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rippled/beast/threads/WaitableEvent.h

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//------------------------------------------------------------------------------
/*
This file is part of Beast: https://github.com/vinniefalco/Beast
Copyright 2013, Vinnie Falco <vinnie.falco@gmail.com>
Portions of this file are from JUCE.
Copyright (c) 2013 - Raw Material Software Ltd.
Please visit http://www.juce.com
Permission to use, copy, modify, and/or distribute this software for any
purpose with or without fee is hereby granted, provided that the above
copyright notice and this permission notice appear in all copies.
THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
ANY SPECIAL , DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
//==============================================================================
#ifndef BEAST_THREADS_WAITABLEEVENT_H_INCLUDED
#define BEAST_THREADS_WAITABLEEVENT_H_INCLUDED
#include <beast/Config.h>
#if ! BEAST_WINDOWS
#include <pthread.h>
#endif
namespace beast {
/** Allows threads to wait for events triggered by other threads.
A thread can call wait() on a WaitableEvent, and this will suspend the
calling thread until another thread wakes it up by calling the signal()
method.
*/
class WaitableEvent
//, LeakChecked <WaitableEvent> // VFALCO TODO Move LeakChecked to beast/
{
public:
//==============================================================================
/** Creates a WaitableEvent object.
@param manualReset If this is false, the event will be reset automatically when the wait()
method is called. If manualReset is true, then once the event is signalled,
the only way to reset it will be by calling the reset() method.
@param initiallySignaled If this is true then the event will be signaled when
the constructor returns.
*/
explicit WaitableEvent (bool manualReset = false, bool initiallySignaled = false);
/** Destructor.
If other threads are waiting on this object when it gets deleted, this
can cause nasty errors, so be careful!
*/
~WaitableEvent();
WaitableEvent (WaitableEvent const&) = delete;
WaitableEvent& operator= (WaitableEvent const&) = delete;
//==============================================================================
/** Suspends the calling thread until the event has been signalled.
This will wait until the object's signal() method is called by another thread,
or until the timeout expires.
After the event has been signalled, this method will return true and if manualReset
was set to false in the WaitableEvent's constructor, then the event will be reset.
@param timeOutMilliseconds the maximum time to wait, in milliseconds. A negative
value will cause it to wait forever.
@returns true if the object has been signalled, false if the timeout expires first.
@see signal, reset
*/
/** @{ */
bool wait () const; // wait forever
// VFALCO TODO Change wait() to seconds instead of millis
bool wait (int timeOutMilliseconds) const; // DEPRECATED
/** @} */
//==============================================================================
/** Wakes up any threads that are currently waiting on this object.
If signal() is called when nothing is waiting, the next thread to call wait()
will return immediately and reset the signal.
If the WaitableEvent is manual reset, all current and future threads that wait upon this
object will be woken, until reset() is explicitly called.
If the WaitableEvent is automatic reset, and one or more threads is waiting upon the object,
then one of them will be woken up. If no threads are currently waiting, then the next thread
to call wait() will be woken up. As soon as a thread is woken, the signal is automatically
reset.
@see wait, reset
*/
void signal() const;
//==============================================================================
/** Resets the event to an unsignalled state.
If it's not already signalled, this does nothing.
*/
void reset() const;
private:
#if BEAST_WINDOWS
void* handle;
#else
mutable pthread_cond_t condition;
mutable pthread_mutex_t mutex;
mutable bool triggered;
mutable bool manualReset;
#endif
};
}
#endif