[libcamera-devel] [PATCH v5 06/23] libcamera: Add IPCPipe
Paul Elder
paul.elder at ideasonboard.com
Sat Dec 5 11:30:49 CET 2020
Create a virtual IPCPipe class that models an IPC/RPC system. IPA proxies
and proxy workers will call into the IPCPipe, rather than implementing
the IPC themselves.
Signed-off-by: Paul Elder <paul.elder at ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo at jmondi.org>
Reviewed-by: Niklas Söderlund <niklas.soderlund at ragnatech.se>
---
Changes in v5:
- fix style
- rename ipa_ipc.[(cpp)h] to ipc_pipe.[(cpp),h]
- rename IPAIPC to IPCPipe
- add IPCMessage to use in the IPCPipe
Change in v4:
- change snake_case to camelCase
- remove ipaModulePath and ipaProxyWorkerPath from parameters in the
IPAIPC base contructor
- include signal.h
Changes in v3:
- expand documentation a bit
- move [[maybe_unused]] to after the parameters in the IPAIPC
constructor, to appease gcc <= 9.1
Changes in v2:
- add documentation
---
.../libcamera/internal/ipa_data_serializer.h | 2 +-
include/libcamera/internal/ipc_pipe.h | 70 ++++++
src/libcamera/ipc_pipe.cpp | 211 ++++++++++++++++++
src/libcamera/meson.build | 1 +
4 files changed, 283 insertions(+), 1 deletion(-)
create mode 100644 include/libcamera/internal/ipc_pipe.h
create mode 100644 src/libcamera/ipc_pipe.cpp
diff --git a/include/libcamera/internal/ipa_data_serializer.h b/include/libcamera/internal/ipa_data_serializer.h
index 0394ab3a..9d4aaba5 100644
--- a/include/libcamera/internal/ipa_data_serializer.h
+++ b/include/libcamera/internal/ipa_data_serializer.h
@@ -286,7 +286,7 @@ public:
fdIter,
fdIter + sizeofFds,
cs);
- ret.insert({key, value});
+ ret.insert({ key, value });
dataIter += sizeofData;
fdIter += sizeofFds;
diff --git a/include/libcamera/internal/ipc_pipe.h b/include/libcamera/internal/ipc_pipe.h
new file mode 100644
index 00000000..0232c3b5
--- /dev/null
+++ b/include/libcamera/internal/ipc_pipe.h
@@ -0,0 +1,70 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2020, Google Inc.
+ *
+ * ipc_pipe.h - Image Processing Algorithm IPC module for IPA proxies
+ */
+#ifndef __LIBCAMERA_INTERNAL_IPA_IPC_H__
+#define __LIBCAMERA_INTERNAL_IPA_IPC_H__
+
+#include <vector>
+
+#include "libcamera/internal/ipc_unixsocket.h"
+
+#include <libcamera/signal.h>
+
+namespace libcamera {
+
+class IPCMessage
+{
+public:
+ struct Header {
+ uint32_t cmd;
+ uint32_t cookie;
+ };
+
+ IPCMessage();
+ IPCMessage(const Header &header);
+ IPCMessage(const IPCUnixSocket::Payload &payload);
+
+ const IPCUnixSocket::Payload payload(const Header *header = nullptr) const;
+
+ Header &header() { return header_; }
+ std::vector<uint8_t> &data() { return data_; }
+ std::vector<int32_t> &fds() { return fds_; }
+
+ const Header &cheader() const { return header_; }
+ const std::vector<uint8_t> &cdata() const { return data_; }
+ const std::vector<int32_t> &cfds() const { return fds_; }
+
+private:
+ Header header_;
+
+ std::vector<uint8_t> data_;
+ std::vector<int32_t> fds_;
+};
+
+class IPCPipe
+{
+public:
+ IPCPipe();
+ virtual ~IPCPipe();
+
+ bool isConnected() const { return connected_; }
+
+ virtual int sendSync(uint32_t cmd,
+ const IPCMessage &in,
+ IPCMessage *out) = 0;
+
+ virtual int sendAsync(uint32_t cmd,
+ const IPCMessage &data) = 0;
+
+ Signal<uint32_t, const IPCMessage &> recv;
+
+protected:
+ bool connected_;
+};
+
+} /* namespace libcamera */
+
+#endif /* __LIBCAMERA_INTERNAL_IPA_IPC_H__ */
diff --git a/src/libcamera/ipc_pipe.cpp b/src/libcamera/ipc_pipe.cpp
new file mode 100644
index 00000000..eb439724
--- /dev/null
+++ b/src/libcamera/ipc_pipe.cpp
@@ -0,0 +1,211 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2020, Google Inc.
+ *
+ * ipc_pipe.cpp - Image Processing Algorithm IPC module for IPA proxies
+ */
+
+#include "libcamera/internal/ipc_pipe.h"
+
+#include "libcamera/internal/log.h"
+
+/**
+ * \file ipc_pipe.h
+ * \brief IPC mechanism for IPA isolation
+ */
+
+namespace libcamera {
+
+LOG_DEFINE_CATEGORY(IPCPipe)
+
+/**
+ * \struct IPCMessage::Header
+ * \brief Container for an IPCMessage header
+ *
+ * Holds a cmd code for the IPC message, and a cookie.
+ */
+
+/**
+ * \var IPCMessage::Header::cmd
+ * \brief Type of IPCMessage
+ *
+ * Typically used to carry a command code for an RPC.
+ */
+
+/**
+ * \var IPCMessage::Header::cookie
+ * \brief Cookie to idetify the message and a corresponding reply.
+ *
+ * Populated and used by IPCPipe implementations for matching calls with
+ * replies.
