701 lines
21 KiB
C
701 lines
21 KiB
C
/*********************************************************************************************************
|
|
* Software License Agreement (BSD License) *
|
|
* Author: Sebastien Decugis <sdecugis@freediameter.net> *
|
|
* *
|
|
* Copyright (c) 2013, WIDE Project and NICT *
|
|
* All rights reserved. *
|
|
* *
|
|
* Redistribution and use of this software in source and binary forms, with or without modification, are *
|
|
* permitted provided that the following conditions are met: *
|
|
* *
|
|
* * Redistributions of source code must retain the above *
|
|
* copyright notice, this list of conditions and the *
|
|
* following disclaimer. *
|
|
* *
|
|
* * Redistributions in binary form must reproduce the above *
|
|
* copyright notice, this list of conditions and the *
|
|
* following disclaimer in the documentation and/or other *
|
|
* materials provided with the distribution. *
|
|
* *
|
|
* * Neither the name of the WIDE Project or NICT nor the *
|
|
* names of its contributors may be used to endorse or *
|
|
* promote products derived from this software without *
|
|
* specific prior written permission of WIDE Project and *
|
|
* NICT. *
|
|
* *
|
|
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED *
|
|
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A *
|
|
* PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR *
|
|
* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT *
|
|
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS *
|
|
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR *
|
|
* TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF *
|
|
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. *
|
|
*********************************************************************************************************/
|
|
|
|
/* FIFO queues module.
|
|
*
|
|
* The threads that call these functions must be in the cancellation state PTHREAD_CANCEL_ENABLE and type PTHREAD_CANCEL_DEFERRED.
|
|
* This is the default state and type on thread creation.
|
|
*
|
|
* In order to destroy properly a queue, the application must:
|
|
* -> shutdown any process that can add into the queue first.
|
|
* -> pthread_cancel any thread that could be waiting on the queue.
|
|
* -> consume any element that is in the queue, using fd_qu_tryget_int.
|
|
* -> then destroy the queue using fd_mq_del.
|
|
*/
|
|
|
|
#include "fdproto-internal.h"
|
|
|
|
/* Definition of a FIFO queue object */
|
|
struct fifo {
|
|
int eyec; /* An eye catcher, also used to check a queue is valid. FIFO_EYEC */
|
|
|
|
pthread_mutex_t mtx; /* Mutex protecting this queue */
|
|
pthread_cond_t cond_pull; /* condition variable for pulling threads */
|
|
pthread_cond_t cond_push; /* condition variable for pushing threads */
|
|
|
|
struct fd_list list; /* sentinel for the list of elements */
|
|
int count; /* number of objects in the list */
|
|
int thrs; /* number of threads waiting for a new element (when count is 0) */
|
|
|
|
int max; /* maximum number of items to accept if not 0 */
|
|
int thrs_push; /* number of threads waitnig to push an item */
|
|
|
|
uint16_t high; /* High level threshold (see libfreeDiameter.h for details) */
|
|
uint16_t low; /* Low level threshhold */
