chore(build): revert to sdl2

vendor/sdl-2.30.5/src/thread/windows/SDL_syssem.c

@@ -0,0 +1,444 @@
+/*
+  Simple DirectMedia Layer
+  Copyright (C) 1997-2024 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_WINDOWS
+
+/**
+ * Semaphore functions using the Win32 API
+ * There are two implementations available based on:
+ * - Kernel Semaphores. Available on all OS versions. (kern)
+ *   Heavy-weight inter-process kernel objects.
+ * - Atomics and WaitOnAddress API. (atom)
+ *   Faster due to significantly less context switches.
+ *   Requires Windows 8 or newer.
+ * which are chosen at runtime.
+ */
+
+#include "../../core/windows/SDL_windows.h"
+
+#include "SDL_hints.h"
+#include "SDL_thread.h"
+#include "SDL_timer.h"
+
+typedef SDL_sem * (*pfnSDL_CreateSemaphore)(Uint32);
+typedef void (*pfnSDL_DestroySemaphore)(SDL_sem *);
+typedef int (*pfnSDL_SemWaitTimeout)(SDL_sem *, Uint32);
+typedef int (*pfnSDL_SemTryWait)(SDL_sem *);
+typedef int (*pfnSDL_SemWait)(SDL_sem *);
+typedef Uint32 (*pfnSDL_SemValue)(SDL_sem *);
+typedef int (*pfnSDL_SemPost)(SDL_sem *);
+
+typedef struct SDL_semaphore_impl_t
+{
+    pfnSDL_CreateSemaphore Create;
+    pfnSDL_DestroySemaphore Destroy;
+    pfnSDL_SemWaitTimeout WaitTimeout;
+    pfnSDL_SemTryWait TryWait;
+    pfnSDL_SemWait Wait;
+    pfnSDL_SemValue Value;
+    pfnSDL_SemPost Post;
+} SDL_sem_impl_t;
+
+/* Implementation will be chosen at runtime based on available Kernel features */
+static SDL_sem_impl_t SDL_sem_impl_active = { 0 };
+
+/**
+ * Atomic + WaitOnAddress implementation
+ */
+
+/* APIs not available on WinPhone 8.1 */
+/* https://www.microsoft.com/en-us/download/details.aspx?id=47328 */
+
+#if !SDL_WINAPI_FAMILY_PHONE
+#ifdef __WINRT__
+/* Functions are guaranteed to be available */
+#define pWaitOnAddress       WaitOnAddress
+#define pWakeByAddressSingle WakeByAddressSingle
+#else
+typedef BOOL(WINAPI *pfnWaitOnAddress)(volatile VOID *, PVOID, SIZE_T, DWORD);
+typedef VOID(WINAPI *pfnWakeByAddressSingle)(PVOID);
+
+static pfnWaitOnAddress pWaitOnAddress = NULL;
+static pfnWakeByAddressSingle pWakeByAddressSingle = NULL;
+#endif
+
+typedef struct SDL_semaphore_atom
+{
+    LONG count;
+} SDL_sem_atom;
+
+static SDL_sem *SDL_CreateSemaphore_atom(Uint32 initial_value)
+{
+    SDL_sem_atom *sem;
+
+    sem = (SDL_sem_atom *)SDL_malloc(sizeof(*sem));
+    if (sem) {
+        sem->count = initial_value;
+    } else {
+        SDL_OutOfMemory();
+    }
+    return (SDL_sem *)sem;
+}
+
+static void SDL_DestroySemaphore_atom(SDL_sem *sem)
+{
+    if (sem) {
+        SDL_free(sem);
+    }
+}
+
+static int SDL_SemTryWait_atom(SDL_sem *_sem)
+{
+    SDL_sem_atom *sem = (SDL_sem_atom *)_sem;
+    LONG count;
+
+    if (!sem) {
+        return SDL_InvalidParamError("sem");
+    }
+
+    count = sem->count;
+    if (count == 0) {
+        return SDL_MUTEX_TIMEDOUT;
+    }
+
+    if (InterlockedCompareExchange(&sem->count, count - 1, count) == count) {
+        return 0;
+    }
+
+    return SDL_MUTEX_TIMEDOUT;
+}
+
+static int SDL_SemWait_atom(SDL_sem *_sem)
+{
+    SDL_sem_atom *sem = (SDL_sem_atom *)_sem;
+    LONG count;
+
+    if (!sem) {
+        return SDL_InvalidParamError("sem");
+    }
+
+    for (;;) {
+        count = sem->count;
+        while (count == 0) {
+            if (pWaitOnAddress(&sem->count, &count, sizeof(sem->count), INFINITE) == FALSE) {
+                return SDL_SetError("WaitOnAddress() failed");
+            }
+            count = sem->count;
+        }
+
+        if (InterlockedCompareExchange(&sem->count, count - 1, count) == count) {
+            return 0;
+        }
+    }
+}
+
+static int SDL_SemWaitTimeout_atom(SDL_sem *_sem, Uint32 timeout)
+{
+    SDL_sem_atom *sem = (SDL_sem_atom *)_sem;
+    LONG count;
+    Uint32 now;
+    Uint32 deadline;
+    DWORD timeout_eff;
+
+    if (timeout == SDL_MUTEX_MAXWAIT) {
+        return SDL_SemWait_atom(_sem);
+    }
+
+    if (!sem) {
+        return SDL_InvalidParamError("sem");
+    }
+
+    /**
+     * WaitOnAddress is subject to spurious and stolen wakeups so we
+     * need to recalculate the effective timeout before every wait
+     */
+    now = SDL_GetTicks();
+    deadline = now + (DWORD)timeout;
+
+    for (;;) {
+        count = sem->count;
+        /* If no semaphore is available we need to wait */
+        while (count == 0) {
+            now = SDL_GetTicks();
