initial commit

[ROCm/clr commit: 3694ab2ce8]

projects/clr/rocclr/runtime/thread/semaphore.cpp

@@ -0,0 +1,96 @@
+//
+// Copyright (c) 2008,2010 Advanced Micro Devices, Inc. All rights reserved.
+//
+
+#include "thread/semaphore.hpp"
+#include "thread/atomic.hpp"
+#include "thread/thread.hpp"
+
+#if defined(_WIN32) || defined(__CYGWIN__)
+# include <windows.h>
+#else // !_WIN32
+# include <semaphore.h>
+# include <errno.h>
+#endif // !_WIN32
+
+namespace amd {
+
+Semaphore::Semaphore()
+  : state_(0)
+{
+#ifdef _WIN32
+    handle_ = static_cast<void*>(CreateSemaphore(NULL, 0, LONG_MAX, NULL));
+    assert(handle_ != NULL && "CreateSemaphore failed");
+#else // !_WIN32
+    if (sem_init(&sem_, 0, 0) != 0) {
+        fatal("sem_init() failed");
+    }
+#endif // !_WIN32
+}
+
+Semaphore::~Semaphore()
+{
+#ifdef _WIN32
+    if (!CloseHandle(static_cast<HANDLE>(handle_))) {
+        fatal("CloseHandle() failed");
+    }
+#else // !_WIN32
+    if (sem_destroy(&sem_) != 0) {
+        fatal("sem_destroy() failed");
+    }
+#endif // !WIN32
+}
+
+void
+Semaphore::post()
+{
+    int state;
+    while (true) {
+        state = state_;
+        if (state > 0) {
+            // Do a load acquire.
+            MemoryOrder::fence();
+            if (state == state_) {
+                return;
+            }
+            continue;
+        }
+        if (state_.compareAndSet(state, state+1)) {
+            break;
+        }
+    }
+
+    if (state < 0) {
+        // We have threads waiting on this event.
+#ifdef _WIN32
+        ReleaseSemaphore(static_cast<HANDLE>(handle_), 1, NULL);
+#else // !_WIN32
+        if (0 != sem_post(&sem_)) {
+            fatal("sem_post() failed");
+        }
+#endif // !_WIN32
+    }
+}
+
+void
+Semaphore::wait()
+{
+    if (state_-- > 0) {
+        return;
+    }
+
+#ifdef _WIN32
+    if (WAIT_OBJECT_0 != WaitForSingleObject(
+            static_cast<HANDLE>(handle_), INFINITE)) {
+        fatal("WaitForSingleObject failed");
+    }
+#else // !_WIN32
+    while (0 != sem_wait(&sem_)) {
+      if (EINTR != errno) {
+        fatal("sem_wait() failed");
+      }
+    }
+#endif // !_WIN32
+}
+
+} // namespace amd