static jboolean installSignals(Env* env) {
#if defined(DARWIN)
// On Darwin SIGBUS is generated when dereferencing NULL pointers
if (installSignalHandlerIfNeeded(SIGBUS, create_sigaction(&signalHandler_npe_so_nochaining), NULL) != 0) {
rvmThrowInternalErrorErrno(env, errno);
return FALSE;
}
#endif
if (installSignalHandlerIfNeeded(SIGSEGV, create_sigaction(&signalHandler_npe_so_nochaining), NULL) != 0) {
rvmThrowInternalErrorErrno(env, errno);
return FALSE;
}
if (installSignalHandlerIfNeeded(DUMP_THREAD_STACK_TRACE_SIGNAL, create_sigaction(&signalHandler_dump_thread), NULL) != 0) {
rvmThrowInternalErrorErrno(env, errno);
return FALSE;
}
int err;
if ((err = pthread_sigmask(0, NULL, &env->currentThread->signalMask)) != 0) {
rvmThrowInternalErrorErrno(env, err);
rvmTearDownSignals(env);
return FALSE;
}
return TRUE;
}
static jboolean installSignalHandlers(Env* env) {
struct sigaction sa;
sigemptyset(&sa.sa_mask);
sa.sa_flags = SA_SIGINFO | SA_ONSTACK;
sa.sa_sigaction = &signalHandler_npe_so;
#if defined(DARWIN)
// On Darwin SIGBUS is generated when dereferencing NULL pointers
if (sigaction(SIGBUS, &sa, NULL) != 0) {
rvmThrowInternalErrorErrno(env, errno);
rvmTearDownSignals(env);
return FALSE;
}
#endif
if (sigaction(SIGSEGV, &sa, NULL) != 0) {
rvmThrowInternalErrorErrno(env, errno);
rvmTearDownSignals(env);
return FALSE;
}
sigemptyset(&sa.sa_mask);
sa.sa_flags = SA_SIGINFO | SA_ONSTACK;
sa.sa_sigaction = &signalHandler_dump_thread;
if (sigaction(DUMP_THREAD_STACK_TRACE_SIGNAL, &sa, NULL) != 0) {
rvmThrowInternalErrorErrno(env, errno);
rvmTearDownSignals(env);
return FALSE;
}
int err;
if ((err = pthread_sigmask(0, NULL, &env->currentThread->signalMask)) != 0) {
rvmThrowInternalErrorErrno(env, err);
rvmTearDownSignals(env);
return FALSE;
}
return TRUE;
}
static jint detachThread(Env* env, jboolean ignoreAttachCount) {
env->attachCount--;
if (!ignoreAttachCount && env->attachCount > 0) {
return JNI_OK;
}
if (env->gatewayFrames) {
rvmAbort("Cannot detach thread when there are non native frames on the call stack");
}
// TODO: Release all monitors still held by this thread (should only be monitors acquired from JNI code)
Thread* thread = env->currentThread;
if (rvmExceptionOccurred(env)) {
threadExitUncaughtException(env, thread);
}
if (thread->threadObj->group) {
rvmCallVoidInstanceMethod(env, thread->threadObj->group, removeThreadMethod, thread->threadObj);
rvmExceptionClear(env);
}
// Set threadPtr to null
rvmAtomicStoreLong(&thread->threadObj->threadPtr, 0);
// Notify anyone waiting on this thread (using Thread.join())
rvmLockObject(env, thread->threadObj->lock);
rvmObjectNotifyAll(env, thread->threadObj->lock);
rvmUnlockObject(env, thread->threadObj->lock);
rvmLockThreadsList();
thread->status = THREAD_ZOMBIE;
DL_DELETE(threads, thread);
pthread_cond_broadcast(&threadsChangedCond);
rvmTearDownSignals(env);
env->currentThread = NULL;
pthread_setspecific(tlsEnvKey, NULL);
rvmUnlockThreadsList();
return JNI_OK;
}
static jint attachThread(VM* vm, Env** envPtr, char* name, Object* group, jboolean daemon) {
Env* env = *envPtr; // env is NULL if rvmAttachCurrentThread() was called. If non NULL rvmInitThreads() was called.
if (!env) {
// If the thread was already attached there's an Env* associated with the thread.
env = (Env*) pthread_getspecific(tlsEnvKey);
if (env) {
env->attachCount++;
*envPtr = env;
return JNI_OK;
}
}
if (!env) {
env = rvmCreateEnv(vm);
if (!env) goto error;
}
setThreadEnv(env);
if (rvmExceptionOccurred(env)) goto error;
Thread* thread = allocThread(env);
if (!thread) goto error;
thread->stackAddr = getStackAddress();
thread->pThread = pthread_self();
env->currentThread = thread;
rvmChangeThreadStatus(env, thread, THREAD_RUNNING);
JavaThread* threadObj = (JavaThread*) rvmAllocateObject(env, java_lang_Thread);
if (!threadObj) goto error;
rvmLockThreadsList();
if (!initThread(env, thread, threadObj)) {
rvmUnlockThreadsList();
goto error;
}
if (!rvmSetupSignals(env)) {
rvmUnlockThreadsList();
goto error;
}
DL_PREPEND(threads, thread);
pthread_cond_broadcast(&threadsChangedCond);
rvmUnlockThreadsList();
Object* threadName = NULL;
if (name) {
threadName = rvmNewStringUTF(env, name, -1);
if (!threadName) goto error_remove;
}
Method* threadConstructor = rvmGetInstanceMethod2(env, java_lang_Thread, "<init>", "(JLjava/lang/String;Ljava/lang/ThreadGroup;Z)V");
if (!threadConstructor) goto error_remove;
rvmCallNonvirtualVoidInstanceMethod(env, (Object*) threadObj, threadConstructor, PTR_TO_LONG(thread), threadName, group, daemon);
if (rvmExceptionOccurred(env)) goto error_remove;
*envPtr = env;
return JNI_OK;
error_remove:
rvmLockThreadsList();
DL_DELETE(threads, thread);
pthread_cond_broadcast(&threadsChangedCond);
rvmTearDownSignals(env);
rvmUnlockThreadsList();
error:
if (env) env->currentThread = NULL;
clearThreadEnv();
return JNI_ERR;
}
