From bf3dbaece91e7f9be00923a225a62a918bf71f5b Mon Sep 17 00:00:00 2001 From: Tomi Valkeinen Date: Fri, 19 Aug 2022 14:16:15 +0300 Subject: py: Switch to non-blocking eventfd Blocking wait can be easily implemented on top in Python, so rather than supporting only blocking reads, or supporting both non-blocking and blocking reads, let's support only non-blocking reads. Signed-off-by: Tomi Valkeinen Reviewed-by: Laurent Pinchart Signed-off-by: Laurent Pinchart --- src/py/examples/simple-cam.py | 5 +++-- src/py/examples/simple-capture.py | 12 ++++++++++-- src/py/examples/simple-continuous-capture.py | 5 +++-- 3 files changed, 16 insertions(+), 6 deletions(-) (limited to 'src/py/examples') diff --git a/src/py/examples/simple-cam.py b/src/py/examples/simple-cam.py index 2b81bb65..b3e97ca7 100755 --- a/src/py/examples/simple-cam.py +++ b/src/py/examples/simple-cam.py @@ -19,8 +19,9 @@ TIMEOUT_SEC = 3 def handle_camera_event(cm): - # cm.get_ready_requests() will not block here, as we know there is an event - # to read. + # cm.get_ready_requests() returns the ready requests, which in our case + # should almost always return a single Request, but in some cases there + # could be multiple or none. reqs = cm.get_ready_requests() diff --git a/src/py/examples/simple-capture.py b/src/py/examples/simple-capture.py index a6a9b33e..5f93574f 100755 --- a/src/py/examples/simple-capture.py +++ b/src/py/examples/simple-capture.py @@ -14,6 +14,7 @@ import argparse import libcamera as libcam +import selectors import sys # Number of frames to capture @@ -107,11 +108,18 @@ def main(): # The main loop. Wait for the queued Requests to complete, process them, # and re-queue them again. + sel = selectors.DefaultSelector() + sel.register(cm.event_fd, selectors.EVENT_READ) + while frames_done < TOTAL_FRAMES: - # cm.get_ready_requests() blocks until there is an event and returns - # all the ready requests. Here we should almost always get a single + # cm.get_ready_requests() does not block, so we use a Selector to wait + # for a camera event. Here we should almost always get a single # Request, but in some cases there could be multiple or none. + events = sel.select() + if not events: + continue + reqs = cm.get_ready_requests() for req in reqs: diff --git a/src/py/examples/simple-continuous-capture.py b/src/py/examples/simple-continuous-capture.py index fe78a2dd..26a8060b 100755 --- a/src/py/examples/simple-continuous-capture.py +++ b/src/py/examples/simple-continuous-capture.py @@ -88,8 +88,9 @@ class CaptureContext: camera_contexts: list[CameraCaptureContext] = [] def handle_camera_event(self): - # cm.get_ready_requests() will not block here, as we know there is an event - # to read. + # cm.get_ready_requests() returns the ready requests, which in our case + # should almost always return a single Request, but in some cases there + # could be multiple or none. reqs = self.cm.get_ready_requests() -- cgit v1.2.1