tequilaOS/platform_system_core
2
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

Add a logging handler on timeout.

Browse source 
If the signal handler doesn't fire in the given time when trying to unwind
a thread, put on a logging handler. This prevents crashes if the signal
does eventually fire.

Bug: 23783762
Change-Id: Ib7abb36b71d079a7043117697c41b535319586fd
This commit is contained in:
Christopher Ferris 2015-09-03 11:25:55 -07:00
parent 03bbd64aa9
commit d7226f9a14
1 changed files with 17 additions and 1 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

18
libbacktrace/BacktraceCurrent.cpp
View file

@ -93,6 +93,10 @@ bool BacktraceCurrent::DiscardFrame(const backtrace_frame_data_t& frame) {
static pthread_mutex_t g_sigaction_mutex = PTHREAD_MUTEX_INITIALIZER;
static void SignalLogOnly(int, siginfo_t*, void*) {
BACK_LOGE("pid %d, tid %d: Received a spurious signal %d\n", getpid(), gettid(), THREAD_SIGNAL);
}
static void SignalHandler(int, siginfo_t*, void* sigcontext) {
ThreadEntry* entry = ThreadEntry::Get(getpid(), gettid(), false);
if (!entry) {
@ -151,9 +155,21 @@ bool BacktraceCurrent::UnwindThread(size_t num_ignore_frames) {
// that we are waiting for the first Wake() call made by the thread.
bool wait_completed = entry->Wait(1);
if (!wait_completed && oldact.sa_sigaction == nullptr) {
// If the wait failed, it could be that the signal could not be delivered
// within the timeout. Add a signal handler that's simply going to log
// something so that we don't crash if the signal eventually gets
// delivered. Only do this if there isn't already an action set up.
memset(&act, 0, sizeof(act));
act.sa_sigaction = SignalLogOnly;
act.sa_flags = SA_RESTART | SA_SIGINFO | SA_ONSTACK;
sigemptyset(&act.sa_mask);
sigaction(THREAD_SIGNAL, &act, nullptr);
} else {
sigaction(THREAD_SIGNAL, &oldact, nullptr);
}
// After the thread has received the signal, allow other unwinders to
// continue.
sigaction(THREAD_SIGNAL, &oldact, nullptr);
pthread_mutex_unlock(&g_sigaction_mutex);
bool unwind_done = false;