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-rw-r--r-- | src/pulse/mainloop.h | 134 |
1 files changed, 134 insertions, 0 deletions
diff --git a/src/pulse/mainloop.h b/src/pulse/mainloop.h new file mode 100644 index 0000000..f1069da --- /dev/null +++ b/src/pulse/mainloop.h @@ -0,0 +1,134 @@ +#ifndef foomainloophfoo +#define foomainloophfoo + +/*** + This file is part of PulseAudio. + + Copyright 2004-2006 Lennart Poettering + Copyright 2006 Pierre Ossman <ossman@cendio.se> for Cendio AB + + PulseAudio is free software; you can redistribute it and/or modify + it under the terms of the GNU Lesser General Public License as published + by the Free Software Foundation; either version 2.1 of the License, + or (at your option) any later version. + + PulseAudio 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 Lesser General Public License + along with PulseAudio; if not, see <http://www.gnu.org/licenses/>. +***/ + +#include <pulse/mainloop-api.h> +#include <pulse/cdecl.h> + +PA_C_DECL_BEGIN + +struct pollfd; + +/** \page mainloop Main Loop + * + * \section overv_sec Overview + * + * The built-in main loop implementation is based on the poll() system call. + * It supports the functions defined in the main loop abstraction and very + * little else. + * + * The main loop is created using pa_mainloop_new() and destroyed using + * pa_mainloop_free(). To get access to the main loop abstraction, + * pa_mainloop_get_api() is used. + * + * \section iter_sec Iteration + * + * The main loop is designed around the concept of iterations. Each iteration + * consists of three steps that repeat during the application's entire + * lifetime: + * + * -# Prepare - Build a list of file descriptors + * that need to be monitored and calculate the next timeout. + * -# Poll - Execute the actual poll() system call. + * -# Dispatch - Dispatch any events that have fired. + * + * When using the main loop, the application can either execute each + * iteration, one at a time, using pa_mainloop_iterate(), or let the library + * iterate automatically using pa_mainloop_run(). + * + * \section thread_sec Threads + * + * The main loop functions are designed to be thread safe, but the objects + * are not. What this means is that multiple main loops can be used, but only + * one object per thread. + * + */ + +/** \file + * + * A minimal main loop implementation based on the C library's poll() + * function. Using the routines defined herein you may create a simple + * main loop supporting the generic main loop abstraction layer as + * defined in \ref mainloop-api.h. This implementation is thread safe + * as long as you access the main loop object from a single thread only. + * + * See also \subpage mainloop + */ + +/** An opaque main loop object */ +typedef struct pa_mainloop pa_mainloop; + +/** Allocate a new main loop object. Free with pa_mainloop_free. */ +pa_mainloop *pa_mainloop_new(void); + +/** Free a main loop object */ +void pa_mainloop_free(pa_mainloop* m); + +/** Prepare for a single iteration of the main loop. Returns a negative value +on error or exit request. timeout specifies a maximum timeout for the subsequent +poll, or -1 for blocking behaviour. The timeout is specified in microseconds. */ +int pa_mainloop_prepare(pa_mainloop *m, int timeout); + +/** Execute the previously prepared poll. Returns a negative value on error.*/ +int pa_mainloop_poll(pa_mainloop *m); + +/** Dispatch timeout, io and deferred events from the previously executed poll. Returns +a negative value on error. On success returns the number of source dispatched. */ +int pa_mainloop_dispatch(pa_mainloop *m); + +/** Return the return value as specified with the main loop's quit() routine. */ +int pa_mainloop_get_retval(const pa_mainloop *m); + +/** Run a single iteration of the main loop. This is a convenience function +for pa_mainloop_prepare(), pa_mainloop_poll() and pa_mainloop_dispatch(). +Returns a negative value on error or exit request. If block is nonzero, +block for events if none are queued. Optionally return the return value as +specified with the main loop's quit() routine in the integer variable retval points +to. On success returns the number of sources dispatched in this iteration. */ +int pa_mainloop_iterate(pa_mainloop *m, int block, int *retval); + +/** Run unlimited iterations of the main loop object until the main loop's +quit() routine is called. Returns a negative value on error. Optionally return +the return value as specified with the main loop's quit() routine in the integer +variable retval points to. */ +int pa_mainloop_run(pa_mainloop *m, int *retval); + +/** Return the abstract main loop abstraction layer vtable for this + main loop. No need to free the API as it is owned by the loop + and is destroyed when the loop is freed. */ +pa_mainloop_api* pa_mainloop_get_api(pa_mainloop*m); + +/** Shutdown the main loop with the specified return value */ +void pa_mainloop_quit(pa_mainloop *m, int retval); + +/** Interrupt a running poll (for threaded systems) */ +void pa_mainloop_wakeup(pa_mainloop *m); + +/** Generic prototype of a poll() like function */ +typedef int (*pa_poll_func)(struct pollfd *ufds, unsigned long nfds, int timeout, void*userdata); + +/** Change the poll() implementation */ +void pa_mainloop_set_poll_func(pa_mainloop *m, pa_poll_func poll_func, void *userdata); + +PA_C_DECL_END + +#endif |