1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
|
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <fcntl.h>
#include <time.h>
#include <sys/mman.h>
#include <cairo/cairo.h>
#include"buffer.h"
#include"misc.h"
static void randomize_string (char *str, size_t len)
{
struct timespec ts;
clock_gettime(CLOCK_REALTIME, &ts);
long r = ts.tv_nsec;
for (size_t i = 0; i < len; i++, str++)
{
/* Use two byte from the current nano-second to pseudo-randomly
* increase the ASCII character 'A' into another character,
* which will then subsitute the character at *str.
*/
*str = (char)('A' + (r&15) + (r&16));
r >>= 5;
}
}
/* Tries to create a shared memory object and returns its file descriptor if
* successful.
*/
static bool get_shm_fd (int *fd, size_t size)
{
char name[] = "/wlclock-RANDOM";
char *rp = name + 9; /* Pointer to random part. */
size_t rl = 6; /* Length of random part. */
/* Try a few times to get a unique name. */
for (int tries = 100; tries > 0; tries--)
{
/* Make the name pseudo-random to not conflict with other
* running instances of Wlclock.
*/
randomize_string(rp, rl);
/* Try to create a shared memory object. Returns -1 if the
* memory object already exists.
*/
errno = 0;
*fd = shm_open(name, O_RDWR | O_CREAT | O_EXCL, 0600);
/* If a shared memory object was created, set its size and
* return its file descriptor.
*/
if ( *fd >= 0 )
{
shm_unlink(name);
if ( ftruncate(*fd, (off_t)size) < 0 )
{
close(*fd);
return false;
}
return true;
}
/* The EEXIST error means that the name is not unique and we
* must try again.
*/
if ( errno != EEXIST )
{
clocklog(NULL, 0, "ERROR: shm_open: %s\n", strerror(errno));
return false;
}
}
return false;
}
static void buffer_handle_release (void *data, struct wl_buffer *wl_buffer)
{
struct Wlclock_buffer *buffer = (struct Wlclock_buffer *)data;
buffer->busy = false;
}
static const struct wl_buffer_listener buffer_listener = {
.release = buffer_handle_release,
};
static bool create_buffer (struct wl_shm *shm, struct Wlclock_buffer *buffer,
uint32_t _w, uint32_t _h)
{
int32_t w = (int32_t)_w, h = (int32_t)_h;
const enum wl_shm_format wl_fmt = WL_SHM_FORMAT_ARGB8888;
const cairo_format_t cairo_fmt = CAIRO_FORMAT_ARGB32;
int32_t stride = cairo_format_stride_for_width(cairo_fmt, w);
size_t size = (size_t)(stride * h);
buffer->w = _w;
buffer->h = _h;
buffer->size = size;
if ( size == 0 )
{
buffer->memory_object = NULL;
buffer->surface = NULL;
buffer->cairo = NULL;
return true;
}
int fd;
if (! get_shm_fd(&fd, size))
return false;
errno = 0;
if ( MAP_FAILED == (buffer->memory_object = mmap(NULL, size,
PROT_READ | PROT_WRITE, MAP_SHARED,
fd, 0)) )
{
close(fd);
clocklog(NULL, 0, "ERROR: mmap: %s\n", strerror(errno));
return false;
}
struct wl_shm_pool *pool = wl_shm_create_pool(shm, fd, (int32_t)size);
buffer->buffer = wl_shm_pool_create_buffer(pool, 0, w, h, stride,
wl_fmt);
wl_buffer_add_listener(buffer->buffer, &buffer_listener, buffer);
wl_shm_pool_destroy(pool);
close(fd);
buffer->surface = cairo_image_surface_create_for_data(
buffer->memory_object, cairo_fmt, w, h, stride);
buffer->cairo = cairo_create(buffer->surface);
return true;
}
void finish_buffer (struct Wlclock_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->memory_object)
munmap(buffer->memory_object, buffer->size);
memset(buffer, 0, sizeof(struct Wlclock_buffer));
}
bool next_buffer (struct Wlclock_buffer **buffer, struct wl_shm *shm,
struct Wlclock_buffer buffers[static 2], uint32_t w, uint32_t h)
{
/* Check if buffers are busy and use first non-busy one, if it exists.
* If all buffers are busy, exit.
*/
if (! buffers[0].busy)
*buffer = &buffers[0];
else if (! buffers[1].busy)
*buffer = &buffers[1];
else
{
clocklog(NULL, 0, "ERROR: All buffers are busy.\n");
*buffer = NULL;
return false;
}
/* If the buffers dimensions do not match, or if there is no wl_buffer
* or if the buffer does not exist, close it and create a new one.
*/
if ( (*buffer)->w != w || (*buffer)->h != h || ! (*buffer)->buffer )
{
finish_buffer(*buffer);
if (! create_buffer(shm, *buffer, w, h))
return false;
}
return true;
}
|
