false, /* low_4gb */ true));
   1080   }
   1081   linear_alloc_.reset(CreateLinearAlloc());
   1082 
   1083   BlockSignals();
   1084   InitPlatformSignalHandlers();
   1085 
   1086   // Change the implicit checks flags based on runtime architecture.
   1087   switch (kRuntimeISA) {
   1088     case kArm:
   1089     case kThumb2:
   1090     case kX86:
   1091     case kArm64:
   1092     case kX86_64:
   1093     case kMips:
   1094     case kMips64:
   1095       implicit_null_checks_ = true;
   1096       // Installing stack protection does not play well with valgrind.
   1097       implicit_so_checks_ = !(RUNNING_ON_MEMORY_TOOL && kMemoryToolIsValgrind);
   1098       break;
   1099     default:
   1100       // Keep the defaults.
   1101       break;
   1102   }
   1103 
   1104   if (!no_sig_chain_) {
   1105     // Dex2Oat's Runtime does not need the signal chain or the fault handler.
   1106 
   1107     // Initialize the signal chain so that any calls to sigaction get
   1108     // correctly routed to the next in the chain regardless of whether we
   1109     // have claimed the signal or not.
   1110     InitializeSignalChain();
   1111 
   1112     if (implicit_null_checks_ || implicit_so_checks_ || implicit_suspend_checks_) {
   1113       fault_manager.Init();
   1114 
   1115       // These need to be in a specific order.  The null point check handler must be
   1116       // after the suspend check and stack overflow check handlers.
   1117       //
   1118       // Note: the instances attach themselves to the fault manager and are handled by it. The manager
   1119       //       will delete the instance on Shutdown().
   1120       if (implicit_suspend_checks_) {
   1121         new SuspensionHandler(&fault_manager);
   1122       }
   1123 
   1124       if (implicit_so_checks_) {
   1125         new StackOverflowHandler(&fault_manager);
   1126       }
   1127 
   1128       if (implicit_null_checks_) {
   1129         new NullPointerHandler(&fault_manager);
   1130       }
   1131 
   1132       if (kEnableJavaStackTraceHandler) {
   1133         new JavaStackTraceHandler(&fault_manager);
   1134       }
   1135     }
   1136   }
   1137 
   1138   java_vm_ = new JavaVMExt(this, runtime_options);
   1139 
   1140   Thread::Startup();
   1141 
   1142   // ClassLinker needs an attached thread, but we can't fully attach a thread without creating
   1143   // objects. We can't supply a thread group yet; it will be fixed later. Since we are the main
   1144   // thread, we do not get a java peer.
   1145   Thread* self = Thread::Attach("main", false, nullptr, false);
   1146   CHECK_EQ(self->GetThreadId(), ThreadList::kMainThreadId);
   1147   CHECK(self != nullptr);
   1148 
   1149   // Set us to runnable so tools using a runtime can allocate and GC by default
   1150   self->TransitionFromSuspendedToRunnable();
   1151 
   1152   // Now we're attached, we can take the heap locks and validate the heap.
   1153   GetHeap()->EnableObjectValidation();
   1154 
   1155   CHECK_GE(GetHeap()->GetContinuousSpaces().size(), 1U);
   1156   class_linker_ = new ClassLinker(intern_table_);
   1157   if (GetHeap()->HasBootImageSpace()) {
   1158     std::string error_msg;
   1159     bool result = class_linker_->InitFromBootImage(&error_msg);
   1160     if (!result) {
   1161       LOG(ERROR) << "Could not initialize from image: " << error_msg;
   1162       return false;
   1163     }
   1164     if (kIsDebugBuild) {
   1165       for (auto image_space : GetHeap()->GetBootImageSpaces()) {
   1166         image_space->VerifyImageAllocations();
   1167       }
   1168     }
   1169     if (boot_class_path_string_.empty()) {
   1170       // The bootclasspath is not explicitly specified: construct it from the loaded dex files.
   1171       const std::vector<const DexFile*>& boot_class_path = GetClassLinker()->GetBootClassPath();
   1172       std::vector<std::string> dex_locations;
   1173       dex_locations.reserve(boot_class_path.size());
   1174       for (const DexFile* dex_file : boot_class_path) {
   1175         dex_locations.push_back(dex_file->GetLocation());
   1176       }
   1177       boot_class_path_string_ = Join(dex_locations, ':');
   1178     }
   1179     {
   1180       ScopedTrace trace2("AddImageStringsToTable");
   1181       GetInternTable()->AddImagesStringsToTable(heap_->GetBootImageSpaces());
   1182     }
   1183     {
   1184       ScopedTrace trace2("MoveImageClassesToClassTable");
   1185       GetClassLinker()->AddBootImageClassesToClassTable();
   1186     }
   1187   } else {
   1188     std::vector<std::string> dex_filenames;
   1189     Split(boot_class_path_string_, ':', &dex_filenames);
   1190 
   1191     std::vector<std::string> dex_locations;
   1192     if (!runtime_options.Exists(Opt::BootClassPathLocations)) {
   1193       dex_locations = dex_filenames;
   1194     } else {
   1195       dex_locations = runtime_options.GetOrDefault(Opt::BootClassPathLocations);
   1196       CHECK_EQ(dex_filenames.size(), dex_locations.size());
   1197     }
   1198 
   1199     std::vector<std::unique_ptr<const DexFile>> boot_class_path;
   1200     if (runtime_options.Exists(Opt::BootClassPathDexList)) {
   1201       boot_class_path.swap(*runtime_options.GetOrDefault(Opt::BootClassPathDexList));
   1202     } else {
   1203       OpenDexFiles(dex_filenames,
   1204                    dex_locations,
   1205                    runtime_options.GetOrDefault(Opt::Image),
   1206                    &boot_class_path);
   1207     }
   1208     instruction_set_ = runtime_options.GetOrDefault(Opt::ImageInstructionSet);
   1209     std::string error_msg;
   1210     if (!class_linker_->InitWithoutImage(std::move(boot_class_path), &error_msg)) {
   1211       LOG(ERROR) << "Could not initialize without image: " << error_msg;
   1212       return false;
   1213     }
   1214 
   1215     // TODO: Should we move the following to InitWithoutImage?
