From f3ab456a17af1c89a6e3be4d20c5944853df1cb0 Mon Sep 17 00:00:00 2001 From: "David M. Lee" Date: Mon, 7 Jan 2013 14:24:28 -0600 Subject: Import pjproject-2.0.1 --- pjlib/include/pj/ioqueue.h | 805 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 805 insertions(+) create mode 100644 pjlib/include/pj/ioqueue.h (limited to 'pjlib/include/pj/ioqueue.h') diff --git a/pjlib/include/pj/ioqueue.h b/pjlib/include/pj/ioqueue.h new file mode 100644 index 0000000..068e7ba --- /dev/null +++ b/pjlib/include/pj/ioqueue.h @@ -0,0 +1,805 @@ +/* $Id: ioqueue.h 3553 2011-05-05 06:14:19Z nanang $ + */ +/* + * Copyright (C) 2008-2011 Teluu Inc. (http://www.teluu.com) + * Copyright (C) 2003-2008 Benny Prijono + * + * 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 + */ +#ifndef __PJ_IOQUEUE_H__ +#define __PJ_IOQUEUE_H__ + +/** + * @file ioqueue.h + * @brief I/O Dispatching Mechanism + */ + +#include + +PJ_BEGIN_DECL + +/** + * @defgroup PJ_IO Input/Output + * @brief Input/Output + * @ingroup PJ_OS + * + * This section contains API building blocks to perform network I/O and + * communications. If provides: + * - @ref PJ_SOCK + *\n + * A highly portable socket abstraction, runs on all kind of + * network APIs such as standard BSD socket, Windows socket, Linux + * \b kernel socket, PalmOS networking API, etc. + * + * - @ref pj_addr_resolve + *\n + * Portable address resolution, which implements #pj_gethostbyname(). + * + * - @ref PJ_SOCK_SELECT + *\n + * A portable \a select() like API (#pj_sock_select()) which can be + * implemented with various back-ends. + * + * - @ref PJ_IOQUEUE + *\n + * Framework for dispatching network events. + * + * For more information see the modules below. + */ + +/** + * @defgroup PJ_IOQUEUE IOQueue: I/O Event Dispatching with Proactor Pattern + * @ingroup PJ_IO + * @{ + * + * I/O Queue provides API for performing asynchronous I/O operations. It + * conforms to proactor pattern, which allows application to submit an + * asynchronous operation and to be notified later when the operation has + * completed. + * + * The I/O Queue can work on both socket and file descriptors. For + * asynchronous file operations however, one must make sure that the correct + * file I/O back-end is used, because not all file I/O back-end can be + * used with the ioqueue. Please see \ref PJ_FILE_IO for more details. + * + * The framework works natively in platforms where asynchronous operation API + * exists, such as in Windows NT with IoCompletionPort/IOCP. In other + * platforms, the I/O queue abstracts the operating system's event poll API + * to provide semantics similar to IoCompletionPort with minimal penalties + * (i.e. per ioqueue and per handle mutex protection). + * + * The I/O queue provides more than just unified abstraction. It also: + * - makes sure that the operation uses the most effective way to utilize + * the underlying mechanism, to achieve the maximum theoritical + * throughput possible on a given platform. + * - choose the most efficient mechanism for event polling on a given + * platform. + * + * Currently, the I/O Queue is implemented using: + * - select(), as the common denominator, but the least + * efficient. Also the number of descriptor is limited to + * \c PJ_IOQUEUE_MAX_HANDLES (which by default is 64). + * - /dev/epoll on Linux (user mode and kernel mode), + * a much faster replacement for select() on Linux (and more importantly + * doesn't have limitation on number of descriptors). + * - I/O Completion ports on Windows NT/2000/XP, which is the most + * efficient way to dispatch events in Windows NT based OSes, and most + * importantly, it doesn't have the limit on how many handles to monitor. + * And it works with files (not only sockets) as well. + * + * + * \section pj_ioqueue_concurrency_sec Concurrency Rules + * + * The ioqueue has been fine tuned to allow multiple threads to poll the + * handles simultaneously, to maximize scalability when the application is + * running on multiprocessor systems. When more than one threads are polling + * the ioqueue and there are more than one handles are signaled, more than + * one threads will execute the callback simultaneously to serve the events. + * These parallel executions are completely safe when the events happen for + * two different handles. + * + * However, with multithreading, care must be taken when multiple events + * happen on the same handle, or when event is happening on a handle (and + * the callback is being executed) and application is performing + * unregistration to the handle at the same time. + * + * The treatments of above scenario differ according to the concurrency + * setting that are applied to the handle. + * + * \subsection pj_ioq_concur_set Concurrency Settings for Handles + * + * Concurrency can be set on per handle (key) basis, by using + * #pj_ioqueue_set_concurrency() function. The default key concurrency value + * for the handle is inherited from the key concurrency setting of the ioqueue, + * and the key concurrency setting for the ioqueue can be changed by using + * #pj_ioqueue_set_default_concurrency(). The default key concurrency setting + * for ioqueue itself is controlled by compile time setting + * PJ_IOQUEUE_DEFAULT_ALLOW_CONCURRENCY. + * + * Note that this key concurrency setting only controls whether multiple + * threads are allowed to operate on the same key at the same time. + * The ioqueue itself always allows multiple threads to enter the ioqeuue at + * the same time, and also simultaneous callback calls to differrent + * keys is always allowed regardless to the key concurrency setting. + * + * \subsection pj_ioq_parallel Parallel Callback Executions for the Same Handle + * + * Note that when key concurrency is enabled (i.e. parallel callback calls on + * the same key is allowed; this is the default setting), the ioqueue will only + * perform simultaneous callback executions on the same key when the key has + * invoked multiple pending operations. This could be done for example by + * calling #pj_ioqueue_recvfrom() more than once on the same key, each with + * the same key but different operation key (pj_ioqueue_op_key_t). With this + * scenario, when multiple packets arrive on the key at the same time, more + * than one threads may execute the callback simultaneously, each with the + * same key but different operation key. + * + * When there is only one pending operation on the key (e.g. there is only one + * #pj_ioqueue_recvfrom() invoked on the key), then events occuring to the + * same key will be queued by the ioqueue, thus no simultaneous callback calls + * will be performed. + * + * \subsection pj_ioq_allow_concur Concurrency is Enabled (Default Value) + * + * The default setting for the ioqueue is to allow multiple threads to + * execute callbacks for the same handle/key. This setting is selected to + * promote good performance and scalability for application. + * + * However this setting has a major drawback with regard to synchronization, + * and application MUST carefully follow the following guidelines to ensure + * that parallel access to the key does not cause problems: + * + * - Always note that callback may be called simultaneously for the same + * key. + * - Care must be taken when unregistering a key from the + * ioqueue. Application must take care that when one thread is issuing + * an unregistration, other thread is not simultaneously invoking the + * callback to the same key. + *\n + * This happens because the ioqueue functions are working with a pointer + * to the key, and there is a possible race condition where the pointer + * has been rendered invalid by other threads before the ioqueue has a + * chance to acquire mutex on it. + * + * \subsection pj_ioq_disallow_concur Concurrency is Disabled + * + * Alternatively, application may disable key concurrency to make + * synchronization easier. As noted above, there are three ways to control + * key concurrency setting: + * - by controlling on per handle/key basis, with #pj_ioqueue_set_concurrency(). + * - by changing default key concurrency setting on the ioqueue, with + * #pj_ioqueue_set_default_concurrency(). + * - by changing the default concurrency on compile time, by declaring + * PJ_IOQUEUE_DEFAULT_ALLOW_CONCURRENCY macro to zero in your config_site.h + * + * \section pj_ioqeuue_examples_sec Examples + * + * For some examples on how to use the I/O Queue, please see: + * + * - \ref page_pjlib_ioqueue_tcp_test + * - \ref page_pjlib_ioqueue_udp_test + * - \ref page_pjlib_ioqueue_perf_test + */ + + +/** + * This structure describes operation specific key to be submitted to + * I/O Queue when performing the asynchronous operation. This key will + * be returned to the application when completion callback is called. + * + * Application normally wants to attach it's specific data in the + * \c user_data field so that it can keep track of which operation has + * completed when the callback is called. Alternatively, application can + * also extend this struct to include its data, because the pointer that + * is returned in the completion callback will be exactly the same as + * the pointer supplied when the asynchronous function is called. + */ +typedef struct pj_ioqueue_op_key_t +{ + void *internal__[32]; /**< Internal I/O Queue data. */ + void *activesock_data; /**< Active socket data. */ + void *user_data; /**< Application data. */ +} pj_ioqueue_op_key_t; + +/** + * This structure describes the callbacks to be called when I/O operation + * completes. + */ +typedef struct pj_ioqueue_callback +{ + /** + * This callback is called when #pj_ioqueue_recv or #pj_ioqueue_recvfrom + * completes. + * + * @param key The key. + * @param op_key Operation key. + * @param bytes_read >= 0 to indicate the amount of data read, + * otherwise negative value containing the error + * code. To obtain the pj_status_t error code, use + * (pj_status_t code = -bytes_read). + */ + void (*on_read_complete)(pj_ioqueue_key_t *key, + pj_ioqueue_op_key_t *op_key, + pj_ssize_t bytes_read); + + /** + * This callback is called when #pj_ioqueue_send or #pj_ioqueue_sendto + * completes. + * + * @param key The key. + * @param op_key Operation key. + * @param bytes_sent >= 0 to indicate the amount of data written, + * otherwise negative value containing the error + * code. To obtain the pj_status_t error code, use + * (pj_status_t code = -bytes_sent). + */ + void (*on_write_complete)(pj_ioqueue_key_t *key, + pj_ioqueue_op_key_t *op_key, + pj_ssize_t bytes_sent); + + /** + * This callback is called when #pj_ioqueue_accept completes. + * + * @param key The key. + * @param op_key Operation key. + * @param sock Newly connected socket. + * @param status Zero if the operation completes successfully. + */ + void (*on_accept_complete)(pj_ioqueue_key_t *key, + pj_ioqueue_op_key_t *op_key, + pj_sock_t sock, + pj_status_t status); + + /** + * This callback is called when #pj_ioqueue_connect completes. + * + * @param key The key. + * @param status PJ_SUCCESS if the operation completes successfully. + */ + void (*on_connect_complete)(pj_ioqueue_key_t *key, + pj_status_t status); +} pj_ioqueue_callback; + + +/** + * Types of pending I/O Queue operation. This enumeration is only used + * internally within the ioqueue. + */ +typedef enum pj_ioqueue_operation_e +{ + PJ_IOQUEUE_OP_NONE = 0, /**< No operation. */ + PJ_IOQUEUE_OP_READ = 1, /**< read() operation. */ + PJ_IOQUEUE_OP_RECV = 2, /**< recv() operation. */ + PJ_IOQUEUE_OP_RECV_FROM = 4, /**< recvfrom() operation. */ + PJ_IOQUEUE_OP_WRITE = 8, /**< write() operation. */ + PJ_IOQUEUE_OP_SEND = 16, /**< send() operation. */ + PJ_IOQUEUE_OP_SEND_TO = 32, /**< sendto() operation. */ +#if defined(PJ_HAS_TCP) && PJ_HAS_TCP != 0 + PJ_IOQUEUE_OP_ACCEPT = 64, /**< accept() operation. */ + PJ_IOQUEUE_OP_CONNECT = 128 /**< connect() operation. */ +#endif /* PJ_HAS_TCP */ +} pj_ioqueue_operation_e; + + +/** + * This macro specifies the maximum number of events that can be + * processed by the ioqueue on a single poll cycle, on implementation + * that supports it. The value is only meaningfull when specified + * during PJLIB build. + */ +#ifndef PJ_IOQUEUE_MAX_EVENTS_IN_SINGLE_POLL +# define PJ_IOQUEUE_MAX_EVENTS_IN_SINGLE_POLL (16) +#endif + +/** + * When this flag is specified in ioqueue's recv() or send() operations, + * the ioqueue will always mark the operation as asynchronous. + */ +#define PJ_IOQUEUE_ALWAYS_ASYNC ((pj_uint32_t)1 << (pj_uint32_t)31) + +/** + * Return the name of the ioqueue implementation. + * + * @return Implementation name. + */ +PJ_DECL(const char*) pj_ioqueue_name(void); + + +/** + * Create a new I/O Queue framework. + * + * @param pool The pool to allocate the I/O queue structure. + * @param max_fd The maximum number of handles to be supported, which + * should not exceed PJ_IOQUEUE_MAX_HANDLES. + * @param ioqueue Pointer to hold the newly created I/O Queue. + * + * @return PJ_SUCCESS on success. + */ +PJ_DECL(pj_status_t) pj_ioqueue_create( pj_pool_t *pool, + pj_size_t max_fd, + pj_ioqueue_t **ioqueue); + +/** + * Destroy the I/O queue. + * + * @param ioque The I/O Queue to be destroyed. + * + * @return PJ_SUCCESS if success. + */ +PJ_DECL(pj_status_t) pj_ioqueue_destroy( pj_ioqueue_t *ioque ); + +/** + * Set the lock object to be used by the I/O Queue. This function can only + * be called right after the I/O queue is created, before any handle is + * registered to the I/O queue. + * + * Initially the I/O queue is created with non-recursive mutex protection. + * Applications can supply alternative lock to be used by calling this + * function. + * + * @param ioque The ioqueue instance. + * @param lock The lock to be used by the ioqueue. + * @param auto_delete In non-zero, the lock will be deleted by the ioqueue. + * + * @return PJ_SUCCESS or the appropriate error code. + */ +PJ_DECL(pj_status_t) pj_ioqueue_set_lock( pj_ioqueue_t *ioque, + pj_lock_t *lock, + pj_bool_t auto_delete ); + +/** + * Set default concurrency policy for this ioqueue. If this function is not + * called, the default concurrency policy for the ioqueue is controlled by + * compile time setting PJ_IOQUEUE_DEFAULT_ALLOW_CONCURRENCY. + * + * Note that changing the concurrency setting to the ioqueue will only affect + * subsequent key registrations. To modify the concurrency setting for + * individual key, use #pj_ioqueue_set_concurrency(). + * + * @param ioqueue The ioqueue instance. + * @param allow Non-zero to allow concurrent callback calls, or + * PJ_FALSE to disallow it. + * + * @return PJ_SUCCESS on success or the appropriate error code. + */ +PJ_DECL(pj_status_t) pj_ioqueue_set_default_concurrency(pj_ioqueue_t *ioqueue, + pj_bool_t allow); + +/** + * Register a socket to the I/O queue framework. + * When a socket is registered to the IOQueue, it may be modified to use + * non-blocking IO. If it is modified, there is no guarantee that this + * modification will be restored after the socket is unregistered. + * + * @param pool To allocate the resource for the specified handle, + * which must be valid until the handle/key is unregistered + * from I/O Queue. + * @param ioque The I/O Queue. + * @param sock The socket. + * @param user_data User data to be associated with the key, which can be + * retrieved later. + * @param cb Callback to be called when I/O operation completes. + * @param key Pointer to receive the key to be associated with this + * socket. Subsequent I/O queue operation will need this + * key. + * + * @return PJ_SUCCESS on success, or the error code. + */ +PJ_DECL(pj_status_t) pj_ioqueue_register_sock( pj_pool_t *pool, + pj_ioqueue_t *ioque, + pj_sock_t sock, + void *user_data, + const pj_ioqueue_callback *cb, + pj_ioqueue_key_t **key ); + +/** + * Unregister from the I/O Queue framework. Caller must make sure that + * the key doesn't have any pending operations before calling this function, + * by calling #pj_ioqueue_is_pending() for all previously submitted + * operations except asynchronous connect, and if necessary call + * #pj_ioqueue_post_completion() to cancel the pending operations. + * + * Note that asynchronous connect operation will automatically be + * cancelled during the unregistration. + * + * Also note that when I/O Completion Port backend is used, application + * MUST close the handle immediately after unregistering the key. This is + * because there is no unregistering API for IOCP. The only way to + * unregister the handle from IOCP is to close the handle. + * + * @param key The key that was previously obtained from registration. + * + * @return PJ_SUCCESS on success or the error code. + * + * @see pj_ioqueue_is_pending + */ +PJ_DECL(pj_status_t) pj_ioqueue_unregister( pj_ioqueue_key_t *key ); + + +/** + * Get user data associated with an ioqueue key. + * + * @param key The key that was previously obtained from registration. + * + * @return The user data associated with the descriptor, or NULL + * on error or if no data is associated with the key during + * registration. + */ +PJ_DECL(void*) pj_ioqueue_get_user_data( pj_ioqueue_key_t *key ); + +/** + * Set or change the user data to be associated with the file descriptor or + * handle or socket descriptor. + * + * @param key The key that was previously obtained from registration. + * @param user_data User data to be associated with the descriptor. + * @param old_data Optional parameter to retrieve the old user data. + * + * @return PJ_SUCCESS on success or the error code. + */ +PJ_DECL(pj_status_t) pj_ioqueue_set_user_data( pj_ioqueue_key_t *key, + void *user_data, + void **old_data); + +/** + * Configure whether the ioqueue is allowed to call the key's callback + * concurrently/in parallel. The default concurrency setting for the key + * is controlled by ioqueue's default concurrency value, which can be + * changed by calling #pj_ioqueue_set_default_concurrency(). + * + * If concurrency is allowed for the key, it means that if there are more + * than one pending operations complete simultaneously, more than one + * threads may call the key's callback at the same time. This generally + * would promote good scalability for application, at the expense of more + * complexity to manage the concurrent accesses in application's code. + * + * Alternatively application may disable the concurrent access by + * setting the \a allow flag to false. With concurrency disabled, only + * one thread can call the key's callback at one time. + * + * @param key The key that was