From 2ced6b09fc0ac120c3f1c15cff7022d334051fa3 Mon Sep 17 00:00:00 2001
From: ds-sloth <[EMAIL REDACTED]>
Date: Tue, 28 Jan 2025 23:14:56 -0500
Subject: [PATCH] Delete src/thread/n3ds/SDL_syscond.c
This PR removes the incorrect implementation of `SDL_cond` currently included with the 3DS port.
Pseudocode of the incorrect implementation of `SDL_CondWait` this PR removes:
* Receive an `SDL_cond` backed by a `libctru` `CondVar` and an `SDL_mutex` backed by a `libctru` `RecursiveLock`.
* Want to call `libctru` function `CondVar_Wait` which expects a `CondVar` and a `LightLock` (non-recursive lock)
* Do so by calling this function with the internal (inadequately protected) `LightLock` member of the `RecursiveLock` (`&mutex->lock.lock` on line 105), without updating any internal thread or lock count fields of the `RecursiveLock`.
Happy to discuss or test some examples. My own use case works much better with the generic cond logic, and this seems like a safe fix to me given that the generic logic is well-tested and this seems not to be.
If you like the PR I'll send another one for the SDL2 branch.
---
src/thread/n3ds/SDL_syscond.c | 111 ----------------------------------
1 file changed, 111 deletions(-)
delete mode 100644 src/thread/n3ds/SDL_syscond.c
diff --git a/src/thread/n3ds/SDL_syscond.c b/src/thread/n3ds/SDL_syscond.c
deleted file mode 100644
index d5c4067da9a53..0000000000000
--- a/src/thread/n3ds/SDL_syscond.c
+++ /dev/null
@@ -1,111 +0,0 @@
-/*
- Simple DirectMedia Layer
- Copyright (C) 1997-2025 Sam Lantinga <slouken@libsdl.org>
-
- This software is provided 'as-is', without any express or implied
- warranty. In no event will the authors be held liable for any damages
- arising from the use of this software.
-
- Permission is granted to anyone to use this software for any purpose,
- including commercial applications, and to alter it and redistribute it
- freely, subject to the following restrictions:
-
- 1. The origin of this software must not be misrepresented; you must not
- claim that you wrote the original software. If you use this software
- in a product, an acknowledgment in the product documentation would be
- appreciated but is not required.
- 2. Altered source versions must be plainly marked as such, and must not be
- misrepresented as being the original software.
- 3. This notice may not be removed or altered from any source distribution.
-*/
-#include "SDL_internal.h"
-
-#ifdef SDL_THREAD_N3DS
-
-// An implementation of condition variables using libctru's CondVar
-
-#include "SDL_sysmutex_c.h"
-
-struct SDL_Condition
-{
- CondVar cond_variable;
-};
-
-// Create a condition variable
-SDL_Condition *SDL_CreateCondition(void)
-{
- SDL_Condition *cond = (SDL_Condition *)SDL_malloc(sizeof(SDL_Condition));
- if (cond) {
- CondVar_Init(&cond->cond_variable);
- }
- return cond;
-}
-
-// Destroy a condition variable
-void SDL_DestroyCondition(SDL_Condition *cond)
-{
- if (cond) {
- SDL_free(cond);
- }
-}
-
-// Restart one of the threads that are waiting on the condition variable
-void SDL_SignalCondition(SDL_Condition *cond)
-{
- if (!cond) {
- return;
- }
-
- CondVar_Signal(&cond->cond_variable);
-}
-
-// Restart all threads that are waiting on the condition variable
-void SDL_BroadcastCondition(SDL_Condition *cond)
-{
- if (!cond) {
- return;
- }
-
- CondVar_Broadcast(&cond->cond_variable);
-}
-
-/* Wait on the condition variable for at most 'timeoutNS' nanoseconds.
- The mutex must be locked before entering this function!
- The mutex is unlocked during the wait, and locked again after the wait.
-
-Typical use:
-
-Thread A:
- SDL_LockMutex(lock);
- while ( ! condition ) {
- SDL_WaitCondition(cond, lock);
- }
- SDL_UnlockMutex(lock);
-
-Thread B:
- SDL_LockMutex(lock);
- ...
- condition = true;
- ...
- SDL_SignalCondition(cond);
- SDL_UnlockMutex(lock);
- */
-bool SDL_WaitConditionTimeoutNS(SDL_Condition *cond, SDL_Mutex *mutex, Sint64 timeoutNS)
-{
- Result res;
-
- if (!cond || !mutex) {
- return true;
- }
-
- res = 0;
- if (timeoutNS < 0) {
- CondVar_Wait(&cond->cond_variable, &mutex->lock.lock);
- } else {
- res = CondVar_WaitTimeout(&cond->cond_variable, &mutex->lock.lock, timeoutNS);
- }
-
- return R_SUCCEEDED(res);
-}
-
-#endif // SDL_THREAD_N3DS