| /* $Id$ */ |
| /* |
| * Copyright (C)2003-2006 Benny Prijono <benny@prijono.org> |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or |
| * (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, write to the Free Software |
| * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| */ |
| |
| /* |
| * sock_select.c |
| * |
| * This is the implementation of IOQueue using pj_sock_select(). |
| * It runs anywhere where pj_sock_select() is available (currently |
| * Win32, Linux, Linux kernel, etc.). |
| */ |
| |
| #include <pj/ioqueue.h> |
| #include <pj/os.h> |
| #include <pj/lock.h> |
| #include <pj/log.h> |
| #include <pj/list.h> |
| #include <pj/pool.h> |
| #include <pj/string.h> |
| #include <pj/assert.h> |
| #include <pj/sock.h> |
| #include <pj/compat/socket.h> |
| #include <pj/sock_select.h> |
| #include <pj/errno.h> |
| |
| /* |
| * Include declaration from common abstraction. |
| */ |
| #include "ioqueue_common_abs.h" |
| |
| /* |
| * ISSUES with ioqueue_select() |
| * |
| * EAGAIN/EWOULDBLOCK error in recv(): |
| * - when multiple threads are working with the ioqueue, application |
| * may receive EAGAIN or EWOULDBLOCK in the receive callback. |
| * This error happens because more than one thread is watching for |
| * the same descriptor set, so when all of them call recv() or recvfrom() |
| * simultaneously, only one will succeed and the rest will get the error. |
| * |
| */ |
| #define THIS_FILE "ioq_select" |
| |
| /* |
| * The select ioqueue relies on socket functions (pj_sock_xxx()) to return |
| * the correct error code. |
| */ |
| #if PJ_RETURN_OS_ERROR(100) != PJ_STATUS_FROM_OS(100) |
| # error "Error reporting must be enabled for this function to work!" |
| #endif |
| |
| /** |
| * Get the number of descriptors in the set. This is defined in sock_select.c |
| * This function will only return the number of sockets set from PJ_FD_SET |
| * operation. When the set is modified by other means (such as by select()), |
| * the count will not be reflected here. |
| * |
| * That's why don't export this function in the header file, to avoid |
| * misunderstanding. |
| * |
| * @param fdsetp The descriptor set. |
| * |
| * @return Number of descriptors in the set. |
| */ |
| PJ_DECL(pj_size_t) PJ_FD_COUNT(const pj_fd_set_t *fdsetp); |
| |
| |
| /* |
| * During debugging build, VALIDATE_FD_SET is set. |
| * This will check the validity of the fd_sets. |
| */ |
| /* |
| #if defined(PJ_DEBUG) && PJ_DEBUG != 0 |
| # define VALIDATE_FD_SET 1 |
| #else |
| # define VALIDATE_FD_SET 0 |
| #endif |
| */ |
| #define VALIDATE_FD_SET 0 |
| |
| /* |
| * This describes each key. |
| */ |
| struct pj_ioqueue_key_t |
| { |
| DECLARE_COMMON_KEY |
| }; |
| |
| /* |
| * This describes the I/O queue itself. |
| */ |
| struct pj_ioqueue_t |
| { |
| DECLARE_COMMON_IOQUEUE |
| |
| unsigned max, count; |
