1 /* 2 * Copyright (C) 2008 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 "java_lang_Thread.h" 18 19 #include "common_throws.h" 20 #include "jni/jni_internal.h" 21 #include "mirror/object.h" 22 #include "monitor.h" 23 #include "native_util.h" 24 #include "nativehelper/jni_macros.h" 25 #include "nativehelper/scoped_utf_chars.h" 26 #include "scoped_fast_native_object_access-inl.h" 27 #include "scoped_thread_state_change-inl.h" 28 #include "thread.h" 29 #include "thread_list.h" 30 #include "verify_object.h" 31 32 namespace art { 33 34 static jobject Thread_currentThread(JNIEnv* env, jclass) { 35 ScopedFastNativeObjectAccess soa(env); 36 return soa.AddLocalReference<jobject>(soa.Self()->GetPeer()); 37 } 38 39 static jboolean Thread_interrupted(JNIEnv* env, jclass) { 40 return static_cast<JNIEnvExt*>(env)->GetSelf()->Interrupted() ? JNI_TRUE : JNI_FALSE; 41 } 42 43 static jboolean Thread_isInterrupted(JNIEnv* env, jobject java_thread) { 44 ScopedFastNativeObjectAccess soa(env); 45 MutexLock mu(soa.Self(), *Locks::thread_list_lock_); 46 Thread* thread = Thread::FromManagedThread(soa, java_thread); 47 return (thread != nullptr) ? thread->IsInterrupted() : JNI_FALSE; 48 } 49 50 static void Thread_nativeCreate(JNIEnv* env, jclass, jobject java_thread, jlong stack_size, 51 jboolean daemon) { 52 // There are sections in the zygote that forbid thread creation. 53 Runtime* runtime = Runtime::Current(); 54 if (runtime->IsZygote() && runtime->IsZygoteNoThreadSection()) { 55 jclass internal_error = env->FindClass("java/lang/InternalError"); 56 CHECK(internal_error != nullptr); 57 env->ThrowNew(internal_error, "Cannot create threads in zygote"); 58 return; 59 } 60 61 Thread::CreateNativeThread(env, java_thread, stack_size, daemon == JNI_TRUE); 62 } 63 64 static jint Thread_nativeGetStatus(JNIEnv* env, jobject java_thread, jboolean has_been_started) { 65 // Ordinals from Java's Thread.State. 66 const jint kJavaNew = 0; 67 const jint kJavaRunnable = 1; 68 const jint kJavaBlocked = 2; 69 const jint kJavaWaiting = 3; 70 const jint kJavaTimedWaiting = 4; 71 const jint kJavaTerminated = 5; 72 73 ScopedObjectAccess soa(env); 74 ThreadState internal_thread_state = (has_been_started ? kTerminated : kStarting); 75 MutexLock mu(soa.Self(), *Locks::thread_list_lock_); 76 Thread* thread = Thread::FromManagedThread(soa, java_thread); 77 if (thread != nullptr) { 78 internal_thread_state = thread->GetState(); 79 } 80 switch (internal_thread_state) { 81 case kTerminated: return kJavaTerminated; 82 case kRunnable: return kJavaRunnable; 83 case kTimedWaiting: return kJavaTimedWaiting; 84 case kSleeping: return kJavaTimedWaiting; 85 case kBlocked: return kJavaBlocked; 86 case kWaiting: return kJavaWaiting; 87 case kStarting: return kJavaNew; 88 case kNative: return kJavaRunnable; 89 case kWaitingForTaskProcessor: return kJavaWaiting; 90 case kWaitingForLockInflation: return kJavaWaiting; 91 case kWaitingForGcToComplete: return kJavaWaiting; 92 case kWaitingPerformingGc: return kJavaWaiting; 93 case kWaitingForCheckPointsToRun: return kJavaWaiting; 94 case kWaitingForDebuggerSend: return kJavaWaiting; 95 case kWaitingForDebuggerToAttach: return kJavaWaiting; 96 case kWaitingInMainDebuggerLoop: return kJavaWaiting; 97 case kWaitingForDebuggerSuspension: return kJavaWaiting; 98 case kWaitingForDeoptimization: return kJavaWaiting; 99 case kWaitingForGetObjectsAllocated: return kJavaWaiting; 100 case kWaitingForJniOnLoad: return kJavaWaiting; 101 case kWaitingForSignalCatcherOutput: return kJavaWaiting; 102 case kWaitingInMainSignalCatcherLoop: return kJavaWaiting; 103 case kWaitingForMethodTracingStart: return kJavaWaiting; 104 case kWaitingForVisitObjects: return kJavaWaiting; 105 case kWaitingWeakGcRootRead: return kJavaRunnable; 106 case kWaitingForGcThreadFlip: return kJavaWaiting; 107 case kNativeForAbort: return kJavaWaiting; 108 case kSuspended: return kJavaRunnable; 109 // Don't add a 'default' here so the compiler can spot incompatible enum changes. 