* Fix -Wundef warnings due to use of unguarded SDL_LOADSO_DISABLED
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DRIVER_WINDOWS
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DRIVER_ANDROID
* Fix -Wundef warnings due to use of unguarded SDL_LOADSO_DUMMY
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DRIVER_COCOA
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DRIVER_UIKIT
* Fix -Wundef warnings due to use of unguarded SDL_TIMERS_DISABLED
* Fix -Wundef warnings due to use of unguarded SDL_EVENTS_DISABLED
* Fix -Wundef warnings due to use of unguarded SDL_TIMER_DUMMY
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DISABLED
* Fix -Wundef warnings due to use of unguarded SDL_AUDIO_DISABLED
* Fix -Wundef warnings due to use of unguarded SDL_JOYSTICK_DISABLED
* Fix -Wundef warnings due to use of unguarded SDL_HAPTIC_DISABLED
* Fix -Wundef warnings due to use of unguarded SDL_SENSOR_DISABLED
* Fix -Wundef warnings due to use of unguarded __ANDROID__
* Fix -Wundef warnings due to use of unguarded __IOS__
* Fix -Wundef warnings due to use of unguarded EMULATE_CAS
* Fix -Wundef warnings due to use of unguarded SDL_ATOMIC_DISABLED
* Fix -Wundef warnings due to use of unguarded SDL_THREADS_DISABLED
* Fix -Wundef warnings due to use of unguarded SDL_AUDIO_DRIVER_SNDIO
* Fix -Wundef warnings due to use of unguarded SDL_AUDIO_DRIVER_NETBSD
* Fix -Wundef warnings due to use of unguarded SDL_AUDIO_DRIVER_WASAPI
* Fix -Wundef warnings due to use of unguarded SDL_AUDIO_DRIVER_DSOUND
* Fix -Wundef warnings due to use of unguarded SDL_AUDIO_DRIVER_HAIKU
* Fix -Wundef warnings due to use of unguarded SDL_AUDIO_DRIVER_COREAUDIO
* Fix -Wundef warnings due to use of unguarded SDL_AUDIO_DRIVER_AAUDIO
* Fix -Wundef warnings due to use of unguarded SDL_AUDIO_DRIVER_OPENSLES
* Fix -Wundef warnings due to use of unguarded SDL_AUDIO_DRIVER_ANDROID
* Fix -Wundef warnings due to use of unguarded SDL_AUDIO_DRIVER_PS2
* Fix -Wundef warnings due to use of unguarded SDL_AUDIO_DRIVER_PSP
* Fix -Wundef warnings due to use of unguarded SDL_AUDIO_DRIVER_VITA
* Fix -Wundef warnings due to use of unguarded SDL_AUDIO_DRIVER_N3DS
* Fix -Wundef warnings due to use of unguarded SDL_AUDIO_DRIVER_EMSCRIPTEN
* Fix -Wundef warnings due to use of unguarded SDL_NEON_INTRINSICS
* Fix -Wundef warnings due to use of unguarded SDL_ALTIVEC_BLITTERS
* Fix -Wundef warnings due to use of unguarded __VITA__
* Fix -Wundef warnings due to use of unguarded __3DS__
* Fix -Wundef warnings due to use of unguarded SDL_DYNAPI_PROC_NO_VARARGS
* Fix -Wundef warnings due to use of unguarded __APPLE__
* Fix -Wundef warnings due to use of unguarded __WINRT__
* Fix -Wundef warnings due to use of unguarded SDL_HIDAPI_DISABLED
* Fix -Wundef warnings due to use of unguarded __TVOS__
* Fix -Wundef warnings due to use of unguarded HAVE_DRIVER_BACKEND
* Fix -Wundef warnings due to use of unguarded SDL_JOYSTICK_XINPUT
* Fix -Wundef warnings due to use of unguarded SDL_JOYSTICK_WGI
* Fix -Wundef warnings due to use of unguarded SDL_JOYSTICK_DINPUT
* Fix -Wundef warnings due to use of unguarded SDL_JOYSTICK_MFI
* Fix -Wundef warnings due to use of unguarded SDL_JOYSTICK_EMSCRIPTEN
* Fix -Wundef warnings due to use of unguarded SDL_JOYSTICK_PS2
* Fix -Wundef warnings due to use of unguarded SDL_JOYSTICK_PSP
* Fix -Wundef warnings due to use of unguarded SDL_JOYSTICK_VITA
* Fix -Wundef warnings due to use of unguarded SDL_JOYSTICK_N3DS
* Fix -Wundef warnings due to use of unguarded __MACOS__