   1216     SetInstructionSet(instruction_set_);
   1217     for (int i = 0; i < Runtime::kLastCalleeSaveType; i++) {
   1218       Runtime::CalleeSaveType type = Runtime::CalleeSaveType(i);
   1219       if (!HasCalleeSaveMethod(type)) {
   1220         SetCalleeSaveMethod(CreateCalleeSaveMethod(), type);
   1221       }
   1222     }
   1223   }
   1224 
   1225   CHECK(class_linker_ != nullptr);
   1226 
   1227   verifier::MethodVerifier::Init();
   1228 
   1229   if (runtime_options.Exists(Opt::MethodTrace)) {
   1230     trace_config_.reset(new TraceConfig());
   1231     trace_config_->trace_file = runtime_options.ReleaseOrDefault(Opt::MethodTraceFile);
   1232     trace_config_->trace_file_size = runtime_options.ReleaseOrDefault(Opt::MethodTraceFileSize);
   1233     trace_config_->trace_mode = Trace::TraceMode::kMethodTracing;
   1234     trace_config_->trace_output_mode = runtime_options.Exists(Opt::MethodTraceStreaming) ?
   1235         Trace::TraceOutputMode::kStreaming :
   1236         Trace::TraceOutputMode::kFile;
   1237   }
   1238 
   1239   {
   1240     auto&& profiler_options = runtime_options.ReleaseOrDefault(Opt::ProfilerOpts);
   1241     profile_output_filename_ = profiler_options.output_file_name_;
   1242 
   1243     // TODO: Don't do this, just change ProfilerOptions to include the output file name?
   1244     ProfilerOptions other_options(
   1245         profiler_options.enabled_,
   1246         profiler_options.period_s_,
   1247         profiler_options.duration_s_,
   1248         profiler_options.interval_us_,
   1249         profiler_options.backoff_coefficient_,
   1250         profiler_options.start_immediately_,
   1251         profiler_options.top_k_threshold_,
   1252         profiler_options.top_k_change_threshold_,
   1253         profiler_options.profile_type_,
   1254         profiler_options.max_stack_depth_);
   1255 
   1256     profiler_options_ = other_options;
   1257   }
   1258 
   1259   // TODO: move this to just be an Trace::Start argument
   1260   Trace::SetDefaultClockSource(runtime_options.GetOrDefault(Opt::ProfileClock));
   1261 
   1262   // Pre-allocate an OutOfMemoryError for the double-OOME case.
   1263   self->ThrowNewException("Ljava/lang/OutOfMemoryError;",
   1264                           "OutOfMemoryError thrown while trying to throw OutOfMemoryError; "
   1265                           "no stack trace available");
   1266   pre_allocated_OutOfMemoryError_ = GcRoot<mirror::Throwable>(self->GetException());
   1267   self->ClearException();
   1268 
   1269   // Pre-allocate a NoClassDefFoundError for the common case of failing to find a system class
   1270   // ahead of checking the application's class loader.
   1271   self->ThrowNewException("Ljava/lang/NoClassDefFoundError;",
   1272                           "Class not found using the boot class loader; no stack trace available");
   1273   pre_allocated_NoClassDefFoundError_ = GcRoot<mirror::Throwable>(self->GetException());
   1274   self->ClearException();
   1275 
   1276   // Look for a native bridge.
   1277   //
   1278   // The intended flow here is, in the case of a running system:
   1279   //
   1280   // Runtime::Init() (zygote):
   1281   //   LoadNativeBridge -> dlopen from cmd line parameter.
   1282   //  |
   1283   //  V
   1284   // Runtime::Start() (zygote):
   1285   //   No-op wrt native bridge.
   1286   //  |
   1287   //  | start app
   1288   //  V
   1289   // DidForkFromZygote(action)
   1290   //   action = kUnload -> dlclose native bridge.
   1291   //   action = kInitialize -> initialize library
   1292   //
   1293   //
   1294   // The intended flow here is, in the case of a simple dalvikvm call:
   1295   //
   1296   // Runtime::Init():
   1297   //   LoadNativeBridge -> dlopen from cmd line parameter.
   1298   //  |
   1299   //  V
   1300   // Runtime::Start():
   1301   //   DidForkFromZygote(kInitialize) -> try to initialize any native bridge given.
   1302   //   No-op wrt native bridge.
   1303   {
   1304     std::string native_bridge_file_name = runtime_options.ReleaseOrDefault(Opt::NativeBridge);
   1305     is_native_bridge_loaded_ = LoadNativeBridge(native_bridge_file_name);
   1306   }
   1307 
   1308   VLOG(startup) << "Runtime::Init exiting";
   1309 
   1310   return true;
   1311 }
   1312 
   1313 void Runtime::InitNativeMethods() {
   1314   VLOG(startup) << "Runtime::InitNativeMethods entering";
   1315   Thread* self = Thread::Current();
   1316   JNIEnv* env = self->GetJniEnv();
   1317 
   1318   // Must be in the kNative state for calling native methods (JNI_OnLoad code).
   1319   CHECK_EQ(self->GetState(), kNative);
   1320 
   1321   // First set up JniConstants, which is used by both the runtime's built-in native
   1322   // methods and libcore.
   1323   JniConstants::init(env);
   1324 
   1325   // Then set up the native methods provided by the runtime itself.
   1326   RegisterRuntimeNativeMethods(env);
   1327 
   1328   // Initialize classes used in JNI. The initialization requires runtime native
   1329   // methods to be loaded first.
   1330   WellKnownClasses::Init(env);
   1331 
   1332   // Then set up libjavacore / libopenjdk, which are just a regular JNI libraries with
   1333   // a regular JNI_OnLoad. Most JNI libraries can just use System.loadLibrary, but
   1334   // libcore can't because it's the library that implements System.loadLibrary!
   1335   {
   1336     std::string error_msg;
   1337     if (!java_vm_->LoadNativeLibrary(env, "libjavacore.so", nullptr, nullptr, &error_msg)) {
   1338       LOG(FATAL) << "LoadNativeLibrary failed for \"libjavacore.so\": " << error_msg;
   1339     }
   1340   }
   1341   {
   1342     constexpr const char* kOpenJdkLibrary = kIsDebugBuild
   1343                                                 ? "libopenjdkd.so"
   1344                                                 : "libopenjdk.so";
   1345     std::string error_msg;
   1346     if (!java_vm_->LoadNativeLibrary(env, kOpenJdkLibrary, nullptr, nullptr, &error_msg)) {
   1347       LOG(FATAL) << "LoadNativeLibrary failed for \"" << kOpenJdkLibrary << "\": " << error_msg;
   1348     }
   1349   }
   1350 
   1351   // Initialize well known classes that may invoke runtime native methods.
