Fix for EINTR returns from Win9X socket operations:

In summary, if a software writer implements timer events or other events
 which generate a signal with a timing fast enough to occur while libpq
is inside connect(), then connect returns -EINTR.  The code following
the connect call does not handle this and generates an error message.
The sum result is that the pg_connect() fails.  If the timer or other
event is right on the window of the connect() completion time, the
pg_connect() may appear to work sporadically.  If the event is too slow,
 pg_connect() will appear to always work and if the event is too fast,
pg_connect() will always fail.

David Ford

diff --git a/src/interfaces/libpq/fe-connect.c b/src/interfaces/libpq/fe-connect.c
index 772e54b..9864aad 100644 (file)
--- a/src/interfaces/libpq/fe-connect.c
+++ b/src/interfaces/libpq/fe-connect.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *       $Header: /cvsroot/pgsql/src/interfaces/libpq/fe-connect.c,v 1.182 2002/03/02 00:49:22 tgl Exp $
+ *       $Header: /cvsroot/pgsql/src/interfaces/libpq/fe-connect.c,v 1.183 2002/04/15 23:34:17 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -913,8 +913,13 @@ connectDBStart(PGconn *conn)
         * Thus, we have to make arrangements for all eventualities.
         * ----------
         */
+retry1:
        if (connect(conn->sock, &conn->raddr.sa, conn->raddr_len) < 0)
        {
+               if (SOCK_ERRNO == EINTR)
+                       /* Interrupted system call - we'll just try again */
+                       goto retry1;
+
                if (SOCK_ERRNO == EINPROGRESS || SOCK_ERRNO == EWOULDBLOCK || SOCK_ERRNO == 0)
                {
                        /*
@@ -949,9 +954,14 @@ connectDBStart(PGconn *conn)
                                                          SOCK_STRERROR(SOCK_ERRNO));
                        goto connect_errReturn;
                }
+retry2:
                /* Now receive the postmasters response */
                if (recv(conn->sock, &SSLok, 1, 0) != 1)
                {
+                       if (SOCK_ERRNO == EINTR)
+                               /* Interrupted system call - we'll just try again */
+                               goto retry2;
+
                        printfPQExpBuffer(&conn->errorMessage,
                                                          libpq_gettext("could not receive server response to SSL negotiation packet: %s\n"),
                                                          SOCK_STRERROR(SOCK_ERRNO));
@@ -2132,8 +2142,12 @@ PQrequestCancel(PGconn *conn)
                           "PQrequestCancel() -- socket() failed: ");
                goto cancel_errReturn;
        }
+retry3:
        if (connect(tmpsock, &conn->raddr.sa, conn->raddr_len) < 0)
        {
+               if (SOCK_ERRNO == EINTR)
+                       /* Interrupted system call - we'll just try again */
+                       goto retry3;
                strcpy(conn->errorMessage.data,
                           "PQrequestCancel() -- connect() failed: ");
                goto cancel_errReturn;
@@ -2150,8 +2164,12 @@ PQrequestCancel(PGconn *conn)
        crp.cp.backendPID = htonl(conn->be_pid);
        crp.cp.cancelAuthCode = htonl(conn->be_key);
 
+retry4:
        if (send(tmpsock, (char *) &crp, sizeof(crp), 0) != (int) sizeof(crp))
        {
+               if (SOCK_ERRNO == EINTR)
+                       /* Interrupted system call - we'll just try again */
+                       goto retry4;
                strcpy(conn->errorMessage.data,
                           "PQrequestCancel() -- send() failed: ");
                goto cancel_errReturn;

diff --git a/src/interfaces/libpq/fe-misc.c b/src/interfaces/libpq/fe-misc.c
index 5f90547..190d378 100644 (file)
--- a/src/interfaces/libpq/fe-misc.c
+++ b/src/interfaces/libpq/fe-misc.c
@@ -25,7 +25,7 @@
  *
  *
  * IDENTIFICATION
- *       $Header: /cvsroot/pgsql/src/interfaces/libpq/fe-misc.c,v 1.68 2002/03/06 06:10:42 momjian Exp $
+ *       $Header: /cvsroot/pgsql/src/interfaces/libpq/fe-misc.c,v 1.69 2002/04/15 23:34:17 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -361,7 +361,7 @@ pqReadReady(PGconn *conn)
        if (!conn || conn->sock < 0)
                return -1;
 
