#include "mpm_fdqueue.h"
#if APR_HAS_THREADS
#include <apr_atomic.h>
static const apr_uint32_t zero_pt = APR_UINT32_MAX/2;
struct recycled_pool
{
apr_pool_t *pool;
struct recycled_pool *next;
};
struct fd_queue_info_t
{
apr_uint32_t volatile idlers;
apr_thread_mutex_t *idlers_mutex;
apr_thread_cond_t *wait_for_idler;
int terminated;
int max_idlers;
int max_recycled_pools;
apr_uint32_t recycled_pools_count;
struct recycled_pool *volatile recycled_pools;
};
struct fd_queue_elem_t
{
apr_socket_t *sd;
void *sd_baton;
apr_pool_t *p;
};
static apr_status_t queue_info_cleanup(void *data_)
{
fd_queue_info_t *qi = data_;
apr_thread_cond_destroy(qi->wait_for_idler);
apr_thread_mutex_destroy(qi->idlers_mutex);
for (;;) {
struct recycled_pool *first_pool = qi->recycled_pools;
if (first_pool == NULL) {
break;
}
if (apr_atomic_casptr((void *)&qi->recycled_pools, first_pool->next,
first_pool) == first_pool) {
apr_pool_destroy(first_pool->pool);
}
}
return APR_SUCCESS;
}
apr_status_t ap_queue_info_create(fd_queue_info_t **queue_info,
apr_pool_t *pool, int max_idlers,
int max_recycled_pools)
{
apr_status_t rv;
fd_queue_info_t *qi;
qi = apr_pcalloc(pool, sizeof(*qi));
rv = apr_thread_mutex_create(&qi->idlers_mutex, APR_THREAD_MUTEX_DEFAULT,
pool);
if (rv != APR_SUCCESS) {
return rv;
}
rv = apr_thread_cond_create(&qi->wait_for_idler, pool);
if (rv != APR_SUCCESS) {
return rv;
}
qi->recycled_pools = NULL;
qi->max_recycled_pools = max_recycled_pools;
qi->max_idlers = max_idlers;
qi->idlers = zero_pt;
apr_pool_cleanup_register(pool, qi, queue_info_cleanup,
apr_pool_cleanup_null);
*queue_info = qi;
return APR_SUCCESS;
}
apr_status_t ap_queue_info_set_idle(fd_queue_info_t *queue_info,
apr_pool_t *pool_to_recycle)
{
apr_status_t rv;
ap_queue_info_push_pool(queue_info, pool_to_recycle);
if (apr_atomic_inc32(&queue_info->idlers) < zero_pt) {
rv = apr_thread_mutex_lock(queue_info->idlers_mutex);
if (rv != APR_SUCCESS) {
AP_DEBUG_ASSERT(0);
return rv;
}
rv = apr_thread_cond_signal(queue_info->wait_for_idler);
if (rv != APR_SUCCESS) {
apr_thread_mutex_unlock(queue_info->idlers_mutex);
return rv;
}
rv = apr_thread_mutex_unlock(queue_info->idlers_mutex);
if (rv != APR_SUCCESS) {
return rv;
}
}
return APR_SUCCESS;
}
apr_status_t ap_queue_info_try_get_idler(fd_queue_info_t *queue_info)
{
for (;;) {
apr_uint32_t idlers = queue_info->idlers;
if (idlers <= zero_pt) {
return APR_EAGAIN;
}
if (apr_atomic_cas32(&queue_info->idlers, idlers - 1,
idlers) == idlers) {
return APR_SUCCESS;
}
}
}
apr_status_t ap_queue_info_wait_for_idler(fd_queue_info_t *queue_info,
int *had_to_block)
{
apr_status_t rv;
if (apr_atomic_add32(&queue_info->idlers, -1) <= zero_pt) {
rv = apr_thread_mutex_lock(queue_info->idlers_mutex);
if (rv != APR_SUCCESS) {
AP_DEBUG_ASSERT(0);
apr_atomic_inc32(&(queue_info->idlers));
return rv;
}
if (queue_info->idlers < zero_pt) {
if (had_to_block) {
*had_to_block = 1;
}
rv = apr_thread_cond_wait(queue_info->wait_for_idler,
queue_info->idlers_mutex);