+ */
+
+/**
+ * \class IPCMessage
+ * \brief IPC message to be passed through IPC message pipe
+ */
+
+/**
+ * \brief Construct an IPCMessage instance
+ */
+IPCMessage::IPCMessage()
+ : header_(Header{ 0, 0 })
+{
+}
+
+/**
+ * \brief Construct an IPCMessage instance with a given header
+ * \param[in] header The header that the constructed IPCMessage will contain
+ */
+IPCMessage::IPCMessage(const Header &header)
+ : header_(header)
+{
+}
+
+/**
+ * \brief Construct an IPCMessage instance from an IPC payload
+ * \param[in] payload The IPCUnixSocket payload to construct from
+ *
+ * This essentially converts an IPCUnixSocket payload into an IPCMessage.
+ * The header is extracted from the payload into the IPCMessage's header field.
+ */
+IPCMessage::IPCMessage(const IPCUnixSocket::Payload &payload)
+{
+ memcpy(&header_, &*payload.data.begin(), sizeof(header_));
+ data_ = std::vector<uint8_t>(payload.data.begin() + sizeof(header_),
+ payload.data.end());
+ fds_ = std::vector<int32_t>(payload.fds.begin(), payload.fds.end());
+}
+
+/**
+ * \brief Create an IPCUnixSocket payload from the IPCMessage
+ * \param[in] header Header to use when constructing the payload, if applicable
+ *
+ * This essentially converts the IPCMessage into an IPCUnixSocket payload. If
+ * \a header is not provided (ie. nullptr), then the header field that is
+ * internal to the IPCMessage will be used.
+ */
+const IPCUnixSocket::Payload IPCMessage::payload(const Header *header) const
+{
+ IPCUnixSocket::Payload message;
+
+ message.data.resize(sizeof(Header) + data_.size());
+ message.fds.reserve(fds_.size());
+
+ memcpy(&*message.data.begin(), header ? header : &header_, sizeof(Header));
+
+ /* \todo Make this work without copy */
+ memcpy(&*(message.data.begin() + sizeof(Header)), data_.data(), data_.size());
+ message.fds = const_cast<std::vector<int32_t> &>(fds_);
+
+ return message;
+}
+
+/**
+ * \fn IPCMessage::header()
+ * \brief Returns a reference to the header
+ */
+
+/**
+ * \fn IPCMessage::data()
+ * \brief Returns a reference to the byte vector containing data
+ */
+
+/**
+ * \fn IPCMessage::fds()
+ * \brief Returns a reference to the vector containing file descriptors
+ */
+
+/**
+ * \fn IPCMessage::cheader()
+ * \brief Returns a const reference to the header
+ */
+
+/**
+ * \fn IPCMessage::cdata()
+ * \brief Returns a const reference to the byte vector containing data
+ */
+
+/**
+ * \fn IPCMessage::cfds()
+ * \brief Returns a const reference to the vector containing file descriptors
+ */
+
+/**
+ * \class IPCPipe
+ * \brief IPC message pipe for IPA isolation
+ *
+ * Virtual class to model an IPC message pipe for use by IPA proxies for IPA
+ * isolation. sendSync() and sendAsync() must be implemented, and the recvMessage
+ * signal must be emitted whenever new data is available.
+ */
+
+/**
+ * \brief Construct an IPCPipe instance
+ */
+IPCPipe::IPCPipe()
+ : connected_(false)
+{
+}
+
+IPCPipe::~IPCPipe()
+{
+}
+
+/**
+ * \fn IPCPipe::isConnected()
+ * \brief Check if the IPCPipe instance is connected
+ *
+ * An IPCPipe instance is connected if IPC is successfully set up.
+ *
+ * \return True if the IPCPipe is connected, false otherwise
+ */
+
+/**
+ * \fn IPCPipe::sendSync()
+ * \brief Send a message over IPC synchronously
+ * \param[in] cmd Command ID
+ * \param[in] in Data to send, as an IPCMessage
+ * \param[in] out IPCMessage instance in which to receive data, if applicable
+ *
+ * This function will not return until a response is received. The event loop
+ * will still continue to execute, however.
+ *
+ * \return Zero on success, negative error code otherwise
+ */
+
+/**
+ * \fn IPCPipe::sendAsync()
+ * \brief Send a message over IPC asynchronously
+ * \param[in] cmd Command ID
+ * \param[in] data Data to send, as an IPCMessage
+ *
+ * This function will return immediately after sending the message.
+ *
+ * \return Zero on success, negative error code otherwise
+ */
+
+/**
+ * \var IPCPipe::recv
+ * \brief Signal to be emitted when data is received over IPC
+ *
+ * When data is received over IPC, this signal shall be emitted. Users must
+ * connect to this to receive new data.
+ *
+ * The parameters of the signal are a vector of bytes and a vector of file
+ * descriptors.
+ */
+
+/**
+ * \var IPCPipe::connected_
+ * \brief Flag to indicate if the IPCPipe instance is connected
+ *
+ * An IPCPipe instance is connected if IPC is successfully set up.
+ *
+ * This flag can be read via IPCPipe::isConnected().
+ *
+ * Implementations of the IPCPipe class should set this flag upon successful
+ * construction.
+ */
+
+} /* namespace libcamera */
diff --git a/src/libcamera/meson.build b/src/libcamera/meson.build
index 1291f1b3..b7cfe0c2 100644
--- a/src/libcamera/meson.build
+++ b/src/libcamera/meson.build
@@ -30,6 +30,7 @@ libcamera_sources = files([
'ipa_manager.cpp',
'ipa_module.cpp',
'ipa_proxy.cpp',
+ 'ipc_pipe.cpp',
'ipc_unixsocket.cpp',
'log.cpp',
'media_device.cpp',
--
2.27.0
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