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