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_RENDER_D3D
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DRIVER_WINRT
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DRIVER_RPI
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_VITA_PVR_OGL
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DRIVER_VIVANTE
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_RENDER_D3D11
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_RENDER_D3D12
* Fix -Wundef warnings due to use of unguarded SDL_RENDER_DISABLED
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_RENDER_METAL
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_RENDER_PS2
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_RENDER_PSP
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_RENDER_VITA_GXM
* Fix -Wundef warnings due to use of unguarded SDL_ARM_SIMD_BLITTERS
* Fix -Wundef warnings due to use of unguarded SDL_ARM_NEON_BLITTERS
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DRIVER_HAIKU
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DRIVER_PS2
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DRIVER_PSP
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DRIVER_VITA
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DRIVER_N3DS
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DRIVER_KMSDRM
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DRIVER_RISCOS
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DRIVER_EMSCRIPTEN
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DRIVER_NGAGE
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_METAL
* Fix -Wundef warnings due to use of unguarded SDL_LSX_INTRINSICS
* Fix -Wundef warnings due to use of unguarded HAVE_PTHREAD_NP_H
* Fix -Wundef warnings due to use of unguarded __RISCOS__
* Fix -Wundef warnings due to use of unguarded FAKE_RECURSIVE_MUTEX
* Fix -Wundef warnings due to use of unguarded USE_POSIX_SPAWN
* textureData is only needed when SDL is built with YUV support
* Fix -Wundef warnings due to use of unguarded SDL_AUDIO_DRIVER_ALSA
* Fix -Wundef warnings due to use of unguarded SDL_SSE3_INTRINSICS
* Fix -Wundef warnings due to use of unguarded SDL_SSE4_2_INTRINSICS
* Fix -Wundef warnings due to use of unguarded SDL_SSE4_1_INTRINSICS
* Fix -Wundef warnings due to use of unguarded SDL_AVX512F_INTRINSICS
* Fix -Wundef warnings due to use of unguarded SDL_SSE2_INTRINSICS
* Fix -Wundef warnings due to use of unguarded SDL_AVX_INTRINSICS
* Fix -Wundef warnings due to use of unguarded SDL_AVX2_INTRINSICS
* Fix -Wundef warnings due to use of unguarded SDL_SSE_INTRINSICS
* Fix -Wundef warnings due to use of unguarded SDL_MMX_INTRINSICS
* Fix -Wundef warnings due to use of unguarded HAVE_CLOCK_GETTIME
* Fix -Wundef warnings due to use of unguarded SDL_AUDIO_DRIVER_DISK
* Fix -Wundef warnings due to use of unguarded SDL_AUDIO_DRIVER_DUMMY
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DRIVER_DUMMY
* Fix -Wundef warnings due to use of unguarded HAVE_GCC_ATOMICS
* Fix -Wundef warnings due to use of unguarded HAVE_GCC_SYNC_LOCK_TEST_AND_SET
* Fix -Wundef warnings due to use of unguarded SDL_USE_LIBDBUS
* Fix -Wundef warnings due to use of unguarded SDL_AUDIO_DRIVER_JACK
* Fix -Wundef warnings due to use of unguarded SDL_JOYSTICK_VIRTUAL
* Fix -Wundef warnings due to use of unguarded SDL_JOYSTICK_LINUX
* Fix -Wundef warnings due to use of unguarded HAVE_LIBC
* Fix -Wundef warnings due to disabling SDL_LIBC
* Fix -Wundef warnings due to use of unguarded HAVE_PLATFORM_BACKEND
