ioqueue_common_abs.c

一个开源SIP协议栈

    }

#   if PJ_HAS_TCP
    if (!pj_list_empty(&h->accept_list)) {

        struct accept_operation *accept_op;
	
        /* Get one accept operation from the list. */
	accept_op = h->accept_list.next;
        pj_list_erase(accept_op);
        accept_op->op = 0;

	/* Clear bit in fdset if there is no more pending accept */
        if (pj_list_empty(&h->accept_list))
            ioqueue_remove_from_set(ioqueue, h, READABLE_EVENT);

	rc=pj_sock_accept(h->fd, accept_op->accept_fd, 
                          accept_op->rmt_addr, accept_op->addrlen);
	if (rc==PJ_SUCCESS && accept_op->local_addr) {
	    rc = pj_sock_getsockname(*accept_op->accept_fd, 
                                     accept_op->local_addr,
				     accept_op->addrlen);
	}

        /* Unlock; from this point we don't need to hold key's mutex. */
        pj_mutex_unlock(h->mutex);

	/* Call callback. */
        if (h->cb.on_accept_complete && !IS_CLOSING(h)) {
	    (*h->cb.on_accept_complete)(h, 
                                        (pj_ioqueue_op_key_t*)accept_op,
                                        *accept_op->accept_fd, rc);
	}

    }
    else
#   endif
    if (key_has_pending_read(h)) {
        struct read_operation *read_op;
        pj_ssize_t bytes_read;

        /* Get one pending read operation from the list. */
        read_op = h->read_list.next;
        pj_list_erase(read_op);

        /* Clear fdset if there is no pending read. */
        if (pj_list_empty(&h->read_list))
            ioqueue_remove_from_set(ioqueue, h, READABLE_EVENT);

        bytes_read = read_op->size;

	if ((read_op->op == PJ_IOQUEUE_OP_RECV_FROM)) {
	    read_op->op = 0;
	    rc = pj_sock_recvfrom(h->fd, read_op->buf, &bytes_read, 
				  read_op->flags,
				  read_op->rmt_addr, 
                                  read_op->rmt_addrlen);
	} else if ((read_op->op == PJ_IOQUEUE_OP_RECV)) {
	    read_op->op = 0;
	    rc = pj_sock_recv(h->fd, read_op->buf, &bytes_read, 
			      read_op->flags);
        } else {
            pj_assert(read_op->op == PJ_IOQUEUE_OP_READ);
	    read_op->op = 0;
            /*
             * User has specified pj_ioqueue_read().
             * On Win32, we should do ReadFile(). But because we got
             * here because of select() anyway, user must have put a
             * socket descriptor on h->fd, which in this case we can
             * just call pj_sock_recv() instead of ReadFile().
             * On Unix, user may put a file in h->fd, so we'll have
             * to call read() here.
             * This may not compile on systems which doesn't have 
             * read(). That's why we only specify PJ_LINUX here so
             * that error is easier to catch.
             */
#	    if defined(PJ_WIN32) && PJ_WIN32 != 0 || \
	       defined(PJ_WIN32_WINCE) && PJ_WIN32_WINCE != 0
                rc = pj_sock_recv(h->fd, read_op->buf, &bytes_read, 
				  read_op->flags);
                //rc = ReadFile((HANDLE)h->fd, read_op->buf, read_op->size,
                //              &bytes_read, NULL);
#           elif (defined(PJ_HAS_UNISTD_H) && PJ_HAS_UNISTD_H != 0)
                bytes_read = read(h->fd, read_op->buf, bytes_read);
                rc = (bytes_read >= 0) ? PJ_SUCCESS : pj_get_os_error();
#	    elif defined(PJ_LINUX_KERNEL) && PJ_LINUX_KERNEL != 0
                bytes_read = sys_read(h->fd, read_op->buf, bytes_read);
                rc = (bytes_read >= 0) ? PJ_SUCCESS : -bytes_read;
#           else
#               error "Implement read() for this platform!"
#           endif
        }
	
	if (rc != PJ_SUCCESS) {
#	    if defined(PJ_WIN32) && PJ_WIN32 != 0
	    /* On Win32, for UDP, WSAECONNRESET on the receive side 
	     * indicates that previous sending has triggered ICMP Port 
	     * Unreachable message.
	     * But we wouldn't know at this point which one of previous 
	     * key that has triggered the error, since UDP socket can
	     * be shared!
	     * So we'll just ignore it!
	     */

	    if (rc == PJ_STATUS_FROM_OS(WSAECONNRESET)) {
		//PJ_LOG(4,(THIS_FILE, 
                //          "Ignored ICMP port unreach. on key=%p", h));
	    }
#	    endif

