--- /dev/null
+/* -*-c-*-
+ *
+ * $Id: ausys-win32.c,v 1.1 2002/02/02 19:16:28 mdw Exp $
+ *
+ * Unix-specific (SDL) audio handling
+ *
+ * (c) 2002 Mark Wooding
+ */
+
+/*----- Licensing notice --------------------------------------------------*
+ *
+ * This file is part of Jog: Programming for a jogging machine.
+ *
+ * Jog is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * Jog 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 General Public License
+ * along with Jog; if not, write to the Free Software Foundation,
+ * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+/*----- Revision history --------------------------------------------------*
+ *
+ * $Log: ausys-win32.c,v $
+ * Revision 1.1 2002/02/02 19:16:28 mdw
+ * New audio subsystem.
+ *
+ */
+
+/*----- Header files ------------------------------------------------------*/
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+
+#include <sys/types.h>
+#include <sys/time.h>
+#include <unistd.h>
+#include <pthread.h>
+
+#include <windows.h>
+
+#include <mLib/alloc.h>
+#include <mLib/bits.h>
+#include <mLib/sub.h>
+#include <mLib/trace.h>
+
+#include "au.h"
+#include "ausys.h"
+#include "err.h"
+#include "jog.h"
+
+/*----- Data structures ---------------------------------------------------*/
+
+/* --- Queue of samples to play --- */
+
+typedef struct qnode {
+ struct qnode *next; /* Next item in the queue */
+ au_data *a; /* Pointer to sample data */
+} qnode;
+
+/*----- Global variables --------------------------------------------------*/
+
+const char *const ausys_suffix = "wav";
+
+/*----- Static data -------------------------------------------------------*/
+
+static qnode *qhead = 0, *qtail = 0; /* Queue of samples to play */
+static qnode *qfree = 0; /* Queue of samples to free */
+
+static pthread_t tid_play; /* The sample-playing thread */
+static pthread_mutex_t mx_queue; /* Mutex for @qhead@ */
+static pthread_cond_t cv_play; /* More samples to play */
+
+static pthread_t tid_free; /* The sample-freeing thread */
+static pthread_mutex_t mx_free; /* Mutex for @qfree@ */
+static pthread_cond_t cv_free; /* More sample data to free */
+
+static pthread_mutex_t mx_sub; /* Protects mLib @sub@ functions */
+
+/*----- Thread structure --------------------------------------------------*
+ *
+ * In order to ensure that samples don't overlap each other, we play them
+ * synchronously in a separate thread. The @play@ function reads samples to
+ * play from the queue at @qhead@. Hence @qhead@ must be locked when it's
+ * modified, using @mx_queue@.
+ *
+ * In order to keep latency down when new sample data is wanted, we don't do
+ * potentially tedious things like freeing sample data blocks in the @play@
+ * thread. Instead, there's a queue of sample blocks which need freeing, and
+ * a separate thread @dofree@ which processes the queue. The queue, @qfree@
+ * is locked by @mx_free@. When new nodes are added to @qfree@, the
+ * condition @cv_free@ is signalled.
+ *
+ * Finally, the mLib `sub' module isn't thread-safe, so it's locked
+ * separately by @mx_sub@.
+ *
+ * There's an ordering on mutexes. If you want more than one mutex at a
+ * time, you must lock the greatest first. The ordering is:
+ *
+ * play > free > sub
+ */
+
+/*----- Main code ---------------------------------------------------------*/
+
+/* --- @dofree@ --- *
+ *
+ * Arguments: @void *u@ = unused pointer
+ *
+ * Returns: An unused pointer.
+ *
+ * Use: Frees unwanted sample queue nodes.
+ */
+
+static void *play(void *u)
+{
+ qnode *q, *qq = 0;
+
+ for (;;) {
+
+ /* --- If we have nothing to do locally, fetch the external queue --- */
+
+ if (!qq) {
+ pthread_mutex_lock(&mx_queue);
+ while (!qhead) {
+ T( trace(T_AUSYS, "ausys: waiting for samples to play"); )
+ pthread_cond_wait(&cv_play, &mx_queue);
+ }
+ qq = qhead;
+ qhead = qtail = 0;
+ pthread_mutex_unlock(&mx_queue);
+ }
+
+ /* --- Play the next sample --- */
+ q = qq;
+ qq = q->next;
+ T( trace(T_AUSYS, "ausys: playing `%s'", SYM_NAME(q->a->s)); )
+ PlaySound((const void *)q->a->p, 0, SND_SYNC | SND_MEMORY);
+
+ /* --- Put it on the free list --- */
+
+ pthread_mutex_lock(&mx_free);
+ q->next = qfree;
+ qfree = q;
+ pthread_mutex_unlock(&mx_free);
+ pthread_cond_signal(&cv_free);
+ }
+}
+
+/* --- @dofree@ --- *
+ *
+ * Arguments: @void *u@ = unused pointer
+ *
+ * Returns: An unused pointer.
+ *
+ * Use: Frees unwanted sample queue nodes.
