1 #ifndef foomainloophfoo 2 #define foomainloophfoo 3 4 /*** 5 This file is part of PulseAudio. 6 7 Copyright 2004-2006 Lennart Poettering 8 Copyright 2006 Pierre Ossman <ossman (at) cendio.se> for Cendio AB 9 10 PulseAudio is free software; you can redistribute it and/or modify 11 it under the terms of the GNU Lesser General Public License as published 12 by the Free Software Foundation; either version 2.1 of the License, 13 or (at your option) any later version. 14 15 PulseAudio is distributed in the hope that it will be useful, but 16 WITHOUT ANY WARRANTY; without even the implied warranty of 17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 18 General Public License for more details. 19 20 You should have received a copy of the GNU Lesser General Public License 21 along with PulseAudio; if not, write to the Free Software 22 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 23 USA. 24 ***/ 25 26 #include <pulse/mainloop-api.h> 27 #include <pulse/cdecl.h> 28 29 PA_C_DECL_BEGIN 30 31 struct pollfd; 32 33 /** \page mainloop Main Loop 34 * 35 * \section overv_sec Overview 36 * 37 * The built-in main loop implementation is based on the poll() system call. 38 * It supports the functions defined in the main loop abstraction and very 39 * little else. 40 * 41 * The main loop is created using pa_mainloop_new() and destroyed using 42 * pa_mainloop_free(). To get access to the main loop abstraction, 43 * pa_mainloop_get_api() is used. 44 * 45 * \section iter_sec Iteration 46 * 47 * The main loop is designed around the concept of iterations. Each iteration 48 * consists of three steps that repeat during the application's entire 49 * lifetime: 50 * 51 * -# Prepare - Build a list of file descriptors 52 * that need to be monitored and calculate the next timeout. 53 * -# Poll - Execute the actual poll() system call. 54 * -# Dispatch - Dispatch any events that have fired. 55 * 56 * When using the main loop, the application can either execute each 57 * iteration, one at a time, using pa_mainloop_iterate(), or let the library 58 * iterate automatically using pa_mainloop_run(). 59 * 60 * \section thread_sec Threads 61 * 62 * The main loop functions are designed to be thread safe, but the objects 63 * are not. What this means is that multiple main loops can be used, but only 64 * one object per thread. 65 * 66 */ 67 68 /** \file 69 * 70 * A minimal main loop implementation based on the C library's poll() 71 * function. Using the routines defined herein you may create a simple 72 * main loop supporting the generic main loop abstraction layer as 73 * defined in \ref mainloop-api.h. This implementation is thread safe 74 * as long as you access the main loop object from a single thread only. 75 * 76 * See also \subpage mainloop 77 */ 78 79 /** An opaque main loop object */ 80 typedef struct pa_mainloop pa_mainloop; 81 82 /** Allocate a new main loop object */ 83 pa_mainloop *pa_mainloop_new(void); 84 85 /** Free a main loop object */ 86 void pa_mainloop_free(pa_mainloop* m); 87 88 /** Prepare for a single iteration of the main loop. Returns a negative value 89 on error or exit request. timeout specifies a maximum timeout for the subsequent 90 poll, or -1 for blocking behaviour. .*/ 91 int pa_mainloop_prepare(pa_mainloop *m, int timeout); 92 93 /** Execute the previously prepared poll. Returns a negative value on error.*/ 94 int pa_mainloop_poll(pa_mainloop *m); 95 96 /** Dispatch timeout, io and deferred events from the previously executed poll. Returns 97 a negative value on error. On success returns the number of source dispatched. */ 98 int pa_mainloop_dispatch(pa_mainloop *m); 99 100 /** Return the return value as specified with the main loop's quit() routine. */ 101 int pa_mainloop_get_retval(pa_mainloop *m); 102 103 /** Run a single iteration of the main loop. This is a convenience function 104 for pa_mainloop_prepare(), pa_mainloop_poll() and pa_mainloop_dispatch(). 105 Returns a negative value on error or exit request. If block is nonzero, 106 block for events if none are queued. Optionally return the return value as 107 specified with the main loop's quit() routine in the integer variable retval points 108 to. On success returns the number of sources dispatched in this iteration. */ 109 int pa_mainloop_iterate(pa_mainloop *m, int block, int *retval); 110 111 /** Run unlimited iterations of the main loop object until the main loop's quit() routine is called. */ 112 int pa_mainloop_run(pa_mainloop *m, int *retval); 113 114 /** Return the abstract main loop abstraction layer vtable for this 115 main loop. No need to free the API as it is owned by the loop 116 and is destroyed when the loop is freed. */ 117 pa_mainloop_api* pa_mainloop_get_api(pa_mainloop*m); 118 119 /** Shutdown the main loop */ 120 void pa_mainloop_quit(pa_mainloop *m, int r); 121 122 /** Interrupt a running poll (for threaded systems) */ 123 void pa_mainloop_wakeup(pa_mainloop *m); 124 125 /** Generic prototype of a poll() like function */ 126 typedef int (*pa_poll_func)(struct pollfd *ufds, unsigned long nfds, int timeout, void*userdata); 127 128 /** Change the poll() implementation */ 129 void pa_mainloop_set_poll_func(pa_mainloop *m, pa_poll_func poll_func, void *userdata); 130 131 PA_C_DECL_END 132 133 #endif 134