|
|
void *data; /* Opaque pointer for threshold callbacks */
|
|
void (*h_cb)(struct fifo *, void **); /* The callbacks */
|
|
void (*l_cb)(struct fifo *, void **);
|
|
int highest;/* The highest count value for which h_cb has been called */
|
|
int highest_ever; /* The max count value this queue has reached (for tweaking) */
|
|
|
|
long long total_items; /* Cumulated number of items that went through this fifo (excluding current count), always increasing. */
|
|
struct timespec total_time; /* Cumulated time all items spent in this queue, including blocking time (always growing, use deltas for monitoring) */
|
|
struct timespec blocking_time; /* Cumulated time threads trying to post new items were blocked (queue full). */
|
|
struct timespec last_time; /* For the last element retrieved from the queue, how long it take between posting (including blocking) and poping */
|
|
|
|
};
|
|
|
|
struct fifo_item {
|
|
struct fd_list item;
|
|
struct timespec posted_on;
|
|
};
|
|
|
|
/* The eye catcher value */
|
|
#define FIFO_EYEC 0xe7ec1130
|
|
|
|
/* Macro to check a pointer */
|
|
#define CHECK_FIFO( _queue ) (( (_queue) != NULL) && ( (_queue)->eyec == FIFO_EYEC) )
|
|
|
|
|
|
/* Create a new queue, with max number of items -- use 0 for no max */
|
|
int fd_fifo_new ( struct fifo ** queue, int max )
|
|
{
|
|
struct fifo * new;
|
|
|
|
TRACE_ENTRY( "%p", queue );
|
|
|
|
CHECK_PARAMS( queue );
|
|
|
|
/* Create a new object */
|
|
CHECK_MALLOC( new = malloc (sizeof (struct fifo) ) );
|
|
|
|
/* Initialize the content */
|
|
memset(new, 0, sizeof(struct fifo));
|
|
|
|
new->eyec = FIFO_EYEC;
|
|
CHECK_POSIX( pthread_mutex_init(&new->mtx, NULL) );
|
|
CHECK_POSIX( pthread_cond_init(&new->cond_pull, NULL) );
|
|
CHECK_POSIX( pthread_cond_init(&new->cond_push, NULL) );
|
|
new->max = max;
|
|
|
|
fd_list_init(&new->list, NULL);
|
|
|
|
/* We're done */
|
|
*queue = new;
|
|
return 0;
|
|
}
|
|
|
|
/* Dump the content of a queue */
|
|
DECLARE_FD_DUMP_PROTOTYPE(fd_fifo_dump, char * name, struct fifo * queue, fd_fifo_dump_item_cb dump_item)
|
|
{
|
|
FD_DUMP_HANDLE_OFFSET();
|
|
|
|
if (name) {
|
|
CHECK_MALLOC_DO( fd_dump_extend( FD_DUMP_STD_PARAMS, "'%s'(@%p): ", name, queue), return NULL);
|
|
} else {
|
|
CHECK_MALLOC_DO( fd_dump_extend( FD_DUMP_STD_PARAMS, "{fifo}(@%p): ", queue), return NULL);
|
|
}
|
|
|
|
if (!CHECK_FIFO( queue )) {
|
|
return fd_dump_extend(FD_DUMP_STD_PARAMS, "INVALID/NULL");
|
|
}
|
|
|
|
CHECK_POSIX_DO( pthread_mutex_lock( &queue->mtx ), /* continue */ );
|
|
CHECK_MALLOC_DO( fd_dump_extend( FD_DUMP_STD_PARAMS, "items:%d,%d,%d threads:%d,%d stats:%lld/%ld.%06ld,%ld.%06ld,%ld.%06ld thresholds:%d,%d,%d,%p,%p,%p",
|
|
queue->count, queue->highest_ever, queue->max,
|
|
queue->thrs, queue->thrs_push,
|
|
queue->total_items,(long)queue->total_time.tv_sec,(long)(queue->total_time.tv_nsec/1000),(long)queue->blocking_time.tv_sec,(long)(queue->blocking_time.tv_nsec/1000),(long)queue->last_time.tv_sec,(long)(queue->last_time.tv_nsec/1000),
|
|
queue->high, queue->low, queue->highest, queue->h_cb, queue->l_cb, queue->data),
|
|
goto error);
|
|
|
|
if (dump_item) {
|
|
struct fd_list * li;
|
|
int i = 0;
|
|
for (li = queue->list.next; li != &queue->list; li = li->next) {
