libcamera: bound_method: Avoid deadlock with ConnectionTypeBlocking

ConnectionTypeBlocking always invokes the method through inter-thread
message passing, which results in deadlocks if the sender and receiver
live in the same thread. The deadlock can easily be avoided by turning
the invocation into a direct call in this case. Do so to make
ConnectionTypeBlocking easier to use when some of the senders live in
the same thread as the receiver while the other senders don't.

Extend the object-invoke test to cover this usage.

While at it reformat the documentation to avoid long \brief lines.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>

1 files changed, 20 insertions, 0 deletions

diff --git a/test/object-invoke.cpp b/test/object-invoke.cpp
index 8e2055ca..fa162c83 100644
--- a/test/object-invoke.cpp
+++ b/test/object-invoke.cpp
@@ -101,6 +101,26 @@ protected:
 		}
 
 		/*
+		 * Test that blocking invocation is delivered directly when the
+		 * caller and callee live in the same thread.
+		 */
+		object_.reset();
+
+		object_.invokeMethod(&InvokedObject::method,
+				     ConnectionTypeBlocking, 42);
+
+		switch (object_.status()) {
+		case InvokedObject::NoCall:
+			cout << "Method not invoked for main thread (blocking)" << endl;
+			return TestFail;
+		case InvokedObject::InvalidThread:
+			cout << "Method invoked in incorrect thread for main thread (blocking)" << endl;
+			return TestFail;
+		default:
+			break;
+		}
+
+		/*
 		 * Move the object to a thread and verify that auto method
 		 * invocation is delivered in the correct thread.
 		 */