java_lang_Thread.cc revision d9c4fc94fa618617f94e1de9af5f034549100753 
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 "common_throws.h"
18#include "debugger.h"
19#include "jni_internal.h"
20#include "monitor.h"
21#include "mirror/object.h"
22#include "scoped_thread_state_change.h"
23#include "ScopedUtfChars.h"
24#include "thread.h"
25#include "thread_list.h"
26
27namespace art {
28
29static jobject Thread_currentThread(JNIEnv* env, jclass) {
30  ScopedObjectAccess soa(env);
31  return soa.AddLocalReference<jobject>(soa.Self()->GetPeer());
32}
33
34static jboolean Thread_interrupted(JNIEnv* env, jclass) {
35  return static_cast<JNIEnvExt*>(env)->self->Interrupted() ? JNI_TRUE : JNI_FALSE;
36}
37
38static jboolean Thread_isInterrupted(JNIEnv* env, jobject java_thread) {
39  ScopedObjectAccess soa(env);
40  MutexLock mu(soa.Self(), *Locks::thread_list_lock_);
41  Thread* thread = Thread::FromManagedThread(soa, java_thread);
42  return (thread != NULL) ? thread->IsInterrupted() : JNI_FALSE;
43}
44
45static void Thread_nativeCreate(JNIEnv* env, jclass, jobject java_thread, jlong stack_size,
46                                jboolean daemon) {
47  Thread::CreateNativeThread(env, java_thread, stack_size, daemon == JNI_TRUE);
48}
49
50static jint Thread_nativeGetStatus(JNIEnv* env, jobject java_thread, jboolean has_been_started) {
51  // Ordinals from Java's Thread.State.
52  const jint kJavaNew = 0;
53  const jint kJavaRunnable = 1;
54  const jint kJavaBlocked = 2;
55  const jint kJavaWaiting = 3;
56  const jint kJavaTimedWaiting = 4;
57  const jint kJavaTerminated = 5;
58
59  ScopedObjectAccess soa(env);
60  ThreadState internal_thread_state = (has_been_started ? kTerminated : kStarting);
61  MutexLock mu(soa.Self(), *Locks::thread_list_lock_);
62  Thread* thread = Thread::FromManagedThread(soa, java_thread);
63  if (thread != NULL) {
64    internal_thread_state = thread->GetState();
65  }
66  switch (internal_thread_state) {
67    case kTerminated:                     return kJavaTerminated;
68    case kRunnable:                       return kJavaRunnable;
69    case kTimedWaiting:                   return kJavaTimedWaiting;
70    case kSleeping:                       return kJavaTimedWaiting;
71    case kBlocked:                        return kJavaBlocked;
72    case kWaiting:                        return kJavaWaiting;
73    case kStarting:                       return kJavaNew;
74    case kNative:                         return kJavaRunnable;
75    case kWaitingForGcToComplete:         return kJavaWaiting;
76    case kWaitingPerformingGc:            return kJavaWaiting;
77    case kWaitingForCheckPointsToRun:     return kJavaWaiting;
78    case kWaitingForDebuggerSend:         return kJavaWaiting;
79    case kWaitingForDebuggerToAttach:     return kJavaWaiting;
80    case kWaitingInMainDebuggerLoop:      return kJavaWaiting;
81    case kWaitingForDebuggerSuspension:   return kJavaWaiting;
82    case kWaitingForJniOnLoad:            return kJavaWaiting;
83    case kWaitingForSignalCatcherOutput:  return kJavaWaiting;
84    case kWaitingInMainSignalCatcherLoop: return kJavaWaiting;
85    case kSuspended:                      return kJavaRunnable;
86    // Don't add a 'default' here so the compiler can spot incompatible enum changes.
87  }
88  return -1;  // Unreachable.
