1 files changed, 50 insertions, 0 deletions

diff --git a/contrib/llvm-project/llvm/lib/Support/Unix/RWMutex.inc b/contrib/llvm-project/llvm/lib/Support/Unix/RWMutex.inc
new file mode 100644
index 000000000000..8b47dfa0f85c
--- /dev/null
+++ b/contrib/llvm-project/llvm/lib/Support/Unix/RWMutex.inc
@@ -0,0 +1,50 @@
+//= llvm/Support/Unix/RWMutex.inc - Unix Reader/Writer Mutual Exclusion Lock  =//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the Unix specific (non-pthread) RWMutex class.
+//
+//===----------------------------------------------------------------------===//
+
+//===----------------------------------------------------------------------===//
+//=== WARNING: Implementation here must contain only generic UNIX code that
+//===          is guaranteed to work on *all* UNIX variants.
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Support/Mutex.h"
+
+namespace llvm {
+
+using namespace sys;
+
+// This naive implementation treats readers the same as writers.  This
+// will therefore deadlock if a thread tries to acquire a read lock
+// multiple times.
+
+RWMutexImpl::RWMutexImpl() : data_(new MutexImpl(false)) { }
+
+RWMutexImpl::~RWMutexImpl() {
+  delete static_cast<MutexImpl *>(data_);
+}
+
+bool RWMutexImpl::reader_acquire() {
+  return static_cast<MutexImpl *>(data_)->acquire();
+}
+
+bool RWMutexImpl::reader_release() {
+  return static_cast<MutexImpl *>(data_)->release();
+}
+
+bool RWMutexImpl::writer_acquire() {
+  return static_cast<MutexImpl *>(data_)->acquire();
+}
+
+bool RWMutexImpl::writer_release() {
+  return static_cast<MutexImpl *>(data_)->release();
+}
+
+}