if (rv != APR_SUCCESS) {
AP_DEBUG_ASSERT(0);
apr_thread_mutex_unlock(queue_info->idlers_mutex);
return rv;
}
}
rv = apr_thread_mutex_unlock(queue_info->idlers_mutex);
if (rv != APR_SUCCESS) {
return rv;
}
}
if (queue_info->terminated) {
return APR_EOF;
}
else {
return APR_SUCCESS;
}
}
apr_uint32_t ap_queue_info_num_idlers(fd_queue_info_t *queue_info)
{
apr_uint32_t val;
val = apr_atomic_read32(&queue_info->idlers);
return (val > zero_pt) ? val - zero_pt : 0;
}
void ap_queue_info_push_pool(fd_queue_info_t *queue_info,
apr_pool_t *pool_to_recycle)
{
struct recycled_pool *new_recycle;
if (!pool_to_recycle)
return;
if (queue_info->max_recycled_pools >= 0) {
apr_uint32_t n = apr_atomic_read32(&queue_info->recycled_pools_count);
if (n >= queue_info->max_recycled_pools) {
apr_pool_destroy(pool_to_recycle);
return;
}
apr_atomic_inc32(&queue_info->recycled_pools_count);
}
apr_pool_clear(pool_to_recycle);
new_recycle = apr_palloc(pool_to_recycle, sizeof *new_recycle);
new_recycle->pool = pool_to_recycle;
for (;;) {
struct recycled_pool *next = queue_info->recycled_pools;
new_recycle->next = next;
if (apr_atomic_casptr((void *)&queue_info->recycled_pools,
new_recycle, next) == next)
break;
}
}
void ap_queue_info_pop_pool(fd_queue_info_t *queue_info,
apr_pool_t **recycled_pool)
{
*recycled_pool = NULL;
for (;;) {
struct recycled_pool *first_pool = queue_info->recycled_pools;
if (first_pool == NULL) {
break;
}
if (apr_atomic_casptr((void *)&queue_info->recycled_pools,
first_pool->next, first_pool) == first_pool) {
*recycled_pool = first_pool->pool;
if (queue_info->max_recycled_pools >= 0)
apr_atomic_dec32(&queue_info->recycled_pools_count);
break;
}
}
}
void ap_queue_info_free_idle_pools(fd_queue_info_t *queue_info)
{
apr_pool_t *p;
queue_info->max_recycled_pools = 0;
for (;;) {
ap_queue_info_pop_pool(queue_info, &p);
if (p == NULL)
break;
apr_pool_destroy(p);
}
apr_atomic_set32(&queue_info->recycled_pools_count, 0);
}
apr_status_t ap_queue_info_term(fd_queue_info_t *queue_info)
{
apr_status_t rv;
rv = apr_thread_mutex_lock(queue_info->idlers_mutex);
if (rv != APR_SUCCESS) {
return rv;
}
queue_info->terminated = 1;
apr_thread_cond_broadcast(queue_info->wait_for_idler);
return apr_thread_mutex_unlock(queue_info->idlers_mutex);
}
#define ap_queue_full(queue) ((queue)->nelts == (queue)->bounds)
#define ap_queue_empty(queue) ((queue)->nelts == 0 && \
APR_RING_EMPTY(&queue->timers, \
timer_event_t, link))
static apr_status_t ap_queue_destroy(void *data)
{
fd_queue_t *queue = data;
apr_thread_cond_destroy(queue->not_empty);
apr_thread_mutex_destroy(queue->one_big_mutex);
return APR_SUCCESS;
}
apr_status_t ap_queue_create(fd_queue_t **pqueue, int capacity, apr_pool_t *p)
{
apr_status_t rv;
fd_queue_t *queue;
queue = apr_pcalloc(p, sizeof *queue);
if ((rv = apr_thread_mutex_create(&queue->one_big_mutex,
APR_THREAD_MUTEX_DEFAULT,
p)) != APR_SUCCESS) {
return rv;
}
if ((rv = apr_thread_cond_create(&queue->not_empty, p)) != APR_SUCCESS) {
