afwlehmann
Sorry for re-opening, but it turns out that the current interval is indeed not updated. I've just checked the source code of the 2.0.3 release again:
163 if (current->canceled) {
164 interval = 0;
165 } else {
166 interval = current->callback(current->interval, current->param);
167 }
168
169 if (interval > 0) {
170 /* Reschedule this timer */
171 current->interval = interval; // <-- this line is missing
172 current->scheduled = tick + interval;
173 SDL_AddTimerInternal(data, current);
174 } else {
According to the documentation: "The callback function is passed the current timer interval and the user supplied parameter from the SDL_AddTimer() call and returns the next timer interval. If the returned value from the callback is 0, the timer is canceled."
If I understand the text correctly, then the current interval should in fact be updated according to the returned value. Otherwise there would be a discrepancy between the next time for which the timer is actually re-scheduled and the value that's passed to the callback once the timer fires again.
This could be fixed by adding line #171.
This allows us to set an explicit stack size (overriding the system default
and the global hint an app might have set), and remove all the macro salsa
for dealing with _beginthreadex and such, as internal threads always set those
to NULL anyhow.
I've taken some guesses on reasonable (and tiny!) stack sizes for our
internal threads, but some of these might turn out to be too small in
practice and need an increase. Most of them are simple functions, though.
It's a long-dead platform, and we don't have any way to build for, test, or
maintain it, so there's no sense in doing acrobatics to support it.
If you need Windows CE support, use SDL 1.2. If you need Windows Phone support,
send SDL 2.0 patches for the newer Windows Mobile platform.
The new timer model is formalized as using a separate thread to handle timer callbacks. This was the case on almost every platform before, but it's now a requirement, and simplifies the implementation and makes it perform consistently across platforms.
Goals:
* Minimize timer thread blocking
* Dispatch timers as accurately as possible
* SDL_AddTimer() and SDL_RemoveTimer() are completely threadsafe
* SDL_RemoveTimer() doesn't crash with a timer that's expired or removed
The thread ID is an unsigned long so it can hold pthread_t so people can do naughty things with it.
I'm going to be adding additional useful thread API functions, but this should prevent crashes in people's existing code on 64-bit architectures.
FIXME:
Change #include <stdlib.h> to #include "SDL_stdlib.h"
Change #include <string.h> to #include "SDL_string.h"
Make sure nothing else broke because of this...
To: sdl@libsdl.org
Date: Sat, 9 Jul 2005 13:59:33 -0400
Subject: [PATCH] fix locking in src/timer/SYS_timer.c
SDL_SetTimer has a typo in CVS. This code was added since 1.2.8. The
result is that the SDL_timer_mutex is locked twice and never unlocked,
breaking systems that use a threaded timer implementation.
-jim
* SDL_timer_running wasn't always updated correctly.
* Fixed occasional crash in SDL_SetTimer() when clearing threaded timers
* It was possible to get both the timer thread and event thread running
* Other misc. cleanup