   1352   WellKnownClasses::LateInit(env);
   1353 
   1354   VLOG(startup) << "Runtime::InitNativeMethods exiting";
   1355 }
   1356 
   1357 void Runtime::ReclaimArenaPoolMemory() {
   1358   arena_pool_->LockReclaimMemory();
   1359 }
   1360 
   1361 void Runtime::InitThreadGroups(Thread* self) {
   1362   JNIEnvExt* env = self->GetJniEnv();
   1363   ScopedJniEnvLocalRefState env_state(env);
   1364   main_thread_group_ =
   1365       env->NewGlobalRef(env->GetStaticObjectField(
   1366           WellKnownClasses::java_lang_ThreadGroup,
   1367           WellKnownClasses::java_lang_ThreadGroup_mainThreadGroup));
   1368   CHECK(main_thread_group_ != nullptr || IsAotCompiler());
   1369   system_thread_group_ =
   1370       env->NewGlobalRef(env->GetStaticObjectField(
   1371           WellKnownClasses::java_lang_ThreadGroup,
   1372           WellKnownClasses::java_lang_ThreadGroup_systemThreadGroup));
   1373   CHECK(system_thread_group_ != nullptr || IsAotCompiler());
   1374 }
   1375 
   1376 jobject Runtime::GetMainThreadGroup() const {
   1377   CHECK(main_thread_group_ != nullptr || IsAotCompiler());
   1378   return main_thread_group_;
   1379 }
   1380 
   1381 jobject Runtime::GetSystemThreadGroup() const {
   1382   CHECK(system_thread_group_ != nullptr || IsAotCompiler());
   1383   return system_thread_group_;
   1384 }
   1385 
   1386 jobject Runtime::GetSystemClassLoader() const {
   1387   CHECK(system_class_loader_ != nullptr || IsAotCompiler());
   1388   return system_class_loader_;
   1389 }
   1390 
   1391 void Runtime::RegisterRuntimeNativeMethods(JNIEnv* env) {
   1392   register_dalvik_system_DexFile(env);
   1393   register_dalvik_system_VMDebug(env);
   1394   register_dalvik_system_VMRuntime(env);
   1395   register_dalvik_system_VMStack(env);
   1396   register_dalvik_system_ZygoteHooks(env);
   1397   register_java_lang_Class(env);
   1398   register_java_lang_DexCache(env);
   1399   register_java_lang_Object(env);
   1400   register_java_lang_ref_FinalizerReference(env);
   1401   register_java_lang_reflect_AbstractMethod(env);
   1402   register_java_lang_reflect_Array(env);
   1403   register_java_lang_reflect_Constructor(env);
   1404   register_java_lang_reflect_Field(env);
   1405   register_java_lang_reflect_Method(env);
   1406   register_java_lang_reflect_Proxy(env);
   1407   register_java_lang_ref_Reference(env);
   1408   register_java_lang_String(env);
   1409   register_java_lang_StringFactory(env);
   1410   register_java_lang_System(env);
   1411   register_java_lang_Thread(env);
   1412   register_java_lang_Throwable(env);
   1413   register_java_lang_VMClassLoader(env);
   1414   register_java_util_concurrent_atomic_AtomicLong(env);
   1415   register_libcore_util_CharsetUtils(env);
   1416   register_org_apache_harmony_dalvik_ddmc_DdmServer(env);
   1417   register_org_apache_harmony_dalvik_ddmc_DdmVmInternal(env);
   1418   register_sun_misc_Unsafe(env);
   1419 }
   1420 
   1421 void Runtime::DumpForSigQuit(std::ostream& os) {
   1422   GetClassLinker()->DumpForSigQuit(os);
   1423   GetInternTable()->DumpForSigQuit(os);
   1424   GetJavaVM()->DumpForSigQuit(os);
   1425   GetHeap()->DumpForSigQuit(os);
   1426   oat_file_manager_->DumpForSigQuit(os);
   1427   if (GetJit() != nullptr) {
   1428     GetJit()->DumpForSigQuit(os);
   1429   } else {
   1430     os << "Running non JIT\n";
   1431   }
   1432   TrackedAllocators::Dump(os);
   1433   os << "\n";
   1434 
   1435   thread_list_->DumpForSigQuit(os);
   1436   BaseMutex::DumpAll(os);
   1437 }
   1438 
   1439 void Runtime::DumpLockHolders(std::ostream& os) {
   1440   uint64_t mutator_lock_owner = Locks::mutator_lock_->GetExclusiveOwnerTid();
   1441   pid_t thread_list_lock_owner = GetThreadList()->GetLockOwner();
   1442   pid_t classes_lock_owner = GetClassLinker()->GetClassesLockOwner();
   1443   pid_t dex_lock_owner = GetClassLinker()->GetDexLockOwner();
   1444   if ((thread_list_lock_owner | classes_lock_owner | dex_lock_owner) != 0) {
   1445     os << "Mutator lock exclusive owner tid: " << mutator_lock_owner << "\n"
   1446        << "ThreadList lock owner tid: " << thread_list_lock_owner << "\n"
   1447        << "ClassLinker classes lock owner tid: " << classes_lock_owner << "\n"
   1448        << "ClassLinker dex lock owner tid: " << dex_lock_owner << "\n";
   1449   }
   1450 }
   1451 
   1452 void Runtime::SetStatsEnabled(bool new_state) {
   1453   Thread* self = Thread::Current();
   1454   MutexLock mu(self, *Locks::instrument_entrypoints_lock_);
   1455   if (new_state == true) {
   1456     GetStats()->Clear(~0);
   1457     // TODO: wouldn't it make more sense to clear _all_ threads' stats?
   1458     self->GetStats()->Clear(~0);
   1459     if (stats_enabled_ != new_state) {
   1460       GetInstrumentation()->InstrumentQuickAllocEntryPointsLocked();
   1461     }
   1462   } else if (stats_enabled_ != new_state) {
   1463     GetInstrumentation()->UninstrumentQuickAllocEntryPointsLocked();
   1464   }
   1465   stats_enabled_ = new_state;
   1466 }
   1467 
   1468 void Runtime::ResetStats(int kinds) {
   1469   GetStats()->Clear(kinds & 0xffff);
   1470   // TODO: wouldn't it make more sense to clear _all_ threads' stats?