            /* In any case we would report this to caller. */
            bytes_read = -rc;
	}

        /* Unlock; from this point we don't need to hold key's mutex. */
        pj_mutex_unlock(h->mutex);

	/* Call callback. */
        if (h->cb.on_read_complete && !IS_CLOSING(h)) {
	    (*h->cb.on_read_complete)(h, 
                                      (pj_ioqueue_op_key_t*)read_op,
                                      bytes_read);
        }

    } else {
        /*
         * This is normal; execution may fall here when multiple threads
         * are signalled for the same event, but only one thread eventually
         * able to process the event.
         */
        pj_mutex_unlock(h->mutex);
    }
}


void ioqueue_dispatch_exception_event( pj_ioqueue_t *ioqueue, 
                                       pj_ioqueue_key_t *h )
{
    pj_mutex_lock(h->mutex);

    if (!h->connecting) {
        /* It is possible that more than one thread was woken up, thus
         * the remaining thread will see h->connecting as zero because
         * it has been processed by other thread.
         */
        pj_mutex_unlock(h->mutex);
        return;
    }

    if (IS_CLOSING(h)) {
	pj_mutex_unlock(h->mutex);
	return;
    }

    /* Clear operation. */
    h->connecting = 0;

    ioqueue_remove_from_set(ioqueue, h, WRITEABLE_EVENT);
    ioqueue_remove_from_set(ioqueue, h, EXCEPTION_EVENT);

    pj_mutex_unlock(h->mutex);

    /* Call callback. */
    if (h->cb.on_connect_complete && !IS_CLOSING(h)) {
	pj_status_t status = -1;
#if (defined(PJ_HAS_SO_ERROR) && PJ_HAS_SO_ERROR!=0)
	int value;
	int vallen = sizeof(value);
	int gs_rc = pj_sock_getsockopt(h->fd, SOL_SOCKET, SO_ERROR, 
				       &value, &vallen);
	if (gs_rc == 0) {
	    status = PJ_RETURN_OS_ERROR(value);
	}
#endif

	(*h->cb.on_connect_complete)(h, status);
    }
}

/*
 * pj_ioqueue_recv()
 *
 * Start asynchronous recv() from the socket.
 */
PJ_DEF(pj_status_t) pj_ioqueue_recv(  pj_ioqueue_key_t *key,
                                      pj_ioqueue_op_key_t *op_key,
				      void *buffer,
				      pj_ssize_t *length,
				      unsigned flags )
{
    struct read_operation *read_op;

    PJ_ASSERT_RETURN(key && op_key && buffer && length, PJ_EINVAL);
    PJ_CHECK_STACK();

    read_op = (struct read_operation*)op_key;
    read_op->op = 0;

    /* Check if key is closing. */
    if (IS_CLOSING(key))
	return PJ_ECANCELLED;

    /* Try to see if there's data immediately available. 
     */
    if ((flags & PJ_IOQUEUE_ALWAYS_ASYNC) == 0) {
	pj_status_t status;
	pj_ssize_t size;

	size = *length;
	status = pj_sock_recv(key->fd, buffer, &size, flags);
	if (status == PJ_SUCCESS) {
	    /* Yes! Data is available! */
	    *length = size;
	    return PJ_SUCCESS;
	} else {
	    /* If error is not EWOULDBLOCK (or EAGAIN on Linux), report
	     * the error to caller.
	     */
	    if (status != PJ_STATUS_FROM_OS(PJ_BLOCKING_ERROR_VAL))
		return status;
	}
    }

    flags &= ~(PJ_IOQUEUE_ALWAYS_ASYNC);

