/* Flush all pending I/O */
void
aioSync(SwapDir * SD)
{
if (!initialised)
return; /* nothing to do then */
/* Flush all pending operations */
debug(32, 1) ("aioSync: flushing pending I/O operations\n");
do {
aioCheckCallbacks(SD);
} while (squidaio_sync());
debug(32, 1) ("aioSync: done\n");
}
static void
squidaio_queue_request(squidaio_request_t * request)
{
static int high_start = 0;
debug(43, 9) ("squidaio_queue_request: %p type=%d result=%p\n",
request, request->request_type, request->resultp);
/* Mark it as not executed (failing result, no error) */
request->ret = -1;
request->err = 0;
/* Internal housekeeping */
request_queue_len += 1;
request->resultp->_data = request;
/* Play some tricks with the request_queue2 queue */
request->next = NULL;
if (!request_queue2.head) {
if (WaitForSingleObject(request_queue.mutex, 0) == WAIT_OBJECT_0) {
/* Normal path */
*request_queue.tailp = request;
request_queue.tailp = &request->next;
if (!SetEvent(request_queue.cond))
fatal("couldn't push queue\n");
if (!ReleaseMutex(request_queue.mutex)) {
/* unexpected error */
fatal("couldn't push queue\n");
}
} else {
/* Oops, the request queue is blocked, use request_queue2 */
*request_queue2.tailp = request;
request_queue2.tailp = &request->next;
}
} else {
/* Secondary path. We have blocked requests to deal with */
/* add the request to the chain */
*request_queue2.tailp = request;
if (WaitForSingleObject(request_queue.mutex, 0) == WAIT_OBJECT_0) {
/* Ok, the queue is no longer blocked */
*request_queue.tailp = request_queue2.head;
request_queue.tailp = &request->next;
if (!SetEvent(request_queue.cond))
fatal("couldn't push queue\n");
if (!ReleaseMutex(request_queue.mutex)) {
/* unexpected error */
fatal("couldn't push queue\n");
}
request_queue2.head = NULL;
request_queue2.tailp = &request_queue2.head;
} else {
/* still blocked, bump the blocked request chain */
request_queue2.tailp = &request->next;
}
}
if (request_queue2.head) {
static int filter = 0;
static int filter_limit = 8;
if (++filter >= filter_limit) {
filter_limit += filter;
filter = 0;
debug(43, 1) ("squidaio_queue_request: WARNING - Queue congestion\n");
}
}
/* Warn if out of threads */
if (request_queue_len > MAGIC1) {
static int last_warn = 0;
static int queue_high, queue_low;
if (high_start == 0) {
high_start = squid_curtime;
queue_high = request_queue_len;
queue_low = request_queue_len;
}
if (request_queue_len > queue_high)
queue_high = request_queue_len;
if (request_queue_len < queue_low)
queue_low = request_queue_len;
if (squid_curtime >= (last_warn + 15) &&
squid_curtime >= (high_start + 5)) {
debug(43, 1) ("squidaio_queue_request: WARNING - Disk I/O overloading\n");
if (squid_curtime >= (high_start + 15))
debug(43, 1) ("squidaio_queue_request: Queue Length: current=%d, high=%d, low=%d, duration=%ld\n",
request_queue_len, queue_high, queue_low, (long int) (squid_curtime - high_start));
last_warn = squid_curtime;
}
} else {
high_start = 0;
}
/* Warn if seriously overloaded */
if (request_queue_len > RIDICULOUS_LENGTH) {
debug(43, 0) ("squidaio_queue_request: Async request queue growing uncontrollably!\n");
debug(43, 0) ("squidaio_queue_request: Syncing pending I/O operations.. (blocking)\n");
squidaio_sync();
debug(43, 0) ("squidaio_queue_request: Synced\n");
}
} /* squidaio_queue_request */
