On 4/6/20 2:39 PM, Sowjanya Komatineni wrote:
On 4/6/20 2:15 PM, Sowjanya Komatineni wrote:
On 4/6/20 2:11 PM, Dmitry Osipenko wrote:
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07.04.2020 00:02, Sowjanya Komatineni пишет:
Am I understanding correctly that this thread will take 100% CPU,
spinning here, if more than 2 frame-captures queued?
on more than 2 frames captures, it breaks thread and on next
wakeup it
continues
The wait_event() won't wait if condition is true.
condition is checked when waitqueue is woken up
https://elixir.bootlin.com/linux/v5.6.2/source/include/linux/wait.h#L462
process is put to sleep until the condition evaluates to true or
signal
is received.
condition is checked each time the waitqueue head is woken up.
This is a wrong assumption in accordance to the code.
process is in sleep until the condition is evaluated and when condition
is true wakeup still happens only when wake_up on waitqueue is called
This is the reason for using this to prevent blocking while waiting for
the buffers.
when every buffer is available as long as we are in streaming, we
should process it.
So if wake up happens when list has buffer, it will be processed but
at a time we limit processing 2 simultaneous buffer capture starts only.
Fixing typo.
I meant when ever buffer is available as long as we are in streaming,
we should process it.
So capture thread processes as long as buffers are available from user
space limiting 2 simultaneous trigger of captures and thread will be
in sleep when capture buffers list is empty or no stop thread is
signaled.
