Most of these are probably harmless, but the changes to SDL_immdevice.c and SDL_pixels.c appear to have fixed genuine bugs.
SDL_audiocvt.c: By separating the calculation of the divisor, I got rid of the suspicion that dividing a double by an integer led to loss of precision.
SDL_immdevice.c: Added a missing test, one that could have otherwise led to dereferencing a null pointer.
SDL_events.c, SDL_gamecontroller.c, SDL_joystick.c, SDL_malloc.c, SDL_video.c: Made it clear the return values weren't used.
SDL_hidapi_shield.c: The size is zero, so nothing bad would have happened, but the SDL_memset() was still being given an address outside of the array's range.
SDL_dinputjoystick.c: Initialize local data, just in case IDirectInputDevice8_GetProperty() isn't guaranteed to write to it.
SDL_render_sw.c: drawstate.viewport could be null (as seen on line 691).
SDL.c: SDL_MostSignificantBitIndex32() could return -1, though I don't know if you want to cope with that (what I did) or SDL_assert() that it can't happen.
SDL_hints.c: Replaced boolean tests on pointer values with comparisons to NULL.
SDL_pixels.c: Looks like the switch is genuinely missing a break!
SDL_rect_impl.h: The MacOS static checker pointed out issues with the X comparisons that were handled by assertions; I added assertions for the Y comparisons.
SDL_yuv.c, SDL_windowskeyboard.c, SDL_windowswindow.c: Checked error-result returns.
- SDL_EventQ.active is a bool variable -> do not use SDL_AtomicGet/Set, it does not help in any way
- protect SDL_EventQ.active with SDL_EventQ.lock
- set SDL_EventQ.active to FALSE by default
SDL_events_need_periodic_poll() and SDL_events_need_polling() are intended to allow the event loop to update joysticks and/or sensors if needed, however those systems only update when the SDL_update_joysticks and/or SDL_update_sensors variables are true. This change brings the behavior of these functions in line with if work will actually need to be performed.
This change allows the hints for AUTO_UPDATE to influence the polling behavior of the event loop such that an app can choose to update joysticks/sensors itself and avoid the expense of constantly sleeping and waking the event loop. Additionally in makes these functions marginally faster in some situations by not searching the active events.
Hint callbacks are called before the actual value in the hint is changed, so the functions SDL_AutoUpdateJoysticksChanged and SDL_AutoUpdateSensorsChanged were not actually properly updating their respective variables in repsonse to their auto update hint changing.
Instead, we pull the new hint value out of the value passed into the callback and use that to update the variables. Assume true on a null value as that was the previous behavior and it matches with the default values of SDL_update_joysticks/SDL_update_sensors.
This reverts commit c477768e6f.
We want to add the sentinel anytime we pump inside SDL_WaitEventTimeout() to avoid pumping again the next time through, as a performance optimization.
We don't want to catch explicit SDL_PumpEvents() calls by the application with
our polling check to avoid stale data. If the call to SDL_PumpEvents() produced
no events, there will be a sentinel sitting in the queue that will cause
SDL_PollEvent() to immediately return 0 next time it is called.
Our SDL_WaitEventTimeout() implementation avoids this issue by always popping
an event after calling SDL_PumpEvents(). This will remove the new sentinel if
we didn't get any new events.
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.
* Avoid unnecessary SDL_PumpEvents calls in SDL_WaitEventTimeout
* Add a sentinel event to avoid infinite poll loops
* Move SDL_POLLSENTINEL to new internal event category
* Tweak documentation to indicate SDL_PumpEvents isn't always called
* Avoid shadowing event variable
* Ignore poll sentinel if more (user) events have been added after
Co-authored-by: Sam Lantinga <slouken@libsdl.org>
Instead do an absolute elapsed time check since the start of the wait. If that is exceeded during any iteration the routine exits as the timeout has elapsed.
There were a few places throughout the SDL code where values were
clamped using SDL_min() and SDL_max(). Now that we have an SDL_clamp()
macro, use this instead.
Not only is it more efficient to batch process pending events, it is
necessary for correctness with the Win32 backend. WIN_PumpEvents() runs
periodic updates of the cursor clip region and disambiguation of
left and right shift keys in addition to standard event processing.
We can be in a situation where we receive a win32 hook callback on the same
thread that is currently waiting. In that case, we do still need to trigger
a wakeup when an event is pushed because the hook itself won't necessarily
do that (depending on what we return from the hook).
When possible use native os functions to make a blocking call waiting for
an incoming event. Previous behavior was to continuously poll the event
queue with a small delay between each poll.
The blocking call uses a new optional video driver event,
WaitEventTimeout, if available. It is called only if an window
already shown is available. If present the window is designated
using the variable wakeup_window to receive a wakeup event if
needed.
The WaitEventTimeout function accept a timeout parameter. If
positive the call will wait for an event or return if the timeout
expired without any event. If the timeout is zero it will
implement a polling behavior. If the timeout is negative the
function will block indefinetely waiting for an event.
To let the main thread sees events sent form a different thread
a "wake-up" signal is sent to the main thread if the main thread
is in a blocking state. The wake-up event is sent to the designated
wakeup_window if present.
The wake-up event is sent only if the PushEvent call is coming
from a different thread. Before sending the wake-up event
the ID of the thread making the blocking call is saved using the
variable blocking_thread_id and it is compared to the current
thread's id to decide if the wake-up event should be sent.
Two new optional video device methods are introduced:
WaitEventTimeout
SendWakeupEvent
in addition the mutex
wakeup_lock
which is defined and initialized but only for the drivers supporting the
methods above.
If the methods are not present the system behaves as previously
performing a periodic polling of the events queue.
The blocking call is disabled if a joystick or sensor is detected
and falls back to previous behavior.
Sylvain
ulatekh
pionere
diddily
chalonverse
Cameron Gutman
Susko3
Sam Lantinga
Brick
David Gow
Francesco Abbate
Ryan C. Gordon