+ */
+
+static void *dofree(void *u)
+{
+ qnode *q, *qq;
+
+ pthread_mutex_lock(&mx_free);
+ for (;;) {
+ T( trace(T_AUSYS, "ausys: dofree sleeping"); )
+ pthread_cond_wait(&cv_free, &mx_free);
+ T( trace(T_AUSYS, "ausys: dofree woken: work to do"); )
+
+ while (qfree) {
+ q = qfree;
+ qfree = 0;
+ pthread_mutex_lock(&mx_sub);
+ while (q) {
+ qq = q->next;
+ T( trace(T_AUSYS, "ausys: freeing `%s'", SYM_NAME(q->a->s)); )
+ au_free_unlocked(q->a);
+ DESTROY(q);
+ q = qq;
+ }
+ pthread_mutex_unlock(&mx_sub);
+ }
+ }
+}
+
+/* --- @ausys_init@ --- *
+ *
+ * Arguments: ---
+ *
+ * Returns: ---
+ *
+ * Use: Does any initialization required by the system-specific audio
+ * handler.
+ */
+
+void ausys_init(void)
+{
+ pthread_attr_t ta;
+ int e;
+
+ if ((e = pthread_mutex_init(&mx_free, 0)) != 0 ||
+ (e = pthread_mutex_init(&mx_sub, 0)) != 0 ||
+ (e = pthread_mutex_init(&mx_queue, 0)) != 0 ||
+ (e = pthread_cond_init(&cv_play, 0)) != 0 ||
+ (e = pthread_cond_init(&cv_free, 0)) != 0 ||
+ (e = pthread_attr_init(&ta)) != 0 ||
+ (e = pthread_attr_setdetachstate(&ta, PTHREAD_CREATE_DETACHED)) != 0 ||
+ (e = pthread_create(&tid_free, &ta, play, 0)) != 0 ||
+ (e = pthread_create(&tid_free, &ta, dofree, 0)) != 0) {
+ err_report(ERR_AUDIO, ERRAU_INIT, e,
+ "couldn't create audio threads: %s", strerror(errno));
+ exit(EXIT_FAILURE);
+ }
+ pthread_attr_destroy(&ta);
+
+ T( trace(T_AUSYS, "ausys: initalized ok"); )
+}
+
+/* --- @ausys_shutdown@ --- *
+ *
+ * Arguments: ---
+ *
+ * Returns: ---
+ *
+ * Use: Does any tidying up required.
+ */
+
+void ausys_shutdown(void)
+{
+ pthread_cancel(tid_free);
+ pthread_cancel(tid_play);
+ T( trace(T_AUSYS, "ausys: shut down ok"); )
+}
+
+/* --- @ausys_lock@, @ausys_unlock@ --- *
+ *
+ * Arguments: ---
+ *
+ * Returns: ---
+ *
+ * Use: Locks or unlocks the audio subsystem. This protects the
+ * audio queue from becoming corrupted during all the tedious
+ * asynchronous stuff.
+ */
+
+void ausys_lock(void)
+{
+ pthread_mutex_lock(&mx_free);
+ pthread_mutex_lock(&mx_sub);
+ T( trace(T_AUSYS, "ausys: acquired lock"); )
+}
+
+void ausys_unlock(void)
+{
+ pthread_mutex_unlock(&mx_sub);
+ pthread_mutex_unlock(&mx_free);
+ T( trace(T_AUSYS, "ausys: released lock"); )
+}
+
+/* --- @ausys_decode@ --- *
+ *
+ * Arguments: @au_sample *s@ = pointer to sample block
+ * @const void *p@ = pointer to sample file contents
+ * @size_t sz@ = size of sample file contents
+ *
+ * Returns: Pointer to a sample data structure.
+ *
+ * Use: Decodes a WAV file into something the system-specific layer
+ * actually wants to deal with.
+ */
+
+au_data *ausys_decode(au_sample *s, const void *p, size_t sz)
+{
+ au_data *a;
+
+ pthread_mutex_lock(&mx_sub);
+ a = CREATE(au_data);
+ pthread_mutex_unlock(&mx_sub);
+ a->p = xmalloc(sz);
+ memcpy(a->p, p, sz);
+ a->sz = sz;
+
+ T( trace(T_AUSYS, "ausys: decoded `%s' ok", SYM_NAME(s)); )
+ return (a);
+}
+
+/* --- @ausys_queue@ --- *
+ *
+ * Arguments: @au_data *a@ = an audio thingy to play
+ *
+ * Returns: ---
+ *
+ * Use: Queues an audio sample to be played. The sample should be
+ * freed (with @au_free@) when it's no longer wanted.
+ */
+
+void ausys_queue(au_data *a)
+{
+ qnode *q;
+
+ pthread_mutex_lock(&mx_sub);
+ q = CREATE(qnode);
+ pthread_mutex_unlock(&mx_sub);
+ q->next = 0;
+ q->a = a;
+ pthread_mutex_lock(&mx_queue);
+ if (qtail)
+ qtail->next = q;
+ else
+ qhead = q;
+ qtail = q;
+ pthread_mutex_unlock(&mx_queue);
+ pthread_cond_signal(&cv_play);
+ T( trace(T_AUSYS, "ausys: queuing `%s'", SYM_NAME(a->s)); )
+}
+
+/* --- @ausys_free@ --- *
+ *
+ * Arguments: @au_data *a@ = an audio thingy to free
+ *
+ * Returns: ---
+ *
+ * Use: Frees a decoded audio sample.
+ */
+
+void ausys_free(au_data *a)
+{
+ xfree(a->p);
+ DESTROY(a);
+ T( trace(T_AUSYS, "ausys: freeing data for `%s' ok", SYM_NAME(a->s)); )
+}
+
+/*----- That's all, folks -------------------------------------------------*/
~mdw / jog / blobdiff