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comparison src/audio/dsp/SDL_dspaudio.c @ 93:fc774f445e10

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Applied Hannu's fix and switched to blocking writes .. seems to work?
author Sam Lantinga <slouken@lokigames.com>
date Sat, 07 Jul 2001 23:27:29 +0000
parents d3bc792e136d
children ae6e6b73333f
comparison
equal deleted inserted replaced
92:dab667b72ccc 93:fc774f445e10
49 49
50 /* The tag name used by DSP audio */ 50 /* The tag name used by DSP audio */
51 #define DSP_DRIVER_NAME "dsp" 51 #define DSP_DRIVER_NAME "dsp"
52 52
53 /* Open the audio device for playback, and don't block if busy */ 53 /* Open the audio device for playback, and don't block if busy */
54 /*#define USE_BLOCKING_WRITES*/ 54 #define USE_BLOCKING_WRITES
55 #ifdef USE_BLOCKING_WRITES 55 #ifdef USE_BLOCKING_WRITES
56 #define OPEN_FLAGS O_WRONLY 56 #define OPEN_FLAGS O_WRONLY
57 #else 57 #else
58 #define OPEN_FLAGS (O_WRONLY|O_NONBLOCK) 58 #define OPEN_FLAGS (O_WRONLY|O_NONBLOCK)
59 #endif 59 #endif
126 }; 126 };
127 127
128 /* This function waits until it is possible to write a full sound buffer */ 128 /* This function waits until it is possible to write a full sound buffer */
129 static void DSP_WaitAudio(_THIS) 129 static void DSP_WaitAudio(_THIS)
130 { 130 {
131 #ifndef USE_BLOCKING_WRITES /* Not necessary because of blocking writes */
132 fd_set fdset;
133
134 /* Check to see if the thread-parent process is still alive */ 131 /* Check to see if the thread-parent process is still alive */
135 { static int cnt = 0; 132 { static int cnt = 0;
136 /* Note that this only works with thread implementations 133 /* Note that this only works with thread implementations
137 that use a different process id for each thread. 134 that use a different process id for each thread.
138 */ 135 */
141 this->enabled = 0; 138 this->enabled = 0;
142 } 139 }
143 } 140 }
144 } 141 }
145 142
143 #ifndef USE_BLOCKING_WRITES /* Not necessary when using blocking writes */
146 /* See if we need to use timed audio synchronization */ 144 /* See if we need to use timed audio synchronization */
147 if ( frame_ticks ) { 145 if ( frame_ticks ) {
148 /* Use timer for general audio synchronization */ 146 /* Use timer for general audio synchronization */
149 Sint32 ticks; 147 Sint32 ticks;
150 148
152 if ( ticks > 0 ) { 150 if ( ticks > 0 ) {
153 SDL_Delay(ticks); 151 SDL_Delay(ticks);
154 } 152 }
155 } else { 153 } else {
156 /* Use select() for audio synchronization */ 154 /* Use select() for audio synchronization */
155 fd_set fdset;
157 struct timeval timeout; 156 struct timeval timeout;
157
158 FD_ZERO(&fdset); 158 FD_ZERO(&fdset);
159 FD_SET(audio_fd, &fdset); 159 FD_SET(audio_fd, &fdset);
160 timeout.tv_sec = 10; 160 timeout.tv_sec = 10;
161 timeout.tv_usec = 0; 161 timeout.tv_usec = 0;
162 #ifdef DEBUG_AUDIO 162 #ifdef DEBUG_AUDIO
184 #endif /* !USE_BLOCKING_WRITES */ 184 #endif /* !USE_BLOCKING_WRITES */
185 } 185 }
186 186
187 static void DSP_PlayAudio(_THIS) 187 static void DSP_PlayAudio(_THIS)
188 { 188 {
189 int written; 189 int written, p=0;
190 190
191 /* Write the audio data, checking for EAGAIN on broken audio drivers */ 191 /* Write the audio data, checking for EAGAIN on broken audio drivers */
192 do { 192 do {
193 written = write(audio_fd, mixbuf, mixlen); 193 written = write(audio_fd, &mixbuf[p], mixlen-p);
194 if ( (written < 0) && ((errno == 0) || (errno == EAGAIN)) ) { 194 if (written>0)
195 p += written;
196 if (written == -1 && errno != 0 && errno != EAGAIN && errno != EINTR)
197 {
198 /* Non recoverable error has occurred. It should be reported!!! */
199 perror("audio");
200 break;
201 }
202
203 if ( p < written || ((written < 0) && ((errno == 0) || (errno == EAGAIN))) ) {
195 SDL_Delay(1); /* Let a little CPU time go by */ 204 SDL_Delay(1); /* Let a little CPU time go by */
196 } 205 }
197 } while ( (written < 0) && 206 } while ( p < written );
198 ((errno == 0) || (errno == EAGAIN) || (errno == EINTR)) );
199 207
200 /* If timer synchronization is enabled, set the next write frame */ 208 /* If timer synchronization is enabled, set the next write frame */
201 if ( frame_ticks ) { 209 if ( frame_ticks ) {
202 next_frame += frame_ticks; 210 next_frame += frame_ticks;
203 } 211 }