previously obtained from registration. + * @param allow Set this to non-zero to allow concurrent callback calls + * and zero (PJ_FALSE) to disallow it. + * + * @return PJ_SUCCESS on success or the appropriate error code. + */ +PJ_DECL(pj_status_t) pj_ioqueue_set_concurrency(pj_ioqueue_key_t *key, + pj_bool_t allow); + +/** + * Acquire the key's mutex. When the key's concurrency is disabled, + * application may call this function to synchronize its operation + * with the key's callback (i.e. this function will block until the + * key's callback returns). + * + * @param key The key that was previously obtained from registration. + * + * @return PJ_SUCCESS on success or the appropriate error code. + */ +PJ_DECL(pj_status_t) pj_ioqueue_lock_key(pj_ioqueue_key_t *key); + +/** + * Release the lock previously acquired with pj_ioqueue_lock_key(). + * + * @param key The key that was previously obtained from registration. + * + * @return PJ_SUCCESS on success or the appropriate error code. + */ +PJ_DECL(pj_status_t) pj_ioqueue_unlock_key(pj_ioqueue_key_t *key); + +/** + * Initialize operation key. + * + * @param op_key The operation key to be initialied. + * @param size The size of the operation key. + */ +PJ_DECL(void) pj_ioqueue_op_key_init( pj_ioqueue_op_key_t *op_key, + pj_size_t size ); + +/** + * Check if operation is pending on the specified operation key. + * The \c op_key must have been initialized with #pj_ioqueue_op_key_init() + * or submitted as pending operation before, or otherwise the result + * is undefined. + * + * @param key The key. + * @param op_key The operation key, previously submitted to any of + * the I/O functions and has returned PJ_EPENDING. + * + * @return Non-zero if operation is still pending. + */ +PJ_DECL(pj_bool_t) pj_ioqueue_is_pending( pj_ioqueue_key_t *key, + pj_ioqueue_op_key_t *op_key ); + + +/** + * Post completion status to the specified operation key and call the + * appropriate callback. When the callback is called, the number of bytes + * received in read/write callback or the status in accept/connect callback + * will be set from the \c bytes_status parameter. + * + * @param key The key. + * @param op_key Pending operation key. + * @param bytes_status Number of bytes or status to be set. A good value + * to put here is -PJ_ECANCELLED. + * + * @return PJ_SUCCESS if completion status has been successfully + * sent. + */ +PJ_DECL(pj_status_t) pj_ioqueue_post_completion( pj_ioqueue_key_t *key, + pj_ioqueue_op_key_t *op_key, + pj_ssize_t bytes_status ); + + + +#if defined(PJ_HAS_TCP) && PJ_HAS_TCP != 0 +/** + * Instruct I/O Queue to accept incoming connection on the specified + * listening socket. This function will return immediately (i.e. non-blocking) + * regardless whether a connection is immediately available. If the function + * can't complete immediately, the caller will be notified about the incoming + * connection when it calls pj_ioqueue_poll(). If a new connection is + * immediately available, the function returns PJ_SUCCESS with the new + * connection; in this case, the callback WILL NOT be called. + * + * @param key The key which registered to the server socket. + * @param op_key An operation specific key to be associated with the + * pending operation, so that application can keep track of + * which operation has been completed when the callback is + * called. + * @param new_sock Argument which contain pointer to receive the new socket + * for the incoming connection. + * @param local Optional argument which contain pointer to variable to + * receive local address. + * @param remote Optional argument which contain pointer to variable to + * receive the remote address. + * @param addrlen On input, contains the length of the buffer for the + * address, and on output, contains the actual length of the + * address. This argument is optional. + * @return + * - PJ_SUCCESS When connection is available immediately, and the + * parameters will be updated to contain information about + * the new connection. In this case, a completion callback + * WILL NOT be called. + * - PJ_EPENDING If no connection is available immediately. When a new + * connection arrives, the callback will be called. + * - non-zero which indicates the appropriate error code. + */ +PJ_DECL(pj_status_t) pj_ioqueue_accept( pj_ioqueue_key_t *key, + pj_ioqueue_op_key_t *op_key, + pj_sock_t *new_sock, + pj_sockaddr_t *local, + pj_sockaddr_t *remote, + int *addrlen ); + +/** + * Initiate non-blocking socket connect. If the socket can NOT be connected + * immediately, asynchronous connect() will be scheduled and caller will be + * notified