   1471   Thread::Current()->GetStats()->Clear(kinds >> 16);
   1472 }
   1473 
   1474 int32_t Runtime::GetStat(int kind) {
   1475   RuntimeStats* stats;
   1476   if (kind < (1<<16)) {
   1477     stats = GetStats();
   1478   } else {
   1479     stats = Thread::Current()->GetStats();
   1480     kind >>= 16;
   1481   }
   1482   switch (kind) {
   1483   case KIND_ALLOCATED_OBJECTS:
   1484     return stats->allocated_objects;
   1485   case KIND_ALLOCATED_BYTES:
   1486     return stats->allocated_bytes;
   1487   case KIND_FREED_OBJECTS:
   1488     return stats->freed_objects;
   1489   case KIND_FREED_BYTES:
   1490     return stats->freed_bytes;
   1491   case KIND_GC_INVOCATIONS:
   1492     return stats->gc_for_alloc_count;
   1493   case KIND_CLASS_INIT_COUNT:
   1494     return stats->class_init_count;
   1495   case KIND_CLASS_INIT_TIME:
   1496     // Convert ns to us, reduce to 32 bits.
   1497     return static_cast<int>(stats->class_init_time_ns / 1000);
   1498   case KIND_EXT_ALLOCATED_OBJECTS:
   1499   case KIND_EXT_ALLOCATED_BYTES:
   1500   case KIND_EXT_FREED_OBJECTS:
   1501   case KIND_EXT_FREED_BYTES:
   1502     return 0;  // backward compatibility
   1503   default:
   1504     LOG(FATAL) << "Unknown statistic " << kind;
   1505     return -1;  // unreachable
   1506   }
   1507 }
   1508 
   1509 void Runtime::BlockSignals() {
   1510   SignalSet signals;
   1511   signals.Add(SIGPIPE);
   1512   // SIGQUIT is used to dump the runtime's state (including stack traces).
   1513   signals.Add(SIGQUIT);
   1514   // SIGUSR1 is used to initiate a GC.
   1515   signals.Add(SIGUSR1);
   1516   signals.Block();
   1517 }
   1518 
   1519 bool Runtime::AttachCurrentThread(const char* thread_name, bool as_daemon, jobject thread_group,
   1520                                   bool create_peer) {
   1521   ScopedTrace trace(__FUNCTION__);
   1522   return Thread::Attach(thread_name, as_daemon, thread_group, create_peer) != nullptr;
   1523 }
   1524 
   1525 void Runtime::DetachCurrentThread() {
   1526   ScopedTrace trace(__FUNCTION__);
   1527   Thread* self = Thread::Current();
   1528   if (self == nullptr) {
   1529     LOG(FATAL) << "attempting to detach thread that is not attached";
   1530   }
   1531   if (self->HasManagedStack()) {
   1532     LOG(FATAL) << *Thread::Current() << " attempting to detach while still running code";
   1533   }
   1534   thread_list_->Unregister(self);
   1535 }
   1536 
   1537 mirror::Throwable* Runtime::GetPreAllocatedOutOfMemoryError() {
   1538   mirror::Throwable* oome = pre_allocated_OutOfMemoryError_.Read();
   1539   if (oome == nullptr) {
   1540     LOG(ERROR) << "Failed to return pre-allocated OOME";
   1541   }
   1542   return oome;
   1543 }
   1544 
   1545 mirror::Throwable* Runtime::GetPreAllocatedNoClassDefFoundError() {
   1546   mirror::Throwable* ncdfe = pre_allocated_NoClassDefFoundError_.Read();
   1547   if (ncdfe == nullptr) {
   1548     LOG(ERROR) << "Failed to return pre-allocated NoClassDefFoundError";
   1549   }
   1550   return ncdfe;
   1551 }
   1552 
   1553 void Runtime::VisitConstantRoots(RootVisitor* visitor) {
   1554   // Visit the classes held as static in mirror classes, these can be visited concurrently and only
   1555   // need to be visited once per GC since they never change.
   1556   mirror::Class::VisitRoots(visitor);
   1557   mirror::Constructor::VisitRoots(visitor);
   1558   mirror::Reference::VisitRoots(visitor);
   1559   mirror::Method::VisitRoots(visitor);
   1560   mirror::StackTraceElement::VisitRoots(visitor);
   1561   mirror::String::VisitRoots(visitor);
   1562   mirror::Throwable::VisitRoots(visitor);
   1563   mirror::Field::VisitRoots(visitor);
   1564   // Visit all the primitive array types classes.
   1565   mirror::PrimitiveArray<uint8_t>::VisitRoots(visitor);   // BooleanArray
   1566   mirror::PrimitiveArray<int8_t>::VisitRoots(visitor);    // ByteArray
   1567   mirror::PrimitiveArray<uint16_t>::VisitRoots(visitor);  // CharArray
   1568   mirror::PrimitiveArray<double>::VisitRoots(visitor);    // DoubleArray
   1569   mirror::PrimitiveArray<float>::VisitRoots(visitor);     // FloatArray
   1570   mirror::PrimitiveArray<int32_t>::VisitRoots(visitor);   // IntArray
   1571   mirror::PrimitiveArray<int64_t>::VisitRoots(visitor);   // LongArray
   1572   mirror::PrimitiveArray<int16_t>::VisitRoots(visitor);   // ShortArray
   1573   // Visiting the roots of these ArtMethods is not currently required since all the GcRoots are
   1574   // null.
