/* GStreamer * Copyright (C) <2009> Collabora Ltd * @author: Olivier Crete <olivier.crete@collabora.co.uk * Copyright (C) <2009> Nokia Inc * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN * THE SOFTWARE. */ /* * None of this code is thread safe, if you want to use it in a * multi-threaded context, please protect it with a mutex. * * First, create a writer with sp_writer_create(), then select() on * the socket returned by sp_get_fd(). If the socket is closed or any * function returns an error, the app should call sp_close() and * assume the other side is dead. The writer calls * sp_writer_accept_client() when there is something to read from the * main server fd. This returns a new ShmClient (representing a client * connection), the writer needs to do a select() on the socket * returned by sp_writer_get_client_fd(). If it gets an error on that * socket, it calls sp_writer_close_client(). If there is something to * read, it calls sp_writer_recv(). * * The writer allocates a block containing a free buffer with * sp_writer_alloc_block(), then writes something in the buffer * (retrieved with sp_writer_block_get_buf(), then calls * sp_writer_send_buf() to send the buffer or a subsection to the * other side. When it is done with the block, it calls * sp_writer_free_block(). If alloc fails, then the server must wait * for events on the client fd (the ones where sp_writer_recv() is * called), and then try to re-alloc. * * The reader (client) connect to the writer with sp_client_open() And * select()s on the fd from sp_get_fd() until there is something to * read. Then they must read using sp_client_recv() which will return * the size of the buffer (positive) if there is a valid buffer (which * is read only). It will return 0 if it is an internal message and a * negative number if there was an error. If there was an error, the * application must close the pipe with sp_close() and assume that all * buffers are no longer valid. If was valid buffer was received, the * client must release it with sp_client_recv_finish() when it is done * reading from it. */ #ifndef __SHMPIPE_H__ #define __SHMPIPE_H__ #include <stdlib.h> #include <stdint.h> #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #ifdef __cplusplus extern "C" { #endif typedef struct _ShmClient ShmClient; typedef struct _ShmPipe ShmPipe; typedef struct _ShmBlock ShmBlock; typedef struct _ShmBuffer ShmBuffer; typedef void (*sp_buffer_free_callback) (void * tag, void * user_data); ShmPipe *sp_writer_create (const char *path, size_t size, mode_t perms); const char *sp_writer_get_path (ShmPipe *pipe); void sp_writer_close (ShmPipe * self, sp_buffer_free_callback callback, void * user_data); void *sp_get_data (ShmPipe * self); void sp_set_data (ShmPipe * self, void *data); int sp_writer_setperms_shm (ShmPipe * self, mode_t perms); int sp_writer_resize (ShmPipe * self, size_t size); int sp_get_fd (ShmPipe * self); const char *sp_get_shm_area_name (ShmPipe *self); int sp_writer_get_client_fd (ShmClient * client); ShmBlock *sp_writer_alloc_block (ShmPipe * self, size_t size); void sp_writer_free_block (ShmBlock *block); int sp_writer_send_buf (ShmPipe * self, char *buf, size_t size, void * tag); char *sp_writer_block_get_buf (ShmBlock *block); ShmPipe *sp_writer_block_get_pipe (ShmBlock *block); size_t sp_writer_get_max_buf_size (ShmPipe * self); ShmClient * sp_writer_accept_client (ShmPipe * self); void sp_writer_close_client (ShmPipe *self, ShmClient * client, sp_buffer_free_callback callback, void * user_data); int sp_writer_recv (ShmPipe * self, ShmClient * client, void ** tag); int sp_writer_pending_writes (ShmPipe * self); ShmBuffer *sp_writer_get_pending_buffers (ShmPipe * self); ShmBuffer *sp_writer_get_next_buffer (ShmBuffer * buffer); void *sp_writer_buf_get_tag (ShmBuffer * buffer); ShmPipe *sp_client_open (const char *path); long int sp_client_recv (ShmPipe * self, char **buf); int sp_client_recv_finish (ShmPipe * self, char *buf); void sp_client_close (ShmPipe * self); #ifdef __cplusplus } #endif #endif /* __SHMPIPE_H__ */