On 2/5/19 4:08 AM, Thomas Huth wrote:
> The semaphore code was only working with SDL1.2 - with SDL2, it causes
> a deadlock. Since we've removed support for SDL1.2 recently, we can
> now completely remove the semaphore code from sdlaudio.c.
>
> Signed-off-by: Thomas Huth <th...@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <phi...@redhat.com>
> ---
> audio/sdlaudio.c | 145
> ++-----------------------------------------------------
> 1 file changed, 5 insertions(+), 140 deletions(-)
>
> diff --git a/audio/sdlaudio.c b/audio/sdlaudio.c
> index 9db5ac9..53bfdbf 100644
> --- a/audio/sdlaudio.c
> +++ b/audio/sdlaudio.c
> @@ -38,14 +38,9 @@
> #define AUDIO_CAP "sdl"
> #include "audio_int.h"
>
> -#define USE_SEMAPHORE (SDL_MAJOR_VERSION < 2)
> -
> typedef struct SDLVoiceOut {
> HWVoiceOut hw;
> int live;
> -#if USE_SEMAPHORE
> - int rpos;
> -#endif
> int decr;
> } SDLVoiceOut;
>
> @@ -57,10 +52,6 @@ static struct {
>
> static struct SDLAudioState {
> int exit;
> -#if USE_SEMAPHORE
> - SDL_mutex *mutex;
> - SDL_sem *sem;
> -#endif
> int initialized;
> bool driver_created;
> } glob_sdl;
> @@ -77,66 +68,6 @@ static void GCC_FMT_ATTR (1, 2) sdl_logerr (const char
> *fmt, ...)
> AUD_log (AUDIO_CAP, "Reason: %s\n", SDL_GetError ());
> }
>
> -static int sdl_lock (SDLAudioState *s, const char *forfn)
> -{
> -#if USE_SEMAPHORE
> - if (SDL_LockMutex (s->mutex)) {
> - sdl_logerr ("SDL_LockMutex for %s failed\n", forfn);
> - return -1;
> - }
> -#else
> - SDL_LockAudio();
> -#endif
> -
> - return 0;
> -}
> -
> -static int sdl_unlock (SDLAudioState *s, const char *forfn)
> -{
> -#if USE_SEMAPHORE
> - if (SDL_UnlockMutex (s->mutex)) {
> - sdl_logerr ("SDL_UnlockMutex for %s failed\n", forfn);
> - return -1;
> - }
> -#else
> - SDL_UnlockAudio();
> -#endif
> -
> - return 0;
> -}
> -
> -static int sdl_post (SDLAudioState *s, const char *forfn)
> -{
> -#if USE_SEMAPHORE
> - if (SDL_SemPost (s->sem)) {
> - sdl_logerr ("SDL_SemPost for %s failed\n", forfn);
> - return -1;
> - }
> -#endif
> -
> - return 0;
> -}
> -
> -#if USE_SEMAPHORE
> -static int sdl_wait (SDLAudioState *s, const char *forfn)
> -{
> - if (SDL_SemWait (s->sem)) {
> - sdl_logerr ("SDL_SemWait for %s failed\n", forfn);
> - return -1;
> - }
> - return 0;
> -}
> -#endif
> -
> -static int sdl_unlock_and_post (SDLAudioState *s, const char *forfn)
> -{
> - if (sdl_unlock (s, forfn)) {
> - return -1;
> - }
> -
> - return sdl_post (s, forfn);
> -}
> -
> static int aud_to_sdlfmt (audfmt_e fmt)
> {
> switch (fmt) {
> @@ -243,9 +174,9 @@ static int sdl_open (SDL_AudioSpec *req, SDL_AudioSpec
> *obt)
> static void sdl_close (SDLAudioState *s)
> {
> if (s->initialized) {
> - sdl_lock (s, "sdl_close");
> + SDL_LockAudio();
> s->exit = 1;
> - sdl_unlock_and_post (s, "sdl_close");
> + SDL_UnlockAudio();
> SDL_PauseAudio (1);
> SDL_CloseAudio ();
> s->initialized = 0;
> @@ -267,30 +198,10 @@ static void sdl_callback (void *opaque, Uint8 *buf, int
> len)
> int to_mix, decr;
>