   1575   BufferedRootVisitor<16> buffered_visitor(visitor, RootInfo(kRootVMInternal));
   1576   const size_t pointer_size = GetClassLinker()->GetImagePointerSize();
   1577   if (HasResolutionMethod()) {
   1578     resolution_method_->VisitRoots(buffered_visitor, pointer_size);
   1579   }
   1580   if (HasImtConflictMethod()) {
   1581     imt_conflict_method_->VisitRoots(buffered_visitor, pointer_size);
   1582   }
   1583   if (imt_unimplemented_method_ != nullptr) {
   1584     imt_unimplemented_method_->VisitRoots(buffered_visitor, pointer_size);
   1585   }
   1586   for (size_t i = 0; i < kLastCalleeSaveType; ++i) {
   1587     auto* m = reinterpret_cast<ArtMethod*>(callee_save_methods_[i]);
   1588     if (m != nullptr) {
   1589       m->VisitRoots(buffered_visitor, pointer_size);
   1590     }
   1591   }
   1592 }
   1593 
   1594 void Runtime::VisitConcurrentRoots(RootVisitor* visitor, VisitRootFlags flags) {
   1595   intern_table_->VisitRoots(visitor, flags);
   1596   class_linker_->VisitRoots(visitor, flags);
   1597   heap_->VisitAllocationRecords(visitor);
   1598   if ((flags & kVisitRootFlagNewRoots) == 0) {
   1599     // Guaranteed to have no new roots in the constant roots.
   1600     VisitConstantRoots(visitor);
   1601   }
   1602   Dbg::VisitRoots(visitor);
   1603 }
   1604 
   1605 void Runtime::VisitTransactionRoots(RootVisitor* visitor) {
   1606   if (preinitialization_transaction_ != nullptr) {
   1607     preinitialization_transaction_->VisitRoots(visitor);
   1608   }
   1609 }
   1610 
   1611 void Runtime::VisitNonThreadRoots(RootVisitor* visitor) {
   1612   java_vm_->VisitRoots(visitor);
   1613   sentinel_.VisitRootIfNonNull(visitor, RootInfo(kRootVMInternal));
   1614   pre_allocated_OutOfMemoryError_.VisitRootIfNonNull(visitor, RootInfo(kRootVMInternal));
   1615   pre_allocated_NoClassDefFoundError_.VisitRootIfNonNull(visitor, RootInfo(kRootVMInternal));
   1616   verifier::MethodVerifier::VisitStaticRoots(visitor);
   1617   VisitTransactionRoots(visitor);
   1618 }
   1619 
   1620 void Runtime::VisitNonConcurrentRoots(RootVisitor* visitor) {
   1621   thread_list_->VisitRoots(visitor);
   1622   VisitNonThreadRoots(visitor);
   1623 }
   1624 
   1625 void Runtime::VisitThreadRoots(RootVisitor* visitor) {
   1626   thread_list_->VisitRoots(visitor);
   1627 }
   1628 
   1629 size_t Runtime::FlipThreadRoots(Closure* thread_flip_visitor, Closure* flip_callback,
   1630                                 gc::collector::GarbageCollector* collector) {
   1631   return thread_list_->FlipThreadRoots(thread_flip_visitor, flip_callback, collector);
   1632 }
   1633 
   1634 void Runtime::VisitRoots(RootVisitor* visitor, VisitRootFlags flags) {
   1635   VisitNonConcurrentRoots(visitor);
   1636   VisitConcurrentRoots(visitor, flags);
   1637 }
   1638 
   1639 void Runtime::VisitImageRoots(RootVisitor* visitor) {
   1640   for (auto* space : GetHeap()->GetContinuousSpaces()) {
   1641     if (space->IsImageSpace()) {
   1642       auto* image_space = space->AsImageSpace();
   1643       const auto& image_header = image_space->GetImageHeader();
   1644       for (size_t i = 0; i < ImageHeader::kImageRootsMax; ++i) {
   1645         auto* obj = image_header.GetImageRoot(static_cast<ImageHeader::ImageRoot>(i));
   1646         if (obj != nullptr) {
   1647           auto* after_obj = obj;
   1648           visitor->VisitRoot(&after_obj, RootInfo(kRootStickyClass));
   1649           CHECK_EQ(after_obj, obj);
   1650         }
   1651       }
   1652     }
   1653   }
   1654 }
   1655 
   1656 ArtMethod* Runtime::CreateImtConflictMethod(LinearAlloc* linear_alloc) {
   1657   ClassLinker* const class_linker = GetClassLinker();
   1658   ArtMethod* method = class_linker->CreateRuntimeMethod(linear_alloc);
   1659   // When compiling, the code pointer will get set later when the image is loaded.
   1660   const size_t pointer_size = GetInstructionSetPointerSize(instruction_set_);
   1661   if (IsAotCompiler()) {
   1662     method->SetEntryPointFromQuickCompiledCodePtrSize(nullptr, pointer_size);
   1663   } else {
   1664     method->SetEntryPointFromQuickCompiledCode(GetQuickImtConflictStub());
   1665   }
   1666   // Create empty conflict table.
   1667   method->SetImtConflictTable(class_linker->CreateImtConflictTable(/*count*/0u, linear_alloc),
   1668                               pointer_size);
   1669   return method;
   1670 }
   1671 
   1672 void Runtime::SetImtConflictMethod(ArtMethod* method) {
   1673   CHECK(method != nullptr);
   1674   CHECK(method->IsRuntimeMethod());
   1675   imt_conflict_method_ = method;
   1676 }
   1677 
   1678 ArtMethod* Runtime::CreateResolutionMethod() {
   1679   auto* method = GetClassLinker()->CreateRuntimeMethod(GetLinearAlloc());
   1680   // When compiling, the code pointer will get set later when the image is loaded.
   1681   if (IsAotCompiler()) {
   1682     size_t pointer_size = GetInstructionSetPointerSize(instruction_set_);
   1683     method->SetEntryPointFromQuickCompiledCodePtrSize(nullptr, pointer_size);
   1684   } else {
   1685     method->SetEntryPointFromQuickCompiledCode(GetQuickResolutionStub());
   1686   }
   1687   return method;
   1688 }
   1689 
   1690 ArtMethod* Runtime::CreateCalleeSaveMethod() {
   1691   auto* method = GetClassLinker()->CreateRuntimeMethod(GetLinearAlloc());
   1692   size_t pointer_size = GetInstructionSetPointerSize(instruction_set_);
   1693   method->SetEntryPointFromQuickCompiledCodePtrSize(nullptr, pointer_size);
   1694   DCHECK_NE(instruction_set_, kNone);
   1695   DCHECK(method->IsRuntimeMethod());
   1696   return method;
   1697 }
   1698 
   1699 void Runtime::DisallowNewSystemWeaks() {
   1700   CHECK(!kUseReadBarrier);
   1701   monitor_list_->DisallowNewMonitors();
   1702   intern_table_->ChangeWeakRootState(gc::kWeakRootStateNoReadsOrWrites);
   1703   java_vm_->DisallowNewWeakGlobals();
   1704   heap_->DisallowNewAllocationRecords();
   1705   lambda_box_table_->DisallowNewWeakBoxedLambdas();
   1706 }
   1707 
   1708 void Runtime::AllowNewSystemWeaks() {
   1709   CHECK(!kUseReadBarrier);
   1710   monitor_list_->AllowNewMonitors();
   1711   intern_table_->ChangeWeakRootState(gc::kWeakRootStateNormal);  // TODO: Do this in the sweeping.