|
|
struct fifo_item * fi = (struct fifo_item *)li;
|
|
CHECK_MALLOC_DO( fd_dump_extend( FD_DUMP_STD_PARAMS, "\n [#%i](@%p)@%ld.%06ld: ",
|
|
i++, fi->item.o, (long)fi->posted_on.tv_sec,(long)(fi->posted_on.tv_nsec/1000)),
|
|
goto error);
|
|
CHECK_MALLOC_DO( (*dump_item)(FD_DUMP_STD_PARAMS, fi->item.o), goto error);
|
|
}
|
|
}
|
|
CHECK_POSIX_DO( pthread_mutex_unlock( &queue->mtx ), /* continue */ );
|
|
|
|
return *buf;
|
|
error:
|
|
CHECK_POSIX_DO( pthread_mutex_unlock( &queue->mtx ), /* continue */ );
|
|
return NULL;
|
|
}
|
|
|
|
/* Delete a queue. It must be empty. */
|
|
int fd_fifo_del ( struct fifo ** queue )
|
|
{
|
|
struct fifo * q;
|
|
int loops = 0;
|
|
|
|
TRACE_ENTRY( "%p", queue );
|
|
|
|
CHECK_PARAMS( queue && CHECK_FIFO( *queue ) );
|
|
|
|
q = *queue;
|
|
|
|
CHECK_POSIX( pthread_mutex_lock( &q->mtx ) );
|
|
|
|
if ((q->count != 0) || (q->data != NULL)) {
|
|
TRACE_DEBUG(INFO, "The queue cannot be destroyed (%d, %p)", q->count, q->data);
|
|
CHECK_POSIX_DO( pthread_mutex_unlock( &q->mtx ), /* no fallback */ );
|
|
return EINVAL;
|
|
}
|
|
|
|
/* Ok, now invalidate the queue */
|
|
q->eyec = 0xdead;
|
|
|
|
/* Have all waiting threads return an error */
|
|
while (q->thrs) {
|
|
CHECK_POSIX( pthread_mutex_unlock( &q->mtx ));
|
|
CHECK_POSIX( pthread_cond_signal(&q->cond_pull) );
|
|
usleep(1000);
|
|
|
|
CHECK_POSIX( pthread_mutex_lock( &q->mtx ) );
|
|
ASSERT( ++loops < 20 ); /* detect infinite loops */
|
|
}
|
|
|
|
/* sanity check */
|
|
ASSERT(FD_IS_LIST_EMPTY(&q->list));
|
|
|
|
/* And destroy it */
|
|
CHECK_POSIX( pthread_mutex_unlock( &q->mtx ) );
|
|
|
|
CHECK_POSIX_DO( pthread_cond_destroy( &q->cond_pull ), );
|
|
|
|
CHECK_POSIX_DO( pthread_cond_destroy( &q->cond_push ), );
|
|
|
|
CHECK_POSIX_DO( pthread_mutex_destroy( &q->mtx ), );
|
|
|
|
free(q);
|
|
*queue = NULL;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Move the content of old into new, and update loc_update atomically. We leave the old queue empty but valid */
|
|
int fd_fifo_move ( struct fifo * old, struct fifo * new, struct fifo ** loc_update )
|
|
{
|
|
int loops = 0;
|
|
|
|
TRACE_ENTRY("%p %p %p", old, new, loc_update);
|
|
CHECK_PARAMS( CHECK_FIFO( old ) && CHECK_FIFO( new ));
|
|
|
|
CHECK_PARAMS( ! old->data );
|
|
if (new->high) {
|
|
TODO("Implement support for thresholds in fd_fifo_move...");
|
|
}
|
|
|
|
/* Update loc_update */
|
|
if (loc_update)
|
|
*loc_update = new;
|
|
|
|
/* Lock the queues */
|
|
CHECK_POSIX( pthread_mutex_lock( &old->mtx ) );
|
|
|
|
CHECK_PARAMS_DO( (! old->thrs_push), {
|
|
pthread_mutex_unlock( &old->mtx );
|
|
return EINVAL;
|
|
} );
|
|
|
|
CHECK_POSIX( pthread_mutex_lock( &new->mtx ) );
|
|
|
|
/* Any waiting thread on the old queue returns an error */
|
|
old->eyec = 0xdead;
|
|
while (old->thrs) {
|
|
CHECK_POSIX( pthread_mutex_unlock( &old->mtx ));
|
|
CHECK_POSIX( pthread_cond_signal( &old->cond_pull ) );
|
|
usleep(1000);
|
|
|
|
CHECK_POSIX( pthread_mutex_lock( &old->mtx ) );
|
|
ASSERT( loops < 20 ); /* detect infinite loops */
|
|
}
|
|
|
|
/* Move all data from old to new */
|
|
fd_list_move_end( &new->list, &old->list );
|
|
if (old->count && (!new->count)) {
|
|
CHECK_POSIX( pthread_cond_signal(&new->cond_pull) );
|
|
}
|
|
