Commit 2443e51e0e410c729a43172d9766ce6dc03423f7

Joel Linn 2020-12-28T11:42:49

Add optional suffix `_generic` to generic SDL_cond impl Allows for runtime selectable implementation

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diff --git a/CMakeLists.txt b/CMakeLists.txt
index 7a29d0f..42a1a04 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1512,13 +1512,15 @@ elseif(WINDOWS)
   endif()
 
   if(SDL_THREADS)
+    set(SDL_THREAD_GENERIC_COND_SUFFIX 1)
     set(SDL_THREAD_WINDOWS 1)
     set(SOURCE_FILES ${SOURCE_FILES}
+      ${SDL2_SOURCE_DIR}/src/thread/generic/SDL_syscond.c
+      ${SDL2_SOURCE_DIR}/src/thread/windows/SDL_syscond_srw.c
       ${SDL2_SOURCE_DIR}/src/thread/windows/SDL_sysmutex.c
       ${SDL2_SOURCE_DIR}/src/thread/windows/SDL_syssem.c
       ${SDL2_SOURCE_DIR}/src/thread/windows/SDL_systhread.c
-      ${SDL2_SOURCE_DIR}/src/thread/windows/SDL_systls.c
-      ${SDL2_SOURCE_DIR}/src/thread/generic/SDL_syscond.c)
+      ${SDL2_SOURCE_DIR}/src/thread/windows/SDL_systls.c)
     set(HAVE_SDL_THREADS TRUE)
   endif()
 
