On Mon, Jan 09, 2012 at 10:35:50AM +0200, Heikki Linnakangas wrote:
> On 08.01.2012 22:18, Ryan Kelly wrote:
> >@@ -1570,7 +1570,13 @@ do_connect(char *dbname, char *user, char *host, char
> >*port)
> > keywords[7] = NULL;
> > values[7] = NULL;
> >
> >- n_conn = PQconnectdbParams(keywords, values, true);
> >+ if (sigsetjmp(sigint_interrupt_jmp, 1) != 0) {
> >+ /* got here with longjmp */
> >+ } else {
> >+ sigint_interrupt_enabled = true;
> >+ n_conn = PQconnectdbParams(keywords, values, true);
> >+ sigint_interrupt_enabled = false;
> >+ }
> >
> > free(keywords);
> > free(values);
>
> That assumes that it's safe to longjmp out of PQconnectdbParams at
> any instant. It's not.
I'm guessing because it could result in a resource leak?
> I think you'd need to use the asynchronous connection functions
> PQconnectStartParams() and PQconnectPoll(), and select().
New patch attached.
>
> --
> Heikki Linnakangas
> EnterpriseDB http://www.enterprisedb.com
-Ryan Kelly
diff --git a/src/bin/psql/command.c b/src/bin/psql/command.c
index 69fac83..7c31891 100644
--- a/src/bin/psql/command.c
+++ b/src/bin/psql/command.c
@@ -1516,7 +1516,7 @@ static bool
do_connect(char *dbname, char *user, char *host, char *port)
{
PGconn *o_conn = pset.db,
- *n_conn;
+ *n_conn = NULL;
char *password = NULL;
if (!dbname)
@@ -1570,14 +1570,69 @@ do_connect(char *dbname, char *user, char *host, char *port)
keywords[7] = NULL;
values[7] = NULL;
- n_conn = PQconnectdbParams(keywords, values, true);
+ /* attempt connection asynchronously */
+ n_conn = PQconnectStartParams(keywords, values, true);
+
+ if (sigsetjmp(sigint_interrupt_jmp, 1) != 0)
+ {
+ /* interrupted during connection attempt */
+ PQfinish(n_conn);
+ n_conn = NULL;
+ } else {
+ int waiting = true, select_ret;
+ struct timeval timeout;
+ fd_set input_mask;
+
+ FD_ZERO(&input_mask);
+ FD_SET(PQsocket(n_conn), &input_mask);
+
+ timeout.tv_sec = 0;
+ timeout.tv_usec = 500000; /* 0.5 sec */
+
+ sigint_interrupt_enabled = true;
+ select_ret = select(PQsocket(n_conn) + 1, &input_mask, NULL, NULL, &timeout);
+ sigint_interrupt_enabled = false;
+
+ /* don't even bother waiting, something wrong with the socket */
+ if (select_ret < 0 && errno != EINTR)
+ {
+ waiting = false;
+ }
+
+ while(waiting)
+ {
+ switch(PQconnectPoll(n_conn))
+ {
+ case PGRES_POLLING_READING:
+ case PGRES_POLLING_WRITING:
+ timeout.tv_sec = 0;
+ timeout.tv_usec = 500000;
+
+ sigint_interrupt_enabled = true;
+ select_ret = select(PQsocket(n_conn) + 1, &input_mask, NULL, NULL, &timeout);
+ sigint_interrupt_enabled = false;
+
+ if (select_ret < 0 && errno != EINTR)
+ {
+ waiting = false;
+ }
+ break;
+ default:
+ waiting = false;
+ break;
+ }
+ }
+ }
free(keywords);
free(values);
/* We can immediately discard the password -- no longer needed */
if (password)
+ {
free(password);
+ password = NULL;
+ }
if (PQstatus(n_conn) == CONNECTION_OK)
break;
@@ -1586,7 +1641,7 @@ do_connect(char *dbname, char *user, char *host, char *port)
* Connection attempt failed; either retry the connection attempt with
* a new password, or give up.
*/
- if (!password && PQconnectionNeedsPassword(n_conn) && pset.getPassword != TRI_NO)
+ if (PQconnectionNeedsPassword(n_conn) && pset.getPassword != TRI_NO)
{
PQfinish(n_conn);
password = prompt_for_password(user);
@@ -1600,7 +1655,8 @@ do_connect(char *dbname, char *user, char *host, char *port)
*/
if (pset.cur_cmd_interactive)
{
- psql_error("%s", PQerrorMessage(n_conn));
+ if (n_conn)
+ psql_error("%s", PQerrorMessage(n_conn));
/* pset.db is left unmodified */
if (o_conn)
@@ -1608,7 +1664,9 @@ do_connect(char *dbname, char *user, char *host, char *port)
}
else
{
- psql_error("\\connect: %s", PQerrorMessage(n_conn));
+ if (n_conn)
+ psql_error("\\connect: %s", PQerrorMessage(n_conn));
+
if (o_conn)
{
PQfinish(o_conn);
diff --git a/src/bin/psql/startup.c b/src/bin/psql/startup.c
index 8b1864c..e53d84c 100644
--- a/src/bin/psql/startup.c
+++ b/src/bin/psql/startup.c
@@ -111,8 +111,6 @@ main(int argc, char *argv[])
setvbuf(stderr, NULL, _IONBF, 0);
#endif
- setup_cancel_handler();
-
pset.progname = get_progname(argv[0]);
pset.db = NULL;
@@ -245,8 +243,9 @@ main(int argc, char *argv[])
}
/*
- * Now find something to do
+ * Now find something to do (and handle cancellation, if applicable)
*/
+ setup_cancel_handler();
/*
* process file given by -f
--
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