+            if (deadline > now) {
+                timeout_eff = deadline - now;
+            } else {
+                return SDL_MUTEX_TIMEDOUT;
+            }
+            if (pWaitOnAddress(&sem->count, &count, sizeof(count), timeout_eff) == FALSE) {
+                if (GetLastError() == ERROR_TIMEOUT) {
+                    return SDL_MUTEX_TIMEDOUT;
+                }
+                return SDL_SetError("WaitOnAddress() failed");
+            }
+            count = sem->count;
+        }
+
+        /* Actually the semaphore is only consumed if this succeeds */
+        /* If it doesn't we need to do everything again */
+        if (InterlockedCompareExchange(&sem->count, count - 1, count) == count) {
+            return 0;
+        }
+    }
+}
+
+static Uint32 SDL_SemValue_atom(SDL_sem *_sem)
+{
+    SDL_sem_atom *sem = (SDL_sem_atom *)_sem;
+
+    if (!sem) {
+        SDL_InvalidParamError("sem");
+        return 0;
+    }
+
+    return (Uint32)sem->count;
+}
+
+static int SDL_SemPost_atom(SDL_sem *_sem)
+{
+    SDL_sem_atom *sem = (SDL_sem_atom *)_sem;
+
+    if (!sem) {
+        return SDL_InvalidParamError("sem");
+    }
+
+    InterlockedIncrement(&sem->count);
+    pWakeByAddressSingle(&sem->count);
+
+    return 0;
+}
+
+static const SDL_sem_impl_t SDL_sem_impl_atom = {
+    &SDL_CreateSemaphore_atom,
+    &SDL_DestroySemaphore_atom,
+    &SDL_SemWaitTimeout_atom,
+    &SDL_SemTryWait_atom,
+    &SDL_SemWait_atom,
+    &SDL_SemValue_atom,
+    &SDL_SemPost_atom,
+};
+#endif /* !SDL_WINAPI_FAMILY_PHONE */
+
+/**
+ * Fallback Semaphore implementation using Kernel Semaphores
+ */
+
+typedef struct SDL_semaphore_kern
+{
+    HANDLE id;
+    LONG count;
+} SDL_sem_kern;
+
+/* Create a semaphore */
+static SDL_sem *SDL_CreateSemaphore_kern(Uint32 initial_value)
+{
+    SDL_sem_kern *sem;
+
+    /* Allocate sem memory */
+    sem = (SDL_sem_kern *)SDL_malloc(sizeof(*sem));
+    if (sem) {
+        /* Create the semaphore, with max value 32K */
+#ifdef __WINRT__
+        sem->id = CreateSemaphoreEx(NULL, initial_value, 32 * 1024, NULL, 0, SEMAPHORE_ALL_ACCESS);
+#else
+        sem->id = CreateSemaphore(NULL, initial_value, 32 * 1024, NULL);
+#endif
+        sem->count = initial_value;
+        if (!sem->id) {
+            SDL_SetError("Couldn't create semaphore");
+            SDL_free(sem);
+            sem = NULL;
+        }
+    } else {
+        SDL_OutOfMemory();
+    }
+    return (SDL_sem *)sem;
+}
+
+/* Free the semaphore */
+static void SDL_DestroySemaphore_kern(SDL_sem *_sem)
+{
+    SDL_sem_kern *sem = (SDL_sem_kern *)_sem;
+    if (sem) {
+        if (sem->id) {
+            CloseHandle(sem->id);
+            sem->id = 0;
+        }
+        SDL_free(sem);
+    }
+}
+
+static int SDL_SemWaitTimeout_kern(SDL_sem *_sem, Uint32 timeout)
+{
+    SDL_sem_kern *sem = (SDL_sem_kern *)_sem;
+    int retval;
+    DWORD dwMilliseconds;
+
+    if (!sem) {
+        return SDL_InvalidParamError("sem");
+    }
+
+    if (timeout == SDL_MUTEX_MAXWAIT) {
+        dwMilliseconds = INFINITE;
+    } else {
+        dwMilliseconds = (DWORD)timeout;
+    }
+    switch (WaitForSingleObjectEx(sem->id, dwMilliseconds, FALSE)) {
+    case WAIT_OBJECT_0:
+        InterlockedDecrement(&sem->count);
+        retval = 0;
+        break;
+    case WAIT_TIMEOUT:
+        retval = SDL_MUTEX_TIMEDOUT;
+        break;
+    default:
+        retval = SDL_SetError("WaitForSingleObject() failed");
+        break;
+    }
+    return retval;
+}
+
+static int SDL_SemTryWait_kern(SDL_sem *sem)
+{
+    return SDL_SemWaitTimeout_kern(sem, 0);
+}
+
+static int SDL_SemWait_kern(SDL_sem *sem)
+{
+    return SDL_SemWaitTimeout_kern(sem, SDL_MUTEX_MAXWAIT);
+}
+
+/* Returns the current count of the semaphore */
+static Uint32 SDL_SemValue_kern(SDL_sem *_sem)
+{
+    SDL_sem_kern *sem = (SDL_sem_kern *)_sem;
+    if (!sem) {
+        SDL_InvalidParamError("sem");
+        return 0;
+    }
+    return (Uint32)sem->count;
+}
+
+static int SDL_SemPost_kern(SDL_sem *_sem)
+{
+    SDL_sem_kern *sem = (SDL_sem_kern *)_sem;
+    if (!sem) {
+        return SDL_InvalidParamError("sem");
+    }
+    /* Increase the counter in the first place, because
+     * after a successful release the semaphore may
+     * immediately get destroyed by another thread which
+     * is waiting for this semaphore.