diff --git a/VisualC-WinRT/WinPhone81_VS2013/SDL-WinPhone81.vcxproj b/VisualC-WinRT/WinPhone81_VS2013/SDL-WinPhone81.vcxproj
index b36d4f1..d684c8e 100644
--- a/VisualC-WinRT/WinPhone81_VS2013/SDL-WinPhone81.vcxproj
+++ b/VisualC-WinRT/WinPhone81_VS2013/SDL-WinPhone81.vcxproj
@@ -132,6 +132,7 @@
     <ClInclude Include="..\..\src\sensor\SDL_syssensor.h" />
     <ClInclude Include="..\..\src\thread\SDL_systhread.h" />
     <ClInclude Include="..\..\src\thread\SDL_thread_c.h" />
+    <ClInclude Include="..\..\src\thread\generic\SDL_syscond_c.h" />
     <ClInclude Include="..\..\src\thread\windows\SDL_systhread_c.h" />
     <ClInclude Include="..\..\src\timer\SDL_timer_c.h" />
     <ClInclude Include="..\..\src\video\dummy\SDL_nullevents_c.h" />
@@ -269,6 +270,7 @@
     <ClCompile Include="..\..\src\stdlib\SDL_strtokr.c" />
     <ClCompile Include="..\..\src\thread\generic\SDL_syscond.c" />
     <ClCompile Include="..\..\src\thread\SDL_thread.c" />
+    <ClCompile Include="..\..\src\thread\windows\SDL_syscond_srw.c" />
     <ClCompile Include="..\..\src\thread\windows\SDL_sysmutex.c" />
     <ClCompile Include="..\..\src\thread\windows\SDL_syssem.c" />
     <ClCompile Include="..\..\src\thread\windows\SDL_systhread.c" />
diff --git a/VisualC-WinRT/WinPhone81_VS2013/SDL-WinPhone81.vcxproj.filters b/VisualC-WinRT/WinPhone81_VS2013/SDL-WinPhone81.vcxproj.filters
index a7fe1a6..0019ae0 100644
--- a/VisualC-WinRT/WinPhone81_VS2013/SDL-WinPhone81.vcxproj.filters
+++ b/VisualC-WinRT/WinPhone81_VS2013/SDL-WinPhone81.vcxproj.filters
@@ -381,6 +381,9 @@
     <ClInclude Include="..\..\src\joystick\windows\SDL_xinputjoystick_c.h">
       <Filter>Source Files</Filter>
     </ClInclude>
+    <ClInclude Include="..\..\src\thread\generic\SDL_syscond_c.h">
+      <Filter>Source Files</Filter>
+    </ClInclude>
     <ClInclude Include="..\..\src\thread\windows\SDL_systhread_c.h">
       <Filter>Source Files</Filter>
     </ClInclude>
@@ -716,6 +719,9 @@
     <ClCompile Include="..\..\src\joystick\windows\SDL_xinputjoystick.c">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="..\..\src\thread\windows\SDL_syscond_srw.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
     <ClCompile Include="..\..\src\thread\windows\SDL_sysmutex.c">
       <Filter>Source Files</Filter>
     </ClCompile>
diff --git a/VisualC-WinRT/WinRT81_VS2013/SDL-WinRT81.vcxproj b/VisualC-WinRT/WinRT81_VS2013/SDL-WinRT81.vcxproj
index 9e4fbe7..3d756ce 100644
--- a/VisualC-WinRT/WinRT81_VS2013/SDL-WinRT81.vcxproj
+++ b/VisualC-WinRT/WinRT81_VS2013/SDL-WinRT81.vcxproj
@@ -146,6 +146,7 @@
     <ClInclude Include="..\..\src\sensor\SDL_sensor_c.h" />
     <ClInclude Include="..\..\src\sensor\SDL_syssensor.h" />
     <ClInclude Include="..\..\src\thread\SDL_thread_c.h" />
+    <ClInclude Include="..\..\src\thread\generic\SDL_syscond_c.h" />
     <ClInclude Include="..\..\src\thread\windows\SDL_systhread_c.h" />
     <ClInclude Include="..\..\src\timer\SDL_timer_c.h" />
     <ClInclude Include="..\..\src\video\dummy\SDL_nullevents_c.h" />
@@ -303,6 +304,7 @@
     <ClCompile Include="..\..\src\stdlib\SDL_strtokr.c" />
     <ClCompile Include="..\..\src\thread\generic\SDL_syscond.c" />
     <ClCompile Include="..\..\src\thread\SDL_thread.c" />
+    <ClCompile Include="..\..\src\thread\windows\SDL_syscond_srw.c" />
     <ClCompile Include="..\..\src\thread\windows\SDL_sysmutex.c" />
     <ClCompile Include="..\..\src\thread\windows\SDL_syssem.c" />
     <ClCompile Include="..\..\src\thread\windows\SDL_systhread.c" />
diff --git a/VisualC-WinRT/WinRT81_VS2013/SDL-WinRT81.vcxproj.filters b/VisualC-WinRT/WinRT81_VS2013/SDL-WinRT81.vcxproj.filters
index b4dfc75..aa52d8a 100644
--- a/VisualC-WinRT/WinRT81_VS2013/SDL-WinRT81.vcxproj.filters
+++ b/VisualC-WinRT/WinRT81_VS2013/SDL-WinRT81.vcxproj.filters
@@ -390,6 +390,9 @@