| pj_ioqueue_key_t key_list; |
| pj_fd_set_t rfdset; |
| pj_fd_set_t wfdset; |
| #if PJ_HAS_TCP |
| pj_fd_set_t xfdset; |
| #endif |
| }; |
| |
| /* Include implementation for common abstraction after we declare |
| * pj_ioqueue_key_t and pj_ioqueue_t. |
| */ |
| #include "ioqueue_common_abs.c" |
| |
| /* |
| * pj_ioqueue_name() |
| */ |
| PJ_DEF(const char*) pj_ioqueue_name(void) |
| { |
| return "select"; |
| } |
| |
| /* |
| * pj_ioqueue_create() |
| * |
| * Create select ioqueue. |
| */ |
| PJ_DEF(pj_status_t) pj_ioqueue_create( pj_pool_t *pool, |
| pj_size_t max_fd, |
| pj_ioqueue_t **p_ioqueue) |
| { |
| pj_ioqueue_t *ioqueue; |
| pj_lock_t *lock; |
| pj_status_t rc; |
| |
| /* Check that arguments are valid. */ |
| PJ_ASSERT_RETURN(pool != NULL && p_ioqueue != NULL && |
| max_fd > 0 && max_fd <= PJ_IOQUEUE_MAX_HANDLES, |
| PJ_EINVAL); |
| |
| /* Check that size of pj_ioqueue_op_key_t is sufficient */ |
| PJ_ASSERT_RETURN(sizeof(pj_ioqueue_op_key_t)-sizeof(void*) >= |
| sizeof(union operation_key), PJ_EBUG); |
| |
| ioqueue = pj_pool_alloc(pool, sizeof(pj_ioqueue_t)); |
| |
| ioqueue_init(ioqueue); |
| |
| ioqueue->max = max_fd; |
| ioqueue->count = 0; |
| PJ_FD_ZERO(&ioqueue->rfdset); |
| PJ_FD_ZERO(&ioqueue->wfdset); |
| #if PJ_HAS_TCP |
| PJ_FD_ZERO(&ioqueue->xfdset); |
| #endif |
| pj_list_init(&ioqueue->key_list); |
| |
| rc = pj_lock_create_simple_mutex(pool, "ioq%p", &lock); |
| if (rc != PJ_SUCCESS) |
| return rc; |
| |
| rc = pj_ioqueue_set_lock(ioqueue, lock, PJ_TRUE); |
| if (rc != PJ_SUCCESS) |
| return rc; |
| |
| PJ_LOG(4, ("pjlib", "select() I/O Queue created (%p)", ioqueue)); |
| |
| *p_ioqueue = ioqueue; |
| return PJ_SUCCESS; |
| } |
| |
| /* |
| * pj_ioqueue_destroy() |
| * |
| * Destroy ioqueue. |
| */ |
| PJ_DEF(pj_status_t) pj_ioqueue_destroy(pj_ioqueue_t *ioqueue) |
| { |
| PJ_ASSERT_RETURN(ioqueue, PJ_EINVAL); |
| |
| pj_lock_acquire(ioqueue->lock); |
| return ioqueue_destroy(ioqueue); |
| } |
| |
| |
| /* |
| * pj_ioqueue_register_sock() |
| * |
| * Register a handle to ioqueue. |
| */ |
| PJ_DEF(pj_status_t) pj_ioqueue_register_sock( pj_pool_t *pool, |
| pj_ioqueue_t *ioqueue, |
| pj_sock_t sock, |
| void *user_data, |
| const pj_ioqueue_callback *cb, |
| pj_ioqueue_key_t **p_key) |
| { |
| pj_ioqueue_key_t *key = NULL; |
| pj_uint32_t value; |
| pj_status_t rc = PJ_SUCCESS; |
| |
| PJ_ASSERT_RETURN(pool && ioqueue && sock != PJ_INVALID_SOCKET && |
| cb && p_key, PJ_EINVAL); |
| |
| pj_lock_acquire(ioqueue->lock); |
| |
| if (ioqueue->count >= ioqueue->max) { |
| rc = PJ_ETOOMANY; |
| goto on_return; |
| } |
| |
| /* Set socket to nonblocking. */ |
| value = 1; |
| #ifdef PJ_WIN32 |
| if (ioctlsocket(sock, FIONBIO, (u_long*)&value)) { |
| #else |
| if (ioctl(sock, FIONBIO, &value)) { |
| #endif |
| rc = pj_get_netos_error(); |
| goto on_return; |
| } |
| |