return rv;
}
APR_RING_INIT(&queue->timers, timer_event_t, link);
queue->data = apr_pcalloc(p, capacity * sizeof(fd_queue_elem_t));
queue->bounds = capacity;
apr_pool_cleanup_register(p, queue, ap_queue_destroy,
apr_pool_cleanup_null);
*pqueue = queue;
return APR_SUCCESS;
}
apr_status_t ap_queue_push_socket(fd_queue_t *queue,
apr_socket_t *sd, void *sd_baton,
apr_pool_t *p)
{
fd_queue_elem_t *elem;
apr_status_t rv;
if ((rv = apr_thread_mutex_lock(queue->one_big_mutex)) != APR_SUCCESS) {
return rv;
}
AP_DEBUG_ASSERT(!queue->terminated);
AP_DEBUG_ASSERT(!ap_queue_full(queue));
elem = &queue->data[queue->in++];
if (queue->in >= queue->bounds)
queue->in -= queue->bounds;
elem->sd = sd;
elem->sd_baton = sd_baton;
elem->p = p;
queue->nelts++;
apr_thread_cond_signal(queue->not_empty);
return apr_thread_mutex_unlock(queue->one_big_mutex);
}
apr_status_t ap_queue_push_timer(fd_queue_t *queue, timer_event_t *te)
{
apr_status_t rv;
if ((rv = apr_thread_mutex_lock(queue->one_big_mutex)) != APR_SUCCESS) {
return rv;
}
AP_DEBUG_ASSERT(!queue->terminated);
APR_RING_INSERT_TAIL(&queue->timers, te, timer_event_t, link);
apr_thread_cond_signal(queue->not_empty);
return apr_thread_mutex_unlock(queue->one_big_mutex);
}
apr_status_t ap_queue_pop_something(fd_queue_t *queue,
apr_socket_t **sd, void **sd_baton,
apr_pool_t **p, timer_event_t **te_out)
{
fd_queue_elem_t *elem;
timer_event_t *te;
apr_status_t rv;
if ((rv = apr_thread_mutex_lock(queue->one_big_mutex)) != APR_SUCCESS) {
return rv;
}
if (ap_queue_empty(queue)) {
if (!queue->terminated) {
apr_thread_cond_wait(queue->not_empty, queue->one_big_mutex);
}
if (ap_queue_empty(queue)) {
rv = apr_thread_mutex_unlock(queue->one_big_mutex);
if (rv != APR_SUCCESS) {
return rv;
}
if (queue->terminated) {
return APR_EOF;
}
else {
return APR_EINTR;
}
}
}
te = NULL;
if (te_out) {
if (!APR_RING_EMPTY(&queue->timers, timer_event_t, link)) {
te = APR_RING_FIRST(&queue->timers);
APR_RING_REMOVE(te, link);
}
*te_out = te;
}
if (!te) {
elem = &queue->data[queue->out++];
if (queue->out >= queue->bounds)
queue->out -= queue->bounds;
queue->nelts--;
*sd = elem->sd;
if (sd_baton) {
*sd_baton = elem->sd_baton;
}
*p = elem->p;
#ifdef AP_DEBUG
elem->sd = NULL;
elem->p = NULL;
#endif
}
return apr_thread_mutex_unlock(queue->one_big_mutex);
}
static apr_status_t queue_interrupt(fd_queue_t *queue, int all, int term)
{
apr_status_t rv;
if ((rv = apr_thread_mutex_lock(queue->one_big_mutex)) != APR_SUCCESS) {
return rv;
}
if (term) {
queue->terminated = 1;
}
if (all)
apr_thread_cond_broadcast(queue->not_empty);
else
apr_thread_cond_signal(queue->not_empty);
return apr_thread_mutex_unlock(queue->one_big_mutex);
}
apr_status_t ap_queue_interrupt_all(fd_queue_t *queue)
{
return queue_interrupt(queue, 1, 0);
}
apr_status_t ap_queue_interrupt_one(fd_queue_t *queue)
{
return queue_interrupt(queue, 0, 0);
}
apr_status_t ap_queue_term(fd_queue_t *queue)
{
return queue_interrupt(queue, 1, 1);
}
#endif