From b28449a58cd4914c13023692b3650cd8e00cc5c2 Mon Sep 17 00:00:00 2001
From: "Ryan C. Gordon" <[EMAIL REDACTED]>
Date: Thu, 24 Apr 2025 22:17:13 -0400
Subject: [PATCH] audio: Tweak SDL_GetAudioDeviceName.
- Add checks that ObtainPhysicalAudioDevice() was previously doing
(is subsystem initialized, is device valid).
- Remove optimizations that copy string to stack to release device_hash_lock
before SDL_GetPersistentString is called. Probably not necessary, and made
the code more complex.
---
src/audio/SDL_audio.c | 35 ++++++++++++++---------------------
1 file changed, 14 insertions(+), 21 deletions(-)
diff --git a/src/audio/SDL_audio.c b/src/audio/SDL_audio.c
index 78faf7fdacd7c..a3a115c48d6b2 100644
--- a/src/audio/SDL_audio.c
+++ b/src/audio/SDL_audio.c
@@ -1502,31 +1502,24 @@ SDL_AudioDevice *SDL_FindPhysicalAudioDeviceByHandle(void *handle)
const char *SDL_GetAudioDeviceName(SDL_AudioDeviceID devid)
{
- bool isstack = false;
- char *string = NULL;
const char *result = NULL;
SDL_AudioDevice *device = NULL;
- // This does not call ObtainPhysicalAudioDevice() because the device's name never changes, so
- // it doesn't have to lock the whole device. However, just to make sure the device pointer itself
- // remains valid (in case the device is unplugged at the wrong moment), we hold the
- // device_hash_lock while we copy the string.
- SDL_LockRWLockForReading(current_audio.device_hash_lock);
- SDL_FindInHashTable(current_audio.device_hash, (const void *) (uintptr_t) devid, (const void **) &device);
- if (device) {
- const size_t slen = SDL_strlen(device->name) + 1;
- // SDL_GetPersistentString might _also_ makes a copy, but it might also create a TLS slot and a hashtable before doing a lookup, malloc+copy, and insert.
- // So just try to tuck this into a little stack space while we're holding device_hash_lock.
- string = SDL_small_alloc(char, slen, &isstack);
- if (string) {
- SDL_strlcpy(string, device->name, slen);
+ if (!SDL_GetCurrentAudioDriver()) {
+ SDL_SetError("Audio subsystem is not initialized");
+ } else {
+ // This does not call ObtainPhysicalAudioDevice() because the device's name never changes, so
+ // it doesn't have to lock the whole device. However, just to make sure the device pointer itself
+ // remains valid (in case the device is unplugged at the wrong moment), we hold the
+ // device_hash_lock while we copy the string.
+ SDL_LockRWLockForReading(current_audio.device_hash_lock);
+ SDL_FindInHashTable(current_audio.device_hash, (const void *) (uintptr_t) devid, (const void **) &device);
+ if (!device) {
+ SDL_SetError("Invalid audio device instance ID");
+ } else {
+ result = SDL_GetPersistentString(device->name);
}
- }
- SDL_UnlockRWLock(current_audio.device_hash_lock);
-
- if (string) {
- result = SDL_GetPersistentString(string);
- SDL_small_free(string, isstack);
+ SDL_UnlockRWLock(current_audio.device_hash_lock);
}
return result;