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
|
/*
libco.x86 (2016-09-14)
author: byuu
license: public domain
*/
#define LIBCO_C
#include "libco.h"
#include "settings.h"
#include <assert.h>
#include <stdlib.h>
#ifdef __cplusplus
extern "C" {
#endif
#if defined(__clang__) || defined(__GNUC__)
#define fastcall __attribute__((fastcall))
#elif defined(_MSC_VER)
#define fastcall __fastcall
#else
#error "libco: please define fastcall macro"
#endif
static thread_local long co_active_buffer[64];
static thread_local cothread_t co_active_handle = 0;
static void (fastcall *co_swap)(cothread_t, cothread_t) = 0;
#ifdef LIBCO_MPROTECT
alignas(4096)
#else
text_section
#endif
/* ABI: fastcall */
static const unsigned char co_swap_function[4096] = {
0x89, 0x22, /* mov [edx],esp */
0x8b, 0x21, /* mov esp,[ecx] */
0x58, /* pop eax */
0x89, 0x6a, 0x04, /* mov [edx+ 4],ebp */
0x89, 0x72, 0x08, /* mov [edx+ 8],esi */
0x89, 0x7a, 0x0c, /* mov [edx+12],edi */
0x89, 0x5a, 0x10, /* mov [edx+16],ebx */
0x8b, 0x69, 0x04, /* mov ebp,[ecx+ 4] */
0x8b, 0x71, 0x08, /* mov esi,[ecx+ 8] */
0x8b, 0x79, 0x0c, /* mov edi,[ecx+12] */
0x8b, 0x59, 0x10, /* mov ebx,[ecx+16] */
0xff, 0xe0, /* jmp eax */
};
#ifdef _WIN32
#include <windows.h>
static void co_init() {
#ifdef LIBCO_MPROTECT
DWORD old_privileges;
VirtualProtect((void*)co_swap_function, sizeof co_swap_function, PAGE_EXECUTE_READ, &old_privileges);
#endif
}
#else
#include <unistd.h>
#include <sys/mman.h>
static void co_init() {
#ifdef LIBCO_MPROTECT
unsigned long addr = (unsigned long)co_swap_function;
unsigned long base = addr - (addr % sysconf(_SC_PAGESIZE));
unsigned long size = (addr - base) + sizeof co_swap_function;
mprotect((void*)base, size, PROT_READ | PROT_EXEC);
#endif
}
#endif
static void crash() {
assert(0); /* called only if cothread_t entrypoint returns */
}
cothread_t co_active() {
if(!co_active_handle) co_active_handle = &co_active_buffer;
return co_active_handle;
}
cothread_t co_create(unsigned int size, void (*entrypoint)(void),
size_t *out_size) {
cothread_t handle;
if(!co_swap) {
co_init();
co_swap = (void (fastcall*)(cothread_t, cothread_t))co_swap_function;
}
if(!co_active_handle) co_active_handle = &co_active_buffer;
size += 256; /* allocate additional space for storage */
size &= ~15; /* align stack to 16-byte boundary */
*out_size = size;
if(handle = (cothread_t)malloc(size)) {
long *p = (long*)((char*)handle + size); /* seek to top of stack */
*--p = (long)crash; /* crash if entrypoint returns */
*--p = (long)entrypoint; /* start of function */
*(long*)handle = (long)p; /* stack pointer */
}
return handle;
}
void co_delete(cothread_t handle) {
free(handle);
}
void co_switch(cothread_t handle) {
register cothread_t co_previous_handle = co_active_handle;
co_swap(co_active_handle = handle, co_previous_handle);
}
#ifdef __cplusplus
}
#endif
|