+     */
+    InterlockedIncrement(&sem->count);
+    if (ReleaseSemaphore(sem->id, 1, NULL) == FALSE) {
+        InterlockedDecrement(&sem->count); /* restore */
+        return SDL_SetError("ReleaseSemaphore() failed");
+    }
+    return 0;
+}
+
+static const SDL_sem_impl_t SDL_sem_impl_kern = {
+    &SDL_CreateSemaphore_kern,
+    &SDL_DestroySemaphore_kern,
+    &SDL_SemWaitTimeout_kern,
+    &SDL_SemTryWait_kern,
+    &SDL_SemWait_kern,
+    &SDL_SemValue_kern,
+    &SDL_SemPost_kern,
+};
+
+/**
+ * Runtime selection and redirection
+ */
+
+SDL_sem *SDL_CreateSemaphore(Uint32 initial_value)
+{
+    if (!SDL_sem_impl_active.Create) {
+        /* Default to fallback implementation */
+        const SDL_sem_impl_t *impl = &SDL_sem_impl_kern;
+
+#if !SDL_WINAPI_FAMILY_PHONE
+        if (!SDL_GetHintBoolean(SDL_HINT_WINDOWS_FORCE_SEMAPHORE_KERNEL, SDL_FALSE)) {
+#ifdef __WINRT__
+            /* Link statically on this platform */
+            impl = &SDL_sem_impl_atom;
+#else
+            /* We already statically link to features from this Api
+             * Set (e.g. WaitForSingleObject). Dynamically loading
+             * API Sets is not explicitly documented but according to
+             * Microsoft our specific use case is legal and correct:
+             * https://github.com/microsoft/STL/pull/593#issuecomment-655799859
+             */
+            HMODULE synch120 = GetModuleHandle(TEXT("api-ms-win-core-synch-l1-2-0.dll"));
+            if (synch120) {
+                /* Try to load required functions provided by Win 8 or newer */
+                pWaitOnAddress = (pfnWaitOnAddress)GetProcAddress(synch120, "WaitOnAddress");
+                pWakeByAddressSingle = (pfnWakeByAddressSingle)GetProcAddress(synch120, "WakeByAddressSingle");
+
+                if (pWaitOnAddress && pWakeByAddressSingle) {
+                    impl = &SDL_sem_impl_atom;
+                }
+            }
+#endif
+        }
+#endif
+
+        /* Copy instead of using pointer to save one level of indirection */
+        SDL_copyp(&SDL_sem_impl_active, impl);
+    }
+    return SDL_sem_impl_active.Create(initial_value);
+}
+
+void SDL_DestroySemaphore(SDL_sem *sem)
+{
+    SDL_sem_impl_active.Destroy(sem);
+}
+
+int SDL_SemWaitTimeout(SDL_sem *sem, Uint32 timeout)
+{
+    return SDL_sem_impl_active.WaitTimeout(sem, timeout);
+}
+
+int SDL_SemTryWait(SDL_sem *sem)
+{
+    return SDL_sem_impl_active.TryWait(sem);
+}
+
+int SDL_SemWait(SDL_sem *sem)
+{
+    return SDL_sem_impl_active.Wait(sem);
+}
+
+Uint32 SDL_SemValue(SDL_sem *sem)
+{
+    return SDL_sem_impl_active.Value(sem);
+}
+
+int SDL_SemPost(SDL_sem *sem)
+{
+    return SDL_sem_impl_active.Post(sem);
+}
+
+#endif /* SDL_THREAD_WINDOWS */
+
+/* vi: set ts=4 sw=4 expandtab: */