* Fix -Wundef warnings due to use of unguarded DEBUG
* Fix -Wundef warnings due to use of unguarded HAVE_LINUX_INPUT_H
* Fix -Werror=unused-variable when building with SDL_LIBC=OFF
* Fix -Wundef warnings due to use of unguqrded SDL_USE_LIBUDEV
* Use SDL alloc functions in libusb/hid.c
* Fix -Wundef warnings due to use of unguarded HAVE_LIBUDEV_H
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_VULKAN
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DRIVER_OFFSCREEN
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_RENDER_OGL
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_OPENGL
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_OPENGL_GLX
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_OPENGL_ES
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_OPENGL_ES2
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_RENDER_OGL_ES2
* Fix -Wundef warnings due to use of unguarded SDL_AUDIO_DRIVER_OSS
* Remove SDL_AUDIO_DRIVER_SUNAUDIO reference since it is never set
* Fix -Wundef warnings due to use of unguarded SDL_AUDIO_DRIVER_PIPEWIRE
* Fix -Wundef warnings due to use of unguarded SDL_AUDIO_DRIVER_PULSEAUDIO
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DRIVER_X11_XCURSOR
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DRIVER_X11_XDBE
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DRIVER_X11_XFIXES
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DRIVER_X11_XINPUT2
* Fix -Wundef warnings due to use of unguarded #if SDL_VIDEO_DRIVER_X11_XINPUT2_SUPPORTS_MULTITOUCH
* Fix -Wundef warnings due to use of unguarded #if SDL_VIDEO_DRIVER_X11_XRANDR
* Fix -Wundef warnings due to use of unguarded #if SDL_VIDEO_DRIVER_X11_XSCRNSAVER
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DRIVER_X11_XSHAPE
* Don't call XShape functions when XShape is diabled
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DRIVER_WAYLAND
* Fix -Wundef warnings due to use of unuarded SDL_VIDEO_DRIVER_X11
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DRIVER_RISCOS
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_OPENGL_EGL
* Disable array when compiled with SDL_EVENTS=OFF
* Fix -Wundef warnings due to use of unguarded SDL_INPUT_LINUXEV
* Fix -Wundef warnings due to use of unguarded SDL_THREAD_PTHREAD
* Fix -Wundef warnings due to use of unguarded SDL_THREAD_WINDOWS
* Fix -Wundef warnings due to use of unguarded SDL_THREAD_PS2
* Fix -Wundef warnings due to use of unguarded SDL_THREAD_PSP
* Fix -Wundef warnings due to use of unguarded SDL_THREAD_VITA
* Fix -Wundef warnings due to use of unguarded SDL_THREAD_N3DS
* Fix -Wundef warnings due to use of unguarded SDL_THREAD_STDCPP
* Fix -Wundef warnings due to use of unguarded SDL_THREAD_NGAGE
* Fix -Wundef warnings due to use of unguarded __WINDOWS__
* Fix -Wundef warnings due to use of unguarded __WINGDK__
* Fix -Wundef warnings due to use of unguarded __ANDROID__
* Fix -Wundef warnings due to use of unguarded SDL_THREAD_GENERIC_COND_SUFFIX
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_VITA_PIB
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_VITA_PVR
* Fix -Wundef warnings due to use of unguarded SDL_FILE_DISABLED
* Fix -Wundef warnings due to use of unguarded __XBOXONE__
* Fix -Wundef warnings due to use of unguarded __XBOXSERIES__
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_OPENGL_WGL
* Fix -Wundef warnings due to use of unguarded SDL_AUDIO_DRIVER_QNX
* Fix -Wundef warnings due to use of unguarded SDL_AUDIO_DRIVER_DISK