110 } 111 LOG(ERROR) << "Unexpected thread state: " << internal_thread_state; 112 return -1; // Unreachable. 113 } 114 115 static jboolean Thread_holdsLock(JNIEnv* env, jclass, jobject java_object) { 116 ScopedObjectAccess soa(env); 117 ObjPtr<mirror::Object> object = soa.Decode<mirror::Object>(java_object); 118 if (object == nullptr) { 119 ThrowNullPointerException("object == null"); 120 return JNI_FALSE; 121 } 122 Thread* thread = soa.Self(); 123 return thread->HoldsLock(object); 124 } 125 126 static void Thread_interrupt0(JNIEnv* env, jobject java_thread) { 127 ScopedFastNativeObjectAccess soa(env); 128 MutexLock mu(soa.Self(), *Locks::thread_list_lock_); 129 Thread* thread = Thread::FromManagedThread(soa, java_thread); 130 if (thread != nullptr) { 131 thread->Interrupt(soa.Self()); 132 } 133 } 134 135 static void Thread_setNativeName(JNIEnv* env, jobject peer, jstring java_name) { 136 ScopedUtfChars name(env, java_name); 137 { 138 ScopedObjectAccess soa(env); 139 if (soa.Decode<mirror::Object>(peer) == soa.Self()->GetPeer()) { 140 soa.Self()->SetThreadName(name.c_str()); 141 return; 142 } 143 } 144 // Suspend thread to avoid it from killing itself while we set its name. We don't just hold the 145 // thread list lock to avoid this, as setting the thread name causes mutator to lock/unlock 146 // in the DDMS send code. 147 ThreadList* thread_list = Runtime::Current()->GetThreadList(); 148 bool timed_out; 149 // Take suspend thread lock to avoid races with threads trying to suspend this one. 150 Thread* thread = thread_list->SuspendThreadByPeer(peer, 151 /* request_suspension= */ true, 152 SuspendReason::kInternal, 153 &timed_out); 154 if (thread != nullptr) { 155 { 156 ScopedObjectAccess soa(env); 157 thread->SetThreadName(name.c_str()); 158 } 159 bool resumed = thread_list->Resume(thread, SuspendReason::kInternal); 160 DCHECK(resumed); 161 } else if (timed_out) { 162 LOG(ERROR) << "Trying to set thread name to '" << name.c_str() << "' failed as the thread " 163 "failed to suspend within a generous timeout."; 164 } 165 } 166 167 /* 168 * Alter the priority of the specified thread. "new_priority" will range 169 * from Thread.MIN_PRIORITY to Thread.MAX_PRIORITY (1-10), with "normal" 170 * threads at Thread.NORM_PRIORITY (5). 171 */ 172 static void Thread_setPriority0(JNIEnv* env, jobject java_thread, jint new_priority) { 173 ScopedObjectAccess soa(env); 174 MutexLock mu(soa.Self(), *Locks::thread_list_lock_); 175 Thread* thread = Thread::FromManagedThread(soa, java_thread); 176 if (thread != nullptr) { 177 thread->SetNativePriority(new_priority); 178 } 179 } 180 181 static void Thread_sleep(JNIEnv* env, jclass, jobject java_lock, jlong ms, jint ns) { 182 ScopedFastNativeObjectAccess soa(env); 183 ObjPtr<mirror::Object> lock = soa.Decode<mirror::Object>(java_lock); 184 Monitor::Wait(Thread::Current(), lock.Ptr(), ms, ns, true, kSleeping); 185 } 186 187 /* 188 * Causes the thread to temporarily pause and allow other threads to execute. 189 * 190 * The exact behavior is poorly defined. Some discussion here: 191 * http://www.cs.umd.edu/~pugh/java/memoryModel/archive/0944.html 192 */ 193 static void Thread_yield(JNIEnv*, jobject) { 194 sched_yield(); 195 } 196 197 static JNINativeMethod gMethods[] = { 198 FAST_NATIVE_METHOD(Thread, currentThread, "()Ljava/lang/Thread;"), 199 FAST_NATIVE_METHOD(Thread, interrupted, "()Z"), 200 FAST_NATIVE_METHOD(Thread, isInterrupted, "()Z"), 201 NATIVE_METHOD(Thread, nativeCreate, "(Ljava/lang/Thread;JZ)V"), 202 NATIVE_METHOD(Thread, nativeGetStatus, "(Z)I"), 203 NATIVE_METHOD(Thread, holdsLock, "(Ljava/lang/Object;)Z"), 204 FAST_NATIVE_METHOD(Thread, interrupt0, "()V"), 205 NATIVE_METHOD(Thread, setNativeName, "(Ljava/lang/String;)V"), 206 NATIVE_METHOD(Thread, setPriority0, "(I)V"), 207 FAST_NATIVE_METHOD(Thread, sleep, "(Ljava/lang/Object;JI)V"), 208 NATIVE_METHOD(Thread, yield, "()V"), 209 }; 210 211 void register_java_lang_Thread(JNIEnv* env) { 212 REGISTER_NATIVE_METHODS("java/lang/Thread"); 213 } 214 215 } // namespace art 216
