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#include <assert.h>
#include <cairo.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mman.h>
#include <time.h>
#include <unistd.h>
#include <wayland-client.h>
#include "pool-buffer.h"
static int anonymous_shm_open(void) {
int retries = 100;
do {
// try a probably-unique name
struct timespec ts;
clock_gettime(CLOCK_MONOTONIC, &ts);
pid_t pid = getpid();
char name[50];
snprintf(name, sizeof(name), "/swaybg-%x-%x",
(unsigned int)pid, (unsigned int)ts.tv_nsec);
// shm_open guarantees that O_CLOEXEC is set
int fd = shm_open(name, O_RDWR | O_CREAT | O_EXCL, 0600);
if (fd >= 0) {
shm_unlink(name);
return fd;
}
--retries;
} while (retries > 0 && errno == EEXIST);
return -1;
}
bool create_buffer(struct pool_buffer *buf, struct wl_shm *shm,
int32_t width, int32_t height, uint32_t format) {
uint32_t stride = width * 4;
size_t size = stride * height;
int fd = anonymous_shm_open();
assert(fd != -1);
if (ftruncate(fd, size) < 0) {
close(fd);
return false;
}
void *data = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
struct wl_shm_pool *pool = wl_shm_create_pool(shm, fd, size);
buf->buffer = wl_shm_pool_create_buffer(pool, 0,
width, height, stride, format);
wl_shm_pool_destroy(pool);
close(fd);
buf->size = size;
buf->data = data;
buf->surface = cairo_image_surface_create_for_data(data,
CAIRO_FORMAT_RGB24, width, height, stride);
buf->cairo = cairo_create(buf->surface);
return true;
}
void destroy_buffer(struct pool_buffer *buffer) {
if (buffer->buffer) {
wl_buffer_destroy(buffer->buffer);
}
if (buffer->cairo) {
cairo_destroy(buffer->cairo);
}
if (buffer->surface) {
cairo_surface_destroy(buffer->surface);
}
if (buffer->data) {
munmap(buffer->data, buffer->size);
}
}
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