Note that this removes the timeGetTime() fallback on Windows; it is a
32-bit counter and SDL2 should never choose to use it, as it only is needed
if QueryPerformanceCounter() isn't available, and QPC is _always_ available
on Windows XP and later.
OS/2 has a similar situation, but since it isn't clear to me that similar
promises can be made about DosTmrQueryTime() even in modern times, I decided
to leave the fallback in, with some heroic measures added to try to provide a
true 64-bit tick counter despite the 49-day wraparound. That approach can
migrate to Windows too, if we discover some truly broken install that doesn't
have QPC and still depends on timeGetTime().
Fixes#4870.
Add a new flag to avoid suppressing EINTR in SDL_IOReady(). Pass the
flag in WaitEventTimeout() to ensure that a SIGINT will wake up
SDL_WaitEvent() without another event coming in.
SDL_config.h *can* define SDL_JOYSTICK_WGI. On builds with the Windows
10 SDK available, this allow implementing trigger rumbling on Xbox One
controllers. The files included in the Visual Studio Solution in
VisualC\SDL.sln *do* have this define set.
fix#4859
Even without the thread, it'll do an initial hardware detection at startup,
but there won't be any further hotplug events after that. But for many cases,
that is likely complete sufficient.
In either case, this cleaned up the code to no longer need a semaphore at
startup.
Fixes#4862.
We can have spurious wakeups in WaitEventTimeout() due to Wayland events
that don't end up causing us to generate an SDL event. Fortunately for us,
SDL_WaitEventTimeout_Device() handles this situation properly by calling
WaitEventTimeout() again with an adjusted timeout.
This will let us automate this so it's managed for us, and as things go
from development to official releases, the documentation will automatically
update!
There are two issues which are stopping the SDL tests from building on
my machine:
- libunwind is not being linked
- Even if it is, it is missing several symbols.
The first is fixed by having the test programs link against libunwind if
available. Technically, SDL2_test should be linking against it, as it's
used in SDL_test_memory.c, but as SDL2_test is a static library, it
can't itself import libunwind. We just assume that if it's present on
the system, we should link it directly to the test programs. This should
strictly be an improvement, as the only case where this'd fail is if
SDL2 was compiled when libunwind was present, but the tests are being
compiled without it, and that'd fail anyway.
The second is fixed by #define-ing UNW_LOCAL_ONLY before including
libunwind.h: this is required to make libunwind link to predicatable
symbols, in what can only be described as a bit of a farce. There are a
few more details in the libunwind man page, but the gist of it is that
it disables support for "remote unwinding": unwinding stack frames in a
different process (and possibly from a different architecture?):
http://www.nongnu.org/libunwind/man/libunwind(3).html
Note that I haven't tried this with CMake: I suspect that it'll work,
though, as the CMakeLists.txt seems to have SDL2 link against libunwind if
it's present. This adds an ugly extra dependency to SDL2, but does mean
that issue 1 isn't present. The UNW_LOCAL_ONLY change shouldn't be
build-system-specific.
Wayland provides the prepare_read()/read_events() family of APIs for
reading from the display fd in a deadlock-free manner across multiple
threads in a multi-threaded application. Let's use those instead of
trying to roll our own solution using a mutex.
This fixes an issue where a call to SDL_GL_SwapWindow() doesn't swap
buffers if it happens to collide with SDL_PumpEvents() in the main
thread. It also allows coexistence with other code or toolkits in
our process that may want read and dispatch events themselves.