| /* Create key. */ |
| key = (pj_ioqueue_key_t*)pj_pool_zalloc(pool, sizeof(pj_ioqueue_key_t)); |
| rc = ioqueue_init_key(pool, ioqueue, key, sock, user_data, cb); |
| if (rc != PJ_SUCCESS) { |
| key = NULL; |
| goto on_return; |
| } |
| |
| /* Register */ |
| pj_list_insert_before(&ioqueue->key_list, key); |
| ++ioqueue->count; |
| |
| on_return: |
| /* On error, socket may be left in non-blocking mode. */ |
| *p_key = key; |
| pj_lock_release(ioqueue->lock); |
| |
| return rc; |
| } |
| |
| /* |
| * pj_ioqueue_unregister() |
| * |
| * Unregister handle from ioqueue. |
| */ |
| PJ_DEF(pj_status_t) pj_ioqueue_unregister( pj_ioqueue_key_t *key) |
| { |
| pj_ioqueue_t *ioqueue; |
| |
| PJ_ASSERT_RETURN(key, PJ_EINVAL); |
| |
| ioqueue = key->ioqueue; |
| |
| pj_lock_acquire(ioqueue->lock); |
| |
| pj_assert(ioqueue->count > 0); |
| --ioqueue->count; |
| pj_list_erase(key); |
| PJ_FD_CLR(key->fd, &ioqueue->rfdset); |
| PJ_FD_CLR(key->fd, &ioqueue->wfdset); |
| #if PJ_HAS_TCP |
| PJ_FD_CLR(key->fd, &ioqueue->xfdset); |
| #endif |
| |
| /* ioqueue_destroy may try to acquire key's mutex. |
| * Since normally the order of locking is to lock key's mutex first |
| * then ioqueue's mutex, ioqueue_destroy may deadlock unless we |
| * release ioqueue's mutex first. |
| */ |
| pj_lock_release(ioqueue->lock); |
| |
| /* Destroy the key. */ |
| ioqueue_destroy_key(key); |
| |
| return PJ_SUCCESS; |
| } |
| |
| |
| /* This supposed to check whether the fd_set values are consistent |
| * with the operation currently set in each key. |
| */ |
| #if VALIDATE_FD_SET |
| static void validate_sets(const pj_ioqueue_t *ioqueue, |
| const pj_fd_set_t *rfdset, |
| const pj_fd_set_t *wfdset, |
| const pj_fd_set_t *xfdset) |
| { |
| pj_ioqueue_key_t *key; |
| |
| /* |
| * This basicly would not work anymore. |
| * We need to lock key before performing the check, but we can't do |
| * so because we're holding ioqueue mutex. If we acquire key's mutex |
| * now, the will cause deadlock. |
| */ |
| pj_assert(0); |
| |
| key = ioqueue->key_list.next; |
| while (key != &ioqueue->key_list) { |
| if (!pj_list_empty(&key->read_list) |
| #if defined(PJ_HAS_TCP) && PJ_HAS_TCP != 0 |
| || !pj_list_empty(&key->accept_list) |
| #endif |
| ) |
| { |
| pj_assert(PJ_FD_ISSET(key->fd, rfdset)); |
| } |
| else { |
| pj_assert(PJ_FD_ISSET(key->fd, rfdset) == 0); |
| } |
| if (!pj_list_empty(&key->write_list) |
| #if defined(PJ_HAS_TCP) && PJ_HAS_TCP != 0 |
| || key->connecting |
| #endif |
| ) |
| { |
| pj_assert(PJ_FD_ISSET(key->fd, wfdset)); |
| } |
| else { |
| pj_assert(PJ_FD_ISSET(key->fd, wfdset) == 0); |
| } |
| #if defined(PJ_HAS_TCP) && PJ_HAS_TCP != 0 |
| if (key->connecting) |
| { |
| pj_assert(PJ_FD_ISSET(key->fd, xfdset)); |
| } |
| else { |
| pj_assert(PJ_FD_ISSET(key->fd, xfdset) == 0); |
| } |
| #endif /* PJ_HAS_TCP */ |
| |
