Sam Lantinga 8077bf3d10 Fixed bug 2618 - incomplete pthread-based lock support should be removed
binarycrusader

Since changeset 358696c354a8, SDL 2.0 has been broken on Solaris when compiling with the Solaris Studio compiler (which uses the pthread implementation of SDL_AtomicLock).

Notably, it gets stuck at the MemoryBarrierRelease in SDL_GetErrBuf:

6585 # 218
6586     if (!tls_errbuf && !tls_being_created) {
6587          SDL_AtomicLock_REAL ( & tls_lock );
6588         if (!tls_errbuf) {
6589             SDL_TLSID slot;
6590             tls_being_created = SDL_TRUE;
6591             slot =  SDL_TLSCreate_REAL ( );
6592             tls_being_created = SDL_FALSE;
6593              { SDL_SpinLock _tmp = 0 ; SDL_AtomicLock_REAL ( & _tmp ) ; SDL_AtomicUnlock_REAL ( & _tmp ) ; };
^^^ loops forever above
6594             tls_errbuf = slot;
6595         }
6596          SDL_AtomicUnlock_REAL ( & tls_lock );
6597     }


Running: testthread
(process id 28926)
^Cdbx: warning: Interrupt ignored but forwarded to child.
signal INT (Interrupt) in __nanosleep at 0xfe52a875
0xfe52a875: __nanosleep+0x0015: jae      __nanosleep+0x23   [ 0xfe52a883, .+0xe ]
Current function is SDL_Delay_REAL
  204           was_error = nanosleep(&tv, &elapsed);
(dbx) where
  [1] __nanosleep(0xfeffe848, 0xfeffe850, 0xfe75a5ac, 0xfe5169d8), at 0xfe52a875
  [2] nanosleep(0xfeffe848, 0xfeffe850), at 0xfe516a3b
=>[3] SDL_Delay_REAL(ms = 0), line 204 in "SDL_systimer.c"
  [4] SDL_AtomicLock_REAL(lock = 0xfeffe88c), line 104 in "SDL_spinlock.c"
  [5] SDL_GetErrBuf(), line 225 in "SDL_thread.c"
  [6] SDL_ClearError_REAL(), line 216 in "SDL_error.c"
  [7] SDL_InitSubSystem_REAL(flags = 0), line 116 in "SDL.c"
  [8] SDL_Init_REAL(flags = 0), line 244 in "SDL.c"
  [9] SDL_Init(a = 0), line 89 in "SDL_dynapi_procs.h"
  [10] main(argc = 1, argv = 0xfeffe948), line 65 in "testthread.c"

As far as I can tell, this is because pthread_spin_trylock() always returns EBUSY for this particular lock; since it works in other places, I'm suspicious.

Different Solaris Studio compiler versions seem to make no difference.

I've verified this is broken on Linux as well if SDL_spinlock.c is modified to use the pthread implementation.

This appears to be because pthread_spin_init() and pthread_spin_destroy() are not used with the locks as required.
2014-07-07 21:27:42 -07:00

                         Simple DirectMedia Layer

                                  (SDL)

                                Version 2.0

---
http://www.libsdl.org/

Simple DirectMedia Layer is a cross-platform development library designed
to provide low level access to audio, keyboard, mouse, joystick, and graphics
hardware via OpenGL and Direct3D. It is used by video playback software,
emulators, and popular games including Valve's award winning catalog
and many Humble Bundle games.

SDL officially supports Windows, Mac OS X, Linux, iOS, and Android.
Support for other platforms may be found in the source code.

SDL is written in C, works natively with C++, and there are bindings 
available for several other languages, including C# and Python.

This library is distributed under the zlib license, which can be found
in the file "COPYING.txt".

The best way to learn how to use SDL is to check out the header files in
the "include" subdirectory and the programs in the "test" subdirectory.
The header files and test programs are well commented and always up to date.
More documentation and FAQs are available online at:
	http://wiki.libsdl.org/

If you need help with the library, or just want to discuss SDL related
issues, you can join the developers mailing list:
	http://www.libsdl.org/mailing-list.php

If you want to report bugs or contribute patches, please submit them to
bugzilla:
    http://bugzilla.libsdl.org/

Enjoy!
	Sam Lantinga				(slouken@libsdl.org)

Description
Simple Directmedia Layer
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