void
ThreadStackHelper::GetStack(HangStack& aStack, nsACString& aRunnableName, bool aStackWalk)
{
aRunnableName.AssignLiteral("???");
if (!PrepareStackBuffer(aStack)) {
return;
}
Array<char, nsThread::kRunnableNameBufSize> runnableName;
runnableName[0] = '\0';
ScopedSetPtr<HangStack> _stackGuard(mStackToFill, &aStack);
ScopedSetPtr<Array<char, nsThread::kRunnableNameBufSize>>
_runnableGuard(mRunnableNameBuffer, &runnableName);
// XXX: We don't need to pass in ProfilerFeature::StackWalk to trigger
// stackwalking, as that is instead controlled by the last argument.
profiler_suspend_and_sample_thread(
mThreadId, ProfilerFeature::Privacy, *this, aStackWalk);
// Copy the name buffer allocation into the output string. We explicitly set
// the last byte to null in case we read in some corrupted data without a null
// terminator.
runnableName[nsThread::kRunnableNameBufSize - 1] = '\0';
aRunnableName.AssignASCII(runnableName.cbegin());
}
void
ThreadStackHelper::GetStack(Stack& aStack)
{
// Always run PrepareStackBuffer first to clear aStack
if (!PrepareStackBuffer(aStack)) {
// Skip and return empty aStack
return;
}
#if defined(XP_LINUX)
if (profiler_is_active()) {
// Profiler can interfere with our Linux signal handling
return;
}
if (!sInitialized) {
MOZ_ASSERT(false);
return;
}
sCurrent = this;
struct sigaction sigact = {};
sigact.sa_sigaction = SigAction;
sigemptyset(&sigact.sa_mask);
sigact.sa_flags = SA_SIGINFO | SA_RESTART;
if (::sigaction(SIGPROF, &sigact, &sOldSigAction)) {
MOZ_ASSERT(false);
return;
}
MOZ_ALWAYS_TRUE(!::syscall(SYS_tgkill, getpid(), mThreadID, SIGPROF));
MOZ_ALWAYS_TRUE(!::sem_wait(&sSem));
#elif defined(XP_WIN)
if (!mInitialized) {
MOZ_ASSERT(false);
return;
}
if (::SuspendThread(mThreadID) == DWORD(-1)) {
MOZ_ASSERT(false);
return;
}
FillStackBuffer();
MOZ_ALWAYS_TRUE(::ResumeThread(mThreadID) != DWORD(-1));
#elif defined(XP_MACOSX)
if (::thread_suspend(mThreadID) != KERN_SUCCESS) {
MOZ_ASSERT(false);
return;
}
FillStackBuffer();
MOZ_ALWAYS_TRUE(::thread_resume(mThreadID) == KERN_SUCCESS);
#endif
aStack = Move(mStackBuffer);
}
void
ThreadStackHelper::GetStack(Stack& aStack)
{
// Always run PrepareStackBuffer first to clear aStack
if (!PrepareStackBuffer(aStack)) {
// Skip and return empty aStack
return;
}
ScopedSetPtr<Stack> stackPtr(mStackToFill, &aStack);
#if defined(XP_LINUX)
if (!sInitialized) {
MOZ_ASSERT(false);
return;
}
siginfo_t uinfo = {};
uinfo.si_signo = sFillStackSignum;
uinfo.si_code = SI_QUEUE;
uinfo.si_pid = getpid();
uinfo.si_uid = getuid();
uinfo.si_value.sival_ptr = this;
if (::syscall(SYS_rt_tgsigqueueinfo, uinfo.si_pid,
mThreadID, sFillStackSignum, &uinfo)) {
// rt_tgsigqueueinfo was added in Linux 2.6.31.
// Could have failed because the syscall did not exist.
return;
}
MOZ_ALWAYS_TRUE(!::sem_wait(&mSem));
#elif defined(XP_WIN)
if (!mInitialized) {
MOZ_ASSERT(false);
return;
}
if (::SuspendThread(mThreadID) == DWORD(-1)) {
MOZ_ASSERT(false);
return;
}
FillStackBuffer();
FillThreadContext();
MOZ_ALWAYS_TRUE(::ResumeThread(mThreadID) != DWORD(-1));
#elif defined(XP_MACOSX)
# if defined(MOZ_VALGRIND) && defined(RUNNING_ON_VALGRIND)
if (RUNNING_ON_VALGRIND) {
/* thread_suspend and thread_resume sometimes hang runs on Valgrind,
for unknown reasons. So, just avoid them. See bug 1100911. */
return;
}
# endif
if (::thread_suspend(mThreadID) != KERN_SUCCESS) {
MOZ_ASSERT(false);
return;
}
FillStackBuffer();
FillThreadContext();
MOZ_ALWAYS_TRUE(::thread_resume(mThreadID) == KERN_SUCCESS);
#endif
}