   1712   java_vm_->AllowNewWeakGlobals();
   1713   heap_->AllowNewAllocationRecords();
   1714   lambda_box_table_->AllowNewWeakBoxedLambdas();
   1715 }
   1716 
   1717 void Runtime::BroadcastForNewSystemWeaks() {
   1718   // This is used for the read barrier case that uses the thread-local
   1719   // Thread::GetWeakRefAccessEnabled() flag.
   1720   CHECK(kUseReadBarrier);
   1721   monitor_list_->BroadcastForNewMonitors();
   1722   intern_table_->BroadcastForNewInterns();
   1723   java_vm_->BroadcastForNewWeakGlobals();
   1724   heap_->BroadcastForNewAllocationRecords();
   1725   lambda_box_table_->BroadcastForNewWeakBoxedLambdas();
   1726 }
   1727 
   1728 void Runtime::SetInstructionSet(InstructionSet instruction_set) {
   1729   instruction_set_ = instruction_set;
   1730   if ((instruction_set_ == kThumb2) || (instruction_set_ == kArm)) {
   1731     for (int i = 0; i != kLastCalleeSaveType; ++i) {
   1732       CalleeSaveType type = static_cast<CalleeSaveType>(i);
   1733       callee_save_method_frame_infos_[i] = arm::ArmCalleeSaveMethodFrameInfo(type);
   1734     }
   1735   } else if (instruction_set_ == kMips) {
   1736     for (int i = 0; i != kLastCalleeSaveType; ++i) {
   1737       CalleeSaveType type = static_cast<CalleeSaveType>(i);
   1738       callee_save_method_frame_infos_[i] = mips::MipsCalleeSaveMethodFrameInfo(type);
   1739     }
   1740   } else if (instruction_set_ == kMips64) {
   1741     for (int i = 0; i != kLastCalleeSaveType; ++i) {
   1742       CalleeSaveType type = static_cast<CalleeSaveType>(i);
   1743       callee_save_method_frame_infos_[i] = mips64::Mips64CalleeSaveMethodFrameInfo(type);
   1744     }
   1745   } else if (instruction_set_ == kX86) {
   1746     for (int i = 0; i != kLastCalleeSaveType; ++i) {
   1747       CalleeSaveType type = static_cast<CalleeSaveType>(i);
   1748       callee_save_method_frame_infos_[i] = x86::X86CalleeSaveMethodFrameInfo(type);
   1749     }
   1750   } else if (instruction_set_ == kX86_64) {
   1751     for (int i = 0; i != kLastCalleeSaveType; ++i) {
   1752       CalleeSaveType type = static_cast<CalleeSaveType>(i);
   1753       callee_save_method_frame_infos_[i] = x86_64::X86_64CalleeSaveMethodFrameInfo(type);
   1754     }
   1755   } else if (instruction_set_ == kArm64) {
   1756     for (int i = 0; i != kLastCalleeSaveType; ++i) {
   1757       CalleeSaveType type = static_cast<CalleeSaveType>(i);
   1758       callee_save_method_frame_infos_[i] = arm64::Arm64CalleeSaveMethodFrameInfo(type);
   1759     }
   1760   } else {
   1761     UNIMPLEMENTED(FATAL) << instruction_set_;
   1762   }
   1763 }
   1764 
   1765 void Runtime::SetCalleeSaveMethod(ArtMethod* method, CalleeSaveType type) {
   1766   DCHECK_LT(static_cast<int>(type), static_cast<int>(kLastCalleeSaveType));
   1767   CHECK(method != nullptr);
   1768   callee_save_methods_[type] = reinterpret_cast<uintptr_t>(method);
   1769 }
   1770 
   1771 void Runtime::RegisterAppInfo(const std::vector<std::string>& code_paths,
   1772                               const std::string& profile_output_filename,
   1773                               const std::string& foreign_dex_profile_path,
   1774                               const std::string& app_dir) {
   1775   if (jit_.get() == nullptr) {
   1776     // We are not JITing. Nothing to do.
   1777     return;
   1778   }
   1779 
   1780   VLOG(profiler) << "Register app with " << profile_output_filename
   1781       << " " << Join(code_paths, ':');
   1782 
   1783   if (profile_output_filename.empty()) {
   1784     LOG(WARNING) << "JIT profile information will not be recorded: profile filename is empty.";
   1785     return;
   1786   }
   1787   if (!FileExists(profile_output_filename)) {
   1788     LOG(WARNING) << "JIT profile information will not be recorded: profile file does not exits.";
   1789     return;
   1790   }
   1791   if (code_paths.empty()) {
   1792     LOG(WARNING) << "JIT profile information will not be recorded: code paths is empty.";
   1793     return;
   1794   }
   1795 
   1796   profile_output_filename_ = profile_output_filename;
   1797   jit_->StartProfileSaver(profile_output_filename,
   1798                           code_paths,
   1799                           foreign_dex_profile_path,
   1800                           app_dir);
   1801 }
   1802 
   1803 void Runtime::NotifyDexLoaded(const std::string& dex_location) {
   1804   VLOG(profiler) << "Notify dex loaded: " << dex_location;
   1805   // We know that if the ProfileSaver is started then we can record profile information.
   1806   if (ProfileSaver::IsStarted()) {
   1807     ProfileSaver::NotifyDexUse(dex_location);
   1808   }
   1809 }
   1810 
   1811 // Transaction support.
