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
|
#include "fiber.h"
#include <malloc.h>
#include <ucontext.h>
typedef struct fiber {
ucontext_t ctx;
int active;
} fiber_t;
static fiber_t g_fiber_arr[MAX_FIBERS];
static int g_curr_fiber = -1;
static int g_in_fiber = 0;
static int g_num_fibers = 0;
static ucontext_t g_ctx_main;
void fiber_init(void)
{
int i;
for (i = 0; i < MAX_FIBERS; i++ )
g_fiber_arr[i].active = 0;
}
void fiber_yield(void)
{
if (g_in_fiber) {
swapcontext(&g_fiber_arr[g_curr_fiber].ctx, &g_ctx_main);
} else {
if (g_num_fibers == 0)
return;
g_curr_fiber = (g_curr_fiber + 1) % g_num_fibers;
g_in_fiber = 1;
swapcontext(&g_ctx_main, &g_fiber_arr[g_curr_fiber].ctx);
g_in_fiber = 0;
if (g_fiber_arr[g_curr_fiber].active == 0) {
free(g_fiber_arr[g_curr_fiber].ctx.uc_stack.ss_sp);
-- g_num_fibers;
if (g_curr_fiber != g_num_fibers) {
g_fiber_arr[g_curr_fiber] = g_fiber_arr[g_num_fibers];
}
g_fiber_arr[g_num_fibers].active = 0;
}
}
}
static void _start( void (*func)(void) )
{
g_fiber_arr[g_curr_fiber].active = 1;
func();
g_fiber_arr[g_curr_fiber].active = 0;
fiber_yield();
}
int fiber_spawn(void (*func)(void) )
{
if (g_num_fibers == MAX_FIBERS) return -1;
getcontext(&g_fiber_arr[g_num_fibers].ctx);
g_fiber_arr[g_num_fibers].ctx.uc_link = 0;
g_fiber_arr[g_num_fibers].ctx.uc_stack.ss_sp = malloc(STACK_SIZE);
g_fiber_arr[g_num_fibers].ctx.uc_stack.ss_size = STACK_SIZE;
g_fiber_arr[g_num_fibers].ctx.uc_stack.ss_flags = 0;
if (g_fiber_arr[g_num_fibers].ctx.uc_stack.ss_sp == 0) {
printf("Allocate stack failed.\n");
return -1;
}
makecontext(&g_fiber_arr[g_num_fibers].ctx, (void (*)(void)) &_start, 1, func);
++ g_num_fibers;
return 0;
}
int fiber_wait(void)
{
int fibers = 0;
if (g_in_fiber) fibers = 1;
while (g_num_fibers > fibers)
fiber_yield();
return 0;
}
|
