Fix pq_getbyte_if_available() function. It was confused on what it

returns if no data is immediately available. Patch by me with numerous
fixes from Fujii Masao and Magnus Hagander.

diff --git a/src/backend/libpq/be-secure.c b/src/backend/libpq/be-secure.c
index ea6b16c13ba6dbf0ecb0a6fedcc94661d15d15d9..9499899950174fb9a02507ec4a1845684d97091b 100644 (file)
--- a/src/backend/libpq/be-secure.c
+++ b/src/backend/libpq/be-secure.c
@@ -11,7 +11,7 @@
  *
  *
  * IDENTIFICATION
- *       $PostgreSQL: pgsql/src/backend/libpq/be-secure.c,v 1.96 2010/01/15 09:19:02 heikki Exp $
+ *       $PostgreSQL: pgsql/src/backend/libpq/be-secure.c,v 1.97 2010/02/18 11:13:45 heikki Exp $
  *
  *       Since the server static private key ($DataDir/server.key)
  *       will normally be stored unencrypted so that the database
@@ -256,7 +256,11 @@ rloop:
                        case SSL_ERROR_WANT_READ:
                        case SSL_ERROR_WANT_WRITE:
                                if (port->noblock)
-                                       return 0;
+                               {
+                                       errno = EWOULDBLOCK;
+                                       n = -1;
+                                       break;
+                               }
 #ifdef WIN32
                                pgwin32_waitforsinglesocket(SSL_get_fd(port->ssl),
                                                                                        (err == SSL_ERROR_WANT_READ) ?

diff --git a/src/backend/libpq/pqcomm.c b/src/backend/libpq/pqcomm.c
index 8f40c93d89207ec8ba26ec28314da27bd3c9ebb9..98b27f1f71acf671e18c890b92d935b2b143afc8 100644 (file)
--- a/src/backend/libpq/pqcomm.c
+++ b/src/backend/libpq/pqcomm.c
@@ -30,7 +30,7 @@
  * Portions Copyright (c) 1996-2010, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- *     $PostgreSQL: pgsql/src/backend/libpq/pqcomm.c,v 1.203 2010/02/16 19:26:02 mha Exp $
+ *     $PostgreSQL: pgsql/src/backend/libpq/pqcomm.c,v 1.204 2010/02/18 11:13:45 heikki Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -821,8 +821,8 @@ pq_peekbyte(void)
  *             pq_getbyte_if_available - get a single byte from connection,
  *                     if available
  *
- * The received byte is stored in *c. Returns 1 if a byte was read, 0 if
- * if no data was available, or EOF.
+ * The received byte is stored in *c. Returns 1 if a byte was read,
+ * 0 if no data was available, or EOF if trouble.
  * --------------------------------
  */
 int
@@ -848,6 +848,33 @@ pq_getbyte_if_available(unsigned char *c)
        PG_TRY();
        {
                r = secure_read(MyProcPort, c, 1);
+               if (r < 0)
+               {
+                       /*
+                        * Ok if no data available without blocking or interrupted
+                        * (though EINTR really shouldn't happen with a non-blocking
+                        * socket). Report other errors.
+                        */
+                       if (errno == EAGAIN || errno == EWOULDBLOCK || errno == EINTR)
+                               r = 0;
+                       else
+                       {
+                               /*
+                                * Careful: an ereport() that tries to write to the client would
+                                * cause recursion to here, leading to stack overflow and core
+                                * dump!  This message must go *only* to the postmaster log.
+                                */
+                               ereport(COMMERROR,
+                                               (errcode_for_socket_access(),
+                                                errmsg("could not receive data from client: %m")));
+                               r = EOF;
+                       }
+               }
+               else if (r == 0)
+               {
+                       /* EOF detected */
+                       r = EOF;
+               }
        }
        PG_CATCH();
        {

diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c
index eb9a5425a2ef00e21a47b57fc87aaf32e5ff0727..bf533fff73dd7238cbe59034281fa0b99a781dc5 100644 (file)
--- a/src/backend/replication/walsender.c
+++ b/src/backend/replication/walsender.c
@@ -30,7 +30,7 @@
  *
  *
  * IDENTIFICATION
- *       $PostgreSQL: pgsql/src/backend/replication/walsender.c,v 1.6 2010/02/17 04:19:39 tgl Exp $
+ *       $PostgreSQL: pgsql/src/backend/replication/walsender.c,v 1.7 2010/02/18 11:13:46 heikki Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -176,14 +176,7 @@ WalSndHandshake(void)
                        ProcessConfigFile(PGC_SIGHUP);
                }
 
-               if (firstchar == EOF)
-               {
-                       /* standby disconnected */
-                       ereport(COMMERROR,
-                                       (errcode(ERRCODE_PROTOCOL_VIOLATION),
-                                        errmsg("unexpected EOF on standby connection")));
-               }
-               else
+               if (firstchar != EOF)
                {
                        /*
                         * Read the message contents. This is expected to be done without
@@ -193,9 +186,7 @@ WalSndHandshake(void)
                                firstchar = EOF;                /* suitable message already logged */
                }
 
-
                /* Handle the very limited subset of commands expected in this phase */
-
                switch (firstchar)
                {
                        case 'Q':       /* Query message */
@@ -286,14 +277,16 @@ WalSndHandshake(void)
                                break;
                        }
 
-                       /* 'X' means that the standby is closing the connection */
                        case 'X':
+                               /* standby is closing the connection */
                                proc_exit(0);
 
                        case EOF:
-                               ereport(ERROR,
+                               /* standby disconnected unexpectedly */
+                               ereport(COMMERROR,
                                                (errcode(ERRCODE_PROTOCOL_VIOLATION),
                                                 errmsg("unexpected EOF on standby connection")));
+                               proc_exit(0);
 
                        default:
                                ereport(FATAL,
@@ -315,36 +308,23 @@ CheckClosedConnection(void)
        r = pq_getbyte_if_available(&firstchar);
        if (r < 0)
        {
-               /* no data available */
-               if (errno == EAGAIN || errno == EWOULDBLOCK)
-                       return;
-
-               /*
-                * Ok if interrupted, though it shouldn't really happen with
-                * a non-blocking operation.
-                */
-               if (errno == EINTR)
-                       return;
-
+               /* unexpected error or EOF */
                ereport(COMMERROR,
-                               (errcode_for_socket_access(),
-                                errmsg("could not receive data from client: %m")));
+                               (errcode(ERRCODE_PROTOCOL_VIOLATION),
+                                errmsg("unexpected EOF on standby connection")));
+               proc_exit(0);
        }
        if (r == 0)
        {
-               /* standby disconnected unexpectedly */
-               ereport(ERROR,
-                               (errcode(ERRCODE_PROTOCOL_VIOLATION),
-                                errmsg("unexpected EOF on standby connection")));
+               /* no data available without blocking */
+               return;
        }
 
        /* Handle the very limited subset of commands expected in this phase */
        switch (firstchar)
        {
                /*
-                * 'X' means that the standby is closing down the socket. EOF means
-                * unexpected loss of standby connection. Either way, perform normal
-                * shutdown.
+                * 'X' means that the standby is closing down the socket.
                 */
                case 'X':
                        proc_exit(0);