1 #define _POSIX_C_SOURCE 200809L
2 #include <assert.h>
3 #include <cairo/cairo.h>
4 #include <fcntl.h>
5 #include <stdio.h>
6 #include <stdlib.h>
7 #include <string.h>
8 #include <sys/mman.h>
9 #include <unistd.h>
10 #include <wayland-client.h>
11 #include "pool-buffer.h"
12
set_cloexec(int fd)13 static bool set_cloexec(int fd) {
14 long flags = fcntl(fd, F_GETFD);
15 if (flags == -1) {
16 return false;
17 }
18
19 if (fcntl(fd, F_SETFD, flags | FD_CLOEXEC) == -1) {
20 return false;
21 }
22
23 return true;
24 }
25
create_pool_file(size_t size,char ** name)26 static int create_pool_file(size_t size, char **name) {
27 static const char template[] = "sway-client-XXXXXX";
28 const char *path = getenv("XDG_RUNTIME_DIR");
29 if (path == NULL) {
30 fprintf(stderr, "XDG_RUNTIME_DIR is not set\n");
31 return -1;
32 }
33
34 size_t name_size = strlen(template) + 1 + strlen(path) + 1;
35 *name = malloc(name_size);
36 if (*name == NULL) {
37 fprintf(stderr, "allocation failed\n");
38 return -1;
39 }
40 snprintf(*name, name_size, "%s/%s", path, template);
41
42 int fd = mkstemp(*name);
43 if (fd < 0) {
44 return -1;
45 }
46
47 if (!set_cloexec(fd)) {
48 close(fd);
49 return -1;
50 }
51
52 if (ftruncate(fd, size) < 0) {
53 close(fd);
54 return -1;
55 }
56
57 return fd;
58 }
59
buffer_release(void * data,struct wl_buffer * wl_buffer)60 static void buffer_release(void *data, struct wl_buffer *wl_buffer) {
61 struct pool_buffer *buffer = data;
62 buffer->busy = false;
63 }
64
65 static const struct wl_buffer_listener buffer_listener = {
66 .release = buffer_release
67 };
68
create_buffer(struct wl_shm * shm,struct pool_buffer * buf,int32_t width,int32_t height,uint32_t format)69 static struct pool_buffer *create_buffer(struct wl_shm *shm,
70 struct pool_buffer *buf, int32_t width, int32_t height,
71 uint32_t format) {
72 uint32_t stride = width * 4;
73 size_t size = stride * height;
74
75 char *name;
76 int fd = create_pool_file(size, &name);
77 assert(fd != -1);
78 void *data = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
79 struct wl_shm_pool *pool = wl_shm_create_pool(shm, fd, size);
80 buf->buffer = wl_shm_pool_create_buffer(pool, 0,
81 width, height, stride, format);
82 wl_shm_pool_destroy(pool);
83 close(fd);
84 unlink(name);
85 free(name);
86 fd = -1;
87
88 buf->size = size;
89 buf->width = width;
90 buf->height = height;
91 buf->data = data;
92 buf->surface = cairo_image_surface_create_for_data(data,
93 CAIRO_FORMAT_ARGB32, width, height, stride);
94 buf->cairo = cairo_create(buf->surface);
95
96 wl_buffer_add_listener(buf->buffer, &buffer_listener, buf);
97 return buf;
98 }
99
destroy_buffer(struct pool_buffer * buffer)100 void destroy_buffer(struct pool_buffer *buffer) {
101 if (buffer->buffer) {
102 wl_buffer_destroy(buffer->buffer);
103 }
104 if (buffer->cairo) {
105 cairo_destroy(buffer->cairo);
106 }
107 if (buffer->surface) {
108 cairo_surface_destroy(buffer->surface);
109 }
110 if (buffer->data) {
111 munmap(buffer->data, buffer->size);
112 }
113 memset(buffer, 0, sizeof(struct pool_buffer));
114 }
115
get_next_buffer(struct wl_shm * shm,struct pool_buffer pool[static2],uint32_t width,uint32_t height)116 struct pool_buffer *get_next_buffer(struct wl_shm *shm,
117 struct pool_buffer pool[static 2], uint32_t width, uint32_t height) {
118 struct pool_buffer *buffer = NULL;
119
120 for (size_t i = 0; i < 2; ++i) {
121 if (pool[i].busy) {
122 continue;
123 }
124 buffer = &pool[i];
125 }
126
127 if (!buffer) {
128 return NULL;
129 }
130
131 if (buffer->width != width || buffer->height != height) {
132 destroy_buffer(buffer);
133 }
134
135 if (!buffer->buffer) {
136 if (!create_buffer(shm, buffer, width, height,
137 WL_SHM_FORMAT_ARGB8888)) {
138 return NULL;
139 }
140 }
141 buffer->busy = true;
142 return buffer;
143 }
144