via completion callback when it calls pj_ioqueue_poll(). If + * socket is connected immediately, the function returns PJ_SUCCESS and + * completion callback WILL NOT be called. + * + * @param key The key associated with TCP socket + * @param addr The remote address. + * @param addrlen The remote address length. + * + * @return + * - PJ_SUCCESS If socket is connected immediately. In this case, the + * completion callback WILL NOT be called. + * - PJ_EPENDING If operation is queued, or + * - non-zero Indicates the error code. + */ +PJ_DECL(pj_status_t) pj_ioqueue_connect( pj_ioqueue_key_t *key, + const pj_sockaddr_t *addr, + int addrlen ); + +#endif /* PJ_HAS_TCP */ + +/** + * Poll the I/O Queue for completed events. + * + * Note: polling the ioqueue is not necessary in Symbian. Please see + * @ref PJ_SYMBIAN_OS for more info. + * + * @param ioque the I/O Queue. + * @param timeout polling timeout, or NULL if the thread wishes to wait + * indefinetely for the event. + * + * @return + * - zero if timed out (no event). + * - (<0) if error occured during polling. Callback will NOT be called. + * - (>1) to indicate numbers of events. Callbacks have been called. + */ +PJ_DECL(int) pj_ioqueue_poll( pj_ioqueue_t *ioque, + const pj_time_val *timeout); + + +/** + * Instruct the I/O Queue to read from the specified handle. This function + * returns immediately (i.e. non-blocking) regardless whether some data has + * been transfered. If the operation can't complete immediately, caller will + * be notified about the completion when it calls pj_ioqueue_poll(). If data + * is immediately available, the function will return PJ_SUCCESS and the + * callback WILL NOT be called. + * + * @param key The key that uniquely identifies the handle. + * @param op_key An operation specific key to be associated with the + * pending operation, so that application can keep track of + * which operation has been completed when the callback is + * called. Caller must make sure that this key remains + * valid until the function completes. + * @param buffer The buffer to hold the read data. The caller MUST make sure + * that this buffer remain valid until the framework completes + * reading the handle. + * @param length On input, it specifies the size of the buffer. If data is + * available to be read immediately, the function returns + * PJ_SUCCESS and this argument will be filled with the + * amount of data read. If the function is pending, caller + * will be notified about the amount of data read in the + * callback. This parameter can point to local variable in + * caller's stack and doesn't have to remain valid for the + * duration of pending operation. + * @param flags Recv flag. If flags has PJ_IOQUEUE_ALWAYS_ASYNC then + * the function will never return PJ_SUCCESS. + * + * @return + * - PJ_SUCCESS If immediate data has been received in the buffer. In this + * case, the callback WILL NOT be called. + * - PJ_EPENDING If the operation has been queued, and the callback will be + * called when data has been received. + * - non-zero The return value indicates the error code. + */ +PJ_DECL(pj_status_t) pj_ioqueue_recv( pj_ioqueue_key_t *key, + pj_ioqueue_op_key_t *op_key, + void *buffer, + pj_ssize_t *length, + pj_uint32_t flags ); + +/** + * This function behaves similarly as #pj_ioqueue_recv(), except that it is + * normally called for socket, and the remote address will also be returned + * along with the data. Caller MUST make sure that both buffer and addr + * remain valid until the framework completes reading the data. + * + * @param key The key that uniquely identifies the handle. + * @param op_key An operation specific key to be associated with the + * pending operation, so that application can keep track of + * which operation has been completed when the callback is + * called. + * @param buffer The buffer to hold the read data. The caller MUST make sure + * that this buffer remain valid until the framework completes + * reading the handle. + * @param length On input, it specifies the size of the buffer. If data is + * available to be read immediately, the function returns + * PJ_SUCCESS and this argument will be filled with the + * amount of data read. If the function is pending, caller + * will be notified about the amount of data read in the + * callback. This parameter can point to local variable in + * caller's stack and doesn't have to remain valid for the + * duration of pending operation. + * @param flags Recv flag. If flags has PJ_IOQUEUE_ALWAYS_ASYNC then + * the function will never return PJ_SUCCESS. + * @param addr Optional Pointer to buffer to