[libcamera-devel] [PATCH v7 08/10] libcamera: Add IPCPipe implementation based on unix socket

Paul Elder paul.elder at ideasonboard.com
Thu Feb 11 08:18:03 CET 2021


Add an implementation of IPCPipe using unix socket.

Signed-off-by: Paul Elder <paul.elder at ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund at ragnatech.se>
Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>

---
Changes in v7:
- implement new sendSync/sendAsync that only deals with IPCMessages
- remove sequence number (the called of sendSync/sendAsync deals with it
  now)
- add underflow check on receive
- cosmetic changes

Changes in v6:
- remove explicit nullptr intializations for unique_ptr members
- move callData_.erase() to the call() error path

Changes in v5:
- rename IPAIPCUnixSocket to IPCPipeUnixSocket
- rename ipa_ipc_unisocket.[(cpp),h] ipc_pipe_unixsocket.[(cpp),h]

Changes in v4:
- change snake_case to camelCase
- change proc_ and socket_ to unique pointers
- move inclusion of corresponding header to first in the include list
- reserve message data and fds size (for sending)

Changes in v3:
- remove unused writeUInt32() and readUInt32()
- remove redundant definition of IPAIPCUnixSocket::isValid()
- remove & 0xff in writeHeader()
- make readHeader, writeHeader, and eraseHeader static class functions
  of IPAIPCUnixSocket instead of globals

Changes in v2:
- specify in doxygen to skip generating documentation for
  IPAIPCUnixSocket
---
 Documentation/Doxyfile.in                     |   2 +
 .../libcamera/internal/ipc_pipe_unixsocket.h  |  49 ++++++
 src/libcamera/ipc_pipe_unixsocket.cpp         | 144 ++++++++++++++++++
 src/libcamera/meson.build                     |   1 +
 4 files changed, 196 insertions(+)
 create mode 100644 include/libcamera/internal/ipc_pipe_unixsocket.h
 create mode 100644 src/libcamera/ipc_pipe_unixsocket.cpp