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DRIVER_QNX
* Fix -Wundef warnings due to use of unguarded DEBUG_RAZOR
* Fix -Wundef warnings due to use of unguarded WINAPI_FAMILY_PHONE_APP
* Fix -Wundef warnings due to use of unguarded SDL_MAC_NO_SANDBOX
* Fix -Wundef warnings due to use of unguarded __(IPHONE|APPLETV|MAC)_OS_VERSION_MAX_ALLOWED
* Fix C4090 warning ('function': different 'const' qualifiers)
* ci: use -isystem for include dirs of pspdev toolchain
* cmake: add -Wundef option
* Fix remaining -Wundef warnings due to use of unguarded SDL_VIDEO_VULKAN and SDL_VIDEO_METAL
* Fix -Wundef warnings due to use of unguarded __MACOS__
* DEBUG_CONVERT is guaranteed to be defined in src/audio/SDL_audiocvt.c
* Fix -Wundef warnings due to use of unguarded HAVE_NANOSLEEP
* Fix -Wundef warnings due to use of unguarded HAVE_DXGI_H
* Fix -Wundef warnings due to use of unguarded HAVE_LINUX_INPUT_H
* fix SDL_VIDEO_DRIVER_WAYLAND
* fix SDL_VIDEO_DRIVER_X11
* Fix -Wundef warnings due to use of unguarded HAVE_MMDEVICEAPI_H
* Fix -Wundef warnings due to use of unguarded HAVE_PTHREAD_SETNAME_NP
* Fix -Wundef warnings due to use of unguarded HAVE_PTHREAD_SET_NAME_NP
* Fix -Wundef warnings due to use of unguarded HAVE_SETJMP
* Fix -Wundef warnings due to use of unguarded HAVE_SIGNAL_H
* Fix -Wundef warnings due to use of unguarded HAVE_TPCSHRD_H
* Fix -Wundef warnings due to use of unguarded MACOSX_COREAUDIO
* Fix -Wundef warnings due to use of unguarded SDL_HAPTIC_DINPUT
* Fix -Wundef warnings due to use of unguarded SDL_HAPTIC_IOKIT
* Fix -Wundef warnings due to use of unguarded SDL_HAPTIC_XINPUT
* Fix -Wundef warnings due to use of unguarded SDL_IPHONE_KEYBOARD
* Fix -Wundef warnings due to use of unguarded SDL_JOYSTICK_RAWINPUT
* Fix -Wundef warnings due to use of unguarded SDL_POWER_ANDROID
* Fix -Wundef warnings due to use of unguarded SDL_POWER_EMSCRIPTEN
* Fix -Wundef warnings due to use of unguarded SDL_POWER_HAIKU
* Fix -Wundef warnings due to use of unguarded SDL_POWER_LINUX
* Fix -Wundef warnings due to use of unguarded SDL_POWER_MACOSX
* Fix -Wundef warnings due to use of unguarded SDL_POWER_PSP
* Fix -Wundef warnings due to use of unguarded SDL_POWER_UIKIT
* Fix -Wundef warnings due to use of unguarded SDL_POWER_VITA
* Fix -Wundef warnings due to use of unguarded SDL_POWER_WINDOWS
* Fix -Wundef warnings due to use of unguarded SDL_THREAD_PTHREAD_RECURSIVE_MUTEX
* Fix -Wundef warnings due to use of unguarded SDL_THREAD_PTHREAD_RECURSIVE_MUTEX_NP
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DRIVER_VIVANTE_VDK
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DRIVER_WAYLAND
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DRIVER_X11_HAS_XKBKEYCODETOKEYSYM
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DRIVER_X11_SUPPORTS_GENERIC_EVENTS
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_OPENGL_CGL
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_OPENGL_EGL
* Fix -Wundef warnings due to use of unguarded __MACOS__
* Fix -Wundef warnings due to use of unguarded __OpenBSD__
* Fix -Wundef warnings due to use of unguarded __FreeBSD__
* Fix -Wundef warnings due to use of unguarded __MWERKS__
* Fix -Wundef warnings due to use of unguarded __WIN32__
* Fix -Wundef warnings due to use of unguarded SDL_IPHONE_LAUNCHSCREEN
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_OPENGL_ES2
* Remove unused HAVE_CONST, HAVE_INLINE and HAVE_VOLATILE
* Revert "Use SDL alloc functions in libusb/hid.c"
This reverts commit 847c64b00d.
