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