diff --git a/Documentation/Doxyfile.in b/Documentation/Doxyfile.in
index 5b64f705..e0de6c6d 100644
--- a/Documentation/Doxyfile.in
+++ b/Documentation/Doxyfile.in
@@ -837,8 +837,10 @@ RECURSIVE              = YES
 EXCLUDE                = @TOP_SRCDIR@/include/libcamera/span.h \
 			 @TOP_SRCDIR@/include/libcamera/internal/device_enumerator_sysfs.h \
 			 @TOP_SRCDIR@/include/libcamera/internal/device_enumerator_udev.h \
+			 @TOP_SRCDIR@/include/libcamera/internal/ipc_pipe_unixsocket.h \
 			 @TOP_SRCDIR@/src/libcamera/device_enumerator_sysfs.cpp \
 			 @TOP_SRCDIR@/src/libcamera/device_enumerator_udev.cpp \
+			 @TOP_SRCDIR@/src/libcamera/ipc_pipe_unixsocket.cpp \
 			 @TOP_SRCDIR@/src/libcamera/pipeline/ \
 			 @TOP_SRCDIR@/src/libcamera/proxy/ \
 			 @TOP_SRCDIR@/src/libcamera/tracepoints.cpp \
diff --git a/include/libcamera/internal/ipc_pipe_unixsocket.h b/include/libcamera/internal/ipc_pipe_unixsocket.h
new file mode 100644
index 00000000..4ffdddcc
--- /dev/null
+++ b/include/libcamera/internal/ipc_pipe_unixsocket.h
@@ -0,0 +1,49 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2020, Google Inc.
+ *
+ * ipc_pipe_unixsocket.h - Image Processing Algorithm IPC module using unix socket
+ */
+#ifndef __LIBCAMERA_INTERNAL_IPA_IPC_UNIXSOCKET_H__
+#define __LIBCAMERA_INTERNAL_IPA_IPC_UNIXSOCKET_H__
+
+#include <map>
+#include <memory>
+#include <vector>
+
+#include "libcamera/internal/ipc_pipe.h"
+#include "libcamera/internal/ipc_unixsocket.h"
+
+namespace libcamera {
+
+class Process;
+
+class IPCPipeUnixSocket : public IPCPipe
+{
+public:
+	IPCPipeUnixSocket(const char *ipaModulePath, const char *ipaProxyWorkerPath);
+	~IPCPipeUnixSocket();
+
+	int sendSync(const IPCMessage &in,
+		     IPCMessage *out = nullptr) override;
+
+	int sendAsync(const IPCMessage &data) override;
+
+private:
+	struct CallData {
+		IPCUnixSocket::Payload *response;
+		bool done;
+	};
+
+	void readyRead(IPCUnixSocket *socket);
+	int call(const IPCUnixSocket::Payload &message,
+		 IPCUnixSocket::Payload *response, uint32_t seq);
+
+	std::unique_ptr<Process> proc_;
+	std::unique_ptr<IPCUnixSocket> socket_;
+	std::map<uint32_t, CallData> callData_;
+};
+
+} /* namespace libcamera */
+
+#endif /* __LIBCAMERA_INTERNAL_IPA_IPC_UNIXSOCKET_H__ */
diff --git a/src/libcamera/ipc_pipe_unixsocket.cpp b/src/libcamera/ipc_pipe_unixsocket.cpp
new file mode 100644
index 00000000..2bdce29e
--- /dev/null
+++ b/src/libcamera/ipc_pipe_unixsocket.cpp
@@ -0,0 +1,144 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2020, Google Inc.
+ *
+ * ipc_pipe_unixsocket.cpp - Image Processing Algorithm IPC module using unix socket
+ */
+
+#include "libcamera/internal/ipc_pipe_unixsocket.h"
+
+#include <vector>
+
+#include "libcamera/internal/event_dispatcher.h"
+#include "libcamera/internal/ipc_pipe.h"
+#include "libcamera/internal/ipc_unixsocket.h"
+#include "libcamera/internal/log.h"
+#include "libcamera/internal/process.h"
+#include "libcamera/internal/thread.h"
+#include "libcamera/internal/timer.h"
+
+namespace libcamera {
+
+LOG_DECLARE_CATEGORY(IPCPipe)
+
+IPCPipeUnixSocket::IPCPipeUnixSocket(const char *ipaModulePath,
+				     const char *ipaProxyWorkerPath)
+	: IPCPipe()
+{
+	std::vector<int> fds;
+	std::vector<std::string> args;
+	args.push_back(ipaModulePath);
+
+	socket_ = std::make_unique<IPCUnixSocket>();
+	int fd = socket_->create();
+	if (fd < 0) {
+		LOG(IPCPipe, Error) << "Failed to create socket";
+		return;
+	}
+	socket_->readyRead.connect(this, &IPCPipeUnixSocket::readyRead);
+	args.push_back(std::to_string(fd));
+	fds.push_back(fd);
+
+	proc_ = std::make_unique<Process>();
+	int ret = proc_->start(ipaProxyWorkerPath, args, fds);
+	if (ret) {
+		LOG(IPCPipe, Error)
+			<< "Failed to start proxy worker process";
+		return;
+	}
+
+	connected_ = true;
+}
+
+IPCPipeUnixSocket::~IPCPipeUnixSocket()
+{
+}
+
+int IPCPipeUnixSocket::sendSync(const IPCMessage &in, IPCMessage *out)
+{
+	IPCUnixSocket::Payload response;
+
+	int ret = call(in.payload(), &response, in.header().cookie);
+	if (ret) {
+		LOG(IPCPipe, Error) << "Failed to call sync";
+		return ret;
+	}
+
+	if (out)
+		*out = IPCMessage(response);
+
+	return 0;
+}
+
+int IPCPipeUnixSocket::sendAsync(const IPCMessage &data)
+{
+	int ret = socket_->send(data.payload());
+	if (ret) {
+		LOG(IPCPipe, Error) << "Failed to call async";
+		return ret;
+	}
+
+	return 0;
+}
+
+void IPCPipeUnixSocket::readyRead(IPCUnixSocket *socket)
+{
+	IPCUnixSocket::Payload payload;
+	int ret = socket->receive(&payload);
+	if (ret) {
+		LOG(IPCPipe, Error) << "Receive message failed" << ret;
+		return;
+	}
+
+	/* \todo Use span to avoid the double copy when callData is found. */
+	IPCMessage ipcMessage(payload);
+	if (payload.data.size() < sizeof(IPCMessage::Header)) {
+		LOG(IPCPipe, Error) << "Not enough data received";
+		return;
+	}
+
+	auto callData = callData_.find(ipcMessage.header().cookie);
+	if (callData != callData_.end()) {
+		*callData->second.response = std::move(payload);
+		callData->second.done = true;
+		return;
+	}
+
+	/* Received unexpected data, this means it's a call from the IPA. */
+	recv.emit(ipcMessage);
+
+	return;
+}
+
+int IPCPipeUnixSocket::call(const IPCUnixSocket::Payload &message,
+			    IPCUnixSocket::Payload *response, uint32_t cookie)
+{
+	Timer timeout;
+	int ret;
+
+	const auto [iter, success] = callData_.insert({ cookie, { response, false } });
+
+	ret = socket_->send(message);
+	if (ret) {
+		callData_.erase(iter);
+		return ret;
+	}
+
+	/* \todo Make this less dangerous, see IPCPipe::sendSync() */
+	timeout.start(2000);
+	while (!iter->second.done) {
+		if (!timeout.isRunning()) {
+			LOG(IPCPipe, Error) << "Call timeout!";
+			callData_.erase(cookie);
+			return -ETIMEDOUT;
+		}
+
+		Thread::current()->eventDispatcher()->processEvents();
+	}
+
+	callData_.erase(iter);
+
+	return 0;
+}
+
+} /* namespace libcamera */
diff --git a/src/libcamera/meson.build b/src/libcamera/meson.build
index e736c41e..efd85849 100644
--- a/src/libcamera/meson.build
+++ b/src/libcamera/meson.build
@@ -32,6 +32,7 @@ libcamera_sources = files([
     'ipa_module.cpp',
     'ipa_proxy.cpp',
     'ipc_pipe.cpp',
+    'ipc_pipe_unixsocket.cpp',
     'ipc_unixsocket.cpp',
     'log.cpp',
     'media_device.cpp',
-- 
2.27.0



More information about the libcamera-devel mailing list