-retry:
+retry1:
        FD_ZERO(&input_mask);
        FD_SET(conn->sock, &input_mask);
        timeout.tv_sec = 0;
@@ -371,7 +371,7 @@ retry:
        {
                if (SOCK_ERRNO == EINTR)
                        /* Interrupted system call - we'll just try again */
-                       goto retry;
+                       goto retry1;
 
                printfPQExpBuffer(&conn->errorMessage,
                                                  libpq_gettext("select() failed: %s\n"),
@@ -395,7 +395,7 @@ pqWriteReady(PGconn *conn)
        if (!conn || conn->sock < 0)
                return -1;
 
-retry:
+retry2:
        FD_ZERO(&input_mask);
        FD_SET(conn->sock, &input_mask);
        timeout.tv_sec = 0;
@@ -405,7 +405,7 @@ retry:
        {
                if (SOCK_ERRNO == EINTR)
                        /* Interrupted system call - we'll just try again */
-                       goto retry;
+                       goto retry2;
 
                printfPQExpBuffer(&conn->errorMessage,
                                                  libpq_gettext("select() failed: %s\n"),
@@ -478,7 +478,7 @@ pqReadData(PGconn *conn)
        }
 
        /* OK, try to read some data */
-tryAgain:
+retry3:
 #ifdef USE_SSL
        if (conn->ssl)
                nread = SSL_read(conn->ssl, conn->inBuffer + conn->inEnd,
@@ -490,7 +490,7 @@ tryAgain:
        if (nread < 0)
        {
                if (SOCK_ERRNO == EINTR)
-                       goto tryAgain;
+                       goto retry3;
                /* Some systems return EAGAIN/EWOULDBLOCK for no data */
 #ifdef EAGAIN
                if (SOCK_ERRNO == EAGAIN)
@@ -531,7 +531,7 @@ tryAgain:
                        (conn->inBufSize - conn->inEnd) >= 8192)
                {
                        someread = 1;
-                       goto tryAgain;
+                       goto retry3;
                }
                return 1;
        }
@@ -564,7 +564,7 @@ tryAgain:
         * Still not sure that it's EOF, because some data could have just
         * arrived.
         */
-tryAgain2:
+retry4:
 #ifdef USE_SSL
        if (conn->ssl)
                nread = SSL_read(conn->ssl, conn->inBuffer + conn->inEnd,
@@ -576,7 +576,7 @@ tryAgain2:
        if (nread < 0)
        {
                if (SOCK_ERRNO == EINTR)
-                       goto tryAgain2;
+                       goto retry4;
                /* Some systems return EAGAIN/EWOULDBLOCK for no data */
 #ifdef EAGAIN
                if (SOCK_ERRNO == EAGAIN)
@@ -804,7 +804,7 @@ pqWait(int forRead, int forWrite, PGconn *conn)
 
        if (forRead || forWrite)
        {
-retry:
+retry5:
                FD_ZERO(&input_mask);
                FD_ZERO(&output_mask);
                FD_ZERO(&except_mask);
@@ -817,7 +817,7 @@ retry:
                                   (struct timeval *) NULL) < 0)
                {
                        if (SOCK_ERRNO == EINTR)
-                               goto retry;
+                               goto retry5;
                        printfPQExpBuffer(&conn->errorMessage,
                                                          libpq_gettext("select() failed: %s\n"),
                                                          SOCK_STRERROR(SOCK_ERRNO));