libcamera: Drop emitter object pointer from signal arguments

Many signals used in internal and public APIs carry the emitter pointer
as a signal argument. This was done to allow slots connected to multiple
signal instances to differentiate between emitters. While starting from
a good intention of facilitating the implementation of slots, it turned
out to be a bad API design as the signal isn't meant to know what it
will be connected to, and thus shouldn't carry parameters that are
solely meant to support a use case specific to the connected slot.

These pointers turn out to be unused in all slots but one. In the only
case where it is needed, it can be obtained by wrapping the slot in a
lambda function when connecting the signal. Do so, and drop the emitter
pointer from all signals.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Umang Jain <umang.jain@ideasonboard.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/include/libcamera/internal/ipc_unixsocket.h b/include/libcamera/internal/ipc_unixsocket.h
index 9f5b0677..2b87196c 100644
--- a/include/libcamera/internal/ipc_unixsocket.h
+++ b/include/libcamera/internal/ipc_unixsocket.h
@@ -37,7 +37,7 @@ public:
 	int send(const Payload &payload);
 	int receive(Payload *payload);
 
-	Signal<IPCUnixSocket *> readyRead;
+	Signal<> readyRead;
 
 private:
 	struct Header {
@@ -48,7 +48,7 @@ private:
 	int sendData(const void *buffer, size_t length, const int32_t *fds, unsigned int num);
 	int recvData(void *buffer, size_t length, int32_t *fds, unsigned int num);
 
-	void dataNotifier(EventNotifier *notifier);
+	void dataNotifier();
 
 	int fd_;
 	bool headerReceived_;