Camera3: don't let dequeueBuffer block indefinitely
The synchronous consumers (e.g. ImageReader) may be very slow when the
clients have computational intensive image processings. When system
load is high, these processing will be even much slower. This could
starve the producer side and then cause dequeue/attach buffer block
indefinitely. If clients intends to close the capture session, right
after a capture request is submitted, the waitUntil drain could be
blocked indefinitely if the capture request dequeue buffer call is
blocked indefinitely, as the request thread will never become idle until
the last dequeue buffer is done and the request is sent.This indefinite
getBuffer() blocking could easily trigger the waitUntilDrained 5s timeout
thus put the camera device into error state although there is nothing
bad happening in the HAL.
Introducing the timeout will avoid such bad situation. When consumer is
slow, there will be no new request being sent to HAL, as there is really
no new buffer available.
Bug:30404840
Change-Id: Ibf08d2745911203bce6f31130800707f36d7f985
diff --git a/services/camera/libcameraservice/device3/Camera3OutputStream.cpp b/services/camera/libcameraservice/device3/Camera3OutputStream.cpp
index d09951a..dff5a49 100644
--- a/services/camera/libcameraservice/device3/Camera3OutputStream.cpp
+++ b/services/camera/libcameraservice/device3/Camera3OutputStream.cpp
@@ -435,6 +435,12 @@
__FUNCTION__, mTransform, strerror(-res), res);
}
+ // Set dequeueBuffer/attachBuffer timeout if the consumer is not hw composer or hw texture.
+ // We need skip these cases as timeout will disable the non-blocking (async) mode.
+ if (!(isConsumedByHWComposer() || isConsumedByHWTexture())) {
+ mConsumer->setDequeueTimeout(kDequeueBufferTimeout);
+ }
+
/**
* Camera3 Buffer manager is only supported by HAL3.3 onwards, as the older HALs requires
* buffers to be statically allocated for internal static buffer registration, while the
@@ -633,6 +639,17 @@
return (usage & GRALLOC_USAGE_HW_COMPOSER) != 0;
}
+bool Camera3OutputStream::isConsumedByHWTexture() const {
+ uint32_t usage = 0;
+ status_t res = getEndpointUsage(&usage);
+ if (res != OK) {
+ ALOGE("%s: getting end point usage failed: %s (%d).", __FUNCTION__, strerror(-res), res);
+ return false;
+ }
+
+ return (usage & GRALLOC_USAGE_HW_TEXTURE) != 0;
+}
+
}; // namespace camera3
}; // namespace android