[PATCH v3 5/6] libcamera: software_isp: Dispatch messages on stop

[Milan Zamazal]

There may be pending messages in SoftwareIsp message queue when
SoftwareIsp stops.  The call to IPAProxySoft::stop() will dispatch them
before SoftwareIsp::stop() finishes.  But this is dependent on
IPAProxySoft::stop() implementation, let's break this dependency and
dispatch messages to SoftwareIsp explicitly in SoftwareIsp::stop().

This also allows dropping `running_' flag.  Since the SoftwareIsp
messages get processed and invoke IPA calls before the IPA proxy is set
to ProxyStopping state and the SoftwareIsp worker thread is no longer
running, it's guaranteed that no new messages come to SoftwareIsp and
attempt to call the stopped IPA proxy.

Signed-off-by: Milan Zamazal <mzamazal at redhat.com>
---
 .../internal/software_isp/software_isp.h      |  1 -
 src/libcamera/software_isp/software_isp.cpp   | 24 ++++++++-----------
 2 files changed, 10 insertions(+), 15 deletions(-)

diff --git a/include/libcamera/internal/software_isp/software_isp.h b/include/libcamera/internal/software_isp/software_isp.h
index 400a4dc5..133b545c 100644
--- a/include/libcamera/internal/software_isp/software_isp.h
+++ b/include/libcamera/internal/software_isp/software_isp.h
@@ -101,7 +101,6 @@ private:
 	DmaBufAllocator dmaHeap_;
 
 	std::unique_ptr<ipa::soft::IPAProxySoft> ipa_;
-	bool running_;
 	std::deque<FrameBuffer *> queuedInputBuffers_;
 	std::deque<FrameBuffer *> queuedOutputBuffers_;
 };
diff --git a/src/libcamera/software_isp/software_isp.cpp b/src/libcamera/software_isp/software_isp.cpp
index beac66fc..193713b9 100644
--- a/src/libcamera/software_isp/software_isp.cpp
+++ b/src/libcamera/software_isp/software_isp.cpp
@@ -14,6 +14,7 @@
 #include <unistd.h>
 
 #include <libcamera/base/log.h>
+#include <libcamera/base/thread.h>
 
 #include <libcamera/controls.h>
 #include <libcamera/formats.h>
@@ -323,7 +324,6 @@ int SoftwareIsp::start()
 	int ret = ipa_->start();
 	if (ret)
 		return ret;
-	running_ = true;
 
 	ispWorkerThread_.start();
 	return 0;
@@ -340,7 +340,8 @@ void SoftwareIsp::stop()
 	ispWorkerThread_.exit();
 	ispWorkerThread_.wait();
 
-	running_ = false;
+	Thread::current()->dispatchMessages(Message::Type::InvokeMessage, this);
+
 	ipa_->stop();
 
 	for (auto buffer : queuedOutputBuffers_) {
@@ -383,26 +384,21 @@ void SoftwareIsp::setSensorCtrls(const ControlList &sensorControls)
 
 void SoftwareIsp::statsReady(uint32_t frame, uint32_t bufferId)
 {
-	if (running_)
-		ispStatsReady.emit(frame, bufferId);
+	ispStatsReady.emit(frame, bufferId);
 }
 
 void SoftwareIsp::inputReady(FrameBuffer *input)
 {
-	if (running_) {
-		ASSERT(queuedInputBuffers_.front() == input);
-		queuedInputBuffers_.pop_front();
-		inputBufferReady.emit(input);
-	}
+	ASSERT(queuedInputBuffers_.front() == input);
+	queuedInputBuffers_.pop_front();
+	inputBufferReady.emit(input);
 }
 
 void SoftwareIsp::outputReady(FrameBuffer *output)
 {
-	if (running_) {
-		ASSERT(queuedOutputBuffers_.front() == output);
-		queuedOutputBuffers_.pop_front();
-		outputBufferReady.emit(output);
-	}
+	ASSERT(queuedOutputBuffers_.front() == output);
+	queuedOutputBuffers_.pop_front();
+	outputBufferReady.emit(output);
 }
 
 } /* namespace libcamera */
-- 
2.48.1