llvm-project/compiler-rt/test/tsan/signal_recursive.cc

132 lines
3.4 KiB
C++

// RUN: %clang_tsan -O1 %s -o %t && %run %t 2>&1 | FileCheck %s
// Test case for recursive signal handlers, adopted from:
// https://code.google.com/p/thread-sanitizer/issues/detail?id=71
#include <pthread.h>
#include <semaphore.h>
#include <signal.h>
#include <unistd.h>
#include <errno.h>
#include <stdlib.h>
#include <stdio.h>
static const int kSigSuspend = SIGUSR1;
static const int kSigRestart = SIGUSR2;
static sigset_t g_suspend_handler_mask;
static sem_t g_thread_suspend_ack_sem;
static bool g_busy_thread_received_restart;
static volatile bool g_busy_thread_garbage_collected;
static void SaveRegistersInStack() {
// Mono walks thread stacks to detect unreferenced objects.
// If last object reference is kept in register the object will be collected
// This is why threads can't be suspended with something like pthread_suspend
};
static void fail(const char *what) {
fprintf(stderr, "FAILED: %s (errno=%d)\n", what, errno);
exit(1);
}
static void SuspendHandler(int sig) {
int old_errno = errno;
SaveRegistersInStack();
// Acknowledge that thread is saved and suspended
if (sem_post(&g_thread_suspend_ack_sem) != 0)
fail("sem_post failed");
do {
g_busy_thread_received_restart = false;
if (sigsuspend(&g_suspend_handler_mask) != -1 || errno != EINTR)
fail("sigsuspend failed");
} while (!g_busy_thread_received_restart);
// Acknowledge that thread restarted
if (sem_post(&g_thread_suspend_ack_sem) != 0)
fail("sem_post failed");
g_busy_thread_garbage_collected = true;
errno = old_errno;
}
static void RestartHandler(int sig) {
g_busy_thread_received_restart = true;
}
static void StopWorld(pthread_t thread) {
int result = pthread_kill(thread, kSigSuspend);
if (result != 0)
fail("pthread_kill failed");
while ((result = sem_wait(&g_thread_suspend_ack_sem)) != 0) {
if (result != EINTR) {
fail("sem_wait failed");
}
}
}
static void StartWorld(pthread_t thread) {
int result = pthread_kill(thread, kSigRestart);
if (result != 0)
fail("pthread_kill failed");
while ((result = sem_wait(&g_thread_suspend_ack_sem)) != 0) {
if (result != EINTR) {
fail("sem_wait failed");
}
}
}
static void CollectGarbage(pthread_t thread) {
StopWorld(thread);
// Walk stacks
StartWorld(thread);
}
static void Init() {
if (sigfillset(&g_suspend_handler_mask) != 0)
fail("sigfillset failed");
if (sigdelset(&g_suspend_handler_mask, kSigRestart) != 0)
fail("sigdelset failed");
if (sem_init(&g_thread_suspend_ack_sem, 0, 0) != 0)
fail("sem_init failed");
struct sigaction act = {};
act.sa_flags = SA_RESTART;
sigfillset(&act.sa_mask);
act.sa_handler = &SuspendHandler;
if (sigaction(kSigSuspend, &act, NULL) != 0)
fail("sigaction failed");
act.sa_handler = &RestartHandler;
if (sigaction(kSigRestart, &act, NULL) != 0)
fail("sigaction failed");
}
void* BusyThread(void *arg) {
(void)arg;
while (!g_busy_thread_garbage_collected) {
usleep(100); // Tsan deadlocks without these sleeps
}
return NULL;
}
int main(int argc, const char *argv[]) {
Init();
pthread_t busy_thread;
pthread_create(&busy_thread, NULL, &BusyThread, NULL);
CollectGarbage(busy_thread);
pthread_join(busy_thread, 0);
fprintf(stderr, "DONE\n");
return 0;
}
// CHECK-NOT: FAILED
// CHECK-NOT: ThreadSanitizer CHECK failed
// CHECK-NOT: WARNING: ThreadSanitizer:
// CHECK: DONE