receive the address. + * @param addrlen On input, specifies the length of the address buffer. + * On output, it will be filled with the actual length of + * the address. This argument can be NULL if \c addr is not + * specified. + * + * @return + * - PJ_SUCCESS If immediate data has been received. In this case, the + * callback must have been called before this function + * returns, and no pending operation is scheduled. + * - PJ_EPENDING If the operation has been queued. + * - non-zero The return value indicates the error code. + */ +PJ_DECL(pj_status_t) pj_ioqueue_recvfrom( pj_ioqueue_key_t *key, + pj_ioqueue_op_key_t *op_key, + void *buffer, + pj_ssize_t *length, + pj_uint32_t flags, + pj_sockaddr_t *addr, + int *addrlen); + +/** + * Instruct the I/O Queue to write to the handle. This function will return + * immediately (i.e. non-blocking) regardless whether some data has been + * transfered. If the function can't complete immediately, the caller will + * be notified about the completion when it calls pj_ioqueue_poll(). If + * operation completes immediately and data has been transfered, the function + * returns PJ_SUCCESS and the callback will NOT be called. + * + * @param key The key that identifies the handle. + * @param op_key An operation specific key to be associated with the + * pending operation, so that application can keep track of + * which operation has been completed when the callback is + * called. + * @param data The data to send. Caller MUST make sure that this buffer + * remains valid until the write operation completes. + * @param length On input, it specifies the length of data to send. When + * data was sent immediately, this function returns PJ_SUCCESS + * and this parameter contains the length of data sent. If + * data can not be sent immediately, an asynchronous operation + * is scheduled and caller will be notified via callback the + * number of bytes sent. This parameter can point to local + * variable on caller's stack and doesn't have to remain + * valid until the operation has completed. + * @param flags Send flags. If flags has PJ_IOQUEUE_ALWAYS_ASYNC then + * the function will never return PJ_SUCCESS. + * + * @return + * - PJ_SUCCESS If data was immediately transfered. In this case, no + * pending operation has been scheduled and the callback + * WILL NOT be called. + * - PJ_EPENDING If the operation has been queued. Once data base been + * transfered, the callback will be called. + * - non-zero The return value indicates the error code. + */ +PJ_DECL(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, + pj_uint32_t flags ); + + +/** + * Instruct the I/O Queue to write to the handle. This function will return + * immediately (i.e. non-blocking) regardless whether some data has been + * transfered. If the function can't complete immediately, the caller will + * be notified about the completion when it calls pj_ioqueue_poll(). If + * operation completes immediately and data has been transfered, the function + * returns PJ_SUCCESS and the callback will NOT be called. + * + * @param key the key that identifies the handle. + * @param op_key An operation specific key to be associated with the + * pending operation, so that application can keep track of + * which operation has been completed when the callback is + * called. + * @param data the data to send. Caller MUST make sure that this buffer + * remains valid until the write operation completes. + * @param length On input, it specifies the length of data to send. When + * data was sent immediately, this function returns PJ_SUCCESS + * and this parameter contains the length of data sent. If + * data can not be sent immediately, an asynchronous operation + * is scheduled and caller will be notified via callback the + * number of bytes sent. This parameter can point to local + * variable on caller's stack and doesn't have to remain + * valid until the operation has completed. + * @param flags send flags. If flags has PJ_IOQUEUE_ALWAYS_ASYNC then + * the function will never return PJ_SUCCESS. + * @param addr Optional remote address. + * @param addrlen Remote address length, \c addr is specified. + * + * @return + * - PJ_SUCCESS If data was immediately written. + * - PJ_EPENDING If the operation has been queued. + * - non-zero The return value indicates the error code. + */ +PJ_DECL(pj_status_t) pj_ioqueue_sendto( pj_ioqueue_key_t *key, + pj_ioqueue_op_key_t *op_key, + const void *data, + pj_ssize_t *length, + pj_uint32_t flags, + const pj_sockaddr_t *addr, + int addrlen); + + +/** + * !} + */ + +PJ_END_DECL + +#endif /* __PJ_IOQUEUE_H__ */ + -- cgit v1.2.3