     <ClInclude Include="..\..\src\joystick\windows\SDL_dinputjoystick_c.h">
       <Filter>Source Files</Filter>
     </ClInclude>
+    <ClInclude Include="..\..\src\thread\generic\SDL_syscond_c.h">
+      <Filter>Source Files</Filter>
+    </ClInclude>
     <ClInclude Include="..\..\src\thread\windows\SDL_systhread_c.h">
       <Filter>Source Files</Filter>
     </ClInclude>
@@ -743,6 +746,9 @@
     <ClCompile Include="..\..\src\joystick\windows\SDL_dinputjoystick.c">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="..\..\src\thread\windows\SDL_syscond_srw.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
     <ClCompile Include="..\..\src\thread\windows\SDL_sysmutex.c">
       <Filter>Source Files</Filter>
     </ClCompile>
diff --git a/VisualC/SDL/SDL.vcxproj b/VisualC/SDL/SDL.vcxproj
index 0e8b293..c573953 100644
--- a/VisualC/SDL/SDL.vcxproj
+++ b/VisualC/SDL/SDL.vcxproj
@@ -359,6 +359,7 @@
     <ClInclude Include="..\..\src\sensor\windows\SDL_windowssensor.h" />
     <ClInclude Include="..\..\src\thread\SDL_systhread.h" />
     <ClInclude Include="..\..\src\thread\SDL_thread_c.h" />
+    <ClInclude Include="..\..\src\thread\generic\SDL_syscond_c.h" />
     <ClInclude Include="..\..\src\thread\windows\SDL_systhread_c.h" />
     <ClInclude Include="..\..\src\timer\SDL_timer_c.h" />
     <ClInclude Include="..\..\src\video\dummy\SDL_nullevents_c.h" />
@@ -512,6 +513,7 @@
     <ClCompile Include="..\..\src\stdlib\SDL_strtokr.c" />
     <ClCompile Include="..\..\src\thread\generic\SDL_syscond.c" />
     <ClCompile Include="..\..\src\thread\SDL_thread.c" />
+    <ClCompile Include="..\..\src\thread\windows\SDL_syscond_srw.c" />
     <ClCompile Include="..\..\src\thread\windows\SDL_sysmutex.c" />
     <ClCompile Include="..\..\src\thread\windows\SDL_syssem.c" />
     <ClCompile Include="..\..\src\thread\windows\SDL_systhread.c" />
diff --git a/VisualC/SDL/SDL.vcxproj.filters b/VisualC/SDL/SDL.vcxproj.filters
index f14a8b5..d7cddb1 100644
--- a/VisualC/SDL/SDL.vcxproj.filters
+++ b/VisualC/SDL/SDL.vcxproj.filters
@@ -301,6 +301,7 @@
     <ClInclude Include="..\..\src\sensor\windows\SDL_windowssensor.h" />
     <ClInclude Include="..\..\src\thread\SDL_systhread.h" />
     <ClInclude Include="..\..\src\thread\SDL_thread_c.h" />
+    <ClInclude Include="..\..\src\thread\generic\SDL_syscond_c.h" />
     <ClInclude Include="..\..\src\thread\windows\SDL_systhread_c.h" />
     <ClInclude Include="..\..\src\timer\SDL_timer_c.h" />
     <ClInclude Include="..\..\src\video\dummy\SDL_nullevents_c.h" />
@@ -456,6 +457,7 @@
     <ClCompile Include="..\..\src\stdlib\SDL_strtokr.c" />
     <ClCompile Include="..\..\src\thread\generic\SDL_syscond.c" />
     <ClCompile Include="..\..\src\thread\SDL_thread.c" />
+    <ClCompile Include="..\..\src\thread\windows\SDL_syscond_srw.c" />
     <ClCompile Include="..\..\src\thread\windows\SDL_sysmutex.c" />
     <ClCompile Include="..\..\src\thread\windows\SDL_syssem.c" />
     <ClCompile Include="..\..\src\thread\windows\SDL_systhread.c" />
diff --git a/configure.ac b/configure.ac
index 379f6cf..79e7835 100644
--- a/configure.ac
+++ b/configure.ac
@@ -3869,6 +3869,7 @@ AS_HELP_STRING([--enable-render-d3d], [enable the Direct3D render driver [[defau
         fi
         # Set up files for the thread library
         if test x$enable_threads = xyes; then
+            AC_DEFINE(SDL_THREAD_GENERIC_COND_SUFFIX, 1, [])
             AC_DEFINE(SDL_THREAD_WINDOWS, 1, [ ])
             SOURCES="$SOURCES $srcdir/src/thread/windows/*.c"
             SOURCES="$SOURCES $srcdir/src/thread/generic/SDL_syscond.c"
diff --git a/include/SDL_config.h.cmake b/include/SDL_config.h.cmake
index e3aae65..f9b1090 100644
--- a/include/SDL_config.h.cmake
+++ b/include/SDL_config.h.cmake
@@ -330,6 +330,7 @@
 #cmakedefine SDL_LOADSO_WINDOWS @SDL_LOADSO_WINDOWS@
 