* Handle FAKE_RECURSIVE_MUTEX in similar way as SDL2
* Don't use defined in macro
```
./src/thread/pthread/SDL_syssem.c:140:12: warning: variable 'retval' is used uninitialized whenever 'while' loop exits because its condition is false [-Wsometimes-uninitialized]
while (sem_trywait(&sem->sem) != 0) {
^~~~~~~~~~~~~~~~~~~~~~~~~~~
./src/thread/pthread/SDL_syssem.c:149:12: note: uninitialized use occurs here
return retval;
^~~~~~
./src/thread/pthread/SDL_syssem.c:140:12: note: remove the condition if it is always true
while (sem_trywait(&sem->sem) != 0) {
```
This was a legitimate bug, thank you clang!
Fixes https://github.com/libsdl-org/SDL/issues/6830
The annotations have been added to SDL_mutex.h and have been made public so applications can enable this for their own code.
Clang assumes that locking and unlocking can't fail, but SDL has the concept of a NULL mutex, so the mutex functions have been changed not to report errors if a mutex hasn't been initialized. We do have mutexes that might be accessed when they are NULL, notably in the event system, so this is an important change.
This commit cleans up a bunch of rare race conditions in the joystick and game controller code so now everything should be completely protected by the joystick lock.
To test this, change the compiler to "clang -Wthread-safety -Werror=thread-safety -DSDL_THREAD_SAFETY_ANALYSIS"
I updated .clang-format and ran clang-format 14 over the src and test directories to standardize the code base.
In general I let clang-format have it's way, and added markup to prevent formatting of code that would break or be completely unreadable if formatted.
The script I ran for the src directory is added as build-scripts/clang-format-src.sh
This fixes:
#6592#6593#6594
* Add braces after if conditions
* More add braces after if conditions
* Add braces after while() conditions
* Fix compilation because of macro being modified
* Add braces to for loop
* Add braces after if/goto
* Move comments up
* Remove extra () in the 'return ...;' statements
* More remove extra () in the 'return ...;' statements
* More remove extra () in the 'return ...;' statements after merge
* Fix inconsistent patterns are xxx == NULL vs !xxx
* More "{}" for "if() break;" and "if() continue;"
* More "{}" after if() short statement
* More "{}" after "if () return;" statement
* More fix inconsistent patterns are xxx == NULL vs !xxx
* Revert some modificaion on SDL_RLEaccel.c
* SDL_RLEaccel: no short statement
* Cleanup 'if' where the bracket is in a new line
* Cleanup 'while' where the bracket is in a new line
* Cleanup 'for' where the bracket is in a new line
* Cleanup 'else' where the bracket is in a new line
I ran this script in the include directory:
```sh
sed -i '' -e 's,#include "\(SDL.*\)",#include <SDL3/\1>,' *.h
```
I ran this script in the src directory:
```sh
for i in ../include/SDL3/SDL*.h
do hdr=$(basename $i)
if [ x"$(echo $hdr | egrep 'SDL_main|SDL_name|SDL_test|SDL_syswm|SDL_opengl|SDL_egl|SDL_vulkan')" != x ]; then
find . -type f -exec sed -i '' -e 's,#include "\('$hdr'\)",#include <SDL3/\1>,' {} \;
else
find . -type f -exec sed -i '' -e '/#include "'$hdr'"/d' {} \;
fi
done
```
Fixes https://github.com/libsdl-org/SDL/issues/6575
It's marked as being a public symbol internally, however, it was missing from the header files and not visible in the shared library. This adds it to the necessary headers and to the DynAPI list to expose it for use by applications.
