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authorPaolo Bonzini <pbonzini@redhat.com>2017-05-15 12:00:59 +0200
committerJeff Cody <jcody@redhat.com>2017-05-16 10:34:50 -0400
commit2bb5c936c5827e1d831002f7a7517cb8c2c2201d (patch)
treea0a51f4bd3d85535a2945022bc343885097e881e
parent28256d8246f8905cc41cae3db50e5967059d4600 (diff)
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curl: do not do aio_poll when waiting for a free CURLState
Instead, put the CURLAIOCB on a wait list and yield; 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 easily use QSIMPLEQ and open-code a CoQueue, protected by the BDRVCURLState QemuMutex instead of a CoMutex. Reviewed-by: Jeff Cody <jcody@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-id: 20170515100059.15795-8-pbonzini@redhat.com Signed-off-by: Jeff Cody <jcody@redhat.com>
-rw-r--r--block/curl.c16
1 files changed, 15 insertions, 1 deletions
diff --git a/block/curl.c b/block/curl.c
index 1c04903..2a244e2 100644
--- a/block/curl.c
+++ b/block/curl.c
@@ -99,6 +99,8 @@ typedef struct CURLAIOCB {
size_t start;
size_t end;
+
+ QSIMPLEQ_ENTRY(CURLAIOCB) next;
} CURLAIOCB;
typedef struct CURLSocket {
@@ -134,6 +136,7 @@ typedef struct BDRVCURLState {
bool accept_range;
AioContext *aio_context;
QemuMutex mutex;
+ QSIMPLEQ_HEAD(, CURLAIOCB) free_state_waitq;
char *username;
char *password;
char *proxyusername;
@@ -533,6 +536,7 @@ 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]);
@@ -549,6 +553,14 @@ 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,
@@ -766,6 +778,7 @@ static int curl_open(BlockDriverState *bs, QDict *options, int flags,
}
DPRINTF("CURL: Opening %s\n", file);
+ QSIMPLEQ_INIT(&s->free_state_waitq);
s->aio_context = bdrv_get_aio_context(bs);
s->url = g_strdup(file);
qemu_mutex_lock(&s->mutex);
@@ -866,8 +879,9 @@ 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);
}