Add SDL_cond implementation using Windows Condition Variables

Is automatically used when the SRW SDL_mutex implementation is active.
Otherwise falls back to the generic implementation.

v2: - Rebase onto master fa3ea1051a4b
This commit is contained in:
Joel Linn 2020-12-28 11:43:11 -08:00
parent 2443e51e0e
commit 8fc0baad98
10 changed files with 254 additions and 33 deletions

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@ -133,6 +133,7 @@
<ClInclude Include="..\..\src\thread\SDL_systhread.h" /> <ClInclude Include="..\..\src\thread\SDL_systhread.h" />
<ClInclude Include="..\..\src\thread\SDL_thread_c.h" /> <ClInclude Include="..\..\src\thread\SDL_thread_c.h" />
<ClInclude Include="..\..\src\thread\generic\SDL_syscond_c.h" /> <ClInclude Include="..\..\src\thread\generic\SDL_syscond_c.h" />
<ClInclude Include="..\..\src\thread\windows\SDL_sysmutex_c.h" />
<ClInclude Include="..\..\src\thread\windows\SDL_systhread_c.h" /> <ClInclude Include="..\..\src\thread\windows\SDL_systhread_c.h" />
<ClInclude Include="..\..\src\timer\SDL_timer_c.h" /> <ClInclude Include="..\..\src\timer\SDL_timer_c.h" />
<ClInclude Include="..\..\src\video\dummy\SDL_nullevents_c.h" /> <ClInclude Include="..\..\src\video\dummy\SDL_nullevents_c.h" />

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@ -384,6 +384,9 @@
<ClInclude Include="..\..\src\thread\generic\SDL_syscond_c.h"> <ClInclude Include="..\..\src\thread\generic\SDL_syscond_c.h">
<Filter>Source Files</Filter> <Filter>Source Files</Filter>
</ClInclude> </ClInclude>
<ClInclude Include="..\..\src\thread\windows\SDL_sysmutex_c.h">
<Filter>Source Files</Filter>
</ClInclude>
<ClInclude Include="..\..\src\thread\windows\SDL_systhread_c.h"> <ClInclude Include="..\..\src\thread\windows\SDL_systhread_c.h">
<Filter>Source Files</Filter> <Filter>Source Files</Filter>
</ClInclude> </ClInclude>

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@ -147,6 +147,7 @@
<ClInclude Include="..\..\src\sensor\SDL_syssensor.h" /> <ClInclude Include="..\..\src\sensor\SDL_syssensor.h" />
<ClInclude Include="..\..\src\thread\SDL_thread_c.h" /> <ClInclude Include="..\..\src\thread\SDL_thread_c.h" />
<ClInclude Include="..\..\src\thread\generic\SDL_syscond_c.h" /> <ClInclude Include="..\..\src\thread\generic\SDL_syscond_c.h" />
<ClInclude Include="..\..\src\thread\windows\SDL_sysmutex_c.h" />
<ClInclude Include="..\..\src\thread\windows\SDL_systhread_c.h" /> <ClInclude Include="..\..\src\thread\windows\SDL_systhread_c.h" />
<ClInclude Include="..\..\src\timer\SDL_timer_c.h" /> <ClInclude Include="..\..\src\timer\SDL_timer_c.h" />
<ClInclude Include="..\..\src\video\dummy\SDL_nullevents_c.h" /> <ClInclude Include="..\..\src\video\dummy\SDL_nullevents_c.h" />

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@ -393,6 +393,9 @@
<ClInclude Include="..\..\src\thread\generic\SDL_syscond_c.h"> <ClInclude Include="..\..\src\thread\generic\SDL_syscond_c.h">
<Filter>Source Files</Filter> <Filter>Source Files</Filter>
</ClInclude> </ClInclude>
<ClInclude Include="..\..\src\thread\windows\SDL_sysmutex_c.h">
<Filter>Source Files</Filter>
</ClInclude>
<ClInclude Include="..\..\src\thread\windows\SDL_systhread_c.h"> <ClInclude Include="..\..\src\thread\windows\SDL_systhread_c.h">
<Filter>Source Files</Filter> <Filter>Source Files</Filter>
</ClInclude> </ClInclude>

