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authorDaniel Stenberg <daniel@haxx.se>2019-05-28 08:23:43 +0200
committerDaniel Stenberg <daniel@haxx.se>2019-05-28 12:17:02 +0200
commit8581e1928ea8e125021408ec071fcedb0276c7fe (patch)
treec97f0418a6a97458f252f058bcb62b21592404eb
parent28526e9c80f7c923fac0aef503c7a63d84994282 (diff)
downloadcurl-8581e1928ea8e125021408ec071fcedb0276c7fe.tar.gz
multi: track users of a socket better
They need to be removed from the socket hash linked list with more care. When sh_delentry() is called to remove a sockethash entry, remove all individual transfers from the list first. To enable this, each Curl_easy struct now stores a pointer to the sockethash entry to know how to remove itself. Reported-by: Tom van der Woerdt and Kunal Ekawde Fixes #3952 Fixes #3904 Closes #3953
-rw-r--r--lib/multi.c38
-rw-r--r--lib/urldata.h1
2 files changed, 27 insertions, 12 deletions
diff --git a/lib/multi.c b/lib/multi.c
index c7c46eefc..ec0318735 100644
--- a/lib/multi.c
+++ b/lib/multi.c
@@ -241,8 +241,17 @@ static struct Curl_sh_entry *sh_addentry(struct curl_hash *sh,
/* delete the given socket + handle from the hash */
-static void sh_delentry(struct curl_hash *sh, curl_socket_t s)
+static void sh_delentry(struct Curl_sh_entry *entry,
+ struct curl_hash *sh, curl_socket_t s)
{
+ struct curl_llist *list = &entry->list;
+ struct curl_llist_element *e;
+ /* clear the list of transfers first */
+ for(e = list->head; e; e = list->head) {
+ struct Curl_easy *dta = e->ptr;
+ Curl_llist_remove(&entry->list, e, NULL);
+ dta->sh_entry = NULL;
+ }
/* We remove the hash entry. This will end up in a call to
sh_freeentry(). */
Curl_hash_delete(sh, (char *)&s, sizeof(curl_socket_t));
@@ -780,6 +789,11 @@ bool Curl_multiplex_wanted(const struct Curl_multi *multi)
static void detach_connnection(struct Curl_easy *data)
{
struct connectdata *conn = data->conn;
+ if(data->sh_entry) {
+ /* still listed as a user of a socket hash entry, remove it */
+ Curl_llist_remove(&data->sh_entry->list, &data->sh_queue, NULL);
+ data->sh_entry = NULL;
+ }
if(conn)
Curl_llist_remove(&conn->easyq, &data->conn_queue, NULL);
data->conn = NULL;
@@ -2276,6 +2290,7 @@ static CURLMcode singlesocket(struct Curl_multi *multi,
/* add 'data' to the list of handles using this socket! */
Curl_llist_insert_next(&entry->list, entry->list.tail,
data, &data->sh_queue);
+ data->sh_entry = entry;
}
comboaction = (entry->writers? CURL_POLL_OUT : 0) |
@@ -2335,11 +2350,7 @@ static CURLMcode singlesocket(struct Curl_multi *multi,
multi->socket_cb(data, s, CURL_POLL_REMOVE,
multi->socket_userp,
entry->socketp);
- sh_delentry(&multi->sockhash, s);
- }
- else {
- /* remove this transfer as a user of this socket */
- Curl_llist_remove(&entry->list, &data->sh_queue, NULL);
+ sh_delentry(entry, &multi->sockhash, s);
}
}
} /* for loop over numsocks */
@@ -2383,7 +2394,7 @@ void Curl_multi_closed(struct Curl_easy *data, curl_socket_t s)
entry->socketp);
/* now remove it from the socket hash */
- sh_delentry(&multi->sockhash, s);
+ sh_delentry(entry, &multi->sockhash, s);
}
}
}
@@ -2474,7 +2485,6 @@ static CURLMcode multi_socket(struct Curl_multi *multi,
return result;
}
if(s != CURL_SOCKET_TIMEOUT) {
-
struct Curl_sh_entry *entry = sh_getentry(&multi->sockhash, s);
if(!entry)
@@ -2487,15 +2497,19 @@ static CURLMcode multi_socket(struct Curl_multi *multi,
else {
struct curl_llist *list = &entry->list;
struct curl_llist_element *e;
+ struct curl_llist_element *enext;
SIGPIPE_VARIABLE(pipe_st);
/* the socket can be shared by many transfers, iterate */
- for(e = list->head; e; e = e->next) {
+ for(e = list->head; e; e = enext) {
data = (struct Curl_easy *)e->ptr;
- if(data->magic != CURLEASY_MAGIC_NUMBER)
- /* bad bad bad bad bad bad bad */
- return CURLM_INTERNAL_ERROR;
+ /* assign 'enext' here since the 'e' struct might be cleared
+ further down in the singlesocket() call */
+ enext = e->next;
+
+ DEBUGASSERT(data);
+ DEBUGASSERT(data->magic == CURLEASY_MAGIC_NUMBER);
if(data->conn && !(data->conn->handler->flags & PROTOPT_DIRLOCK))
/* set socket event bitmask if they're not locked */
diff --git a/lib/urldata.h b/lib/urldata.h
index d759592d9..af51b6942 100644
--- a/lib/urldata.h
+++ b/lib/urldata.h
@@ -1778,6 +1778,7 @@ struct Curl_easy {
struct connectdata *conn;
struct curl_llist_element connect_queue;
struct curl_llist_element sh_queue; /* list per Curl_sh_entry */
+ struct Curl_sh_entry *sh_entry; /* the socket hash this was added to */
struct curl_llist_element conn_queue; /* list per connectdata */
CURLMstate mstate; /* the handle's state */