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  1. 18 Feb, 2009 1 commit
  3. 17 Feb, 2009 6 commits
    • Sam Lantinga's avatar
      Fixed bug #684 · aad9f51b
      Sam Lantinga authored 
      Reworked Pierre's patch a little bit, which added SDL_WaitEventTimeout()

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    • Sam Lantinga's avatar
      indent · a0978cdf
      Sam Lantinga authored 
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    • Sam Lantinga's avatar
      Fixed bug #681 · 90b4c693
      Sam Lantinga authored 
         Description From  Philipp   2009-01-16 20:50:01   (-) [reply]

The File test/README from the svn says this:

    testgl        A very simple example of using OpenGL with SDL
    testgl2        Improved version of testgl

It is actually exchanged.

testgl.c is the improved version right now and testgl2.c the simple one.

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    • Sam Lantinga's avatar
      Date: Thu, 27 Dec 2007 07:38:25 +0000 · 605f1db1
      Sam Lantinga authored 
      From: John Bartholomew
Subject: [SDL] SDL Semaphore implementation broken on Windows?
Hi,

Over the past couple of days, I've been battling with SDL, SDL_Mixer and SMPEG to try to find an audio hang bug.  I believe I've found the problem, which I think is a race condition inside SDL's semaphore implementation (at least the Windows implementation).  The semaphore code uses Windows' built in semaphore functions, but it also maintains a separate count value.  This count value is updated with bare increment and decrement operations in SemPost and SemWaitTimeout - no locking primitives to protect them.

In tracking down the apparent audio bug, I found that at some point a semaphore's count value was being decremented to -1, which is clearly not a valid value for it to take.

I'm still not certain exactly what sequence of operations is occuring for this to happen, but I believe that overall it's a race condition between a thread calling SemPost (which increments the count) and the thread on the other end calling SemWait (which decrements it).

I will try to make a test case to verify this, but I'm not sure if I'll be able to   (threading errors being difficult to reproduce even in the best    circumstances).

However, assuming this is the cause of my problems, there is a very
simple fix:
Windows provides InterlockedIncrement() and InterlockedDecrement()
functions to perform increments and decrements which are guaranteed to be atomic.  So the fix is in thread/win32/SDL_syssem.c: replace occurrences of --sem->count with InterlockedDecrement(&sem->count); and replace occurrences of ++sem->count with InterlockedIncrement(&sem->count);

This is using SDL v1.2.12, built with VC++ 2008 Express, running on a
Core 2 duo processor.

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    • Sam Lantinga's avatar
      Fixed bug #633 · d9d69026
      Sam Lantinga authored 
         Description From  Michael Stone   2008-09-25 19:27:29   (-) [reply]

To determine whether a pid is occupied with the kill(pid, 0) idiom, you have to
test

#include <signal.h>
#include <errno.h>
kill(pid, 0) < 0 && errno == ESRCH

not just

#include <signal.h>
kill(pid, 0) < 0

otherwise you get incorrect results when pid is running as a different user
(causing kill(pid, 0) to return -1 + EPERM).

src/audio/alsa/SDL_alsa_audio.c is certainly affected by this bug in both
1.2.13 and 1.3-trunk. It probably occurs in other places as well.

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    • Sam Lantinga's avatar
      Fixed bug #537 · d2e9f851
      Sam Lantinga authored 
      Description From  esigra   2008-01-07 16:20:21   (-) [reply]

I try to get a clean compile for a project using SDL. But I get warnings
from SDL headers when I use -Wold-style-cast. This is especially bad
because I plan to build the software with -Werror=old-style-cast when we
have switched over to GCC 4.2, which has that option.

But this problem can be fixed in the SDL headers. I checked out the SVN
version and made some patches. See the attached patch.

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  5. 15 Feb, 2009 1 commit
  7. 14 Feb, 2009 2 commits
  9. 12 Feb, 2009 1 commit
  11. 09 Feb, 2009 6 commits
  13. 08 Feb, 2009 1 commit
  15. 07 Feb, 2009 2 commits
  17. 30 Jan, 2009 2 commits
  19. 29 Jan, 2009 1 commit
    • Sam Lantinga's avatar
      · 9bb60da0
      Sam Lantinga authored 
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  21. 25 Jan, 2009 1 commit
  23. 19 Jan, 2009 4 commits
  25. 18 Jan, 2009 1 commit
  27. 15 Jan, 2009 1 commit
  29. 14 Jan, 2009 4 commits
  31. 13 Jan, 2009 6 commits