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@ -360,6 +360,7 @@
<ClInclude Include="..\..\src\thread\SDL_systhread.h" /> <ClInclude Include="..\..\src\thread\SDL_systhread.h" />
<ClInclude Include="..\..\src\thread\SDL_thread_c.h" /> <ClInclude Include="..\..\src\thread\SDL_thread_c.h" />
<ClInclude Include="..\..\src\thread\generic\SDL_syscond_c.h" /> <ClInclude Include="..\..\src\thread\generic\SDL_syscond_c.h" />
<ClInclude Include="..\..\src\thread\windows\SDL_sysmutex_c.h" />
<ClInclude Include="..\..\src\thread\windows\SDL_systhread_c.h" /> <ClInclude Include="..\..\src\thread\windows\SDL_systhread_c.h" />
<ClInclude Include="..\..\src\timer\SDL_timer_c.h" /> <ClInclude Include="..\..\src\timer\SDL_timer_c.h" />
<ClInclude Include="..\..\src\video\dummy\SDL_nullevents_c.h" /> <ClInclude Include="..\..\src\video\dummy\SDL_nullevents_c.h" />

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@ -302,6 +302,7 @@
<ClInclude Include="..\..\src\thread\SDL_systhread.h" /> <ClInclude Include="..\..\src\thread\SDL_systhread.h" />
<ClInclude Include="..\..\src\thread\SDL_thread_c.h" /> <ClInclude Include="..\..\src\thread\SDL_thread_c.h" />
<ClInclude Include="..\..\src\thread\generic\SDL_syscond_c.h" /> <ClInclude Include="..\..\src\thread\generic\SDL_syscond_c.h" />
<ClInclude Include="..\..\src\thread\windows\SDL_sysmutex_c.h" />
<ClInclude Include="..\..\src\thread\windows\SDL_systhread_c.h" /> <ClInclude Include="..\..\src\thread\windows\SDL_systhread_c.h" />
<ClInclude Include="..\..\src\timer\SDL_timer_c.h" /> <ClInclude Include="..\..\src\timer\SDL_timer_c.h" />
<ClInclude Include="..\..\src\video\dummy\SDL_nullevents_c.h" /> <ClInclude Include="..\..\src\video\dummy\SDL_nullevents_c.h" />

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@ -1202,6 +1202,9 @@ extern "C" {
* They offer better performance, allocate no kernel ressources and * They offer better performance, allocate no kernel ressources and
* use less memory. SDL will fall back to Critical Sections on older * use less memory. SDL will fall back to Critical Sections on older
* OS versions or if forced to by this hint. * OS versions or if forced to by this hint.
* This also affects Condition Variables. When SRW mutexes are used,
* SDL will use Windows Condition Variables as well. Else, a generic
* SDL_cond implementation will be used that works with all mutexes.
* *
* This variable can be set to the following values: * This variable can be set to the following values:
* "0" - Use SRW Locks when available. If not, fall back to Critical Sections. (default) * "0" - Use SRW Locks when available. If not, fall back to Critical Sections. (default)

