Revision dcc772e2 async.c
| b/async.c | ||
|---|---|---|
| 47 | 47 |
bh->ctx = ctx; |
| 48 | 48 |
bh->cb = cb; |
| 49 | 49 |
bh->opaque = opaque; |
| 50 |
qemu_mutex_lock(&ctx->bh_lock); |
|
| 50 | 51 |
bh->next = ctx->first_bh; |
| 52 |
/* Make sure that the members are ready before putting bh into list */ |
|
| 53 |
smp_wmb(); |
|
| 51 | 54 |
ctx->first_bh = bh; |
| 55 |
qemu_mutex_unlock(&ctx->bh_lock); |
|
| 52 | 56 |
return bh; |
| 53 | 57 |
} |
| 54 | 58 |
|
| 59 |
/* Multiple occurrences of aio_bh_poll cannot be called concurrently */ |
|
| 55 | 60 |
int aio_bh_poll(AioContext *ctx) |
| 56 | 61 |
{
|
| 57 | 62 |
QEMUBH *bh, **bhp, *next; |
| ... | ... | |
| 61 | 66 |
|
| 62 | 67 |
ret = 0; |
| 63 | 68 |
for (bh = ctx->first_bh; bh; bh = next) {
|
| 69 |
/* Make sure that fetching bh happens before accessing its members */ |
|
| 70 |
smp_read_barrier_depends(); |
|
| 64 | 71 |
next = bh->next; |
| 65 | 72 |
if (!bh->deleted && bh->scheduled) {
|
| 66 | 73 |
bh->scheduled = 0; |
| 74 |
/* Paired with write barrier in bh schedule to ensure reading for |
|
| 75 |
* idle & callbacks coming after bh's scheduling. |
|
| 76 |
*/ |
|
| 77 |
smp_rmb(); |
|
| 67 | 78 |
if (!bh->idle) |
| 68 | 79 |
ret = 1; |
| 69 | 80 |
bh->idle = 0; |
| ... | ... | |
| 75 | 86 |
|
| 76 | 87 |
/* remove deleted bhs */ |
| 77 | 88 |
if (!ctx->walking_bh) {
|
| 89 |
qemu_mutex_lock(&ctx->bh_lock); |
|
| 78 | 90 |
bhp = &ctx->first_bh; |
| 79 | 91 |
while (*bhp) {
|
| 80 | 92 |
bh = *bhp; |
| ... | ... | |
| 85 | 97 |
bhp = &bh->next; |
| 86 | 98 |
} |
| 87 | 99 |
} |
| 100 |
qemu_mutex_unlock(&ctx->bh_lock); |
|
| 88 | 101 |
} |
| 89 | 102 |
|
| 90 | 103 |
return ret; |
| ... | ... | |
| 94 | 107 |
{
|
| 95 | 108 |
if (bh->scheduled) |
| 96 | 109 |
return; |
| 97 |
bh->scheduled = 1; |
|
| 98 | 110 |
bh->idle = 1; |
| 111 |
/* Make sure that idle & any writes needed by the callback are done |
|
| 112 |
* before the locations are read in the aio_bh_poll. |
|
| 113 |
*/ |
|
| 114 |
smp_wmb(); |
|
| 115 |
bh->scheduled = 1; |
|
| 99 | 116 |
} |
| 100 | 117 |
|
| 101 | 118 |
void qemu_bh_schedule(QEMUBH *bh) |
| 102 | 119 |
{
|
| 103 | 120 |
if (bh->scheduled) |
| 104 | 121 |
return; |
| 105 |
bh->scheduled = 1; |
|
| 106 | 122 |
bh->idle = 0; |
| 123 |
/* Make sure that idle & any writes needed by the callback are done |
|
| 124 |
* before the locations are read in the aio_bh_poll. |
|
| 125 |
*/ |
|
| 126 |
smp_wmb(); |
|
| 127 |
bh->scheduled = 1; |
|
| 107 | 128 |
aio_notify(bh->ctx); |
| 108 | 129 |
} |
| 109 | 130 |
|
| 131 |
|
|
| 132 |
/* This func is async. |
|
| 133 |
*/ |
|
| 110 | 134 |
void qemu_bh_cancel(QEMUBH *bh) |
| 111 | 135 |
{
|
| 112 | 136 |
bh->scheduled = 0; |
| 113 | 137 |
} |
| 114 | 138 |
|
| 139 |
/* This func is async.The bottom half will do the delete action at the finial |
|
| 140 |
* end. |
|
| 141 |
*/ |
|
| 115 | 142 |
void qemu_bh_delete(QEMUBH *bh) |
| 116 | 143 |
{
|
| 117 | 144 |
bh->scheduled = 0; |
| ... | ... | |
| 176 | 203 |
thread_pool_free(ctx->thread_pool); |
| 177 | 204 |
aio_set_event_notifier(ctx, &ctx->notifier, NULL, NULL); |
| 178 | 205 |
event_notifier_cleanup(&ctx->notifier); |
| 206 |
qemu_mutex_destroy(&ctx->bh_lock); |
|
| 179 | 207 |
g_array_free(ctx->pollfds, TRUE); |
| 180 | 208 |
} |
| 181 | 209 |
|
| ... | ... | |
| 211 | 239 |
ctx = (AioContext *) g_source_new(&aio_source_funcs, sizeof(AioContext)); |
| 212 | 240 |
ctx->pollfds = g_array_new(FALSE, FALSE, sizeof(GPollFD)); |
| 213 | 241 |
ctx->thread_pool = NULL; |
| 242 |
qemu_mutex_init(&ctx->bh_lock); |
|
| 214 | 243 |
event_notifier_init(&ctx->notifier, false); |
| 215 | 244 |
aio_set_event_notifier(ctx, &ctx->notifier, |
| 216 | 245 |
(EventNotifierHandler *) |
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