On Wed, May 10, 2017 at 04:32:05PM +0200, Paolo Bonzini wrote:
> Instead, put the CURLAIOCB on a wait list; curl_clean_state will
> wake the corresponding coroutine.
>
> Because of CURL's callback-based structure, we cannot easily convert
> everything to CoMutex/CoQueue; keeping the QemuMutex is simpler.
> However, CoQueue is a simple wrapper around a linked list, so we can
> use QSIMPLEQ easily to open-code a CoQueue that has a QemuMutex's
> protection instead of a CoMutex's.
>
> Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
> ---
> block/curl.c | 16 +++++++++++++++-
> 1 file changed, 15 insertions(+), 1 deletion(-)
>
> diff --git a/block/curl.c b/block/curl.c
> index 80870bd60c..4ccdf63510 100644
> --- a/block/curl.c
> +++ b/block/curl.c
> @@ -98,6 +98,8 @@ typedef struct CURLAIOCB {
>
> size_t start;
> size_t end;
> +
> + QSIMPLEQ_ENTRY(CURLAIOCB) next;
> } CURLAIOCB;
>
> typedef struct CURLSocket {
> @@ -133,6 +135,7 @@ typedef struct BDRVCURLState {
> bool accept_range;
> AioContext *aio_context;
> QemuMutex mutex;
> + QSIMPLEQ_HEAD(, CURLAIOCB) free_state_waitq;
> char *username;
> char *password;
> char *proxyusername;
> @@ -532,6 +535,7 @@ static int curl_init_state(BDRVCURLState *s, CURLState
> *state)
> /* Called with s->mutex held. */
> static void curl_clean_state(CURLState *s)
> {
> + CURLAIOCB *next;
> int j;
> for (j=0; j<CURL_NUM_ACB; j++) {
> assert(!s->acb[j]);
> @@ -548,6 +552,14 @@ static void curl_clean_state(CURLState *s)
> }
>
> s->in_use = 0;
> +
> + next = QSIMPLEQ_FIRST(&s->s->free_state_waitq);
> + if (next) {
> + QSIMPLEQ_REMOVE_HEAD(&s->s->free_state_waitq, next);
> + qemu_mutex_unlock(&s->s->mutex);
> + aio_co_wake(next->co);
> + qemu_mutex_lock(&s->s->mutex);
> + }
> }
>
> static void curl_parse_filename(const char *filename, QDict *options,
> @@ -744,6 +756,7 @@ static int curl_open(BlockDriverState *bs, QDict
> *options, int flags,
>
> DPRINTF("CURL: Opening %s\n", file);
> qemu_mutex_init(&s->mutex);
> + QSIMPLEQ_INIT(&s->free_state_waitq);
> s->aio_context = bdrv_get_aio_context(bs);
> s->url = g_strdup(file);
> qemu_mutex_lock(&s->mutex);
> @@ -843,8 +856,9 @@ static void curl_setup_preadv(BlockDriverState *bs,
> CURLAIOCB *acb)
> if (state) {
> break;
> }
> + QSIMPLEQ_INSERT_TAIL(&s->free_state_waitq, acb, next);
> qemu_mutex_unlock(&s->mutex);
> - aio_poll(bdrv_get_aio_context(bs), true);
> + qemu_coroutine_yield();
> qemu_mutex_lock(&s->mutex);
> }
>
> --
> 2.12.2
>
Reviewed-by: Jeff Cody <jc...@redhat.com>
