Periodically wake up the thread in monitor::wait

There is a small window where a thread can go to sleep in
Monitor::wait after releasing the lock but before another thread
notifies the monitor and updates the on-deck thread.

A simple approach to fix this problem is to wake-up the Monitor::wait
every 10 milliseconds and check if it is on-deck.

Change-Id: I4b9abda89d1fc653cdae2b4c84cdda01efde1cf2


[ROCm/clr commit: 5079410c94]

projects/clr/rocclr/thread/monitor.cpp

@@ -251,7 +251,7 @@ void Monitor::wait() {
     }
     // now go to sleep
     else {
-      suspend.wait();
+      suspend.timedWait(10);
     }
     spinCount++;
   }

projects/clr/rocclr/thread/semaphore.cpp

@@ -74,7 +74,7 @@ void Semaphore::post() {
 // We have threads waiting on this event.
 #ifdef _WIN32
     ReleaseSemaphore(static_cast<HANDLE>(handle_), 1, NULL);
-#else  // !_WIN32
+#else   // !_WIN32
     if (0 != sem_post(&sem_)) {
       fatal("sem_post() failed");
     }
@@ -100,4 +100,40 @@ void Semaphore::wait() {
 #endif  // !_WIN32
 }
 
+void Semaphore::timedWait(int millis) {
+  if (state_-- > 0) {
+    return;
+  }
+
+#ifdef _WIN32
+  DWORD status = WaitForSingleObject(static_cast<HANDLE>(handle_), millis);
+  if (WAIT_OBJECT_0 != status && WAIT_TIMEOUT != status) {
+    fatal("WaitForSingleObject failed");
+  }
+#else   // !_WIN32
+  struct timespec ts;
+
+  if (clock_gettime(CLOCK_REALTIME, &ts) == -1) {
+    fatal("clock_gettime() failed");
+  }
+
+  ts.tv_sec += millis / 1000;
+  ts.tv_nsec += ((long)millis % 1000) * 1000000;
+
+  if (ts.tv_nsec >= 1000000000) {
+    ts.tv_sec += 1;
+    ts.tv_nsec -= 1000000000;
+  }
+
+  int status;
+  while ((status = sem_timedwait(&sem_, &ts)) != 0) {
+    if (ETIMEDOUT == errno) {
+      break;
+    } else if (EINTR != errno) {
+      fatal("sem_wait() failed");
+    }
+  }
+#endif  // !_WIN32
+}
+
 }  // namespace amd

projects/clr/rocclr/thread/semaphore.hpp

@@ -58,6 +58,7 @@ public:
 
   //! \brief Decrement this semaphore
   void wait();
+  void timedWait(int millis);
 
   //! \brief Increment this semaphore
   void post();