SIGPIPE handling - Mailing list pgsql-patches

Hi,

attached is an update of my automatic sigaction patch: I've moved the
actual sigaction calls into pqsignal.c and added a helper function
(pgsignalinquire(signo)). I couldn't remove the include <signal.h> from
fe-connect.c: it's required for the SIGPIPE definition.
Additionally I've added a -a flag for pgbench that sets the signal
handler before calling PQconnectdb.

Tested on Fedora Core 1 (Redhat Linux) with pgbench.

--
    Manfred
Index: src/interfaces/libpq/fe-connect.c
===================================================================
RCS file: /projects/cvsroot/pgsql-server/src/interfaces/libpq/fe-connect.c,v
retrieving revision 1.263
diff -c -r1.263 fe-connect.c
*** src/interfaces/libpq/fe-connect.c    18 Oct 2003 05:02:06 -0000    1.263
--- src/interfaces/libpq/fe-connect.c    16 Nov 2003 11:44:47 -0000
***************
*** 41,46 ****
--- 41,48 ----
  #include <netinet/tcp.h>
  #endif
  #include <arpa/inet.h>
+ #include <signal.h>
+ #include "pqsignal.h"
  #endif

  #include "libpq/ip.h"
***************
*** 881,886 ****
--- 883,891 ----
      struct addrinfo hint;
      const char *node = NULL;
      int            ret;
+ #ifndef WIN32
+     pqsigfunc pipehandler;
+ #endif

      if (!conn)
          return 0;
***************
*** 950,955 ****
--- 955,976 ----
          conn->allow_ssl_try = false;
      else if (conn->sslmode[0] == 'a')    /* "allow" */
          conn->wait_ssl_try = true;
+ #endif
+ #ifndef WIN32
+     /*
+      * Autodetect SIGPIPE signal handling:
+      * The default action per Unix spec is kill current process and
+      * that's not acceptable. If the current setting is not the default,
+      * then assume that the caller knows what he's doing and leave the
+      * signal handler unchanged. Otherwise set the signal handler to
+      * SIG_IGN around each send() syscall. Unfortunately this is both
+      * unreliable and slow for multithreaded apps.
+      */
+     pipehandler = pqsignalinquire(SIGPIPE);
+     if (pipehandler == SIG_DFL || pipehandler == SIG_ERR)
+         conn->do_sigaction = true;
+     else
+         conn->do_sigaction = false;
  #endif

      /*
Index: src/interfaces/libpq/fe-secure.c
===================================================================
RCS file: /projects/cvsroot/pgsql-server/src/interfaces/libpq/fe-secure.c,v
retrieving revision 1.32
diff -c -r1.32 fe-secure.c
*** src/interfaces/libpq/fe-secure.c    29 Sep 2003 16:38:04 -0000    1.32
--- src/interfaces/libpq/fe-secure.c    16 Nov 2003 11:44:47 -0000
***************
*** 348,354 ****
      ssize_t        n;

  #ifndef WIN32
!     pqsigfunc    oldsighandler = pqsignal(SIGPIPE, SIG_IGN);
  #endif

  #ifdef USE_SSL
--- 348,357 ----
      ssize_t        n;

  #ifndef WIN32
!     pqsigfunc    oldsighandler = NULL;
!
!     if (conn->do_sigaction)
!         oldsighandler = pqsignal(SIGPIPE, SIG_IGN);
  #endif

  #ifdef USE_SSL
***************
*** 408,414 ****
          n = send(conn->sock, ptr, len, 0);

  #ifndef WIN32
!     pqsignal(SIGPIPE, oldsighandler);
  #endif

      return n;
--- 411,418 ----
          n = send(conn->sock, ptr, len, 0);

