1 files changed, 251 insertions, 0 deletions
diff --git a/xpcom/threads/ReentrantMonitor.h b/xpcom/threads/ReentrantMonitor.h
new file mode 100644
index 0000000000..09debad577
--- /dev/null
+++ b/xpcom/threads/ReentrantMonitor.h
@@ -0,0 +1,251 @@
+/* -*- 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/. */
+
+#ifndef mozilla_ReentrantMonitor_h
+#define mozilla_ReentrantMonitor_h
+
+#include "prmon.h"
+
+#if defined(MOZILLA_INTERNAL_API) && !defined(DEBUG)
+#  include "mozilla/ProfilerThreadSleep.h"
+#endif  // defined( MOZILLA_INTERNAL_API) && !defined(DEBUG)
+
+#include "mozilla/BlockingResourceBase.h"
+#include "mozilla/ThreadSafety.h"
+#include "nsISupports.h"
+//
+// Provides:
+//
+//  - ReentrantMonitor, a Java-like monitor
+//  - ReentrantMonitorAutoEnter, an RAII class for ensuring that
+//    ReentrantMonitors are properly entered and exited
+//
+// Using ReentrantMonitorAutoEnter is MUCH preferred to making bare calls to
+// ReentrantMonitor.Enter and Exit.
+//
+namespace mozilla {
+
+/**
+ * ReentrantMonitor
+ * Java-like monitor.
+ * When possible, use ReentrantMonitorAutoEnter to hold this monitor within a
+ * scope, instead of calling Enter/Exit directly.
+ **/
+class MOZ_CAPABILITY("reentrant monitor") ReentrantMonitor
+    : BlockingResourceBase {
+ public:
+  /**
+   * ReentrantMonitor
+   * @param aName A name which can reference this monitor
+   */
+  explicit ReentrantMonitor(const char* aName)
+      : BlockingResourceBase(aName, eReentrantMonitor)
+#ifdef DEBUG
+        ,
+        mEntryCount(0)
+#endif
+  {
+    MOZ_COUNT_CTOR(ReentrantMonitor);
+    mReentrantMonitor = PR_NewMonitor();
+    if (!mReentrantMonitor) {
+      MOZ_CRASH("Can't allocate mozilla::ReentrantMonitor");
+    }
+  }
+
+  /**
+   * ~ReentrantMonitor
+   **/
+  ~ReentrantMonitor() {
+    NS_ASSERTION(mReentrantMonitor,
+                 "improperly constructed ReentrantMonitor or double free");
+    PR_DestroyMonitor(mReentrantMonitor);
+    mReentrantMonitor = 0;
+    MOZ_COUNT_DTOR(ReentrantMonitor);
+  }
+
+#ifndef DEBUG
+  /**
+   * Enter
+   * @see prmon.h
+   **/
+  void Enter() MOZ_CAPABILITY_ACQUIRE() { PR_EnterMonitor(mReentrantMonitor); }
+
+  /**
+   * Exit
+   * @see prmon.h
+   **/
+  void Exit() MOZ_CAPABILITY_RELEASE() { PR_ExitMonitor(mReentrantMonitor); }
+
+  /**
+   * Wait
+   * @see prmon.h
+   **/
+  nsresult Wait(PRIntervalTime aInterval = PR_INTERVAL_NO_TIMEOUT) {
+    PR_ASSERT_CURRENT_THREAD_IN_MONITOR(mReentrantMonitor);
+#  ifdef MOZILLA_INTERNAL_API
+    AUTO_PROFILER_THREAD_SLEEP;
+#  endif  // MOZILLA_INTERNAL_API
+    return PR_Wait(mReentrantMonitor, aInterval) == PR_SUCCESS
+               ? NS_OK
+               : NS_ERROR_FAILURE;
+  }
+
+#else  // ifndef DEBUG
+  void Enter() MOZ_CAPABILITY_ACQUIRE();
+  void Exit() MOZ_CAPABILITY_RELEASE();
+  nsresult Wait(PRIntervalTime aInterval = PR_INTERVAL_NO_TIMEOUT);
+
+#endif  // ifndef DEBUG
+
+  /**
+   * Notify
+   * @see prmon.h
+   **/
+  nsresult Notify() {
+    return PR_Notify(mReentrantMonitor) == PR_SUCCESS ? NS_OK
+                                                      : NS_ERROR_FAILURE;
+  }
+
+  /**
+   * NotifyAll
+   * @see prmon.h
+   **/
+  nsresult NotifyAll() {
+    return PR_NotifyAll(mReentrantMonitor) == PR_SUCCESS ? NS_OK
+                                                         : NS_ERROR_FAILURE;
+  }
+
+#ifdef DEBUG
+  /**
+   * AssertCurrentThreadIn
+   * @see prmon.h
+   **/
+  void AssertCurrentThreadIn() MOZ_ASSERT_CAPABILITY(this) {
+    PR_ASSERT_CURRENT_THREAD_IN_MONITOR(mReentrantMonitor);
+  }
+
+  /**
+   * AssertNotCurrentThreadIn
+   * @see prmon.h
+   **/
+  void AssertNotCurrentThreadIn() MOZ_ASSERT_CAPABILITY(!this) {
+    // FIXME bug 476536
+  }
+
+#else
+  void AssertCurrentThreadIn() MOZ_ASSERT_CAPABILITY(this) {}
+  void AssertNotCurrentThreadIn() MOZ_ASSERT_CAPABILITY(!this) {}
+
+#endif  // ifdef DEBUG
+
+ private:
+  ReentrantMonitor();
+  ReentrantMonitor(const ReentrantMonitor&);
+  ReentrantMonitor& operator=(const ReentrantMonitor&);
+
+  PRMonitor* mReentrantMonitor;
+#ifdef DEBUG
+  int32_t mEntryCount;
+#endif
+};
+
+/**
+ * ReentrantMonitorAutoEnter
+ * Enters the ReentrantMonitor when it enters scope, and exits it when
+ * it leaves scope.
