Atlas - SDL_systimer.c
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[FILE BEGIN]
1/*
2  Simple DirectMedia Layer
3  Copyright (C) 1997-2025 Sam Lantinga <[email protected]>
4
5  This software is provided 'as-is', without any express or implied
6  warranty.  In no event will the authors be held liable for any damages
7  arising from the use of this software.
8
9  Permission is granted to anyone to use this software for any purpose,
10  including commercial applications, and to alter it and redistribute it
11  freely, subject to the following restrictions:
12
13  1. The origin of this software must not be misrepresented; you must not
14     claim that you wrote the original software. If you use this software
15     in a product, an acknowledgment in the product documentation would be
16     appreciated but is not required.
17  2. Altered source versions must be plainly marked as such, and must not be
18     misrepresented as being the original software.
19  3. This notice may not be removed or altered from any source distribution.
20*/
21#include "SDL_internal.h"
22
23#ifdef SDL_TIMER_WINDOWS
24
25#include "../../core/windows/SDL_windows.h"
26
27Uint64 SDL_GetPerformanceCounter(void)
28{
29    LARGE_INTEGER counter;
30    const BOOL rc = QueryPerformanceCounter(&counter);
31    SDL_assert(rc != 0); // this should _never_ fail if you're on XP or later.
32    return (Uint64)counter.QuadPart;
33}
34
35Uint64 SDL_GetPerformanceFrequency(void)
36{
37    LARGE_INTEGER frequency;
38    const BOOL rc = QueryPerformanceFrequency(&frequency);
39    SDL_assert(rc != 0); // this should _never_ fail if you're on XP or later.
40    return (Uint64)frequency.QuadPart;
41}
42
43static void SDL_CleanupWaitableHandle(void *handle)
44{
45    CloseHandle(handle);
46}
47
48static HANDLE SDL_GetWaitableEvent(void)
49{
50    static SDL_TLSID TLS_event_handle;
51    HANDLE event;
52
53    event = SDL_GetTLS(&TLS_event_handle);
54    if (!event) {
55        event = CreateEvent(NULL, FALSE, FALSE, NULL);
56        if (event) {
57            SDL_SetTLS(&TLS_event_handle, event, SDL_CleanupWaitableHandle);
58        }
59    }
60    return event;
61}
62
63/* CREATE_WAITABLE_TIMER_HIGH_RESOLUTION flag was added in Windows 10 version 1803. */
64#ifndef CREATE_WAITABLE_TIMER_HIGH_RESOLUTION
65#define CREATE_WAITABLE_TIMER_HIGH_RESOLUTION 0x2
66#endif
67
68typedef HANDLE (WINAPI *pfnCreateWaitableTimerExW)(LPSECURITY_ATTRIBUTES lpTimerAttributes, LPCWSTR lpTimerName, DWORD dwFlags, DWORD dwDesiredAccess);
69static pfnCreateWaitableTimerExW pCreateWaitableTimerExW;
70
71#if WINVER < _WIN32_WINNT_WIN7
72typedef struct _REASON_CONTEXT REASON_CONTEXT;
73typedef REASON_CONTEXT * PREASON_CONTEXT;
74#endif
75typedef BOOL (WINAPI *pfnSetWaitableTimerEx)(HANDLE hTimer, const LARGE_INTEGER *lpDueTime, LONG lPeriod, PTIMERAPCROUTINE pfnCompletionRoutine, LPVOID lpArgToCompletionRoutine, PREASON_CONTEXT WakeContext, ULONG TolerableDelay);
76static pfnSetWaitableTimerEx pSetWaitableTimerEx;
77
78typedef HANDLE (WINAPI *pfnCreateWaitableTimerW)(LPSECURITY_ATTRIBUTES lpTimerAttributes, BOOL bManualReset, LPCWSTR lpTimerName);
79static pfnCreateWaitableTimerW pCreateWaitableTimerW;
80
81typedef BOOL (WINAPI *pfnSetWaitableTimer)(HANDLE hTimer, const LARGE_INTEGER *lpDueTime, LONG lPeriod, PTIMERAPCROUTINE pfnCompletionRoutine, LPVOID lpArgToCompletionRoutine, BOOL fResume);
82static pfnSetWaitableTimer pSetWaitableTimer;
83
84static HANDLE SDL_GetWaitableTimer(void)
85{
86    static SDL_TLSID TLS_timer_handle;
87    HANDLE timer;
88    static bool initialized;
89
90    if (!initialized) {
91        HMODULE module = GetModuleHandle(TEXT("kernel32.dll"));
92        if (module) {
93            pCreateWaitableTimerExW = (pfnCreateWaitableTimerExW)GetProcAddress(module, "CreateWaitableTimerExW"); // Windows 7 and up
94            if (!pCreateWaitableTimerExW) {
95                pCreateWaitableTimerW = (pfnCreateWaitableTimerW)GetProcAddress(module, "CreateWaitableTimerW");
96            }
97            pSetWaitableTimerEx = (pfnSetWaitableTimerEx)GetProcAddress(module, "SetWaitableTimerEx"); // Windows Vista and up
98            if (!pSetWaitableTimerEx) {
99                pSetWaitableTimer = (pfnSetWaitableTimer)GetProcAddress(module, "SetWaitableTimer");
100            }
101            initialized =
102                (pCreateWaitableTimerExW || pCreateWaitableTimerW) &&
103                (pSetWaitableTimerEx || pSetWaitableTimer);
104        }
105        if (!initialized) {
106            return NULL;
107        }
108    }
109
110    timer = SDL_GetTLS(&TLS_timer_handle);
111    if (!timer) {
112        if (pCreateWaitableTimerExW) {
113            timer = pCreateWaitableTimerExW(NULL, NULL, CREATE_WAITABLE_TIMER_HIGH_RESOLUTION, TIMER_ALL_ACCESS);
114        } else {
115            timer = pCreateWaitableTimerW(NULL, TRUE, NULL);
116        }
117        if (timer) {
118            SDL_SetTLS(&TLS_timer_handle, timer, SDL_CleanupWaitableHandle);
119        }
120    }
121    return timer;
122}
123
124void SDL_SYS_DelayNS(Uint64 ns)
125{
126    HANDLE timer = SDL_GetWaitableTimer();
127    if (timer) {
128        LARGE_INTEGER due_time;
129        due_time.QuadPart = -((LONGLONG)ns / 100);
130        if ((pSetWaitableTimerEx && pSetWaitableTimerEx(timer, &due_time, 0, NULL, NULL, NULL, 0)) || pSetWaitableTimer(timer, &due_time, 0, NULL, NULL, 0)) {
131            WaitForSingleObject(timer, INFINITE);
132        }
133        return;
134    }
135
136    const Uint64 max_delay = 0xffffffffLL * SDL_NS_PER_MS;
137    if (ns > max_delay) {
138        ns = max_delay;
139    }
140    const DWORD delay = (DWORD)SDL_NS_TO_MS(ns);
141
142    HANDLE event = SDL_GetWaitableEvent();
143    if (event) {
144        WaitForSingleObjectEx(event, delay, FALSE);
145        return;
146    }
147
148    Sleep(delay);
149}
150
151#endif // SDL_TIMER_WINDOWS
152
[FILE END]
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