/*--------------------------------------------------------------------------------------
* Purpose: Write a new item into the queue
* Input: queue to write item and the item itself
* Output: returns 0, exits on fatal error if write fails
* He Yan @ June 15, 2008
* -------------------------------------------------------------------------------------*/
int
writeQueue( QueueWriter writer, void *item )
{
int i;
// lock the queue
Queue q = writer->queue;
if ( pthread_mutex_lock( &q->queueLock ) )
log_fatal( "lockQueue: failed");
// if the queue is full, move the positions of slowest readers to the tail
if (( q->tail - q->head) >= QUEUE_MAX_ITEMS )
{
#ifdef DEBUG
log_warning("queue %s is full, head=%ld, tail=%ld; adjusting slowest readers", q->name, q->head, q->tail);
#endif
for ( i = 0; i < MAX_QUEUE_READERS; i++ )
{
#ifdef DEBUG
debug(__FUNCTION__, "queue %s's head is %ld", q->name, q->head);
if (q->nextItem[i] >= 0)
{
debug(__FUNCTION__, "queue %s's reader %d's next item is %ld", q->name, i, q->nextItem[i]);
}
#endif
// if this reader is the slowest one, adjust it
if ( q->head == q->nextItem[i] )
{
if(q->newPacingEnable == FALSE)
adjustSlowestQueueReader(q, i);
else
{
long j = q->nextItem[i] % QUEUE_MAX_ITEMS;
q->items[j].count--;
if ( q->items[j].count == 0 )
{
free( q->items[j].messagBuf );
q->items[j].messagBuf = NULL;
q->head++;
}
q->nextItem[i]++;
#ifdef DEBUG
log_warning("Move the slowest client 1 pos forward");
#endif
}
}
}
}
// should not happen, fatal error if it happens
if (( q->tail - q->head ) >= QUEUE_MAX_ITEMS )
log_fatal("%s queue is still FULL after adjusting readers", q->name);
// not reached
// old pacing: update pacing limit and reset readcout and writecount if needed
// new pacing: update write count moveing average
updateInterval(q);
// only for the new pacing algorithm
if(q->newPacingEnable == TRUE)
{
if ( ( (float)(q->tail - q->head)/(float)QUEUE_MAX_ITEMS ) >= QueueConfig.pacingOnThresh)
{
#ifdef DEBUG
log_warning("queue %s is over pacing threshold, head=%ld, tail=%ld; adjusting slowest readers", q->name, QueueConfig.pacingOnThresh, q->head, q->tail);
#endif
for ( i = 0; i < MAX_QUEUE_READERS; i++ )
{
#ifdef DEBUG
debug(__FUNCTION__, "queue %s's head is %ld", q->name, q->head);
if (q->nextItem[i] >= 0)
{
debug(__FUNCTION__, "queue %s's reader %d's next item is %ld", q->name, i, q->nextItem[i]);
}
#endif
// if this reader is the slowest one, adjust it
if ( q->head == q->nextItem[i] )
{
adjustSlowestQueueReader(q, i);
}
}
}
}
// only for the old pacing algorithm, otherwise skip this step
if(q->newPacingEnable == FALSE)
{
// check if need to stop pacing
if( checkPacingStop(q) )
log_fatal("%s queue error stopping pacing rules", q->name);
}
// write the data to the next spot in the queue
q->writeCount++;
if( q->readercount > 0 )
{
q->writeCounts[writer->index]++;
long l = q->tail % QUEUE_MAX_ITEMS;
q->items[l].count = q->readercount;
q->items[l].messagBuf = (void *)item;
q->tail++;
if ( (q->tail - q->head) > q->logMaxItems)
q->logMaxItems = q->tail - q->head;
}
else
free( item );
// only if use the old pacing, otherwise skip this step
if(q->newPacingEnable == FALSE)
{
// apply pacing rules to the current writer
if ( applyPacing(q, writer->index) )
log_fatal("%s queue error applying pacing rules", q->name);
