code.delx.au - pulseaudio/blob - src/pulsecore/asyncq.h

   1 #ifndef foopulseasyncqhfoo
   2 #define foopulseasyncqhfoo
   3
   4 /* $Id$ */
   5
   6 /***
   7   This file is part of PulseAudio.
   8
   9   Copyright 2004-2006 Lennart Poettering
  10
  11   PulseAudio is free software; you can redistribute it and/or modify
  12   it under the terms of the GNU Lesser General Public License as
  13   published by the Free Software Foundation; either version 2.1 of the
  14   License, or (at your option) any later version.
  15
  16   PulseAudio is distributed in the hope that it will be useful, but
  17   WITHOUT ANY WARRANTY; without even the implied warranty of
  18   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  19   Lesser General Public License for more details.
  20
  21   You should have received a copy of the GNU Lesser General Public
  22   License along with PulseAudio; if not, write to the Free Software
  23   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  24   USA.
  25 ***/
  26
  27 #include <sys/types.h>
  28 #include <pulse/def.h>
  29
  30 /* A simple, asynchronous, lock-free (if requested also wait-free)
  31  * queue. Not multiple-reader/multiple-writer safe. If that is
  32  * required both sides can be protected by a mutex each. --- Which is
  33  * not a bad thing in most cases, since this queue is intended for
  34  * communication between a normal thread and a single real-time
  35  * thread. Only the real-time side needs to be lock-free/wait-free.
  36  *
  37  * If the queue is full and another entry shall be pushed, or when the
  38  * queue is empty and another entry shall be popped and the "wait"
  39  * argument is non-zero, the queue will block on a UNIX FIFO object --
  40  * that will probably require locking on the kernel side -- which
  41  * however is probably not problematic, because we do it only on
  42  * starvation or overload in which case we have to block anyway.  */
  43
  44 typedef struct pa_asyncq pa_asyncq;
  45
  46 pa_asyncq* pa_asyncq_new(unsigned size);
  47 void pa_asyncq_free(pa_asyncq* q, pa_free_cb_t free_cb);
  48
  49 void* pa_asyncq_pop(pa_asyncq *q, int wait);
  50 int pa_asyncq_push(pa_asyncq *q, void *p, int wait);
  51
  52 int pa_asyncq_get_fd(pa_asyncq *q);
  53 int pa_asyncq_before_poll(pa_asyncq *a);
  54 void pa_asyncq_after_poll(pa_asyncq *a);
  55
  56 #endif