initial commit, 4.5 stable

thirdparty/sdl/thread/pthread/SDL_syscond.c

@@ -0,0 +1,128 @@
+/*
+  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"
+
+#include <sys/time.h>
+#include <time.h>
+#include <unistd.h>
+#include <errno.h>
+#include <pthread.h>
+
+#include "SDL_sysmutex_c.h"
+
+struct SDL_Condition
+{
+    pthread_cond_t cond;
+};
+
+// Create a condition variable
+SDL_Condition *SDL_CreateCondition(void)
+{
+    SDL_Condition *cond;
+
+    cond = (SDL_Condition *)SDL_malloc(sizeof(SDL_Condition));
+    if (cond) {
+        if (pthread_cond_init(&cond->cond, NULL) != 0) {
+            SDL_SetError("pthread_cond_init() failed");
+            SDL_free(cond);
+            cond = NULL;
+        }
+    }
+    return cond;
+}
+
+// Destroy a condition variable
+void SDL_DestroyCondition(SDL_Condition *cond)
+{
+    if (cond) {
+        pthread_cond_destroy(&cond->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;
+    }
+
+    pthread_cond_signal(&cond->cond);
+}
+
+// Restart all threads that are waiting on the condition variable
+void SDL_BroadcastCondition(SDL_Condition *cond)
+{
+    if (!cond) {
+        return;
+    }
+
+    pthread_cond_broadcast(&cond->cond);
+}
+
+bool SDL_WaitConditionTimeoutNS(SDL_Condition *cond, SDL_Mutex *mutex, Sint64 timeoutNS)
+{
+#ifndef HAVE_CLOCK_GETTIME
+    struct timeval delta;
+#endif
+    struct timespec abstime;
+
+    if (!cond || !mutex) {
+        return true;
+    }
+
+    if (timeoutNS < 0) {
+        return (pthread_cond_wait(&cond->cond, &mutex->id) == 0);
+    }
+
+#ifdef HAVE_CLOCK_GETTIME
+    clock_gettime(CLOCK_REALTIME, &abstime);
+
+    abstime.tv_sec += (timeoutNS / SDL_NS_PER_SECOND);
+    abstime.tv_nsec += (timeoutNS % SDL_NS_PER_SECOND);
+#else
+    gettimeofday(&delta, NULL);
+
+    abstime.tv_sec = delta.tv_sec + (timeoutNS / SDL_NS_PER_SECOND);
+    abstime.tv_nsec = SDL_US_TO_NS(delta.tv_usec) + (timeoutNS % SDL_NS_PER_SECOND);
+#endif
+    while (abstime.tv_nsec >= 1000000000) {
+        abstime.tv_sec += 1;
+        abstime.tv_nsec -= 1000000000;
+    }
+
+    bool result;
+    int rc;
+tryagain:
+    rc = pthread_cond_timedwait(&cond->cond, &mutex->id, &abstime);
+    switch (rc) {
+    case EINTR:
+        goto tryagain;
+        // break; -Wunreachable-code-break
+    case ETIMEDOUT:
+        result = false;
+        break;
+    default:
+        result = true;
+        break;
+    }
+    return result;
+}