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/*******************************************************************************
* Copyright (c) 2007, 2010 Wind River Systems, Inc. and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* and Eclipse Distribution License v1.0 which accompany this distribution.
* The Eclipse Public License is available at
* http://www.eclipse.org/legal/epl-v10.html
* and the Eclipse Distribution License is available at
* http://www.eclipse.org/org/documents/edl-v10.php.
* You may elect to redistribute this code under either of these licenses.
*
* Contributors:
* Wind River Systems - initial API and implementation
*******************************************************************************/
/*
* Event queue manager.
* Event is a data pointer plus a function pointer (a.k.a. event handler).
*
* Posting event means placing event into event queue.
* Dispatching event means removing event from the queue and then calling
* event function with event data as argument.
*
* All events are dispatched by single thread - dispatch thread. This makes it safe
* to access global data structures from event handlers without further synchronization,
* while allows for high level of concurrency.
*/
#ifndef D_events
#define D_events
typedef void EventCallBack(void *);
/*
* Causes event to have its handler
* function called in the dispatch thread of the framework.
* Events are dispatched in same order as queued.
* If post_event is called from the dispatching thread
* the handler will still be deferred until
* all pending events have been processed.
*
* This function can be invoked from any thread.
*
* handler - the function that should be executed asynchronously.
* arg - pointer to event data.
*/
extern void post_event(EventCallBack * handler, void * arg);
/*
* Causes event to have its handler
* function called in the dispatch thread of the framework.
* The event is dispatched after given delay.
*
* This function can be invoked from any thread.
*
* handler - the function that should be executed asynchronously.
* arg - pointer to event data.
* us_delay - microseconds to delay event dispatch.
*/
extern void post_event_with_delay(EventCallBack * handler, void * arg, unsigned long us_delay);
/*
* Cancel pending event with matching 'handler' and 'arg', or if event
* is not pending and 'wait' is true then wait for matching event to
* be posted. Can only be called from the dispatch thread. Returns
* true if a posted event was cancelled.
*/
extern int cancel_event(EventCallBack * handler, void * arg, int wait);
/*
* Returns true if the calling thread is TCF event dispatch thread.
* Use this call the ensure that a given task is being executed (or not being)
* on dispatch thread.
*/
extern int is_dispatch_thread(void);
/*
* Run TCF event loop.
* Calling thread becomes event dispatch thread.
* Event loop runs until it is canceled by cancel_event_loop().
*/
extern void run_event_loop(void);
/*
* Cancel event loop.
* The function causes run_event_loop() to stop event dispatching and return.
*/
extern void cancel_event_loop(void);
/*
* Initialize event queue.
* Should be called from main before run_event_loop().
*/
extern void ini_events_queue(void);
#endif /* D_events */
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