 /* Enable various threading systems */
+#cmakedefine SDL_THREAD_GENERIC_COND_SUFFIX @SDL_THREAD_GENERIC_COND_SUFFIX@
 #cmakedefine SDL_THREAD_PTHREAD @SDL_THREAD_PTHREAD@
 #cmakedefine SDL_THREAD_PTHREAD_RECURSIVE_MUTEX @SDL_THREAD_PTHREAD_RECURSIVE_MUTEX@
 #cmakedefine SDL_THREAD_PTHREAD_RECURSIVE_MUTEX_NP @SDL_THREAD_PTHREAD_RECURSIVE_MUTEX_NP@
diff --git a/include/SDL_config.h.in b/include/SDL_config.h.in
index 07b94f4..88af73c 100644
--- a/include/SDL_config.h.in
+++ b/include/SDL_config.h.in
@@ -331,6 +331,7 @@
 #undef SDL_LOADSO_WINDOWS
 
 /* Enable various threading systems */
+#undef SDL_THREAD_GENERIC_COND_SUFFIX
 #undef SDL_THREAD_PTHREAD
 #undef SDL_THREAD_PTHREAD_RECURSIVE_MUTEX
 #undef SDL_THREAD_PTHREAD_RECURSIVE_MUTEX_NP
diff --git a/include/SDL_config_windows.h b/include/SDL_config_windows.h
index 5190148..0eaef90 100644
--- a/include/SDL_config_windows.h
+++ b/include/SDL_config_windows.h
@@ -237,6 +237,7 @@ typedef unsigned int uintptr_t;
 #define SDL_LOADSO_WINDOWS  1
 
 /* Enable various threading systems */
+#define SDL_THREAD_GENERIC_COND_SUFFIX 1
 #define SDL_THREAD_WINDOWS  1
 
 /* Enable various timer systems */
diff --git a/include/SDL_config_winrt.h b/include/SDL_config_winrt.h
index 2144b79..a00185a 100644
--- a/include/SDL_config_winrt.h
+++ b/include/SDL_config_winrt.h
@@ -212,6 +212,7 @@ typedef unsigned int uintptr_t;
 
 /* Enable various threading systems */
 #if (NTDDI_VERSION >= NTDDI_WINBLUE)
+#define SDL_THREAD_GENERIC_COND_SUFFIX 1
 #define SDL_THREAD_WINDOWS  1
 #else
 /* WinRT on Windows 8.0 and Windows Phone 8.0 don't support CreateThread() */
diff --git a/src/thread/generic/SDL_syscond.c b/src/thread/generic/SDL_syscond.c
index 5cd9745..0e31c2d 100644
--- a/src/thread/generic/SDL_syscond.c
+++ b/src/thread/generic/SDL_syscond.c
@@ -28,41 +28,57 @@
 
 #include "SDL_thread.h"
 
-struct SDL_cond
+#include "../generic/SDL_syscond_c.h"
+
+/* If two implementations are to be compiled into SDL (the active one
+ * will be chosen at runtime), the function names need to be
+ * suffixed
+ */
+#if !SDL_THREAD_GENERIC_COND_SUFFIX
+#define SDL_CreateCond_generic      SDL_CreateCond
+#define SDL_DestroyCond_generic     SDL_DestroyCond
+#define SDL_CondSignal_generic      SDL_CondSignal
+#define SDL_CondBroadcast_generic   SDL_CondBroadcast
+#define SDL_CondWait_generic        SDL_CondWait
+#define SDL_CondWaitTimeout_generic SDL_CondWaitTimeout
+#endif
+
+typedef struct SDL_cond_generic
 {
     SDL_mutex *lock;
     int waiting;
     int signals;
     SDL_sem *wait_sem;
     SDL_sem *wait_done;
-};
+} SDL_cond_generic;
 