new->count += old->count;
|
|
|
|
/* Reset old */
|
|
old->count = 0;
|
|
old->eyec = FIFO_EYEC;
|
|
|
|
/* Merge the stats in the new queue */
|
|
new->total_items += old->total_items;
|
|
old->total_items = 0;
|
|
|
|
new->total_time.tv_nsec += old->total_time.tv_nsec;
|
|
new->total_time.tv_sec += old->total_time.tv_sec + (new->total_time.tv_nsec / 1000000000);
|
|
new->total_time.tv_nsec %= 1000000000;
|
|
old->total_time.tv_nsec = 0;
|
|
old->total_time.tv_sec = 0;
|
|
|
|
new->blocking_time.tv_nsec += old->blocking_time.tv_nsec;
|
|
new->blocking_time.tv_sec += old->blocking_time.tv_sec + (new->blocking_time.tv_nsec / 1000000000);
|
|
new->blocking_time.tv_nsec %= 1000000000;
|
|
old->blocking_time.tv_nsec = 0;
|
|
old->blocking_time.tv_sec = 0;
|
|
|
|
/* Unlock, we're done */
|
|
CHECK_POSIX( pthread_mutex_unlock( &new->mtx ) );
|
|
CHECK_POSIX( pthread_mutex_unlock( &old->mtx ) );
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Get the information on the queue */
|
|
int fd_fifo_getstats( struct fifo * queue, int * current_count, int * limit_count, int * highest_count, long long * total_count,
|
|
struct timespec * total, struct timespec * blocking, struct timespec * last)
|
|
{
|
|
TRACE_ENTRY( "%p %p %p %p %p %p %p %p", queue, current_count, limit_count, highest_count, total_count, total, blocking, last);
|
|
|
|
/* Check the parameters */
|
|
CHECK_PARAMS( CHECK_FIFO( queue ) );
|
|
|
|
/* lock the queue */
|
|
CHECK_POSIX( pthread_mutex_lock( &queue->mtx ) );
|
|
|
|
if (current_count)
|
|
*current_count = queue->count;
|
|
|
|
if (limit_count)
|
|
*limit_count = queue->max;
|
|
|
|
if (highest_count)
|
|
*highest_count = queue->highest_ever;
|
|
|
|
if (total_count)
|
|
*total_count = queue->total_items;
|
|
|
|
if (total)
|
|
memcpy(total, &queue->total_time, sizeof(struct timespec));
|
|
|
|
if (blocking)
|
|
memcpy(blocking, &queue->blocking_time, sizeof(struct timespec));
|
|
|
|
if (last)
|
|
memcpy(last, &queue->last_time, sizeof(struct timespec));
|
|
|
|
/* Unlock */
|
|
CHECK_POSIX( pthread_mutex_unlock( &queue->mtx ) );
|
|
|
|
/* Done */
|
|
return 0;
|
|
}
|
|
|
|
|
|
/* alternate version with no error checking */
|
|
int fd_fifo_length ( struct fifo * queue )
|
|
{
|
|
if ( !CHECK_FIFO( queue ) )
|
|
return 0;
|
|
|
|
return queue->count; /* Let's hope it's read atomically, since we are not locking... */
|
|
}
|
|
|
|
/* Set the thresholds of the queue */
|
|
int fd_fifo_setthrhd ( struct fifo * queue, void * data, uint16_t high, void (*h_cb)(struct fifo *, void **), uint16_t low, void (*l_cb)(struct fifo *, void **) )
|
|
{
|
|
TRACE_ENTRY( "%p %p %hu %p %hu %p", queue, data, high, h_cb, low, l_cb );
|
|
|
|
/* Check the parameters */
|
|
CHECK_PARAMS( CHECK_FIFO( queue ) && (high > low) && (queue->data == NULL) );
|
|
|
|
/* lock the queue */
|
|
CHECK_POSIX( pthread_mutex_lock( &queue->mtx ) );
|
|
|
|
/* Save the values */
|
|
queue->high = high;
|
|
queue->low = low;
|
|
queue->data = data;
|
|
queue->h_cb = h_cb;
|
|
queue->l_cb = l_cb;
|
|
|
|
/* Unlock */
|
|
CHECK_POSIX( pthread_mutex_unlock( &queue->mtx ) );
|
|
|
|
/* Done */
|
|
return 0;
|
|
}
|
|
|
|
|
|
/* This handler is called when a thread is blocked on a queue, and cancelled */
|
|
