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// somebar - dwl bar
// See LICENSE file for copyright and license details.
#include <fcntl.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <unistd.h>
#include "shm_buffer.hpp"
#include "common.hpp"
static int createAnonShm();
constexpr int n = 2;
ShmBuffer::ShmBuffer(int w, int h, wl_shm_format format)
: width(w)
, height(h)
, stride(w*4)
{
auto oneSize = stride*size_t(h);
auto totalSize = oneSize * n;
auto fd = createAnonShm();
if (fd < 0) {
diesys("memfd_create");
}
if (ftruncate(fd, totalSize) < 0) {
diesys("ftruncate");
}
auto pool = wl_shm_create_pool(shm, fd, totalSize);
auto ptr = reinterpret_cast<uint8_t*>(mmap(nullptr, totalSize, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0));
if (!ptr) {
diesys("mmap");
}
_mapping = MemoryMapping {ptr, totalSize};
close(fd);
for (auto i=0; i<n; i++) {
auto offset = oneSize*i;
_buffers[i] = {
ptr+offset,
wl_unique_ptr<wl_buffer> { wl_shm_pool_create_buffer(pool, offset, width, height, stride, format) },
};
}
wl_shm_pool_destroy(pool);
}
uint8_t* ShmBuffer::data()
{
return _buffers[_current].data;
}
wl_buffer* ShmBuffer::buffer()
{
return _buffers[_current].buffer.get();
}
void ShmBuffer::flip()
{
_current = 1-_current;
}
#if defined(__linux__)
int createAnonShm() {
return memfd_create("wl_shm", MFD_CLOEXEC);
}
#elif defined(__FreeBSD__)
int createAnonShm() {
auto fd = shm_open(SHM_ANON, O_CREAT | O_RDWR, 0600);
setCloexec(fd);
return fd;
}
#elif defined(__OpenBSD__)
int createAnonShm() {
char name[] = "/wl_shm-XXXXXX";
auto fd = shm_mkstemp(name);
if (fd >= 0) {
auto res = shm_unlink(name);
if (res < 0) {
return res;
}
}
setCloexec(fd);
return fd;
}
#else
#error "your system has no sane method of creating an anonymous shared memory object. no, calling shm_open in a loop is not sane."
#endif
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