 /* Create a condition variable */
 SDL_cond *
-SDL_CreateCond(void)
+SDL_CreateCond_generic(void)
 {
-    SDL_cond *cond;
+    SDL_cond_generic *cond;
 
-    cond = (SDL_cond *) SDL_malloc(sizeof(SDL_cond));
+    cond = (SDL_cond_generic *) SDL_malloc(sizeof(SDL_cond_generic));
     if (cond) {
         cond->lock = SDL_CreateMutex();
         cond->wait_sem = SDL_CreateSemaphore(0);
         cond->wait_done = SDL_CreateSemaphore(0);
         cond->waiting = cond->signals = 0;
         if (!cond->lock || !cond->wait_sem || !cond->wait_done) {
-            SDL_DestroyCond(cond);
+            SDL_DestroyCond_generic((SDL_cond *)cond);
             cond = NULL;
         }
     } else {
         SDL_OutOfMemory();
     }
-    return (cond);
+    return (SDL_cond *)cond;
 }
 
 /* Destroy a condition variable */
 void
-SDL_DestroyCond(SDL_cond * cond)
+SDL_DestroyCond_generic(SDL_cond * _cond)
 {
+    SDL_cond_generic *cond = (SDL_cond_generic *)_cond;
     if (cond) {
         if (cond->wait_sem) {
             SDL_DestroySemaphore(cond->wait_sem);
@@ -79,8 +95,9 @@ SDL_DestroyCond(SDL_cond * cond)
 
 /* Restart one of the threads that are waiting on the condition variable */
 int
-SDL_CondSignal(SDL_cond * cond)
+SDL_CondSignal_generic(SDL_cond * _cond)
 {
+    SDL_cond_generic *cond = (SDL_cond_generic *)_cond;
     if (!cond) {
         return SDL_SetError("Passed a NULL condition variable");
     }
@@ -103,8 +120,9 @@ SDL_CondSignal(SDL_cond * cond)
 
 /* Restart all threads that are waiting on the condition variable */
 int
-SDL_CondBroadcast(SDL_cond * cond)
+SDL_CondBroadcast_generic(SDL_cond * _cond)
 {
+    SDL_cond_generic *cond = (SDL_cond_generic *)_cond;
     if (!cond) {
         return SDL_SetError("Passed a NULL condition variable");
     }
@@ -157,8 +175,9 @@ Thread B:
     SDL_UnlockMutex(lock);
  */
 int
-SDL_CondWaitTimeout(SDL_cond * cond, SDL_mutex * mutex, Uint32 ms)
+SDL_CondWaitTimeout_generic(SDL_cond * _cond, SDL_mutex * mutex, Uint32 ms)
 {
+    SDL_cond_generic *cond = (SDL_cond_generic *)_cond;
     int retval;
 
     if (!cond) {
@@ -212,9 +231,9 @@ SDL_CondWaitTimeout(SDL_cond * cond, SDL_mutex * mutex, Uint32 ms)
 
 /* Wait on the condition variable forever */
 int
-SDL_CondWait(SDL_cond * cond, SDL_mutex * mutex)
+SDL_CondWait_generic(SDL_cond * cond, SDL_mutex * mutex)
 {
-    return SDL_CondWaitTimeout(cond, mutex, SDL_MUTEX_MAXWAIT);
+    return SDL_CondWaitTimeout_generic(cond, mutex, SDL_MUTEX_MAXWAIT);
 }
 
