Merge System into Support.

llvm-svn: 120298

1 files changed, 58 insertions, 0 deletions

diff --git a/llvm/lib/Support/Windows/RWMutex.inc b/llvm/lib/Support/Windows/RWMutex.inc
new file mode 100644
index 00000000000..82ae8af1e52
--- /dev/null
+++ b/llvm/lib/Support/Windows/RWMutex.inc
@@ -0,0 +1,58 @@
+//= llvm/System/Win32/Mutex.inc - Win32 Reader/Writer Mutual Exclusion Lock  =//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the Win32 specific (non-pthread) RWMutex class.
+//
+//===----------------------------------------------------------------------===//
+
+//===----------------------------------------------------------------------===//
+//=== WARNING: Implementation here must contain only generic Win32 code that
+//===          is guaranteed to work on *all* Win32 variants.
+//===----------------------------------------------------------------------===//
+
+#include "Windows.h"
+
+// FIXME: Windows does not have reader-writer locks pre-Vista.  If you want
+// real reader-writer locks, you a threads implementation for Windows.
+
+namespace llvm {
+using namespace sys;
+
+RWMutexImpl::RWMutexImpl() {
+  data_ = calloc(1, sizeof(CRITICAL_SECTION));
+  InitializeCriticalSection(static_cast<LPCRITICAL_SECTION>(data_));
+}
+
+RWMutexImpl::~RWMutexImpl() {
+  DeleteCriticalSection(static_cast<LPCRITICAL_SECTION>(data_));
+  free(data_);
+}
+
+bool RWMutexImpl::reader_acquire() {
+  EnterCriticalSection(static_cast<LPCRITICAL_SECTION>(data_));
+  return true;
+}
+
+bool RWMutexImpl::reader_release() {
+  LeaveCriticalSection(static_cast<LPCRITICAL_SECTION>(data_));
+  return true;
+}
+
+bool RWMutexImpl::writer_acquire() {
+  EnterCriticalSection(static_cast<LPCRITICAL_SECTION>(data_));
+  return true;
+}
+
+bool RWMutexImpl::writer_release() {
+  LeaveCriticalSection(static_cast<LPCRITICAL_SECTION>(data_));
+  return true;
+}
+
+
+}