src/pulsecore/thread-mq.c

   1 /***
   2   This file is part of PulseAudio.
   3
   4   Copyright 2006 Lennart Poettering
   5
   6   PulseAudio is free software; you can redistribute it and/or modify
   7   it under the terms of the GNU Lesser General Public License as
   8   published by the Free Software Foundation; either version 2.1 of the
   9   License, or (at your option) any later version.
  10
  11   PulseAudio is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   Lesser General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public
  17   License along with PulseAudio; if not, write to the Free Software
  18   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  19   USA.
  20 ***/
  21
  22 #ifdef HAVE_CONFIG_H
  23 #include <config.h>
  24 #endif
  25
  26 #include <unistd.h>
  27 #include <errno.h>
  28
  29 #include <pulsecore/thread.h>
  30 #include <pulsecore/semaphore.h>
  31 #include <pulsecore/macro.h>
  32
  33 #include "thread-mq.h"
  34
  35 PA_STATIC_TLS_DECLARE_NO_FREE(thread_mq);
  36
  37 static void asyncmsgq_read_cb(pa_mainloop_api*api, pa_io_event* e, int fd, pa_io_event_flags_t events, void *userdata) {
  38     pa_thread_mq *q = userdata;
  39     pa_asyncmsgq *aq;
  40
  41     pa_assert(pa_asyncmsgq_read_fd(q->outq) == fd);
  42     pa_assert(events == PA_IO_EVENT_INPUT);
  43
  44     pa_asyncmsgq_ref(aq = q->outq);
  45     pa_asyncmsgq_write_after_poll(aq);
  46
  47     for (;;) {
  48         pa_msgobject *object;
  49         int code;
  50         void *data;
  51         int64_t offset;
  52         pa_memchunk chunk;
  53
  54         /* Check whether there is a message for us to process */
  55         while (pa_asyncmsgq_get(aq, &object, &code, &data, &offset, &chunk, 0) >= 0) {
  56             int ret;
  57
  58             ret = pa_asyncmsgq_dispatch(object, code, data, offset, &chunk);
  59             pa_asyncmsgq_done(aq, ret);
  60         }
  61
  62         if (pa_asyncmsgq_read_before_poll(aq) == 0)
  63             break;
  64     }
  65
  66     pa_asyncmsgq_unref(aq);
  67 }
  68
  69 static void asyncmsgq_write_cb(pa_mainloop_api*api, pa_io_event* e, int fd, pa_io_event_flags_t events, void *userdata) {
  70     pa_thread_mq *q = userdata;
  71
  72     pa_assert(pa_asyncmsgq_write_fd(q->inq) == fd);
  73     pa_assert(events == PA_IO_EVENT_INPUT);
  74
  75     pa_asyncmsgq_write_after_poll(q->inq);
  76     pa_asyncmsgq_write_before_poll(q->inq);
  77 }
  78
  79 void pa_thread_mq_init(pa_thread_mq *q, pa_mainloop_api *mainloop, pa_rtpoll *rtpoll) {
  80     pa_assert(q);
  81     pa_assert(mainloop);
  82
  83     q->mainloop = mainloop;
  84     pa_assert_se(q->inq = pa_asyncmsgq_new(0));
  85     pa_assert_se(q->outq = pa_asyncmsgq_new(0));
  86
  87     pa_assert_se(pa_asyncmsgq_read_before_poll(q->outq) == 0);
  88     pa_assert_se(q->read_event = mainloop->io_new(mainloop, pa_asyncmsgq_read_fd(q->outq), PA_IO_EVENT_INPUT, asyncmsgq_read_cb, q));
  89
  90     pa_asyncmsgq_write_before_poll(q->inq);
  91     pa_assert_se(q->write_event = mainloop->io_new(mainloop, pa_asyncmsgq_write_fd(q->inq), PA_IO_EVENT_INPUT, asyncmsgq_write_cb, q));
  92
  93     pa_rtpoll_item_new_asyncmsgq_read(rtpoll, PA_RTPOLL_EARLY, q->inq);
  94     pa_rtpoll_item_new_asyncmsgq_write(rtpoll, PA_RTPOLL_LATE, q->outq);
  95 }
  96
  97 void pa_thread_mq_done(pa_thread_mq *q) {
  98     pa_assert(q);
  99
 100     /* Since we are called from main context we can be sure that the
 101      * inq is empty. However, the outq might still contain messages
 102      * for the main loop, which we need to dispatch (e.g. release
 103      * msgs, other stuff). Hence do so if we aren't currently
 104      * dispatching anyway. */
 105
 106     if (!pa_asyncmsgq_dispatching(q->outq))
 107         pa_asyncmsgq_flush(q->outq, TRUE);
 108
 109     q->mainloop->io_free(q->read_event);
 110     q->mainloop->io_free(q->write_event);
 111     q->read_event = q->write_event = NULL;
 112
 113     pa_asyncmsgq_unref(q->inq);
 114     pa_asyncmsgq_unref(q->outq);
 115     q->inq = q->outq = NULL;
 116
 117     q->mainloop = NULL;
 118 }
 119
 120 void pa_thread_mq_install(pa_thread_mq *q) {
 121     pa_assert(q);
 122
 123     pa_assert(!(PA_STATIC_TLS_GET(thread_mq)));
 124     PA_STATIC_TLS_SET(thread_mq, q);
 125 }
 126
 127 pa_thread_mq *pa_thread_mq_get(void) {
 128     return PA_STATIC_TLS_GET(thread_mq);
 129 }