aio: tweak walking in dispatch phase

Preparing for the following patch, use QLIST_FOREACH_SAFE and
modify the placement of walking_handlers increment/decrement.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Message-id: 20170112180800.21085-7-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
This commit is contained in:
Paolo Bonzini 2017-01-12 19:07:56 +01:00 committed by Stefan Hajnoczi
parent 56d2c3c60d
commit abf90d3921
2 changed files with 24 additions and 28 deletions

View File

@ -369,19 +369,17 @@ bool aio_pending(AioContext *ctx)
static bool aio_dispatch_handlers(AioContext *ctx)
{
AioHandler *node;
AioHandler *node, *tmp;
bool progress = false;
/*
* We have to walk very carefully in case aio_set_fd_handler is
* called while we're walking.
*/
node = QLIST_FIRST(&ctx->aio_handlers);
while (node) {
AioHandler *tmp;
int revents;
ctx->walking_handlers++;
ctx->walking_handlers++;
QLIST_FOREACH_SAFE(node, &ctx->aio_handlers, node, tmp) {
int revents;
revents = node->pfd.revents & node->pfd.events;
node->pfd.revents = 0;
@ -405,17 +403,17 @@ static bool aio_dispatch_handlers(AioContext *ctx)
progress = true;
}
tmp = node;
node = QLIST_NEXT(node, node);
ctx->walking_handlers--;
if (!ctx->walking_handlers && tmp->deleted) {
QLIST_REMOVE(tmp, node);
g_free(tmp);
if (node->deleted) {
ctx->walking_handlers--;
if (!ctx->walking_handlers) {
QLIST_REMOVE(node, node);
g_free(node);
}
ctx->walking_handlers++;
}
}
ctx->walking_handlers--;
return progress;
}

View File

@ -227,20 +227,18 @@ bool aio_pending(AioContext *ctx)
static bool aio_dispatch_handlers(AioContext *ctx, HANDLE event)
{
AioHandler *node;
AioHandler *node, *tmp;
bool progress = false;
ctx->walking_handlers++;
/*
* We have to walk very carefully in case aio_set_fd_handler is
* called while we're walking.
*/
node = QLIST_FIRST(&ctx->aio_handlers);
while (node) {
AioHandler *tmp;
QLIST_FOREACH_SAFE(node, &ctx->aio_handlers, node, tmp) {
int revents = node->pfd.revents;
ctx->walking_handlers++;
if (!node->deleted &&
(revents || event_notifier_get_handle(node->e) == event) &&
node->io_notify) {
@ -275,17 +273,17 @@ static bool aio_dispatch_handlers(AioContext *ctx, HANDLE event)
}
}
tmp = node;
node = QLIST_NEXT(node, node);
ctx->walking_handlers--;
if (!ctx->walking_handlers && tmp->deleted) {
QLIST_REMOVE(tmp, node);
g_free(tmp);
if (node->deleted) {
ctx->walking_handlers--;
if (!ctx->walking_handlers) {
QLIST_REMOVE(node, node);
g_free(node);
}
ctx->walking_handlers++;
}
}
ctx->walking_handlers--;
return progress;
}