| key = key->next; |
| } |
| } |
| #endif /* VALIDATE_FD_SET */ |
| |
| |
| /* ioqueue_remove_from_set() |
| * This function is called from ioqueue_dispatch_event() to instruct |
| * the ioqueue to remove the specified descriptor from ioqueue's descriptor |
| * set for the specified event. |
| */ |
| static void ioqueue_remove_from_set( pj_ioqueue_t *ioqueue, |
| pj_sock_t fd, |
| enum ioqueue_event_type event_type) |
| { |
| pj_lock_acquire(ioqueue->lock); |
| |
| if (event_type == READABLE_EVENT) |
| PJ_FD_CLR((pj_sock_t)fd, &ioqueue->rfdset); |
| else if (event_type == WRITEABLE_EVENT) |
| PJ_FD_CLR((pj_sock_t)fd, &ioqueue->wfdset); |
| else if (event_type == EXCEPTION_EVENT) |
| PJ_FD_CLR((pj_sock_t)fd, &ioqueue->xfdset); |
| else |
| pj_assert(0); |
| |
| pj_lock_release(ioqueue->lock); |
| } |
| |
| /* |
| * ioqueue_add_to_set() |
| * This function is called from pj_ioqueue_recv(), pj_ioqueue_send() etc |
| * to instruct the ioqueue to add the specified handle to ioqueue's descriptor |
| * set for the specified event. |
| */ |
| static void ioqueue_add_to_set( pj_ioqueue_t *ioqueue, |
| pj_sock_t fd, |
| enum ioqueue_event_type event_type ) |
| { |
| pj_lock_acquire(ioqueue->lock); |
| |
| if (event_type == READABLE_EVENT) |
| PJ_FD_SET((pj_sock_t)fd, &ioqueue->rfdset); |
| else if (event_type == WRITEABLE_EVENT) |
| PJ_FD_SET((pj_sock_t)fd, &ioqueue->wfdset); |
| else if (event_type == EXCEPTION_EVENT) |
| PJ_FD_SET((pj_sock_t)fd, &ioqueue->xfdset); |
| else |
| pj_assert(0); |
| |
| pj_lock_release(ioqueue->lock); |
| } |
| |
| /* |
| * pj_ioqueue_poll() |
| * |
| * Few things worth written: |
| * |
| * - we used to do only one callback called per poll, but it didn't go |
| * very well. The reason is because on some situation, the write |
| * callback gets called all the time, thus doesn't give the read |
| * callback to get called. This happens, for example, when user |
| * submit write operation inside the write callback. |
| * As the result, we changed the behaviour so that now multiple |
| * callbacks are called in a single poll. It should be fast too, |
| * just that we need to be carefull with the ioqueue data structs. |
| * |
| * - to guarantee preemptiveness etc, the poll function must strictly |
| * work on fd_set copy of the ioqueue (not the original one). |
| */ |
| PJ_DEF(int) pj_ioqueue_poll( pj_ioqueue_t *ioqueue, const pj_time_val *timeout) |
| { |
| pj_fd_set_t rfdset, wfdset, xfdset; |
| int count, counter; |
| pj_ioqueue_key_t *h; |
| struct event |
| { |
| pj_ioqueue_key_t *key; |
| enum ioqueue_event_type event_type; |
| } event[PJ_IOQUEUE_MAX_EVENTS_IN_SINGLE_POLL]; |
| |
| PJ_ASSERT_RETURN(ioqueue, PJ_EINVAL); |
| |
| /* Lock ioqueue before making fd_set copies */ |
| pj_lock_acquire(ioqueue->lock); |
| |
| /* We will only do select() when there are sockets to be polled. |
