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
|
/*
* emscripten fiber coroutine initialization code
* based on coroutine-ucontext.c
*
* Copyright (C) 2006 Anthony Liguori <anthony@codemonkey.ws>
* Copyright (C) 2011 Kevin Wolf <kwolf@redhat.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.0 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
#include "qemu/osdep.h"
#include "qemu/coroutine_int.h"
#include "qemu/coroutine-tls.h"
#include <emscripten/fiber.h>
typedef struct {
Coroutine base;
void *stack;
size_t stack_size;
void *asyncify_stack;
size_t asyncify_stack_size;
CoroutineAction action;
emscripten_fiber_t fiber;
} CoroutineEmscripten;
/**
* Per-thread coroutine bookkeeping
*/
QEMU_DEFINE_STATIC_CO_TLS(Coroutine *, current);
QEMU_DEFINE_STATIC_CO_TLS(CoroutineEmscripten *, leader);
size_t leader_asyncify_stack_size = COROUTINE_STACK_SIZE;
static void coroutine_trampoline(void *co_)
{
Coroutine *co = co_;
while (true) {
co->entry(co->entry_arg);
qemu_coroutine_switch(co, co->caller, COROUTINE_TERMINATE);
}
}
Coroutine *qemu_coroutine_new(void)
{
CoroutineEmscripten *co;
co = g_malloc0(sizeof(*co));
co->stack_size = COROUTINE_STACK_SIZE;
co->stack = qemu_alloc_stack(&co->stack_size);
co->asyncify_stack_size = COROUTINE_STACK_SIZE;
co->asyncify_stack = g_malloc0(co->asyncify_stack_size);
emscripten_fiber_init(&co->fiber, coroutine_trampoline, &co->base,
co->stack, co->stack_size, co->asyncify_stack,
co->asyncify_stack_size);
return &co->base;
}
void qemu_coroutine_delete(Coroutine *co_)
{
CoroutineEmscripten *co = DO_UPCAST(CoroutineEmscripten, base, co_);
qemu_free_stack(co->stack, co->stack_size);
g_free(co->asyncify_stack);
g_free(co);
}
CoroutineAction qemu_coroutine_switch(Coroutine *from_, Coroutine *to_,
CoroutineAction action)
{
CoroutineEmscripten *from = DO_UPCAST(CoroutineEmscripten, base, from_);
CoroutineEmscripten *to = DO_UPCAST(CoroutineEmscripten, base, to_);
set_current(to_);
to->action = action;
emscripten_fiber_swap(&from->fiber, &to->fiber);
return from->action;
}
Coroutine *qemu_coroutine_self(void)
{
Coroutine *self = get_current();
if (!self) {
CoroutineEmscripten *leaderp = get_leader();
if (!leaderp) {
leaderp = g_malloc0(sizeof(*leaderp));
leaderp->asyncify_stack = g_malloc0(leader_asyncify_stack_size);
leaderp->asyncify_stack_size = leader_asyncify_stack_size;
emscripten_fiber_init_from_current_context(
&leaderp->fiber,
leaderp->asyncify_stack,
leaderp->asyncify_stack_size);
leaderp->stack = leaderp->fiber.stack_limit;
leaderp->stack_size =
leaderp->fiber.stack_base - leaderp->fiber.stack_limit;
set_leader(leaderp);
}
self = &leaderp->base;
set_current(self);
}
return self;
}
bool qemu_in_coroutine(void)
{
Coroutine *self = get_current();
return self && self->caller;
}
|