// not reached
}
// unlock the queue
if ( pthread_mutex_unlock( &q->queueLock ) )
log_fatal( "unlockQueue: failed");
// notify blocked readers new data has appeared
if( q->readercount > 0 )
pthread_cond_broadcast( &q->queueCond );
#ifdef DEBUG
debug(__FUNCTION__, "Writer %d (%d writes in last interval(%d)) wrote to queue %s; tail/head: %ld/%ld ",
writer->index, q->writeCounts[writer->index], QueueConfig.pacingInterval, q->name, q->tail, q->head);
#endif
/* log a message if we are past the log interval */
int now = time( NULL );
if ( now > q->lastLogTime + QueueConfig.logInterval)
{
q->lastLogTime = now;
log_msg("Queue %s status: tail=%ld head=%ld", q->name, q->tail, q->head);
log_msg("Queue %s usage: currentItems=%ld, usedBytes=%ld, peakItems=%ld, allowedItems=%ld",
q->name, getItemsUsed(q->name), getBytesUsed(q->name), q->logMaxItems, QUEUE_MAX_ITEMS);
log_msg("Queue %s writers: current=%d, peak=%d, allowed=%d",
q->name, getWriterCount(q->name), q->logMaxWriters, MAX_QUEUE_WRITERS);
log_msg("Queue %s readers: current=%d, peak=%d, allowed=%d",
q->name, getReaderCount(q->name), q->logMaxReaders, MAX_QUEUE_READERS);
}
return(0);
}
/*--------------------------------------------------------------------------------------
* Purpose: Write a new item into the queue
* Input: queue to write item and the item itself
* Output: returns 0 on success, 1 on queue_full, but success, -1 on failure
* He Yan @ June 15, 2008
* -------------------------------------------------------------------------------------*/
int
writeQueue( QueueWriter writer, void *item )
{
Queue q = writer->queue;
// lock the queue
if ( pthread_mutex_lock( &q->queueLock ) ){
log_warning( "lockQueue: failed");
return -1;
}
int q_full = pacing_write_post_lock(q);
// write the data to the next spot in the queue
q->writeCount++;
if( q->readercount > 0 ){
q->writeCounts[writer->index]++;
long l = q->tail % QUEUE_MAX_ITEMS;
q->items[l].count = q->readercount;
q->items[l].messagBuf = (void *)item;
q->tail++;
if ( (q->tail - q->head) > q->logMaxItems){
q->logMaxItems = q->tail - q->head;
}
} else{
free( item );
}
pacing_write_post_write(q,writer->index);
// unlock the queue
if ( pthread_mutex_unlock( &q->queueLock ) ){
log_warning( "unlockQueue: failed");
return -1;
}
// notify blocked readers new data has appeared
if( q->readercount > 0 ){
pthread_cond_broadcast( q->queueGroupCond );
}
#ifdef DEBUG
debug(__FUNCTION__, "Writer %d (%d writes in last interval(%d)) wrote to queue %s; tail/head: %ld/%ld ",
writer->index, q->writeCounts[writer->index], QueueConfig.pacingInterval, q->name, q->tail, q->head);
#endif
/* log a message if we are past the log interval */
int now = time( NULL );
if ( now > q->lastLogTime + QueueConfig.logInterval) {
q->lastLogTime = now;
log_msg("Queue %s status: tail=%ld head=%ld", q->name, q->tail, q->head);
log_msg("Queue %s usage: currentItems=%ld, usedBytes=%ld, peakItems=%ld, allowedItems=%ld",
q->name, getItemsUsed(q->name), getBytesUsed(q->name), q->logMaxItems, QUEUE_MAX_ITEMS);
log_msg("Queue %s writers: current=%d, peak=%d, allowed=%d",
q->name, getWriterCount(q->name), q->logMaxWriters, MAX_QUEUE_WRITERS);
log_msg("Queue %s readers: current=%d, peak=%d, allowed=%d",
q->name, getReaderCount(q->name), q->logMaxReaders, MAX_QUEUE_READERS);
}
return q_full;
}