 /* vi: set ts=4 sw=4 expandtab: */
diff --git a/src/thread/generic/SDL_syscond_c.h b/src/thread/generic/SDL_syscond_c.h
new file mode 100644
index 0000000..a6f368c
--- /dev/null
+++ b/src/thread/generic/SDL_syscond_c.h
@@ -0,0 +1,42 @@
+/*
+  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 "SDL_thread.h"
+
+#ifndef SDL_syscond_generic_h_
+#define SDL_syscond_generic_h_
+
+#if SDL_THREAD_GENERIC_COND_SUFFIX
+
+SDL_cond * SDL_CreateCond_generic(void);
+void SDL_DestroyCond_generic(SDL_cond * cond);
+int SDL_CondSignal_generic(SDL_cond * cond);
+int SDL_CondBroadcast_generic(SDL_cond * cond);
+int SDL_CondWait_generic(SDL_cond * cond, SDL_mutex * mutex);
+int SDL_CondWaitTimeout_generic(SDL_cond * cond,
+                                SDL_mutex * mutex, Uint32 ms);
+
+#endif /* SDL_THREAD_GENERIC_COND_SUFFIX */
+
+#endif /* SDL_syscond_generic_h_ */
+
+/* vi: set ts=4 sw=4 expandtab: */
diff --git a/src/thread/windows/SDL_syscond_srw.c b/src/thread/windows/SDL_syscond_srw.c
new file mode 100644
index 0000000..ef8c802
--- /dev/null
+++ b/src/thread/windows/SDL_syscond_srw.c
@@ -0,0 +1,102 @@
+/*
+  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 "SDL_hints.h"
+#include "SDL_thread.h"
+
+#include "../generic/SDL_syscond_c.h"
+
+typedef SDL_cond * (*pfnSDL_CreateCond)(void);
+typedef void (*pfnSDL_DestroyCond)(SDL_cond *);
+typedef int (*pfnSDL_CondSignal)(SDL_cond *);
+typedef int (*pfnSDL_CondBroadcast)(SDL_cond *);
+typedef int (*pfnSDL_CondWait)(SDL_cond *, SDL_mutex *);
+typedef int (*pfnSDL_CondWaitTimeout)(SDL_cond *, SDL_mutex *, Uint32);
+
+typedef struct SDL_cond_impl_t
+{
+    pfnSDL_CreateCond       Create;
+    pfnSDL_DestroyCond      Destroy;
+    pfnSDL_CondSignal       Signal;
+    pfnSDL_CondBroadcast    Broadcast;
+    pfnSDL_CondWait         Wait;
+    pfnSDL_CondWaitTimeout  WaitTimeout;
+} SDL_cond_impl_t;
+
+/* Implementation will be chosen at runtime based on available Kernel features */
+static SDL_cond_impl_t SDL_cond_impl_active = {0};
+
+/**
+ * Generic Condition Variable implementation using SDL_mutex and SDL_sem
+ */
+
+static const SDL_cond_impl_t SDL_cond_impl_generic =
+{
+    &SDL_CreateCond_generic,
+    &SDL_DestroyCond_generic,
+    &SDL_CondSignal_generic,
+    &SDL_CondBroadcast_generic,
+    &SDL_CondWait_generic,
+    &SDL_CondWaitTimeout_generic,
+};
+
+
+SDL_cond *
+SDL_CreateCond(void)
+{
+    if (SDL_cond_impl_active.Create == NULL) {
+        SDL_memcpy(&SDL_cond_impl_active, &SDL_cond_impl_generic, sizeof(SDL_cond_impl_active));
+    }
+    return SDL_cond_impl_active.Create();
+}
+
+void
+SDL_DestroyCond(SDL_cond * cond)
+{
+    SDL_cond_impl_active.Destroy(cond);
+}
+
+int
+SDL_CondSignal(SDL_cond * cond)
+{
+    return SDL_cond_impl_active.Signal(cond);
+}
+
+int
+SDL_CondBroadcast(SDL_cond * cond)
+{
+    return SDL_cond_impl_active.Broadcast(cond);
+}
+
+int
+SDL_CondWaitTimeout(SDL_cond * cond, SDL_mutex * mutex, Uint32 ms)
+{
+    return SDL_cond_impl_active.WaitTimeout(cond, mutex, ms);
+}
+
+int
+SDL_CondWait(SDL_cond * cond, SDL_mutex * mutex)
+{
+    return SDL_cond_impl_active.Wait(cond, mutex);
+}
+
+/* vi: set ts=4 sw=4 expandtab: */