+ *
+ * MUCH PREFERRED to bare calls to ReentrantMonitor.Enter and Exit.
+ */
+class MOZ_SCOPED_CAPABILITY MOZ_STACK_CLASS ReentrantMonitorAutoEnter {
+ public:
+  /**
+   * Constructor
+   * The constructor aquires the given lock.  The destructor
+   * releases the lock.
+   *
+   * @param aReentrantMonitor A valid mozilla::ReentrantMonitor*.
+   **/
+  explicit ReentrantMonitorAutoEnter(
+      mozilla::ReentrantMonitor& aReentrantMonitor)
+      MOZ_CAPABILITY_ACQUIRE(aReentrantMonitor)
+      : mReentrantMonitor(&aReentrantMonitor) {
+    NS_ASSERTION(mReentrantMonitor, "null monitor");
+    mReentrantMonitor->Enter();
+  }
+
+  ~ReentrantMonitorAutoEnter(void) MOZ_CAPABILITY_RELEASE() {
+    mReentrantMonitor->Exit();
+  }
+
+  nsresult Wait(PRIntervalTime aInterval = PR_INTERVAL_NO_TIMEOUT) {
+    return mReentrantMonitor->Wait(aInterval);
+  }
+
+  nsresult Notify() { return mReentrantMonitor->Notify(); }
+  nsresult NotifyAll() { return mReentrantMonitor->NotifyAll(); }
+
+ private:
+  ReentrantMonitorAutoEnter();
+  ReentrantMonitorAutoEnter(const ReentrantMonitorAutoEnter&);
+  ReentrantMonitorAutoEnter& operator=(const ReentrantMonitorAutoEnter&);
+  static void* operator new(size_t) noexcept(true);
+
+  friend class ReentrantMonitorAutoExit;
+
+  mozilla::ReentrantMonitor* mReentrantMonitor;
+};
+
+/**
+ * ReentrantMonitorAutoExit
+ * Exit the ReentrantMonitor when it enters scope, and enters it when it leaves
+ * scope.
+ *
+ * MUCH PREFERRED to bare calls to ReentrantMonitor.Exit and Enter.
+ */
+class MOZ_SCOPED_CAPABILITY MOZ_STACK_CLASS ReentrantMonitorAutoExit {
+ public:
+  /**
+   * Constructor
+   * The constructor releases the given lock.  The destructor
+   * acquires the lock. The lock must be held before constructing
+   * this object!
+   *
+   * @param aReentrantMonitor A valid mozilla::ReentrantMonitor*. It
+   *                 must be already locked.
+   **/
+  explicit ReentrantMonitorAutoExit(ReentrantMonitor& aReentrantMonitor)
+      MOZ_EXCLUSIVE_RELEASE(aReentrantMonitor)
+      : mReentrantMonitor(&aReentrantMonitor) {
+    NS_ASSERTION(mReentrantMonitor, "null monitor");
+    mReentrantMonitor->AssertCurrentThreadIn();
+    mReentrantMonitor->Exit();
+  }
+
+  explicit ReentrantMonitorAutoExit(
+      ReentrantMonitorAutoEnter& aReentrantMonitorAutoEnter)
+      MOZ_EXCLUSIVE_RELEASE(aReentrantMonitorAutoEnter.mReentrantMonitor)
+      : mReentrantMonitor(aReentrantMonitorAutoEnter.mReentrantMonitor) {
+    NS_ASSERTION(mReentrantMonitor, "null monitor");
+    mReentrantMonitor->AssertCurrentThreadIn();
+    mReentrantMonitor->Exit();
+  }
+
+  ~ReentrantMonitorAutoExit(void) MOZ_EXCLUSIVE_RELEASE() {
+    mReentrantMonitor->Enter();
+  }
+
+ private:
+  ReentrantMonitorAutoExit();
+  ReentrantMonitorAutoExit(const ReentrantMonitorAutoExit&);
+  ReentrantMonitorAutoExit& operator=(const ReentrantMonitorAutoExit&);
+  static void* operator new(size_t) noexcept(true);
+
+  ReentrantMonitor* mReentrantMonitor;
+};
+
+}  // namespace mozilla
+
+#endif  // ifndef mozilla_ReentrantMonitor_h