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/*
* This file is subject to the terms of the GFX License. If a copy of
* the license was not distributed with this file, you can obtain one at:
*
* http://chibios-gfx.com/license.html
*/
/**
* @file src/gevent/gevent.c
* @brief GEVENT Driver code.
*
* @addtogroup GEVENT
* @{
*/
#include "gfx.h"
#if GFX_USE_GEVENT || defined(__DOXYGEN__)
#if GEVENT_ASSERT_NO_RESOURCE
#define GEVENT_ASSERT(x) assert(x)
#else
#define GEVENT_ASSERT(x)
#endif
/* This mutex protects access to our tables */
static gfxMutex geventMutex;
/* Our table of listener/source pairs */
static GSourceListener Assignments[GEVENT_MAX_SOURCE_LISTENERS];
/* Loop through the assignment table deleting this listener/source pair. */
/* Null is treated as a wildcard. */
static void deleteAssignments(GListener *pl, GSourceHandle gsh) {
GSourceListener *psl;
for(psl = Assignments; psl < Assignments+GEVENT_MAX_SOURCE_LISTENERS; psl++) {
if ((!pl || psl->pListener == pl) && (!gsh || psl->pSource == gsh)) {
if (gfxSemCounter(&psl->pListener->waitqueue) < 0) {
gfxSemWait(&psl->pListener->eventlock, TIME_INFINITE); // Obtain the buffer lock
psl->pListener->event.type = GEVENT_EXIT; // Set up the EXIT event
gfxSemSignal(&psl->pListener->waitqueue); // Wake up the listener
gfxSemSignal(&psl->pListener->eventlock); // Release the buffer lock
}
psl->pListener = 0;
}
}
}
void _geventInit(void) {
gfxMutexInit(&geventMutex);
}
void geventListenerInit(GListener *pl) {
gfxSemInit(&pl->waitqueue, 0, MAX_SEMAPHORE_COUNT); // Next wait'er will block
gfxSemInit(&pl->eventlock, 1, 1); // Only one thread at a time looking at the event buffer
pl->callback = 0; // No callback active
pl->event.type = GEVENT_NULL; // Always safety
}
bool_t geventAttachSource(GListener *pl, GSourceHandle gsh, unsigned flags) {
GSourceListener *psl, *pslfree;
// Safety first
if (!pl || !gsh) {
GEVENT_ASSERT(FALSE);
return FALSE;
}
gfxMutexEnter(&geventMutex);
// Check if this pair is already in the table (scan for a free slot at the same time)
pslfree = 0;
for(psl = Assignments; psl < Assignments+GEVENT_MAX_SOURCE_LISTENERS; psl++) {
if (pl == psl->pListener && gsh == psl->pSource) {
// Just update the flags
gfxSemWait(&pl->eventlock, TIME_INFINITE); // Safety first - just in case a source is using it
psl->listenflags = flags;
gfxSemSignal(&pl->eventlock); // Release this lock
gfxMutexExit(&geventMutex);
return TRUE;
}
if (!pslfree && !psl->pListener)
pslfree = psl;
}
// A free slot was found - allocate it
if (pslfree) {
pslfree->pListener = pl;
pslfree->pSource = gsh;
pslfree->listenflags = flags;
pslfree->srcflags = 0;
}
gfxMutexExit(&geventMutex);
GEVENT_ASSERT(pslfree != 0);
return pslfree != 0;
}
void geventDetachSource(GListener *pl, GSourceHandle gsh) {
if (pl) {
gfxMutexEnter(&geventMutex);
deleteAssignments(pl, gsh);
if (!gsh && gfxSemCounter(&pl->waitqueue) < 0) {
gfxSemWait(&pl->eventlock, TIME_INFINITE); // Obtain the buffer lock
pl->event.type = GEVENT_EXIT; // Set up the EXIT event
gfxSemSignal(&pl->waitqueue); // Wake up the listener
gfxSemSignal(&pl->eventlock); // Release the buffer lock
}
gfxMutexExit(&geventMutex);
}
}
GEvent *geventEventWait(GListener *pl, delaytime_t timeout) {
if (pl->callback || gfxSemCounter(&pl->waitqueue) < 0)
return 0;
return gfxSemWait(&pl->waitqueue, timeout) ? &pl->event : 0;
}
void geventRegisterCallback(GListener *pl, GEventCallbackFn fn, void *param) {
if (pl) {
gfxMutexEnter(&geventMutex);
gfxSemWait(&pl->eventlock, TIME_INFINITE); // Obtain the buffer lock
pl->param = param; // Set the param
pl->callback = fn; // Set the callback function
if (gfxSemCounter(&pl->waitqueue) < 0) {
pl->event.type = GEVENT_EXIT; // Set up the EXIT event
gfxSemSignal(&pl->waitqueue); // Wake up the listener
}
gfxSemSignal(&pl->eventlock); // Release the buffer lock
gfxMutexExit(&geventMutex);
}
}
GSourceListener *geventGetSourceListener(GSourceHandle gsh, GSourceListener *lastlr) {
GSourceListener *psl;
// Safety first
if (!gsh)
return 0;
gfxMutexEnter(&geventMutex);
// Unlock the last listener event buffer
if (lastlr)
gfxSemSignal(&lastlr->pListener->eventlock);
// Loop through the table looking for attachments to this source
for(psl = lastlr ? (lastlr+1) : Assignments; psl < Assignments+GEVENT_MAX_SOURCE_LISTENERS; psl++) {
if (gsh == psl->pSource) {
gfxSemWait(&psl->pListener->eventlock, TIME_INFINITE); // Obtain a lock on the listener event buffer
gfxMutexExit(&geventMutex);
return psl;
}
}
gfxMutexExit(&geventMutex);
return 0;
}
GEvent *geventGetEventBuffer(GSourceListener *psl) {
// We already know we have the event lock
return &psl->pListener->callback || gfxSemCounter(&psl->pListener->waitqueue) < 0 ? &psl->pListener->event : 0;
}
void geventSendEvent(GSourceListener *psl) {
gfxMutexEnter(&geventMutex);
if (psl->pListener->callback) { // This test needs to be taken inside the mutex
gfxMutexExit(&geventMutex);
// We already know we have the event lock
psl->pListener->callback(psl->pListener->param, &psl->pListener->event);
} else {
// Wake up the listener
if (gfxSemCounter(&psl->pListener->waitqueue) <= 0)
gfxSemSignal(&psl->pListener->waitqueue);
gfxMutexExit(&geventMutex);
}
}
void geventDetachSourceListeners(GSourceHandle gsh) {
gfxMutexEnter(&geventMutex);
deleteAssignments(0, gsh);
gfxMutexExit(&geventMutex);
}
#endif /* GFX_USE_GEVENT */
/** @} */
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