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.
Michael Sartain
This is a quick pass at adding Linux RealtimeKit thread priority support to SDL.
It allows me to bump the thread priority to high without root privileges or setting any caps, etc.
rtkit readme here:
http://git.0pointer.net/rtkit.git/tree/README
Most pthread functions return 0 on success and non-zero on error, but those
errors might be positive or negative, so checking for return values in the
Unix style, where errors are less than zero, is a bug.
Fixes Bugzilla #4039.
SDL now builds with gcc 7.2 with the following command line options:
-Wall -pedantic-errors -Wno-deprecated-declarations -Wno-overlength-strings --std=c99
Sylvain
After a long time, I found out more clearly what was going wrong.
The native libraries should be built with a "APP_PLATFORM" as low as possible.
Ideally, APP_PLATFORM should be equals to the minSdkVersion of the AndroidManifest.xml
So that the application never runs on a lower APP_PLATFORM than it has been built for.
An additional good patch would be to write explicitly in "jni/Application.mk": APP_PLATFORM=android-10
(If no APP_PLATFORM is set, the "targetSdkVersion" of the AndroidManifest.xml is applied as an APP_PLATFORM to the native libraries. And currently, this is bad, because targetSdkVersion is 12, whereas minSdkLevel is 10.
And in fact, there is a warning from ndk: "Android NDK: WARNING: APP_PLATFORM android-12 is larger than android:minSdkVersion 10 in ./AndroidManifest.xml".)
to precise what happened in the initial reported test-case:
Let say the "c" code contains a call to "srand()".
with APP_PLATFORM=android-21, libSDL2.so contains a undef reference to "srand()".
with APP_PLATFORM=android-10, libSDL2.so contains a undef reference to "srand48()".
but srand() is missing on devices with APP_PLATFORM=android-10 (it was in fact replaced by srand48()).
So, if you build for android-21 (where srand() is available), you will really have a call to "srand()" and it will fail on android-10.
That was the issue. The path tried to fix this by in fact always calling srand48().
SDL patches that were applied are beneficial anyway, there are implicitly allowing they backward compatibility of using android-21 on a android-10 platform.
It can be helpful in case you want to target a higher APP_PLATFORM than minSdkVersion to have potentially access to more functions.
Eg you want to have access to GLES3 functions (or other) of "android-21". But, if dlopen() fails (on android-10), you do a fall-back to GLES2.
The internal function SDL_EGL_LoadLibrary() did not delete and remove a mostly
uninitialized data structure if loading the library first failed. A later try to
use EGL then skipped initialization and assumed it was previously successful
because the data structure now already existed. This led to at least one crash
in the internal function SDL_EGL_ChooseConfig() because a NULL pointer was
dereferenced to make a call to eglBindAPI().