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@ -24,6 +24,7 @@
#include "SDL_thread.h" #include "SDL_thread.h"
#include "../generic/SDL_syscond_c.h" #include "../generic/SDL_syscond_c.h"
#include "SDL_sysmutex_c.h"
typedef SDL_cond * (*pfnSDL_CreateCond)(void); typedef SDL_cond * (*pfnSDL_CreateCond)(void);
typedef void (*pfnSDL_DestroyCond)(SDL_cond *); typedef void (*pfnSDL_DestroyCond)(SDL_cond *);
@ -45,6 +46,136 @@ typedef struct SDL_cond_impl_t
/* Implementation will be chosen at runtime based on available Kernel features */ /* Implementation will be chosen at runtime based on available Kernel features */
static SDL_cond_impl_t SDL_cond_impl_active = {0}; static SDL_cond_impl_t SDL_cond_impl_active = {0};
/**
* Native Windows Condition Variable (SRW Locks)
*/
#ifndef CONDITION_VARIABLE_INIT
#define CONDITION_VARIABLE_INIT {0}
typedef struct CONDITION_VARIABLE {
PVOID Ptr;
} CONDITION_VARIABLE, *PCONDITION_VARIABLE;
#endif
#if __WINRT__
#define pWakeConditionVariable WakeConditionVariable
#define pWakeAllConditionVariable WakeAllConditionVariable
#define pSleepConditionVariableSRW SleepConditionVariableSRW
#else
typedef VOID(WINAPI *pfnWakeConditionVariable)(PCONDITION_VARIABLE);
typedef VOID(WINAPI *pfnWakeAllConditionVariable)(PCONDITION_VARIABLE);
typedef BOOL(WINAPI *pfnSleepConditionVariableSRW)(PCONDITION_VARIABLE, PSRWLOCK, DWORD, ULONG);
static pfnWakeConditionVariable pWakeConditionVariable = NULL;
static pfnWakeAllConditionVariable pWakeAllConditionVariable = NULL;
static pfnSleepConditionVariableSRW pSleepConditionVariableSRW = NULL;
#endif
typedef struct SDL_cond_srw
{
CONDITION_VARIABLE cond;
} SDL_cond_srw;
static SDL_cond *
SDL_CreateCond_srw(void)
{
SDL_cond_srw *cond;
/* Relies on CONDITION_VARIABLE_INIT == 0. */
cond = (SDL_cond_srw *) SDL_calloc(1, sizeof(*cond));
if (!cond) {
SDL_OutOfMemory();
}
return (SDL_cond *)cond;
}
static void
SDL_DestroyCond_srw(SDL_cond * cond)
{
if (cond) {
/* There are no kernel allocated resources */
SDL_free(cond);
}
}
static int
SDL_CondSignal_srw(SDL_cond * _cond)
{
SDL_cond_srw *cond = (SDL_cond_srw *)_cond;
if (!cond) {
return SDL_SetError("Passed a NULL condition variable");
}
pWakeConditionVariable(&cond->cond);
return 0;
}
static int
SDL_CondBroadcast_srw(SDL_cond * _cond)
{
SDL_cond_srw *cond = (SDL_cond_srw *)_cond;
if (!cond) {
return SDL_SetError("Passed a NULL condition variable");
}
pWakeAllConditionVariable(&cond->cond);
return 0;
}
static int
SDL_CondWaitTimeout_srw(SDL_cond * _cond, SDL_mutex * _mutex, Uint32 ms)
{
SDL_cond_srw *cond = (SDL_cond_srw *)_cond;
SDL_mutex_srw *mutex = (SDL_mutex_srw *)_mutex;
DWORD timeout;
if (!cond) {
return SDL_SetError("Passed a NULL condition variable");
}
if (!mutex) {
return SDL_SetError("Passed a NULL mutex");
}
if (mutex->count != 1) {
return SDL_SetError("Passed mutex is not locked or locked recursively");
}
if (ms == SDL_MUTEX_MAXWAIT) {
timeout = INFINITE;
} else {
timeout = (DWORD) ms;
}
if (pSleepConditionVariableSRW(&cond->cond, &mutex->srw, timeout, 0) == FALSE) {
if (GetLastError() == ERROR_TIMEOUT) {
return SDL_MUTEX_TIMEDOUT;
}
return SDL_SetError("SleepConditionVariableSRW() failed");
}
return 0;
}
static int
SDL_CondWait_srw(SDL_cond * cond, SDL_mutex * mutex) {
return SDL_CondWaitTimeout_srw(cond, mutex, SDL_MUTEX_MAXWAIT);
}
static const SDL_cond_impl_t SDL_cond_impl_srw =
{
&SDL_CreateCond_srw,
&SDL_DestroyCond_srw,
&SDL_CondSignal_srw,
&SDL_CondBroadcast_srw,
&SDL_CondWait_srw,
&SDL_CondWaitTimeout_srw,
};
/** /**
* Generic Condition Variable implementation using SDL_mutex and SDL_sem * Generic Condition Variable implementation using SDL_mutex and SDL_sem
*/ */
@ -64,7 +195,43 @@ SDL_cond *
SDL_CreateCond(void) SDL_CreateCond(void)
{ {
if (SDL_cond_impl_active.Create == NULL) { if (SDL_cond_impl_active.Create == NULL) {
SDL_memcpy(&SDL_cond_impl_active, &SDL_cond_impl_generic, sizeof(SDL_cond_impl_active)); /* Default to generic implementation, works with all mutex implementations */
const SDL_cond_impl_t * impl = &SDL_cond_impl_generic;
if (SDL_mutex_impl_active.Type == SDL_MUTEX_INVALID) {
/* The mutex implementation isn't decided yet, trigger it */
SDL_mutex *mutex = SDL_CreateMutex();
if (!mutex) {
return NULL;
}
SDL_DestroyMutex(mutex);
SDL_assert(SDL_mutex_impl_active.Type != SDL_MUTEX_INVALID);
}
/* It is required SRW Locks are used */
if (SDL_mutex_impl_active.Type == SDL_MUTEX_SRW) {
#if __WINRT__
/* Link statically on this platform */
impl = &SDL_cond_impl_srw;
#else
HMODULE kernel32 = GetModuleHandleW(L"kernel32.dll");
if (kernel32) {
pWakeConditionVariable = (pfnWakeConditionVariable) GetProcAddress(kernel32, "WakeConditionVariable");
pWakeAllConditionVariable = (pfnWakeAllConditionVariable) GetProcAddress(kernel32, "WakeAllConditionVariable");
pSleepConditionVariableSRW = (pfnSleepConditionVariableSRW) GetProcAddress(kernel32, "SleepConditionVariableSRW");
if (pWakeConditionVariable && pWakeAllConditionVariable && pSleepConditionVariableSRW) {
/* Use the Windows provided API */
impl = &SDL_cond_impl_srw;
}
}
if (!(kernel32 && pWakeConditionVariable && pWakeAllConditionVariable && pSleepConditionVariableSRW)) {
SDL_LogWarn(SDL_LOG_CATEGORY_SYSTEM, "Could not load required imports for SRW Condition Variables although SRW Locks are used!");
}
#endif
}
SDL_memcpy(&SDL_cond_impl_active, impl, sizeof(SDL_cond_impl_active));
} }
return SDL_cond_impl_active.Create(); return SDL_cond_impl_active.Create();
} }

