[runtime] Make the stack walking code async safe when run in an async context.

[mono.git] / mono / utils / mono-semaphore.c

diff --git a/mono/utils/mono-semaphore.c b/mono/utils/mono-semaphore.c
index c6bf58885c552ae8a5b31958827aa07c21b71a98..0af2dd3a2995b8b2788baadab9bd17d7bfdf6790 100644 (file)
--- a/mono/utils/mono-semaphore.c
+++ b/mono/utils/mono-semaphore.c
@@ -17,11 +17,14 @@
 #include <unistd.h>
 #endif
 
-#if (defined(HAVE_SEMAPHORE_H) || defined(USE_MACH_SEMA))
+#if (defined (HAVE_SEMAPHORE_H) || defined (USE_MACH_SEMA)) && !defined(HOST_WIN32)
 /* sem_* or semaphore_* functions in use */
 #  ifdef USE_MACH_SEMA
 #    define TIMESPEC mach_timespec_t
 #    define WAIT_BLOCK(a,b) semaphore_timedwait (*(a), *(b))
+#  elif defined(__native_client__) && defined(USE_NEWLIB)
+#    define TIMESPEC struct timespec
+#    define WAIT_BLOCK(a, b) sem_trywait(a)
 #  elif defined(__OpenBSD__)
 #    define TIMESPEC struct timespec
 #    define WAIT_BLOCK(a) sem_trywait(a)
@@ -30,6 +33,7 @@
 #    define WAIT_BLOCK(a,b) sem_timedwait (a, b)
 #  endif
 
+#define NSEC_PER_SEC 1000000000
 int
 mono_sem_timedwait (MonoSemType *sem, guint32 timeout_ms, gboolean alertable)
 {
@@ -42,16 +46,20 @@ mono_sem_timedwait (MonoSemType *sem, guint32 timeout_ms, gboolean alertable)
 
 #ifndef USE_MACH_SEMA
        if (timeout_ms == 0)
-               return (!sem_trywait (sem));
+               return sem_trywait (sem);
 #endif
        if (timeout_ms == (guint32) 0xFFFFFFFF)
                return mono_sem_wait (sem, alertable);
 
+#ifdef USE_MACH_SEMA
+       memset (&t, 0, sizeof (TIMESPEC));
+#else
        gettimeofday (&t, NULL);
+#endif
        ts.tv_sec = timeout_ms / 1000 + t.tv_sec;
        ts.tv_nsec = (timeout_ms % 1000) * 1000000 + t.tv_usec * 1000;
-       while (ts.tv_nsec > 1000000000) {
-               ts.tv_nsec -= 1000000000;
+       while (ts.tv_nsec > NSEC_PER_SEC) {
+               ts.tv_nsec -= NSEC_PER_SEC;
                ts.tv_sec++;
        }
 #if defined(__OpenBSD__)
@@ -68,12 +76,35 @@ mono_sem_timedwait (MonoSemType *sem, guint32 timeout_ms, gboolean alertable)
        }
 #else
        copy = ts;
-       while ((res = WAIT_BLOCK (sem, &ts) == -1) && errno == EINTR) {
+       while ((res = WAIT_BLOCK (sem, &ts)) == -1 && errno == EINTR) {
+               struct timeval current;
                if (alertable)
                        return -1;
+#ifdef USE_MACH_SEMA
+               memset (&current, 0, sizeof (TIMESPEC));
+#else
+               gettimeofday (&current, NULL);
+#endif
                ts = copy;
+               ts.tv_sec -= (current.tv_sec - t.tv_sec);
+               ts.tv_nsec -= (current.tv_usec - t.tv_usec) * 1000;
+               if (ts.tv_nsec < 0) {
+                       if (ts.tv_sec <= 0) {
+                               ts.tv_nsec = 0;
+                       } else {
+                               ts.tv_sec--;
+                               ts.tv_nsec += NSEC_PER_SEC;
+                       }
+               }
+               if (ts.tv_sec < 0) {
+                       ts.tv_sec = 0;
+                       ts.tv_nsec = 0;
+               }
        }
 #endif
+       /* OSX might return > 0 for error */
+       if (res != 0)
+               res = -1;
        return res;
 }
 
@@ -82,14 +113,17 @@ mono_sem_wait (MonoSemType *sem, gboolean alertable)
 {
        int res;
 #ifndef USE_MACH_SEMA
-       while ((res = sem_wait (sem) == -1) && errno == EINTR)
+       while ((res = sem_wait (sem)) == -1 && errno == EINTR)
 #else
-       while ((res = semaphore_wait (*sem) == -1) && errno == EINTR)
+       while ((res = semaphore_wait (*sem)) == KERN_ABORTED)
 #endif
        {
                if (alertable)
                        return -1;
        }
+       /* OSX might return > 0 for error */
+       if (res != 0)
+               res = -1;
        return res;
 }
 
@@ -98,9 +132,12 @@ mono_sem_post (MonoSemType *sem)
 {
        int res;
 #ifndef USE_MACH_SEMA
-       while ((res = sem_post (sem) == -1) && errno == EINTR);
+       while ((res = sem_post (sem)) == -1 && errno == EINTR);
 #else
-       while ((res = semaphore_signal (*sem) == -1) && errno == EINTR);
+       res = semaphore_signal (*sem);
+       /* OSX might return > 0 for error */
+       if (res != KERN_SUCCESS)
+               res = -1;
 #endif
        return res;
 }
@@ -118,10 +155,19 @@ mono_sem_timedwait (MonoSemType *sem, guint32 timeout_ms, gboolean alertable)
 {
        gboolean res;
 
-       res = WaitForSingleObjectEx (*sem, timeout_ms, alertable);
-       if (!res)
+       while ((res = WaitForSingleObjectEx (*sem, timeout_ms, alertable)) == WAIT_IO_COMPLETION) {
+               if (alertable) {
+                       errno = EINTR;
+                       return -1;
+               }
+       }
+       switch (res) {
+       case WAIT_OBJECT_0:
+               return 0;    
+       // WAIT_TIMEOUT and WAIT_FAILED
+       default:
                return -1;
-       return 0;
+       }
 }
 
 int