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[Qemu-block] [PATCH 7/7] curl: do not do aio_poll when waiting for a fre
From: |
Paolo Bonzini |
Subject: |
[Qemu-block] [PATCH 7/7] curl: do not do aio_poll when waiting for a free CURLState |
Date: |
Wed, 10 May 2017 16:32:05 +0200 |
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 <address@hidden>
---
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
- Re: [Qemu-block] [PATCH 3/7] curl: avoid recursive locking of BDRVCURLState mutex, (continued)
- [Qemu-block] [PATCH 4/7] curl: split curl_find_state/curl_init_state, Paolo Bonzini, 2017/05/10
- [Qemu-block] [PATCH 5/7] curl: convert CURLAIOCB to byte values, Paolo Bonzini, 2017/05/10
- [Qemu-block] [PATCH 7/7] curl: do not do aio_poll when waiting for a free CURLState,
Paolo Bonzini <=
- [Qemu-block] [PATCH 6/7] curl: convert readv to coroutines, Paolo Bonzini, 2017/05/10
- Re: [Qemu-block] [Qemu-devel] [PATCH v2 0/7] curl: locking cleanups/fixes, coroutine conversion, remove aio_poll, no-reply, 2017/05/10
- Re: [Qemu-block] [PATCH v2 0/7] curl: locking cleanups/fixes, coroutine conversion, remove aio_poll, Richard W.M. Jones, 2017/05/10