static void fifo_cleanup_push(void * queue)
|
|
{
|
|
struct fifo * q = (struct fifo *)queue;
|
|
TRACE_ENTRY( "%p", queue );
|
|
|
|
/* The thread has been cancelled, therefore it does not wait on the queue anymore */
|
|
q->thrs_push--;
|
|
|
|
/* Now unlock the queue, and we're done */
|
|
CHECK_POSIX_DO( pthread_mutex_unlock( &q->mtx ), /* nothing */ );
|
|
|
|
/* End of cleanup handler */
|
|
return;
|
|
}
|
|
|
|
|
|
/* Post a new item in the queue */
|
|
int fd_fifo_post_internal ( struct fifo * queue, void ** item, int skip_max )
|
|
{
|
|
struct fifo_item * new;
|
|
int call_cb = 0;
|
|
struct timespec posted_on, queued_on;
|
|
|
|
/* Get the timing of this call */
|
|
CHECK_SYS( clock_gettime(CLOCK_REALTIME, &posted_on) );
|
|
|
|
/* lock the queue */
|
|
CHECK_POSIX( pthread_mutex_lock( &queue->mtx ) );
|
|
|
|
if ((!skip_max) && (queue->max)) {
|
|
while (queue->count >= queue->max) {
|
|
int ret = 0;
|
|
|
|
/* We have to wait for an item to be pulled */
|
|
queue->thrs_push++ ;
|
|
pthread_cleanup_push( fifo_cleanup_push, queue);
|
|
ret = pthread_cond_wait( &queue->cond_push, &queue->mtx );
|
|
pthread_cleanup_pop(0);
|
|
queue->thrs_push-- ;
|
|
|
|
ASSERT( ret == 0 );
|
|
}
|
|
}
|
|
|
|
/* Create a new list item */
|
|
CHECK_MALLOC_DO( new = malloc (sizeof (struct fifo_item)) , {
|
|
pthread_mutex_unlock( &queue->mtx );
|
|
return ENOMEM;
|
|
} );
|
|
|
|
fd_list_init(&new->item, *item);
|
|
*item = NULL;
|
|
|
|
/* Add the new item at the end */
|
|
fd_list_insert_before( &queue->list, &new->item);
|
|
queue->count++;
|
|
if (queue->highest_ever < queue->count)
|
|
queue->highest_ever = queue->count;
|
|
if (queue->high && ((queue->count % queue->high) == 0)) {
|
|
call_cb = 1;
|
|
queue->highest = queue->count;
|
|
}
|
|
|
|
/* store timing */
|
|
memcpy(&new->posted_on, &posted_on, sizeof(struct timespec));
|
|
|
|
/* update queue timing info "blocking time" */
|
|
{
|
|
long long blocked_ns;
|
|
CHECK_SYS( clock_gettime(CLOCK_REALTIME, &queued_on) );
|
|
blocked_ns = (queued_on.tv_sec - posted_on.tv_sec) * 1000000000;
|
|
blocked_ns += (queued_on.tv_nsec - posted_on.tv_nsec);
|
|
blocked_ns += queue->blocking_time.tv_nsec;
|
|
queue->blocking_time.tv_sec += blocked_ns / 1000000000;
|
|
queue->blocking_time.tv_nsec = blocked_ns % 1000000000;
|
|
}
|
|
|
|
/* Signal if threads are asleep */
|
|
if (queue->thrs > 0) {
|
|
CHECK_POSIX( pthread_cond_signal(&queue->cond_pull) );
|
|
}
|
|
if (queue->thrs_push > 0) {
|
|
/* cascade */
|
|
CHECK_POSIX( pthread_cond_signal(&queue->cond_push) );
|
|
}
|
|
|
|
/* Unlock */
|
|
CHECK_POSIX( pthread_mutex_unlock( &queue->mtx ) );
|
|
|
|
/* Call high-watermark cb as needed */
|
|
if (call_cb && queue->h_cb)
|
|
(*queue->h_cb)(queue, &queue->data);
|
|
|
|
/* Done */
|
|
return 0;
|
|
}
|
|
|
|
/* Post a new item in the queue */
|
|
int fd_fifo_post_int ( struct fifo * queue, void ** item )
|
|
{
|
|
TRACE_ENTRY( "%p %p", queue, item );
|
|
|
|
/* Check the parameters */
|
|
CHECK_PARAMS( CHECK_FIFO( queue ) && item && *item );
|
|
|
|
return fd_fifo_post_internal ( queue,item, 0 );
|
|
|
|
}
|
|
|
|
/* Post a new item in the queue, not blocking */
|
|
int fd_fifo_post_noblock ( struct fifo * queue, void ** item )
|
|
{
|
|
