ShuriZma
/
flycast
mirror of https://github.com/flyinghead/flycast.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

sdl audio: fix crash when decrasing audio buffer size. fix deadlock 

sample_count wasn't reset to 0 on init, so it could point past the end
of the audio buffer if buffer size is decreased, leading to a crash.
Fix for MINIDUMP-29

Deadlock if audio buffer size is too small (< 1024 samples)
This commit is contained in:
Flyinghead 2023-01-15 12:07:26 +01:00
parent 2b37a5dc08
commit 1e195b7237
1 changed files with 8 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
core/oslib/audiobackend_sdl2.cpp
View File

@ -14,6 +14,7 @@ class SDLAudioBackend : AudioBackend
cResetEvent read_wait; cResetEvent read_wait;
std::mutex stream_mutex; std::mutex stream_mutex;
uint32_t *sample_buffer; uint32_t *sample_buffer;
unsigned sample_buffer_size = 0;
unsigned sample_count = 0; unsigned sample_count = 0;
SDL_AudioCVT audioCvt; SDL_AudioCVT audioCvt;
@ -75,7 +76,9 @@ public:
} }
} }
sample_buffer = new uint32_t[config::AudioBufferSize](); sample_buffer_size = std::max<u32>(SAMPLE_COUNT * 2, config::AudioBufferSize);
sample_buffer = new uint32_t[sample_buffer_size]();
sample_count = 0;
// Support 44.1KHz (native) but also upsampling to 48KHz // Support 44.1KHz (native) but also upsampling to 48KHz
SDL_AudioSpec wav_spec, out_spec; SDL_AudioSpec wav_spec, out_spec;
@ -86,6 +89,7 @@ public:
wav_spec.samples = SAMPLE_COUNT * 2; // Must be power of two wav_spec.samples = SAMPLE_COUNT * 2; // Must be power of two
wav_spec.callback = audioCallback; wav_spec.callback = audioCallback;
wav_spec.userdata = this; wav_spec.userdata = this;
needs_resampling = false;
// Try 44.1KHz which should be faster since it's native. // Try 44.1KHz which should be faster since it's native.
audiodev = SDL_OpenAudioDevice(NULL, 0, &wav_spec, &out_spec, 0); audiodev = SDL_OpenAudioDevice(NULL, 0, &wav_spec, &out_spec, 0);
@ -126,7 +130,7 @@ public:
// If wait, then wait for the buffer to be smaller than a certain size. // If wait, then wait for the buffer to be smaller than a certain size.
stream_mutex.lock(); stream_mutex.lock();
if (wait) { if (wait) {
while (sample_count + samples > (u32)config::AudioBufferSize) { while (sample_count + samples > sample_buffer_size) {
stream_mutex.unlock(); stream_mutex.unlock();
read_wait.Wait(); read_wait.Wait();
stream_mutex.lock(); stream_mutex.lock();
@ -134,7 +138,7 @@ public:
} }
// Copy as many samples as possible, drop any remaining (this should not happen usually) // Copy as many samples as possible, drop any remaining (this should not happen usually)
unsigned free_samples = config::AudioBufferSize - sample_count; unsigned free_samples = sample_buffer_size - sample_count;
unsigned tocopy = samples < free_samples ? samples : free_samples; unsigned tocopy = samples < free_samples ? samples : free_samples;
memcpy(&sample_buffer[sample_count], frame, tocopy * sizeof(uint32_t)); memcpy(&sample_buffer[sample_count], frame, tocopy * sizeof(uint32_t));
sample_count += tocopy; sample_count += tocopy;