Co-authored-by: Frank Praznik <frank.praznik@oh.rr.com>
- cmake, configure (CheckDLOPEN): --enable-sdl-dlopen is now history..
detach the dl api discovery from SDL_LOADSO_DLOPEN functionality.
define HAVE_DLOPEN. also define DYNAPI_NEEDS_DLOPEN (CheckDLOPEN is
called only for relevant platforms.)
- update SDL_config.in and SDL_config.cmake accordingly.
- SDL_dynapi.h: set SDL_DYNAMIC_API to 0 if DYNAPI_NEEDS_DLOPEN is
defined, but HAVE_DLOPEN is not.
- pthread/SDL_systhread.c: conditionalize dl api use to HAVE_DLOPEN
- SDL_x11opengl.c, SDL_DirectFB_opengl.c, SDL_naclopengles.c: rely
on HAVE_DLOPEN, not SDL_LOADSO_DLOPEN.
- SDL_config_android.h, SDL_config_iphoneos.h, SDL_config_macosx.h,
SDL_config_pandora.h, and SDL_config_wiz.h: define HAVE_DLOPEN.
Closes: https://github.com/libsdl-org/SDL/pull/4351
Drop include of SDL_platform.h as SDL_plaform.h is already included by
SDL_internal.h -> SDL_config.h -> SDL_platform.h
Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
As the name suggests, the hint should only apply to SDL_THREAD_PRIORITY_TIME_CRITICAL
The resulting priorities for my current distro result in these values:
| High | Time Critical
Hint |--------------|-----------------
0 | P=10 N=-10 | P=5 N=-15
1 | P=10 N=-10 | P=-21 N=0
When we request realtime priority from rtkit, we have a rttime limit. If we exceed
that limit, the kernel will send SIGKILL to the process to terminate it.
This isn't something that most high priority processes will want, only processes
that selectively opt into SCHED_RR/FIFO through SDL_HINT_THREAD_PRIORITY_POLICY
should be subject to this level of scrutiny.
This change:
* Switches non-apple posix OSs to use SCHED_OTHER instead of SCHED_RR
for SDL_THREAD_PRIORITY_HIGH/SDL_THREAD_PRIORITY_TIME_CRITICAL.
* Fixes using a hardcoded RLIMIT_RTTIME, instead queries it from rtkit
* Only sets RLIMIT_RTTIME for MakeRealtime rtkit requests
* Adds a note regarding the possible SIGKILL with SDL_HINT_THREAD_PRIORITY_POLICY
* Introduces SDL_HINT_THREAD_FORCE_REALTIME_TIME_CRITICAL to allow apps to acquire realtime scheduling policies on Linux
1. Comment that SDL_SetThreadPriority will make any necessary system changes when applying priority.
2. Add a hint to override SDL's default behavior for scheduler policy.
3. Modify the pthreads SDL_SetThreadPriority so that instead of just using the current thread scheduler policy it will change it to a policy that should work best for the requested priority.
4. Add hint checks in SDL_SetThreadPriority so that #3 can be overridden if desired.
5. Modify the Linux SDL_SetThreadPriority so that in the case that policy, either by SDL defaults or from the hint, is a realtime policy it uses the realtime rtkit API.
6. Prior to calling rtkit on Linux make the necessary thread state changes that rtkit requires. Currently this is done every time as it isn't expected that SDL_SetThreadPriority will be called repeatedly for a thread.
This avoids the need to malloc something extra, use a semaphore, etc, and
fixes Emscripten with pthreads support, which might not spin up a web worker
until after SDL_CreateThread returns and thus can't wait on a semaphore at
this point in any case.
Fixes Bugzilla #5064.
