1 files changed, 120 insertions, 0 deletions
diff --git a/xpcom/threads/RecursiveMutex.h b/xpcom/threads/RecursiveMutex.h
new file mode 100644
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+++ b/xpcom/threads/RecursiveMutex.h
@@ -0,0 +1,120 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+// A lock that can be acquired multiple times on the same thread.
+
+#ifndef mozilla_RecursiveMutex_h
+#define mozilla_RecursiveMutex_h
+
+#include "mozilla/ThreadSafety.h"
+#include "mozilla/BlockingResourceBase.h"
+
+#ifndef XP_WIN
+#  include <pthread.h>
+#endif
+
+namespace mozilla {
+
+class MOZ_CAPABILITY("recursive mutex") RecursiveMutex
+    : public BlockingResourceBase {
+ public:
+  explicit RecursiveMutex(const char* aName);
+  ~RecursiveMutex();
+
+#ifdef DEBUG
+  void Lock() MOZ_CAPABILITY_ACQUIRE();
+  void Unlock() MOZ_CAPABILITY_RELEASE();
+#else
+  void Lock() MOZ_CAPABILITY_ACQUIRE() { LockInternal(); }
+  void Unlock() MOZ_CAPABILITY_RELEASE() { UnlockInternal(); }
+#endif
+
+#ifdef DEBUG
+  /**
+   * AssertCurrentThreadIn
+   **/
+  void AssertCurrentThreadIn() const MOZ_ASSERT_CAPABILITY(this);
+  /**
+   * AssertNotCurrentThreadIn
+   **/
+  void AssertNotCurrentThreadIn() const MOZ_EXCLUDES(this) {
+    // Not currently implemented. See bug 476536 for discussion.
+  }
+#else
+  void AssertCurrentThreadIn() const MOZ_ASSERT_CAPABILITY(this) {}
+  void AssertNotCurrentThreadIn() const MOZ_EXCLUDES(this) {}
+#endif
+
+ private:
+  RecursiveMutex() = delete;
+  RecursiveMutex(const RecursiveMutex&) = delete;
+  RecursiveMutex& operator=(const RecursiveMutex&) = delete;
+
+  void LockInternal();
+  void UnlockInternal();
+
+#ifdef DEBUG
+  PRThread* mOwningThread;
+  size_t mEntryCount;
+#endif
+
+#if !defined(XP_WIN)
+  pthread_mutex_t mMutex;
+#else
+  // We eschew including windows.h and using CRITICAL_SECTION here so that files
+  // including us don't also pull in windows.h.  Just use a type that's big
+  // enough for CRITICAL_SECTION, and we'll fix it up later.
+  void* mMutex[6];
+#endif
+};
+
+class MOZ_RAII MOZ_SCOPED_CAPABILITY RecursiveMutexAutoLock {
+ public:
+  explicit RecursiveMutexAutoLock(RecursiveMutex& aRecursiveMutex)
+      MOZ_CAPABILITY_ACQUIRE(aRecursiveMutex)
+      : mRecursiveMutex(&aRecursiveMutex) {
+    NS_ASSERTION(mRecursiveMutex, "null mutex");
+    mRecursiveMutex->Lock();
+  }
+
+  ~RecursiveMutexAutoLock(void) MOZ_CAPABILITY_RELEASE() {
+    mRecursiveMutex->Unlock();
+  }
+
+ private:
+  RecursiveMutexAutoLock() = delete;
+  RecursiveMutexAutoLock(const RecursiveMutexAutoLock&) = delete;
+  RecursiveMutexAutoLock& operator=(const RecursiveMutexAutoLock&) = delete;
+  static void* operator new(size_t) noexcept(true);
+
+  mozilla::RecursiveMutex* mRecursiveMutex;
+};
+
+class MOZ_RAII MOZ_SCOPED_CAPABILITY RecursiveMutexAutoUnlock {
+ public:
+  explicit RecursiveMutexAutoUnlock(RecursiveMutex& aRecursiveMutex)
+      MOZ_SCOPED_UNLOCK_RELEASE(aRecursiveMutex)
+      : mRecursiveMutex(&aRecursiveMutex) {
+    NS_ASSERTION(mRecursiveMutex, "null mutex");
+    mRecursiveMutex->Unlock();
+  }
+
+  ~RecursiveMutexAutoUnlock(void) MOZ_SCOPED_UNLOCK_REACQUIRE() {
+    mRecursiveMutex->Lock();
+  }
+
+ private:
+  RecursiveMutexAutoUnlock() = delete;
+  RecursiveMutexAutoUnlock(const RecursiveMutexAutoUnlock&) = delete;
+  RecursiveMutexAutoUnlock& operator=(const RecursiveMutexAutoUnlock&) = delete;
+  static void* operator new(size_t) noexcept(true);
+
+  mozilla::RecursiveMutex* mRecursiveMutex;
+};
+
+}  // namespace mozilla
+
+#endif  // mozilla_RecursiveMutex_h