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Diffstat (limited to 'src/libcamera/ipc_pipe.cpp')
| -rw-r--r-- | src/libcamera/ipc_pipe.cpp | 218 |
1 files changed, 218 insertions, 0 deletions
diff --git a/src/libcamera/ipc_pipe.cpp b/src/libcamera/ipc_pipe.cpp new file mode 100644 index 00000000..c402c8d0 --- /dev/null +++ b/src/libcamera/ipc_pipe.cpp @@ -0,0 +1,218 @@ +/* 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 identify 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 empty IPCMessage instance + */ +IPCMessage::IPCMessage() + : header_(Header{ 0, 0 }) +{ +} + +/** + * \brief Construct an IPCMessage instance with a given command code + * \param[in] cmd The command code + */ +IPCMessage::IPCMessage(uint32_t cmd) + : header_(Header{ cmd, 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.data(), sizeof(header_)); + data_ = std::vector<uint8_t>(payload.data.begin() + sizeof(header_), + payload.data.end()); + fds_ = payload.fds; +} + +/** + * \brief Create an IPCUnixSocket payload from the IPCMessage + * + * This essentially converts the IPCMessage into an IPCUnixSocket payload. + * + * \todo Resolve the layering violation (add other converters later?) + */ +IPCUnixSocket::Payload IPCMessage::payload() const +{ + IPCUnixSocket::Payload payload; + + payload.data.resize(sizeof(Header) + data_.size()); + payload.fds.reserve(fds_.size()); + + memcpy(payload.data.data(), &header_, sizeof(Header)); + + /* \todo Make this work without copy */ + memcpy(payload.data.data() + sizeof(Header), data_.data(), data_.size()); + payload.fds = fds_; + + return payload; +} + +/** + * \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::header() const + * \brief Returns a const reference to the header + */ + +/** + * \fn IPCMessage::data() const + * \brief Returns a const reference to the byte vector containing data + */ + +/** + * \fn IPCMessage::fds() const + * \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] in Data to send + * \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 + * + * \todo Determine if the event loop should limit the types of messages it + * processes, to avoid reintrancy in the caller, and carefully document what + * the caller needs to implement to make this safe. + */ + +/** + * \fn IPCPipe::sendAsync() + * \brief Send a message over IPC asynchronously + * \param[in] data Data to send + * + * 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 a message is received over IPC + * + * When a message is received over IPC, this signal shall be emitted. Users must + * connect to this to receive messages. + */ + +/** + * \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 + * connection. + */ + +} /* namespace libcamera */ |