pgpool2.git / summary / log / commit / refs

commit    a536699c5ee4693c07c5779d0d4eeb76c9e826d2
Author:   Tatsuo Ishii <ishii at sraoss.co.jp>
Date:     Mon Jul 20 12:06:25 2009 +0000

    Add pool_set_timeout() to control pool_check_fd()'s behavior.
    This can be used for various places.
    The first user is reset_backend() to fix following scenario:
    Do COPY_FROM(for example pgbench -i)
    Cancel pgbench
    pgpool waits for response from backend while sending reset queries and
    hang.
    Backend waits for data coming from pgpool forever.
    
    BTW, I don't think PostgreSQL's befaviro for COPY_FROM is quite
    correct since the doc stats:"Receipt of any other non-copy message
    type constitutes an error that will abort the copy-in state as
    described above"
    If my understanding correct, COPY_FROM should abort copy-in state
    if it receives ABORT (issued in reset_backend).
    It seems PostgreSQL is not implemented as stated in the doc...


 pool.h               |  1 +
 pool_process_query.c | 38 +++++++++++++++++++++++++++++++++++---
 2 files changed, 36 insertions(+), 3 deletions(-)

diff --git a/pool.h b/pool.h
index a286d4613..57b767e63 100644
--- a/pool.h
+++ b/pool.h
@@ -483,6 +483,7 @@ extern int connect_unix_domain_socket(int secondary_backend);
 extern int connect_inet_domain_socket_by_port(char *host, int port);
 extern int connect_unix_domain_socket_by_port(int port, char *socket_dir);
 
+extern void pool_set_timeout(int timeoutval);
 extern int pool_check_fd(POOL_CONNECTION *cp);
 
 extern void pool_send_frontend_exits(POOL_CONNECTION_POOL *backend);
diff --git a/pool_process_query.c b/pool_process_query.c
index d8ef5f12b..252e559df 100644
--- a/pool_process_query.c
+++ b/pool_process_query.c
@@ -74,6 +74,9 @@ static void free_select_result(POOL_SELECT_RESULT *result);
 static bool is_internal_transaction_needed(Node *node);
 static int compare(const void *p1, const void *p2);
 
+/* timeout sec for pool_check_fd */
+static int timeoutsec;
+
 int in_load_balance;	/* non 0 if in load balance mode */
 int selected_slot;		/* selected DB node */
 int master_slave_dml;	/* non 0 if master/slave mode is specified in config file */
@@ -873,9 +876,20 @@ int synchronize(POOL_CONNECTION *cp)
 	return pool_check_fd(cp);
 }
 
+/*
+ * set timeout in seconds for pool_check_fd
+ * if timeoutval < 0, we assume no timeout(wait forever).
+ */
+void pool_set_timeout(int timeoutval)
+{
+	if (timeoutval > 0)
+		timeoutsec = timeoutval;
+	else
+		timeoutsec = 0;
+}
+
 /*
  * wait until read data is ready
- * if notimeout is non 0, wait forever.
  */
 int pool_check_fd(POOL_CONNECTION *cp)
 {
@@ -883,9 +897,20 @@ int pool_check_fd(POOL_CONNECTION *cp)
 	fd_set exceptmask;
 	int fd;
 	int fds;
+	struct timeval timeout;
+	struct timeval *timeoutp;
 
 	fd = cp->fd;
 
+	if (timeoutsec > 0)
+	{
+		timeout.tv_sec = timeoutsec;
+		timeout.tv_usec = 0;
+		timeoutp = &timeout;
+	}
+	else
+		timeoutp = NULL;
+
 	for (;;)
 	{
 		FD_ZERO(&readmask);
@@ -893,8 +918,7 @@ int pool_check_fd(POOL_CONNECTION *cp)
 		FD_SET(fd, &readmask);
 		FD_SET(fd, &exceptmask);
 
-		/* no timeout */
-		fds = select(fd+1, &readmask, NULL, &exceptmask, NULL);
+		fds = select(fd+1, &readmask, NULL, &exceptmask, timeoutp);
 		if (fds == -1)
 		{
 			if (errno == EAGAIN || errno == EINTR)
@@ -903,6 +927,8 @@ int pool_check_fd(POOL_CONNECTION *cp)
 			pool_error("pool_check_fd: select() failed. reason %s", strerror(errno));
 			break;
 		}
+		else if (fds == 0)		/* timeout */
+			break;
 
 		if (FD_ISSET(fd, &exceptmask))
 		{
@@ -2067,9 +2093,15 @@ static int reset_backend(POOL_CONNECTION_POOL *backend, int qcnt)
 
 	/* if transaction state is idle, we don't need to issue ABORT */
 	if (TSTATE(backend) == 'I' && !strcmp("ABORT", query))
+	pool_set_timeout(10);
+
 		return 0;
+	{
+		pool_set_timeout(0);
 
+	}
 	if (SimpleQuery(NULL, backend, query) != POOL_CONTINUE)
+	pool_set_timeout(0);
 		return -1;
 
 	return 1;


[parent: cbb414b93a31]