dam/poolbuf.h
2024-06-28 09:06:38 +03:00

112 lines
2.2 KiB
C

/*
* poolbuf - https://codeberg.org/sewn/drwl
* See LICENSE file for copyright and license details.
*/
#include <stddef.h>
#include <stdint.h>
#include <sys/mman.h>
#include <fcntl.h>
#include <unistd.h>
#include <wayland-client.h>
#include "drwl.h"
typedef struct {
struct wl_buffer *wl_buf;
int32_t stride;
int32_t size;
void *data;
} PoolBuf;
#if defined(__linux__) || defined(___FreeBSD__)
#ifdef __linux__
#include <linux/memfd.h>
#endif
#define __POOLBUF_HAS_MEMFD_CREATE
int memfd_create(const char *, unsigned);
#else
static void
randname(char *buf)
{
struct timespec ts;
clock_gettime(CLOCK_REALTIME, &ts);
long r = ts.tv_nsec;
for (int i = 0; i < 6; ++i) {
buf[i] = 'A'+(r&15)+(r&16)*2;
r >>= 5;
}
}
static int
create_shm(void)
{
char name[] = "/drwl-XXXXXX";
int retries = 100;
do {
randname(name + sizeof(name) - 7);
--retries;
int fd = shm_open(name, O_RDWR | O_CREAT | O_EXCL, 0600);
if (fd >= 0) {
shm_unlink(name);
return fd;
}
} while (retries > 0 && errno == EEXIST);
return -1;
}
#endif
/* Caller must call poolbuf_destroy after finalizing usage */
static PoolBuf *
poolbuf_create(struct wl_shm *shm, int32_t width, int32_t height)
{
int fd;
void *data;
struct wl_shm_pool *shm_pool;
struct wl_buffer *wl_buf;
int32_t stride = drwl_stride(width);
int32_t size = stride * height;
PoolBuf *buf;
#ifdef __POOLBUF_HAS_MEMFD_CREATE
fd = memfd_create("drwl-shm-buffer-pool",
MFD_CLOEXEC | MFD_ALLOW_SEALING | MFD_NOEXEC_SEAL);
#else
fd = create_shm();
#endif
if (fd < 0)
return NULL;
if ((ftruncate(fd, size)) < 0) {
close(fd);
return NULL;
}
data = mmap(NULL, size,
PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
if (data == MAP_FAILED) {
close(fd);
return NULL;
}
shm_pool = wl_shm_create_pool(shm, fd, size);
wl_buf = wl_shm_pool_create_buffer(shm_pool, 0,
width, height, stride, WL_SHM_FORMAT_ARGB8888);
wl_shm_pool_destroy(shm_pool);
close(fd);
buf = calloc(1, sizeof(PoolBuf));
buf->wl_buf = wl_buf;
buf->stride = stride;
buf->size = size;
buf->data = data;
return buf;
}
static void
poolbuf_destroy(PoolBuf *buf)
{
wl_buffer_destroy(buf->wl_buf);
munmap(buf->data, buf->size);
free(buf);
}