    /*
     * No data is immediately available.
     * Must schedule asynchronous operation to the ioqueue.
     */
    read_op->op = PJ_IOQUEUE_OP_RECV;
    read_op->buf = buffer;
    read_op->size = *length;
    read_op->flags = flags;

    pj_mutex_lock(key->mutex);
    pj_list_insert_before(&key->read_list, read_op);
    ioqueue_add_to_set(key->ioqueue, key, READABLE_EVENT);
    pj_mutex_unlock(key->mutex);

    return PJ_EPENDING;
}

/*
 * pj_ioqueue_recvfrom()
 *
 * Start asynchronous recvfrom() from the socket.
 */
PJ_DEF(pj_status_t) pj_ioqueue_recvfrom( pj_ioqueue_key_t *key,
                                         pj_ioqueue_op_key_t *op_key,
				         void *buffer,
				         pj_ssize_t *length,
                                         unsigned flags,
				         pj_sockaddr_t *addr,
				         int *addrlen)
{
    struct read_operation *read_op;

    PJ_ASSERT_RETURN(key && op_key && buffer && length, PJ_EINVAL);
    PJ_CHECK_STACK();

    /* Check if key is closing. */
    if (IS_CLOSING(key))
	return PJ_ECANCELLED;

    read_op = (struct read_operation*)op_key;
    read_op->op = 0;

    /* Try to see if there's data immediately available. 
     */
    if ((flags & PJ_IOQUEUE_ALWAYS_ASYNC) == 0) {
	pj_status_t status;
	pj_ssize_t size;

	size = *length;
	status = pj_sock_recvfrom(key->fd, buffer, &size, flags,
				  addr, addrlen);
	if (status == PJ_SUCCESS) {
	    /* Yes! Data is available! */
	    *length = size;
	    return PJ_SUCCESS;
	} else {
	    /* If error is not EWOULDBLOCK (or EAGAIN on Linux), report
	     * the error to caller.
	     */
	    if (status != PJ_STATUS_FROM_OS(PJ_BLOCKING_ERROR_VAL))
		return status;
	}
    }

    flags &= ~(PJ_IOQUEUE_ALWAYS_ASYNC);

    /*
     * No data is immediately available.
     * Must schedule asynchronous operation to the ioqueue.
     */
    read_op->op = PJ_IOQUEUE_OP_RECV_FROM;
    read_op->buf = buffer;
    read_op->size = *length;
    read_op->flags = flags;
    read_op->rmt_addr = addr;
    read_op->rmt_addrlen = addrlen;

    pj_mutex_lock(key->mutex);
    pj_list_insert_before(&key->read_list, read_op);
    ioqueue_add_to_set(key->ioqueue, key, READABLE_EVENT);
    pj_mutex_unlock(key->mutex);

    return PJ_EPENDING;
}

/*
 * pj_ioqueue_send()
 *
 * Start asynchronous send() to the descriptor.
 */
PJ_DEF(pj_status_t) pj_ioqueue_send( pj_ioqueue_key_t *key,
                                     pj_ioqueue_op_key_t *op_key,
			             const void *data,
			             pj_ssize_t *length,
                                     unsigned flags)
{
    struct write_operation *write_op;
    pj_status_t status;
    unsigned retry;
    pj_ssize_t sent;

    PJ_ASSERT_RETURN(key && op_key && data && length, PJ_EINVAL);
    PJ_CHECK_STACK();

    /* Check if key is closing. */
    if (IS_CLOSING(key))
	return PJ_ECANCELLED;

    /* We can not use PJ_IOQUEUE_ALWAYS_ASYNC for socket write. */
    flags &= ~(PJ_IOQUEUE_ALWAYS_ASYNC);

    /* Fast track:
     *   Try to send data immediately, only if there's no pending write!
     * Note:
     *  We are speculating that the list is empty here without properly
     *  acquiring ioqueue's mutex first. This is intentional, to maximize
     *  performance via parallelism.
     *
     *  This should be safe, because:
     *      - by convention, we require caller to make sure that the
     *        key is not unregistered while other threads are invoking
     *        an operation on the same key.
     *      - pj_list_empty() is safe to be invoked by multiple threads,
     *        even when other threads are modifying the list.
     */
    if (pj_list_empty(&key->write_list)) {
        /*
         * See if data can be sent immediately.
         */
        sent = *length;
        status = pj_sock_send(key->fd, data, &sent, flags);
        if (status == PJ_SUCCESS) {
            /* Success! */
            *length = sent;
            return PJ_SUCCESS;
        } else {
            /* If error is not EWOULDBLOCK (or EAGAIN on Linux), report
             * the error to caller.
             */
            if (status != PJ_STATUS_FROM_OS(PJ_BLOCKING_ERROR_VAL)) {
                return status;
            }