89}
90
91static jboolean Thread_nativeHoldsLock(JNIEnv* env, jobject java_thread, jobject java_object) {
92  ScopedObjectAccess soa(env);
93  mirror::Object* object = soa.Decode<mirror::Object*>(java_object);
94  if (object == NULL) {
95    ThrowNullPointerException(NULL, "object == null");
96    return JNI_FALSE;
97  }
98  MutexLock mu(soa.Self(), *Locks::thread_list_lock_);
99  Thread* thread = Thread::FromManagedThread(soa, java_thread);
100  return thread->HoldsLock(object);
101}
102
103static void Thread_nativeInterrupt(JNIEnv* env, jobject java_thread) {
104  ScopedObjectAccess soa(env);
105  MutexLock mu(soa.Self(), *Locks::thread_list_lock_);
106  Thread* thread = Thread::FromManagedThread(soa, java_thread);
107  if (thread != NULL) {
108    thread->Interrupt();
109  }
110}
111
112static void Thread_nativeSetName(JNIEnv* env, jobject peer, jstring java_name) {
113  ScopedUtfChars name(env, java_name);
114  {
115    ScopedObjectAccess soa(env);
116    if (soa.Decode<mirror::Object*>(peer) == soa.Self()->GetPeer()) {
117      soa.Self()->SetThreadName(name.c_str());
118      return;
119    }
120  }
121  // Suspend thread to avoid it from killing itself while we set its name. We don't just hold the
122  // thread list lock to avoid this, as setting the thread name causes mutator to lock/unlock
123  // in the DDMS send code.
124  bool timed_out;
125  Thread* thread = ThreadList::SuspendThreadByPeer(peer, true, false, &timed_out);
126  if (thread != NULL) {
127    {
128      ScopedObjectAccess soa(env);
129      thread->SetThreadName(name.c_str());
130    }
131    Runtime::Current()->GetThreadList()->Resume(thread, false);
132  } else if (timed_out) {
133    LOG(ERROR) << "Trying to set thread name to '" << name.c_str() << "' failed as the thread "
134        "failed to suspend within a generous timeout.";
135  }
136}
137
138/*
139 * Alter the priority of the specified thread.  "new_priority" will range
140 * from Thread.MIN_PRIORITY to Thread.MAX_PRIORITY (1-10), with "normal"
141 * threads at Thread.NORM_PRIORITY (5).
142 */
143static void Thread_nativeSetPriority(JNIEnv* env, jobject java_thread, jint new_priority) {
144  ScopedObjectAccess soa(env);
145  MutexLock mu(soa.Self(), *Locks::thread_list_lock_);
146  Thread* thread = Thread::FromManagedThread(soa, java_thread);
147  if (thread != NULL) {
148    thread->SetNativePriority(new_priority);
149  }
150}
151
152static void Thread_sleep(JNIEnv* env, jclass, jobject java_lock, jlong ms, jint ns) {
153  ScopedObjectAccess soa(env);
154  mirror::Object* lock = soa.Decode<mirror::Object*>(java_lock);
155  Monitor::Wait(Thread::Current(), lock, ms, ns, true, kSleeping);
156}
157
158/*
159 * Causes the thread to temporarily pause and allow other threads to execute.
160 *
161 * The exact behavior is poorly defined.  Some discussion here:
162 *   http://www.cs.umd.edu/~pugh/java/memoryModel/archive/0944.html
163 */
164static void Thread_yield(JNIEnv*, jobject) {
165  sched_yield();
166}
167
168static JNINativeMethod gMethods[] = {
169  NATIVE_METHOD(Thread, currentThread, "()Ljava/lang/Thread;"),
170  NATIVE_METHOD(Thread, interrupted, "()Z"),
171  NATIVE_METHOD(Thread, isInterrupted, "()Z"),
172  NATIVE_METHOD(Thread, nativeCreate, "(Ljava/lang/Thread;JZ)V"),
173  NATIVE_METHOD(Thread, nativeGetStatus, "(Z)I"),
174  NATIVE_METHOD(Thread, nativeHoldsLock, "(Ljava/lang/Object;)Z"),
175  NATIVE_METHOD(Thread, nativeInterrupt, "()V"),
176  NATIVE_METHOD(Thread, nativeSetName, "(Ljava/lang/String;)V"),
177  NATIVE_METHOD(Thread, nativeSetPriority, "(I)V"),
178  NATIVE_METHOD(Thread, sleep, "(Ljava/lang/Object;JI)V"),
179  NATIVE_METHOD(Thread, yield, "()V"),
180};
181
182void register_java_lang_Thread(JNIEnv* env) {
183  REGISTER_NATIVE_METHODS("java/lang/Thread");
184}
185
186}  // namespace art
187