TRACE_ENTRY( "%p %p", queue, item );
|
|
|
|
/* Check the parameters */
|
|
CHECK_PARAMS( CHECK_FIFO( queue ) && item && *item );
|
|
|
|
return fd_fifo_post_internal ( queue,item, 1 );
|
|
|
|
}
|
|
|
|
/* Pop the first item from the queue */
|
|
static void * mq_pop(struct fifo * queue)
|
|
{
|
|
void * ret = NULL;
|
|
struct fifo_item * fi;
|
|
struct timespec now;
|
|
|
|
ASSERT( ! FD_IS_LIST_EMPTY(&queue->list) );
|
|
|
|
fi = (struct fifo_item *)(queue->list.next);
|
|
ret = fi->item.o;
|
|
fd_list_unlink(&fi->item);
|
|
queue->count--;
|
|
queue->total_items++;
|
|
|
|
/* Update the timings */
|
|
CHECK_SYS_DO( clock_gettime(CLOCK_REALTIME, &now), goto skip_timing );
|
|
{
|
|
long long elapsed = (now.tv_sec - fi->posted_on.tv_sec) * 1000000000;
|
|
elapsed += now.tv_nsec - fi->posted_on.tv_nsec;
|
|
|
|
queue->last_time.tv_sec = elapsed / 1000000000;
|
|
queue->last_time.tv_nsec = elapsed % 1000000000;
|
|
|
|
elapsed += queue->total_time.tv_nsec;
|
|
queue->total_time.tv_sec += elapsed / 1000000000;
|
|
queue->total_time.tv_nsec = elapsed % 1000000000;
|
|
}
|
|
skip_timing:
|
|
free(fi);
|
|
|
|
if (queue->thrs_push) {
|
|
CHECK_POSIX_DO( pthread_cond_signal( &queue->cond_push ), );
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
/* Check if the low watermark callback must be called. */
|
|
static __inline__ int test_l_cb(struct fifo * queue)
|
|
{
|
|
if ((queue->high == 0) || (queue->low == 0) || (queue->l_cb == 0))
|
|
return 0;
|
|
|
|
if (((queue->count % queue->high) == queue->low) && (queue->highest > queue->count)) {
|
|
queue->highest -= queue->high;
|
|
return 1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Try poping an item */
|
|
int fd_fifo_tryget_int ( struct fifo * queue, void ** item )
|
|
{
|
|
int wouldblock = 0;
|
|
int call_cb = 0;
|
|
|
|
TRACE_ENTRY( "%p %p", queue, item );
|
|
|
|
/* Check the parameters */
|
|
CHECK_PARAMS( CHECK_FIFO( queue ) && item );
|
|
|
|
/* lock the queue */
|
|
CHECK_POSIX( pthread_mutex_lock( &queue->mtx ) );
|
|
|
|
/* Check queue status */
|
|
if (queue->count > 0) {
|
|
got_item:
|
|
/* There are elements in the queue, so pick the first one */
|
|
*item = mq_pop(queue);
|
|
call_cb = test_l_cb(queue);
|
|
} else {
|
|
if (queue->thrs_push > 0) {
|
|
/* A thread is trying to push something, let's give it a chance */
|
|
CHECK_POSIX( pthread_mutex_unlock( &queue->mtx ) );
|
|
CHECK_POSIX( pthread_cond_signal( &queue->cond_push ) );
|
|
usleep(1000);
|
|
CHECK_POSIX( pthread_mutex_lock( &queue->mtx ) );
|
|
if (queue->count > 0)
|
|
goto got_item;
|
|
}
|
|
|
|
wouldblock = 1;
|
|
*item = NULL;
|
|
}
|
|
|
|
/* Unlock */
|
|
CHECK_POSIX( pthread_mutex_unlock( &queue->mtx ) );
|
|
|
|
/* Call low watermark callback as needed */
|
|
if (call_cb)
|
|
(*queue->l_cb)(queue, &queue->data);
|
|
|
|
/* Done */
|
|
return wouldblock ? EWOULDBLOCK : 0;
|
|
}
|
|
|
|
/* This handler is called when a thread is blocked on a queue, and cancelled */
|
|
static void fifo_cleanup(void * queue)
|
|
{
|
|
struct fifo * q = (struct fifo *)queue;
|
|
TRACE_ENTRY( "%p", queue );
|
|
|
|
/* The thread has been cancelled, therefore it does not wait on the queue anymore */
|
|
q->thrs--;
|
|
|
|
/* Now unlock the queue, and we're done */
|
|