   1812 void Runtime::EnterTransactionMode(Transaction* transaction) {
   1813   DCHECK(IsAotCompiler());
   1814   DCHECK(transaction != nullptr);
   1815   DCHECK(!IsActiveTransaction());
   1816   preinitialization_transaction_ = transaction;
   1817 }
   1818 
   1819 void Runtime::ExitTransactionMode() {
   1820   DCHECK(IsAotCompiler());
   1821   DCHECK(IsActiveTransaction());
   1822   preinitialization_transaction_ = nullptr;
   1823 }
   1824 
   1825 bool Runtime::IsTransactionAborted() const {
   1826   if (!IsActiveTransaction()) {
   1827     return false;
   1828   } else {
   1829     DCHECK(IsAotCompiler());
   1830     return preinitialization_transaction_->IsAborted();
   1831   }
   1832 }
   1833 
   1834 void Runtime::AbortTransactionAndThrowAbortError(Thread* self, const std::string& abort_message) {
   1835   DCHECK(IsAotCompiler());
   1836   DCHECK(IsActiveTransaction());
   1837   // Throwing an exception may cause its class initialization. If we mark the transaction
   1838   // aborted before that, we may warn with a false alarm. Throwing the exception before
   1839   // marking the transaction aborted avoids that.
   1840   preinitialization_transaction_->ThrowAbortError(self, &abort_message);
   1841   preinitialization_transaction_->Abort(abort_message);
   1842 }
   1843 
   1844 void Runtime::ThrowTransactionAbortError(Thread* self) {
   1845   DCHECK(IsAotCompiler());
   1846   DCHECK(IsActiveTransaction());
   1847   // Passing nullptr means we rethrow an exception with the earlier transaction abort message.
   1848   preinitialization_transaction_->ThrowAbortError(self, nullptr);
   1849 }
   1850 
   1851 void Runtime::RecordWriteFieldBoolean(mirror::Object* obj, MemberOffset field_offset,
   1852                                       uint8_t value, bool is_volatile) const {
   1853   DCHECK(IsAotCompiler());
   1854   DCHECK(IsActiveTransaction());
   1855   preinitialization_transaction_->RecordWriteFieldBoolean(obj, field_offset, value, is_volatile);
   1856 }
   1857 
   1858 void Runtime::RecordWriteFieldByte(mirror::Object* obj, MemberOffset field_offset,
   1859                                    int8_t value, bool is_volatile) const {
   1860   DCHECK(IsAotCompiler());
   1861   DCHECK(IsActiveTransaction());
   1862   preinitialization_transaction_->RecordWriteFieldByte(obj, field_offset, value, is_volatile);
   1863 }
   1864 
   1865 void Runtime::RecordWriteFieldChar(mirror::Object* obj, MemberOffset field_offset,
   1866                                    uint16_t value, bool is_volatile) const {
   1867   DCHECK(IsAotCompiler());
   1868   DCHECK(IsActiveTransaction());
   1869   preinitialization_transaction_->RecordWriteFieldChar(obj, field_offset, value, is_volatile);
   1870 }
   1871 
   1872 void Runtime::RecordWriteFieldShort(mirror::Object* obj, MemberOffset field_offset,
   1873                                     int16_t value, bool is_volatile) const {
   1874   DCHECK(IsAotCompiler());
   1875   DCHECK(IsActiveTransaction());
   1876   preinitialization_transaction_->RecordWriteFieldShort(obj, field_offset, value, is_volatile);
   1877 }
   1878 
   1879 void Runtime::RecordWriteField32(mirror::Object* obj, MemberOffset field_offset,
   1880                                  uint32_t value, bool is_volatile) const {
   1881   DCHECK(IsAotCompiler());
   1882   DCHECK(IsActiveTransaction());
   1883   preinitialization_transaction_->RecordWriteField32(obj, field_offset, value, is_volatile);
   1884 }
   1885 
   1886 void Runtime::RecordWriteField64(mirror::Object* obj, MemberOffset field_offset,
   1887                                  uint64_t value, bool is_volatile) const {
   1888   DCHECK(IsAotCompiler());
   1889   DCHECK(IsActiveTransaction());
   1890   preinitialization_transaction_->RecordWriteField64(obj, field_offset, value, is_volatile);
   1891 }
   1892 
   1893 void Runtime::RecordWriteFieldReference(mirror::Object* obj, MemberOffset field_offset,
   1894                                         mirror::Object* value, bool is_volatile) const {
   1895   DCHECK(IsAotCompiler());
   1896   DCHECK(IsActiveTransaction());
   1897   preinitialization_transaction_->RecordWriteFieldReference(obj, field_offset, value, is_volatile);
   1898 }
   1899 
   1900 void Runtime::RecordWriteArray(mirror::Array* array, size_t index, uint64_t value) const {
   1901   DCHECK(IsAotCompiler());
   1902   DCHECK(IsActiveTransaction());
   1903   preinitialization_transaction_->RecordWriteArray(array, index, value);
   1904 }
   1905 
   1906 void Runtime::RecordStrongStringInsertion(mirror::String* s) const {
   1907   DCHECK(IsAotCompiler());
   1908   DCHECK(IsActiveTransaction());
   1909   preinitialization_transaction_->RecordStrongStringInsertion(s);
   1910 }
   1911 
   1912 void Runtime::RecordWeakStringInsertion(mirror::String* s) const {
   1913   DCHECK(IsAotCompiler());
   1914   DCHECK(IsActiveTransaction());
   1915   preinitialization_transaction_->RecordWeakStringInsertion(s);
   1916 }
   1917 
   1918 void Runtime::RecordStrongStringRemoval(mirror::String* s) const {
   1919   DCHECK(IsAotCompiler());
   1920   DCHECK(IsActiveTransaction());
   1921   preinitialization_transaction_->RecordStrongStringRemoval(s);
   1922 }
   1923 
   1924 void Runtime::RecordWeakStringRemoval(mirror::String* s) const {
   1925   DCHECK(IsAotCompiler());
   1926   DCHECK(IsActiveTransaction());
   1927   preinitialization_transaction_->RecordWeakStringRemoval(s);
   1928 }
   1929 
   1930 void Runtime::SetFaultMessage(const std::string& message) {
   1931   MutexLock mu(Thread::Current(), fault_message_lock_);
   1932   fault_message_ = message;
   1933 }
   1934 
   1935 void Runtime::AddCurrentRuntimeFeaturesAsDex2OatArguments(std::vector<std::string>* argv)
   1936     const {
   1937   if (GetInstrumentation()->InterpretOnly()) {
   1938     argv->push_back("--compiler-filter=interpret-only");
   1939   }
   1940 
   1941   // Make the dex2oat instruction set match that of the launching runtime. If we have multiple
   1942   // architecture support, dex2oat may be compiled as a different instruction-set than that
   1943   // currently being executed.
