ce3c8a5082
The SharedMemObject has been imported directly into the libcamera internal components. Adapt the SIZE constant of the class to match the libcamera coding style. Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Milan Zamazal <mzamazal@redhat.com> Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
125 lines
2.0 KiB
C++
125 lines
2.0 KiB
C++
/* SPDX-License-Identifier: LGPL-2.1-or-later */
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/*
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* Copyright (C) 2023, Raspberry Pi Ltd
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*
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* shared_mem_object.h - Helper class for shared memory allocations
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*/
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#pragma once
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#include <fcntl.h>
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#include <stddef.h>
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#include <string>
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#include <sys/mman.h>
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#include <sys/stat.h>
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#include <unistd.h>
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#include <utility>
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#include <libcamera/base/class.h>
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#include <libcamera/base/shared_fd.h>
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namespace libcamera {
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template<class T>
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class SharedMemObject
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{
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public:
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static constexpr std::size_t kSize = sizeof(T);
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SharedMemObject()
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: obj_(nullptr)
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{
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}
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template<class... Args>
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SharedMemObject(const std::string &name, Args &&...args)
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: name_(name), obj_(nullptr)
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{
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void *mem;
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int ret;
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ret = memfd_create(name_.c_str(), MFD_CLOEXEC);
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if (ret < 0)
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return;
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fd_ = SharedFD(std::move(ret));
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if (!fd_.isValid())
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return;
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ret = ftruncate(fd_.get(), kSize);
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if (ret < 0)
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return;
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mem = mmap(nullptr, kSize, PROT_READ | PROT_WRITE, MAP_SHARED,
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fd_.get(), 0);
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if (mem == MAP_FAILED)
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return;
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obj_ = new (mem) T(std::forward<Args>(args)...);
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}
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SharedMemObject(SharedMemObject<T> &&rhs)
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{
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this->name_ = std::move(rhs.name_);
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this->fd_ = std::move(rhs.fd_);
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this->obj_ = rhs.obj_;
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rhs.obj_ = nullptr;
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}
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~SharedMemObject()
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{
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if (obj_) {
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obj_->~T();
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munmap(obj_, kSize);
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}
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}
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/* Make SharedMemObject non-copyable for now. */
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LIBCAMERA_DISABLE_COPY(SharedMemObject)
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SharedMemObject<T> &operator=(SharedMemObject<T> &&rhs)
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{
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this->name_ = std::move(rhs.name_);
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this->fd_ = std::move(rhs.fd_);
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this->obj_ = rhs.obj_;
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rhs.obj_ = nullptr;
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return *this;
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}
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T *operator->()
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{
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return obj_;
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}
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const T *operator->() const
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{
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return obj_;
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}
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T &operator*()
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{
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return *obj_;
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}
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const T &operator*() const
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{
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return *obj_;
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}
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const SharedFD &fd() const
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{
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return fd_;
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}
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explicit operator bool() const
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{
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return !!obj_;
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}
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private:
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std::string name_;
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SharedFD fd_;
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T *obj_;
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};
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} /* namespace libcamera */
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