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authorMatt A. Tobin <mattatobin@localhost.localdomain>2018-02-02 04:16:08 -0500
committerMatt A. Tobin <mattatobin@localhost.localdomain>2018-02-02 04:16:08 -0500
commit5f8de423f190bbb79a62f804151bc24824fa32d8 (patch)
tree10027f336435511475e392454359edea8e25895d /xpcom/glue/Monitor.h
parent49ee0794b5d912db1f95dce6eb52d781dc210db5 (diff)
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Add m-esr52 at 52.6.0
Diffstat (limited to 'xpcom/glue/Monitor.h')
-rw-r--r--xpcom/glue/Monitor.h135
1 files changed, 135 insertions, 0 deletions
diff --git a/xpcom/glue/Monitor.h b/xpcom/glue/Monitor.h
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+/* -*- 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_Monitor_h
+#define mozilla_Monitor_h
+
+#include "mozilla/CondVar.h"
+#include "mozilla/Mutex.h"
+
+namespace mozilla {
+
+/**
+ * Monitor provides a *non*-reentrant monitor: *not* a Java-style
+ * monitor. If your code needs support for reentrancy, use
+ * ReentrantMonitor instead. (Rarely should reentrancy be needed.)
+ *
+ * Instead of directly calling Monitor methods, it's safer and simpler
+ * to instead use the RAII wrappers MonitorAutoLock and
+ * MonitorAutoUnlock.
+ */
+class Monitor
+{
+public:
+ explicit Monitor(const char* aName)
+ : mMutex(aName)
+ , mCondVar(mMutex, "[Monitor.mCondVar]")
+ {
+ }
+
+ ~Monitor() {}
+
+ void Lock() { mMutex.Lock(); }
+ void Unlock() { mMutex.Unlock(); }
+
+ nsresult Wait(PRIntervalTime aInterval = PR_INTERVAL_NO_TIMEOUT)
+ {
+ return mCondVar.Wait(aInterval);
+ }
+
+ nsresult Notify() { return mCondVar.Notify(); }
+ nsresult NotifyAll() { return mCondVar.NotifyAll(); }
+
+ void AssertCurrentThreadOwns() const
+ {
+ mMutex.AssertCurrentThreadOwns();
+ }
+
+ void AssertNotCurrentThreadOwns() const
+ {
+ mMutex.AssertNotCurrentThreadOwns();
+ }
+
+private:
+ Monitor();
+ Monitor(const Monitor&);
+ Monitor& operator=(const Monitor&);
+
+ Mutex mMutex;
+ CondVar mCondVar;
+};
+
+/**
+ * Lock the monitor for the lexical scope instances of this class are
+ * bound to (except for MonitorAutoUnlock in nested scopes).
+ *
+ * The monitor must be unlocked when instances of this class are
+ * created.
+ */
+class MOZ_STACK_CLASS MonitorAutoLock
+{
+public:
+ explicit MonitorAutoLock(Monitor& aMonitor)
+ : mMonitor(&aMonitor)
+ {
+ mMonitor->Lock();
+ }
+
+ ~MonitorAutoLock()
+ {
+ mMonitor->Unlock();
+ }
+
+ nsresult Wait(PRIntervalTime aInterval = PR_INTERVAL_NO_TIMEOUT)
+ {
+ return mMonitor->Wait(aInterval);
+ }
+
+ nsresult Notify() { return mMonitor->Notify(); }
+ nsresult NotifyAll() { return mMonitor->NotifyAll(); }
+
+private:
+ MonitorAutoLock();
+ MonitorAutoLock(const MonitorAutoLock&);
+ MonitorAutoLock& operator=(const MonitorAutoLock&);
+ static void* operator new(size_t) CPP_THROW_NEW;
+
+ Monitor* mMonitor;
+};
+
+/**
+ * Unlock the monitor for the lexical scope instances of this class
+ * are bound to (except for MonitorAutoLock in nested scopes).
+ *
+ * The monitor must be locked by the current thread when instances of
+ * this class are created.
+ */
+class MOZ_STACK_CLASS MonitorAutoUnlock
+{
+public:
+ explicit MonitorAutoUnlock(Monitor& aMonitor)
+ : mMonitor(&aMonitor)
+ {
+ mMonitor->Unlock();
+ }
+
+ ~MonitorAutoUnlock()
+ {
+ mMonitor->Lock();
+ }
+
+private:
+ MonitorAutoUnlock();
+ MonitorAutoUnlock(const MonitorAutoUnlock&);
+ MonitorAutoUnlock& operator=(const MonitorAutoUnlock&);
+ static void* operator new(size_t) CPP_THROW_NEW;
+
+ Monitor* mMonitor;
+};
+
+} // namespace mozilla
+
+#endif // mozilla_Monitor_h