| * Otherwise select() will return error. |
| */ |
| if (PJ_FD_COUNT(&ioqueue->rfdset)==0 && |
| PJ_FD_COUNT(&ioqueue->wfdset)==0 && |
| PJ_FD_COUNT(&ioqueue->xfdset)==0) |
| { |
| pj_lock_release(ioqueue->lock); |
| if (timeout) |
| pj_thread_sleep(PJ_TIME_VAL_MSEC(*timeout)); |
| return 0; |
| } |
| |
| /* Copy ioqueue's pj_fd_set_t to local variables. */ |
| pj_memcpy(&rfdset, &ioqueue->rfdset, sizeof(pj_fd_set_t)); |
| pj_memcpy(&wfdset, &ioqueue->wfdset, sizeof(pj_fd_set_t)); |
| #if PJ_HAS_TCP |
| pj_memcpy(&xfdset, &ioqueue->xfdset, sizeof(pj_fd_set_t)); |
| #else |
| PJ_FD_ZERO(&xfdset); |
| #endif |
| |
| #if VALIDATE_FD_SET |
| validate_sets(ioqueue, &rfdset, &wfdset, &xfdset); |
| #endif |
| |
| /* Unlock ioqueue before select(). */ |
| pj_lock_release(ioqueue->lock); |
| |
| count = pj_sock_select(FD_SETSIZE, &rfdset, &wfdset, &xfdset, timeout); |
| |
| if (count <= 0) |
| return count; |
| else if (count > PJ_IOQUEUE_MAX_EVENTS_IN_SINGLE_POLL) |
| count = PJ_IOQUEUE_MAX_EVENTS_IN_SINGLE_POLL; |
| |
| /* Scan descriptor sets for event and add the events in the event |
| * array to be processed later in this function. We do this so that |
| * events can be processed in parallel without holding ioqueue lock. |
| */ |
| pj_lock_acquire(ioqueue->lock); |
| |
| counter = 0; |
| |
| /* Scan for writable sockets first to handle piggy-back data |
| * coming with accept(). |
| */ |
| h = ioqueue->key_list.next; |
| for ( ; h!=&ioqueue->key_list && counter<count; h = h->next) { |
| if ( (key_has_pending_write(h) || key_has_pending_connect(h)) |
| && PJ_FD_ISSET(h->fd, &wfdset)) |
| { |
| event[counter].key = h; |
| event[counter].event_type = WRITEABLE_EVENT; |
| ++counter; |
| } |
| |
| /* Scan for readable socket. */ |
| if ((key_has_pending_read(h) || key_has_pending_accept(h)) |
| && PJ_FD_ISSET(h->fd, &rfdset)) |
| { |
| event[counter].key = h; |
| event[counter].event_type = READABLE_EVENT; |
| ++counter; |
| } |
| |
| #if PJ_HAS_TCP |
| if (key_has_pending_connect(h) && PJ_FD_ISSET(h->fd, &xfdset)) { |
| event[counter].key = h; |
| event[counter].event_type = EXCEPTION_EVENT; |
| ++counter; |
| } |
| #endif |
| } |
| |
| pj_lock_release(ioqueue->lock); |
| |
| count = counter; |
| |
| /* Now process all events. The dispatch functions will take care |
| * of locking in each of the key |
| */ |
| for (counter=0; counter<count; ++counter) { |
| switch (event[counter].event_type) { |
| case READABLE_EVENT: |
| ioqueue_dispatch_read_event(ioqueue, event[counter].key); |
| break; |
| case WRITEABLE_EVENT: |
| ioqueue_dispatch_write_event(ioqueue, event[counter].key); |
| break; |
| case EXCEPTION_EVENT: |
| ioqueue_dispatch_exception_event(ioqueue, event[counter].key); |
| break; |
| case NO_EVENT: |
| pj_assert(!"Invalid event!"); |
| break; |
| } |
| } |
| |
| return count; |
| } |
| |