Ian Abbott
I just spotted what I think is a bug in "src/thread/pthread/SDL_sysmutex.c" in the SDL_TryLockMutex function when FAKE_RECURSIVE_MUTEX is defined (for an implementation of Pthreads with no recursive mutex support). It calls pthread_mutex_lock instead of pthread_mutex_trylock, so it will block until the mutex is available instead of returning SDL_MUTEX_TIMEDOUT if it cannot lock the mutex immediately.
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.
Sylvain
When using API 21 and running on an old device (android < 5.0 ?) some function are missing.
functions are (at least) : signal, sigemptyset, atof, stpcpy (strcat and strcpy), srand, rand.
Very few modifications on SDL to get this working :
on SDL
======
Undefine android configuration :
HAVE_SIGNAL
HAVE_SIGACTION
HAVE_ATOF
In "SDL_systrhead.c", comment out the few block of lines with "sigemptyset".
Android.mk:
remove the compilation of "test" directory because it contains a few rand/srand calls
Also, there are more discussions about this in internet :
https://groups.google.com/forum/#!topic/android-ndk/RjO9WmG9pfEhttp://stackoverflow.com/questions/25475055/android-ndk-load-library-cannot-locate-srand
Ozkan Sezer
pthread/SDL_syssem.c requires _GNU_SOURCE predefined (like SDL_sysmutex.c),
otherwise sem_timedwait() prototype might not be available to it. Problem
seen with glibc-2.3.4.
Haiku uses most of the standard pthread API, with a few #ifdefs where we
still need to fallback onto the old BeOS APIs.
BeOS, however, does not support pthreads (or maybe doesn't support it well),
so I'm unplugging support for the platform with this changeset. Be Inc went
out of business in 2001.
SDL_syssem.c:159 comparison of unsigned expression >= 0 is always true
Solved by comparing unsigneds directly
SDL_systimer.c:164: warning: control may reach end of Compile
Solved by returning the default value if all else fails.
SDL_androidgl.c:41:1: warning: type specifier missing, defaults to 'int'
SDL_androidgl.c:47:1: warning: control reaches end of non-void function
Solved by adding void return type to the function implementation
* Added a destructor to clean up TLS memory at thread shutdown
* Refactored the TLS code to have platform independent code and a small platform dependent core with a fallback to generic code if platform dependent functions fail.
* Fixed recursion issues with SDL_GetErrBuf()
This lets us change things like this...
if (Failed) {
SDL_SetError("We failed");
return -1;
}
...into this...
if (Failed) {
return SDL_SetError("We failed");
}
Fixes Bugzilla #1778.