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@ -31,41 +31,19 @@
*/ */
#include "../../core/windows/SDL_windows.h"
#include "SDL_hints.h" #include "SDL_hints.h"
#include "SDL_mutex.h"
typedef SDL_mutex * (*pfnSDL_CreateMutex)(void); #include "SDL_sysmutex_c.h"
typedef int (*pfnSDL_LockMutex)(SDL_mutex *);
typedef int (*pfnSDL_TryLockMutex)(SDL_mutex *);
typedef int (*pfnSDL_UnlockMutex)(SDL_mutex *);
typedef void (*pfnSDL_DestroyMutex)(SDL_mutex *);
typedef struct SDL_mutex_impl_t
{
pfnSDL_CreateMutex Create;
pfnSDL_DestroyMutex Destroy;
pfnSDL_LockMutex Lock;
pfnSDL_TryLockMutex TryLock;
pfnSDL_UnlockMutex Unlock;
} SDL_mutex_impl_t;
/* Implementation will be chosen at runtime based on available Kernel features */ /* Implementation will be chosen at runtime based on available Kernel features */
static SDL_mutex_impl_t SDL_mutex_impl_active = {0}; SDL_mutex_impl_t SDL_mutex_impl_active = {0};
/** /**
* Implementation based on Slim Reader/Writer (SRW) Locks for Win 7 and newer. * Implementation based on Slim Reader/Writer (SRW) Locks for Win 7 and newer.
*/ */
#ifndef SRWLOCK_INIT
#define SRWLOCK_INIT {0}
typedef struct _SRWLOCK {
PVOID Ptr;
} SRWLOCK, *PSRWLOCK;
#endif
#if __WINRT__ #if __WINRT__
/* Functions are guaranteed to be available */ /* Functions are guaranteed to be available */
#define pReleaseSRWLockExclusive ReleaseSRWLockExclusive #define pReleaseSRWLockExclusive ReleaseSRWLockExclusive
@ -80,14 +58,6 @@ static pfnAcquireSRWLockExclusive pAcquireSRWLockExclusive = NULL;
static pfnTryAcquireSRWLockExclusive pTryAcquireSRWLockExclusive = NULL; static pfnTryAcquireSRWLockExclusive pTryAcquireSRWLockExclusive = NULL;
#endif #endif
typedef struct SDL_mutex_srw
{
SRWLOCK srw;
/* SRW Locks are not recursive, that has to be handled by SDL: */
DWORD count;
DWORD owner;
} SDL_mutex_srw;
static SDL_mutex * static SDL_mutex *
SDL_CreateMutex_srw(void) SDL_CreateMutex_srw(void)
{ {
@ -189,6 +159,7 @@ static const SDL_mutex_impl_t SDL_mutex_impl_srw =
&SDL_LockMutex_srw, &SDL_LockMutex_srw,
&SDL_TryLockMutex_srw, &SDL_TryLockMutex_srw,
&SDL_UnlockMutex_srw, &SDL_UnlockMutex_srw,
SDL_MUTEX_SRW,
}; };
@ -283,6 +254,7 @@ static const SDL_mutex_impl_t SDL_mutex_impl_cs =
&SDL_LockMutex_cs, &SDL_LockMutex_cs,
&SDL_TryLockMutex_cs, &SDL_TryLockMutex_cs,
&SDL_UnlockMutex_cs, &SDL_UnlockMutex_cs,
SDL_MUTEX_CS,
}; };