CHECK_POSIX_DO( pthread_mutex_unlock( &q->mtx ), /* nothing */ );
|
|
|
|
/* End of cleanup handler */
|
|
return;
|
|
}
|
|
|
|
/* The internal function for fd_fifo_timedget and fd_fifo_get */
|
|
static int fifo_tget ( struct fifo * queue, void ** item, int istimed, const struct timespec *abstime)
|
|
{
|
|
int call_cb = 0;
|
|
int ret = 0;
|
|
|
|
/* Check the parameters */
|
|
CHECK_PARAMS( CHECK_FIFO( queue ) && item && (abstime || !istimed) );
|
|
|
|
/* Initialize the return value */
|
|
*item = NULL;
|
|
|
|
/* lock the queue */
|
|
CHECK_POSIX( pthread_mutex_lock( &queue->mtx ) );
|
|
|
|
awaken:
|
|
/* Check queue status */
|
|
if (!CHECK_FIFO( queue )) {
|
|
/* The queue is being destroyed */
|
|
CHECK_POSIX( pthread_mutex_unlock( &queue->mtx ) );
|
|
TRACE_DEBUG(FULL, "The queue is being destroyed -> EPIPE");
|
|
return EPIPE;
|
|
}
|
|
|
|
if (queue->count > 0) {
|
|
/* There are items in the queue, so pick the first one */
|
|
*item = mq_pop(queue);
|
|
call_cb = test_l_cb(queue);
|
|
} else {
|
|
/* We have to wait for a new item */
|
|
queue->thrs++ ;
|
|
pthread_cleanup_push( fifo_cleanup, queue);
|
|
if (istimed) {
|
|
ret = pthread_cond_timedwait( &queue->cond_pull, &queue->mtx, abstime );
|
|
} else {
|
|
ret = pthread_cond_wait( &queue->cond_pull, &queue->mtx );
|
|
}
|
|
pthread_cleanup_pop(0);
|
|
queue->thrs-- ;
|
|
if (ret == 0)
|
|
goto awaken; /* test for spurious wake-ups */
|
|
|
|
/* otherwise (ETIMEDOUT / other error) just continue */
|
|
}
|
|
|
|
/* Unlock */
|
|
CHECK_POSIX( pthread_mutex_unlock( &queue->mtx ) );
|
|
|
|
/* Call low watermark callback as needed */
|
|
if (call_cb)
|
|
(*queue->l_cb)(queue, &queue->data);
|
|
|
|
/* Done */
|
|
return ret;
|
|
}
|
|
|
|
/* Get the next available item, block until there is one */
|
|
int fd_fifo_get_int ( struct fifo * queue, void ** item )
|
|
{
|
|
TRACE_ENTRY( "%p %p", queue, item );
|
|
return fifo_tget(queue, item, 0, NULL);
|
|
}
|
|
|
|
/* Get the next available item, block until there is one, or the timeout expires */
|
|
int fd_fifo_timedget_int ( struct fifo * queue, void ** item, const struct timespec *abstime )
|
|
{
|
|
TRACE_ENTRY( "%p %p %p", queue, item, abstime );
|
|
return fifo_tget(queue, item, 1, abstime);
|
|
}
|
|
|
|
/* Test if data is available in the queue, without pulling it */
|
|
int fd_fifo_select ( struct fifo * queue, const struct timespec *abstime )
|
|
{
|
|
int ret = 0;
|
|
TRACE_ENTRY( "%p %p", queue, abstime );
|
|
|
|
CHECK_PARAMS_DO( CHECK_FIFO( queue ), return -EINVAL );
|
|
|
|
/* lock the queue */
|
|
CHECK_POSIX_DO( pthread_mutex_lock( &queue->mtx ), return -__ret__ );
|
|
|
|
awaken:
|
|
ret = (queue->count > 0 ) ? queue->count : 0;
|
|
if ((ret == 0) && (abstime != NULL)) {
|
|
/* We have to wait for a new item */
|
|
queue->thrs++ ;
|
|
pthread_cleanup_push( fifo_cleanup, queue);
|
|
ret = pthread_cond_timedwait( &queue->cond_pull, &queue->mtx, abstime );
|
|
pthread_cleanup_pop(0);
|
|
queue->thrs-- ;
|
|
if (ret == 0)
|
|
goto awaken; /* test for spurious wake-ups */
|
|
|
|
if (ret == ETIMEDOUT)
|
|
ret = 0;
|
|
else
|
|
ret = -ret;
|
|
}
|
|
|
|
/* Unlock */
|
|
CHECK_POSIX_DO( pthread_mutex_unlock( &queue->mtx ), return -__ret__ );
|
|
|
|
return ret;
|
|
}
|