1 files changed, 126 insertions, 0 deletions
diff --git a/common/alsem.cpp b/common/alsem.cpp
new file mode 100644
index 00000000..6a92b35c
--- /dev/null
+++ b/common/alsem.cpp
@@ -0,0 +1,126 @@
+/**
+ * OpenAL cross platform audio library
+ * Copyright (C) 1999-2007 by authors.
+ * This library is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU Library General Public
+ *  License as published by the Free Software Foundation; either
+ *  version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ *  License along with this library; if not, write to the
+ *  Free Software Foundation, Inc.,
+ *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ * Or go to http://www.gnu.org/copyleft/lgpl.html
+ */
+
+#include "config.h"
+
+#include "alsem.h"
+
+#include <system_error>
+
+#include "opthelpers.h"
+
+
+#ifdef _WIN32
+#define WIN32_LEAN_AND_MEAN
+#include <windows.h>
+
+#include <limits>
+
+namespace al {
+
+semaphore::semaphore(unsigned int initial)
+{
+    if(initial > static_cast<unsigned int>(std::numeric_limits<int>::max()))
+        throw std::system_error(std::make_error_code(std::errc::value_too_large));
+    mSem = CreateSemaphore(nullptr, initial, std::numeric_limits<int>::max(), nullptr);
+    if(mSem == nullptr)
+        throw std::system_error(std::make_error_code(std::errc::resource_unavailable_try_again));
+}
+
+semaphore::~semaphore()
+{ CloseHandle(mSem); }
+
+void semaphore::post()
+{
+    if(!ReleaseSemaphore(static_cast<HANDLE>(mSem), 1, nullptr))
+        throw std::system_error(std::make_error_code(std::errc::value_too_large));
+}
+
+void semaphore::wait() noexcept
+{ WaitForSingleObject(static_cast<HANDLE>(mSem), INFINITE); }
+
+bool semaphore::try_wait() noexcept
+{ return WaitForSingleObject(static_cast<HANDLE>(mSem), 0) == WAIT_OBJECT_0; }
+
+} // namespace al
+
+#else
+
+/* Do not try using libdispatch on systems where it is absent. */
+#if defined(AL_APPLE_HAVE_DISPATCH)
+
+namespace al {
+
+semaphore::semaphore(unsigned int initial)
+{
+    mSem = dispatch_semaphore_create(initial);
+    if(!mSem)
+        throw std::system_error(std::make_error_code(std::errc::resource_unavailable_try_again));
+}
+
+semaphore::~semaphore()
+{ dispatch_release(mSem); }
+
+void semaphore::post()
+{ dispatch_semaphore_signal(mSem); }
+
+void semaphore::wait() noexcept
+{ dispatch_semaphore_wait(mSem, DISPATCH_TIME_FOREVER); }
+
+bool semaphore::try_wait() noexcept
+{ return dispatch_semaphore_wait(mSem, DISPATCH_TIME_NOW) == 0; }
+
+} // namespace al
+
+#else /* !__APPLE__ */
+
+#include <cerrno>
+
+namespace al {
+
+semaphore::semaphore(unsigned int initial)
+{
+    if(sem_init(&mSem, 0, initial) != 0)
+        throw std::system_error(std::make_error_code(std::errc::resource_unavailable_try_again));
+}
+
+semaphore::~semaphore()
+{ sem_destroy(&mSem); }
+
+void semaphore::post()
+{
+    if(sem_post(&mSem) != 0)
+        throw std::system_error(std::make_error_code(std::errc::value_too_large));
+}
+
+void semaphore::wait() noexcept
+{
+    while(sem_wait(&mSem) == -1 && errno == EINTR) {
+    }
+}
+
+bool semaphore::try_wait() noexcept
+{ return sem_trywait(&mSem) == 0; }
+
+} // namespace al
+
+#endif /* __APPLE__ */
+
+#endif /* _WIN32 */