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@ -0,0 +1,69 @@
/*
Simple DirectMedia Layer
Copyright (C) 1997-2020 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 "../../core/windows/SDL_windows.h"
#include "SDL_mutex.h"
typedef SDL_mutex * (*pfnSDL_CreateMutex)(void);
typedef int (*pfnSDL_LockMutex)(SDL_mutex *);
typedef int (*pfnSDL_TryLockMutex)(SDL_mutex *);
typedef int (*pfnSDL_UnlockMutex)(SDL_mutex *);
typedef void (*pfnSDL_DestroyMutex)(SDL_mutex *);
typedef enum
{
SDL_MUTEX_INVALID = 0,
SDL_MUTEX_SRW,
SDL_MUTEX_CS,
} SDL_MutexType;
typedef struct SDL_mutex_impl_t
{
pfnSDL_CreateMutex Create;
pfnSDL_DestroyMutex Destroy;
pfnSDL_LockMutex Lock;
pfnSDL_TryLockMutex TryLock;
pfnSDL_UnlockMutex Unlock;
/* Needed by SDL_cond: */
SDL_MutexType Type;
} SDL_mutex_impl_t;
extern SDL_mutex_impl_t SDL_mutex_impl_active;
#ifndef SRWLOCK_INIT
#define SRWLOCK_INIT {0}
typedef struct _SRWLOCK {
PVOID Ptr;
} SRWLOCK, *PSRWLOCK;
#endif
typedef struct SDL_mutex_srw
{
SRWLOCK srw;
/* SRW Locks are not recursive, that has to be handled by SDL: */
DWORD count;
DWORD owner;
} SDL_mutex_srw;
/* vi: set ts=4 sw=4 expandtab: */