   1944   std::string instruction_set("--instruction-set=");
   1945   instruction_set += GetInstructionSetString(kRuntimeISA);
   1946   argv->push_back(instruction_set);
   1947 
   1948   std::unique_ptr<const InstructionSetFeatures> features(InstructionSetFeatures::FromCppDefines());
   1949   std::string feature_string("--instruction-set-features=");
   1950   feature_string += features->GetFeatureString();
   1951   argv->push_back(feature_string);
   1952 }
   1953 
   1954 void Runtime::CreateJit() {
   1955   CHECK(!IsAotCompiler());
   1956   if (kIsDebugBuild && GetInstrumentation()->IsForcedInterpretOnly()) {
   1957     DCHECK(!jit_options_->UseJitCompilation());
   1958   }
   1959   std::string error_msg;
   1960   jit_.reset(jit::Jit::Create(jit_options_.get(), &error_msg));
   1961   if (jit_.get() == nullptr) {
   1962     LOG(WARNING) << "Failed to create JIT " << error_msg;
   1963   }
   1964 }
   1965 
   1966 bool Runtime::CanRelocate() const {
   1967   return !IsAotCompiler() || compiler_callbacks_->IsRelocationPossible();
   1968 }
   1969 
   1970 bool Runtime::IsCompilingBootImage() const {
   1971   return IsCompiler() && compiler_callbacks_->IsBootImage();
   1972 }
   1973 
   1974 void Runtime::SetResolutionMethod(ArtMethod* method) {
   1975   CHECK(method != nullptr);
   1976   CHECK(method->IsRuntimeMethod()) << method;
   1977   resolution_method_ = method;
   1978 }
   1979 
   1980 void Runtime::SetImtUnimplementedMethod(ArtMethod* method) {
   1981   CHECK(method != nullptr);
   1982   CHECK(method->IsRuntimeMethod());
   1983   imt_unimplemented_method_ = method;
   1984 }
   1985 
   1986 void Runtime::FixupConflictTables() {
   1987   // We can only do this after the class linker is created.
   1988   const size_t pointer_size = GetClassLinker()->GetImagePointerSize();
   1989   if (imt_unimplemented_method_->GetImtConflictTable(pointer_size) == nullptr) {
   1990     imt_unimplemented_method_->SetImtConflictTable(
   1991         ClassLinker::CreateImtConflictTable(/*count*/0u, GetLinearAlloc(), pointer_size),
   1992         pointer_size);
   1993   }
   1994   if (imt_conflict_method_->GetImtConflictTable(pointer_size) == nullptr) {
   1995     imt_conflict_method_->SetImtConflictTable(
   1996           ClassLinker::CreateImtConflictTable(/*count*/0u, GetLinearAlloc(), pointer_size),
   1997           pointer_size);
   1998   }
   1999 }
   2000 
   2001 bool Runtime::IsVerificationEnabled() const {
   2002   return verify_ == verifier::VerifyMode::kEnable ||
   2003       verify_ == verifier::VerifyMode::kSoftFail;
   2004 }
   2005 
   2006 bool Runtime::IsVerificationSoftFail() const {
   2007   return verify_ == verifier::VerifyMode::kSoftFail;
   2008 }
   2009 
   2010 LinearAlloc* Runtime::CreateLinearAlloc() {
   2011   // For 64 bit compilers, it needs to be in low 4GB in the case where we are cross compiling for a
   2012   // 32 bit target. In this case, we have 32 bit pointers in the dex cache arrays which can't hold
   2013   // when we have 64 bit ArtMethod pointers.
   2014   return (IsAotCompiler() && Is64BitInstructionSet(kRuntimeISA))
   2015       ? new LinearAlloc(low_4gb_arena_pool_.get())
   2016       : new LinearAlloc(arena_pool_.get());
   2017 }
   2018 
   2019 double Runtime::GetHashTableMinLoadFactor() const {
   2020   return is_low_memory_mode_ ? kLowMemoryMinLoadFactor : kNormalMinLoadFactor;
   2021 }
   2022 
   2023 double Runtime::GetHashTableMaxLoadFactor() const {
   2024   return is_low_memory_mode_ ? kLowMemoryMaxLoadFactor : kNormalMaxLoadFactor;
   2025 }
   2026 
   2027 void Runtime::UpdateProcessState(ProcessState process_state) {
   2028   ProcessState old_process_state = process_state_;
   2029   process_state_ = process_state;
   2030   GetHeap()->UpdateProcessState(old_process_state, process_state);
   2031 }
   2032 
   2033 void Runtime::RegisterSensitiveThread() const {
   2034   Thread::SetJitSensitiveThread();
   2035 }
   2036 
   2037 // Returns true if JIT compilations are enabled. GetJit() will be not null in this case.
   2038 bool Runtime::UseJitCompilation() const {
   2039   return (jit_ != nullptr) && jit_->UseJitCompilation();
   2040 }
   2041 
   2042 // Returns true if profile saving is enabled. GetJit() will be not null in this case.
   2043 bool Runtime::SaveProfileInfo() const {
   2044   return (jit_ != nullptr) && jit_->SaveProfilingInfo();
   2045 }
   2046 
   2047 void Runtime::EnvSnapshot::TakeSnapshot() {
   2048   char** env = GetEnviron();
   2049   for (size_t i = 0; env[i] != nullptr; ++i) {
   2050     name_value_pairs_.emplace_back(new std::string(env[i]));
   2051   }
   2052   // The strings in name_value_pairs_ retain ownership of the c_str, but we assign pointers
   2053   // for quick use by GetSnapshot.  This avoids allocation and copying cost at Exec.
   2054   c_env_vector_.reset(new char*[name_value_pairs_.size() + 1]);
   2055   for (size_t i = 0; env[i] != nullptr; ++i) {
   2056     c_env_vector_[i] = const_cast<char*>(name_value_pairs_[i]->c_str());
   2057   }
   2058   c_env_vector_[name_value_pairs_.size()] = nullptr;
   2059 }
   2060 
   2061 char** Runtime::EnvSnapshot::GetSnapshot() const {
   2062   return c_env_vector_.get();
   2063 }
   2064 
   2065 }  // namespace art
   2066