> /* dolog ("in callback samples=%d\n", samples); */
> -#if USE_SEMAPHORE
> - sdl_wait (s, "sdl_callback");
> - if (s->exit) {
> - return;
> - }
> -
> - if (sdl_lock (s, "sdl_callback")) {
> - return;
> - }
> -
> - if (audio_bug(__func__, sdl->live < 0 || sdl->live > hw->samples)) {
> - dolog ("sdl->live=%d hw->samples=%d\n",
> - sdl->live, hw->samples);
> - return;
> - }
>
> - if (!sdl->live) {
> - goto again;
> - }
> -#else
> if (s->exit || !sdl->live) {
> break;
> }
> -#endif
>
> /* dolog ("in callback live=%d\n", live); */
> to_mix = audio_MIN (samples, sdl->live);
> @@ -301,33 +212,20 @@ static void sdl_callback (void *opaque, Uint8 *buf, int
> len)
>
> /* dolog ("in callback to_mix %d, chunk %d\n", to_mix, chunk); */
> hw->clip (buf, src, chunk);
> -#if USE_SEMAPHORE
> - sdl->rpos = (sdl->rpos + chunk) % hw->samples;
> -#else
> hw->rpos = (hw->rpos + chunk) % hw->samples;
> -#endif
> to_mix -= chunk;
> buf += chunk << hw->info.shift;
> }
> samples -= decr;
> sdl->live -= decr;
> sdl->decr += decr;
> -
> -#if USE_SEMAPHORE
> - again:
> - if (sdl_unlock (s, "sdl_callback")) {
> - return;
> - }
> -#endif
> }
> /* dolog ("done len=%d\n", len); */
>
> -#if (SDL_MAJOR_VERSION >= 2)
> /* SDL2 does not clear the remaining buffer for us, so do it on our own
> */
> if (samples) {
> memset(buf, 0, samples << hw->info.shift);
> }
> -#endif
> }
>
> static int sdl_write_out (SWVoiceOut *sw, void *buf, int len)
> @@ -339,11 +237,8 @@ static int sdl_run_out (HWVoiceOut *hw, int live)
> {
> int decr;
> SDLVoiceOut *sdl = (SDLVoiceOut *) hw;
> - SDLAudioState *s = &glob_sdl;
>
> - if (sdl_lock (s, "sdl_run_out")) {
> - return 0;
> - }
> + SDL_LockAudio();
>
> if (sdl->decr > live) {
> ldebug ("sdl->decr %d live %d sdl->live %d\n",
> @@ -355,19 +250,10 @@ static int sdl_run_out (HWVoiceOut *hw, int live)
> decr = audio_MIN (sdl->decr, live);
> sdl->decr -= decr;
>
> -#if USE_SEMAPHORE
> - sdl->live = live - decr;
> - hw->rpos = sdl->rpos;
> -#else
> sdl->live = live;
> -#endif
>
> - if (sdl->live > 0) {
> - sdl_unlock_and_post (s, "sdl_run_out");
> - }
> - else {
> - sdl_unlock (s, "sdl_run_out");
> - }
> + SDL_UnlockAudio();
> +
> return decr;
> }
>
> @@ -449,23 +335,6 @@ static void *sdl_audio_init (void)
> return NULL;
> }
>
> -#if USE_SEMAPHORE
> - s->mutex = SDL_CreateMutex ();
> - if (!s->mutex) {
> - sdl_logerr ("Failed to create SDL mutex\n");
> - SDL_QuitSubSystem (SDL_INIT_AUDIO);
> - return NULL;
> - }
> -
> - s->sem = SDL_CreateSemaphore (0);
> - if (!s->sem) {
> - sdl_logerr ("Failed to create SDL semaphore\n");
> - SDL_DestroyMutex (s->mutex);
> - SDL_QuitSubSystem (SDL_INIT_AUDIO);
> - return NULL;
> - }
> -#endif
> -
> s->driver_created = true;
> return s;
> }
> @@ -474,10 +343,6 @@ static void sdl_audio_fini (void *opaque)
> {
> SDLAudioState *s = opaque;
> sdl_close (s);
> -#if USE_SEMAPHORE
> - SDL_DestroySemaphore (s->sem);
> - SDL_DestroyMutex (s->mutex);
> -#endif
> SDL_QuitSubSystem (SDL_INIT_AUDIO);
> s->driver_created = false;
> }
>
