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/*
* Copyright 2022 The WebRTC project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#ifndef MODULES_PORTAL_PIPEWIRE_UTILS_H_
#define MODULES_PORTAL_PIPEWIRE_UTILS_H_
#include <errno.h>
#include <stdint.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
// static
struct dma_buf_sync {
uint64_t flags;
};
#define DMA_BUF_SYNC_READ (1 << 0)
#define DMA_BUF_SYNC_START (0 << 2)
#define DMA_BUF_SYNC_END (1 << 2)
#define DMA_BUF_BASE 'b'
#define DMA_BUF_IOCTL_SYNC _IOW(DMA_BUF_BASE, 0, struct dma_buf_sync)
struct pw_thread_loop;
namespace webrtc {
constexpr int kInvalidPipeWireFd = -1;
// Prepare PipeWire so that it is ready to be used. If it needs to be dlopen'd
// this will do so. Note that this does not guarantee a PipeWire server is
// running nor does it establish a connection to one.
bool InitializePipeWire();
// Locks pw_thread_loop in the current scope
class PipeWireThreadLoopLock {
public:
explicit PipeWireThreadLoopLock(pw_thread_loop* loop);
~PipeWireThreadLoopLock();
private:
pw_thread_loop* const loop_;
};
// We should synchronize DMA Buffer object access from CPU to avoid potential
// cache incoherency and data loss.
// See
// https://01.org/linuxgraphics/gfx-docs/drm/driver-api/dma-buf.html#cpu-access-to-dma-buffer-objects
static bool SyncDmaBuf(int fd, uint64_t start_or_end) {
struct dma_buf_sync sync = {0};
sync.flags = start_or_end | DMA_BUF_SYNC_READ;
while (true) {
int ret;
ret = ioctl(fd, DMA_BUF_IOCTL_SYNC, &sync);
if (ret == -1 && errno == EINTR) {
continue;
} else if (ret == -1) {
return false;
} else {
break;
}
}
return true;
}
class ScopedBuf {
public:
ScopedBuf() {}
ScopedBuf(uint8_t* map, int map_size, int fd, bool is_dma_buf = false)
: map_(map), map_size_(map_size), fd_(fd), is_dma_buf_(is_dma_buf) {}
~ScopedBuf() {
if (map_ != MAP_FAILED) {
if (is_dma_buf_) {
SyncDmaBuf(fd_, DMA_BUF_SYNC_END);
}
munmap(map_, map_size_);
}
}
explicit operator bool() { return map_ != MAP_FAILED; }
void initialize(uint8_t* map, int map_size, int fd, bool is_dma_buf = false) {
map_ = map;
map_size_ = map_size;
is_dma_buf_ = is_dma_buf;
fd_ = fd;
if (is_dma_buf_) {
SyncDmaBuf(fd_, DMA_BUF_SYNC_START);
}
}
uint8_t* get() { return map_; }
protected:
uint8_t* map_ = static_cast<uint8_t*>(MAP_FAILED);
int map_size_;
int fd_;
bool is_dma_buf_;
};
} // namespace webrtc
#endif // MODULES_PORTAL_PIPEWIRE_UTILS_H_
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