  #ifndef WIN32
!     if (conn->do_sigaction)
!         pqsignal(SIGPIPE, oldsighandler);
  #endif

      return n;
Index: src/interfaces/libpq/libpq-int.h
===================================================================
RCS file: /projects/cvsroot/pgsql-server/src/interfaces/libpq/libpq-int.h,v
retrieving revision 1.82
diff -c -r1.82 libpq-int.h
*** src/interfaces/libpq/libpq-int.h    5 Sep 2003 02:08:36 -0000    1.82
--- src/interfaces/libpq/libpq-int.h    16 Nov 2003 11:44:48 -0000
***************
*** 329,334 ****
--- 329,337 ----
      char        peer_dn[256 + 1];        /* peer distinguished name */
      char        peer_cn[SM_USER + 1];    /* peer common name */
  #endif
+ #ifndef WIN32
+     bool        do_sigaction;    /* set SIGPIPE to SIG_IGN around every send() call */
+ #endif

      /* Buffer for current error message */
      PQExpBufferData errorMessage;        /* expansible string */
Index: src/interfaces/libpq/pqsignal.c
===================================================================
RCS file: /projects/cvsroot/pgsql-server/src/interfaces/libpq/pqsignal.c,v
retrieving revision 1.17
diff -c -r1.17 pqsignal.c
*** src/interfaces/libpq/pqsignal.c    4 Aug 2003 02:40:20 -0000    1.17
--- src/interfaces/libpq/pqsignal.c    16 Nov 2003 11:44:48 -0000
***************
*** 40,42 ****
--- 40,61 ----
      return oact.sa_handler;
  #endif   /* !HAVE_POSIX_SIGNALS */
  }
+
+ pqsigfunc
+ pqsignalinquire(int signo)
+ {
+ #if !defined(HAVE_POSIX_SIGNALS)
+     pqsigfunc old;
+      old = signal(SIGPIPE, SIG_IGN);
+     signal(SIGPIPE, old);
+     return old;
+ #else
+     struct sigaction oact;
+
+     if (sigaction(SIGPIPE, NULL, &oact) != 0)
+            return SIG_ERR;
+     return oact.sa_handler;
+ #endif   /* !HAVE_POSIX_SIGNALS */
+
+
+ }
Index: src/interfaces/libpq/pqsignal.h
===================================================================
RCS file: /projects/cvsroot/pgsql-server/src/interfaces/libpq/pqsignal.h,v
retrieving revision 1.15
diff -c -r1.15 pqsignal.h
*** src/interfaces/libpq/pqsignal.h    4 Aug 2003 02:40:20 -0000    1.15
--- src/interfaces/libpq/pqsignal.h    16 Nov 2003 11:44:48 -0000
***************
*** 24,27 ****
--- 24,29 ----

  extern pqsigfunc pqsignal(int signo, pqsigfunc func);

+ extern pqsigfunc pqsignalinquire(int signo);
+
  #endif   /* PQSIGNAL_H */
Index: contrib/pgbench/README.pgbench
===================================================================
RCS file: /projects/cvsroot/pgsql-server/contrib/pgbench/README.pgbench,v
retrieving revision 1.9
diff -c -r1.9 README.pgbench
*** contrib/pgbench/README.pgbench    10 Jun 2003 09:07:15 -0000    1.9
--- contrib/pgbench/README.pgbench    16 Nov 2003 11:44:39 -0000
***************
*** 112,117 ****
--- 112,121 ----
          might be a security hole since ps command will
          show the password. Use this for TESTING PURPOSE ONLY.

+     -a
+         Disable SIGPIPE delivery globally instead of within each
+         libpq operation.
+
      -n
          No vacuuming and cleaning the history table prior to the
          test is performed.
Index: contrib/pgbench/pgbench.c
===================================================================
RCS file: /projects/cvsroot/pgsql-server/contrib/pgbench/pgbench.c,v
retrieving revision 1.27
diff -c -r1.27 pgbench.c
*** contrib/pgbench/pgbench.c    27 Sep 2003 19:15:34 -0000    1.27
--- contrib/pgbench/pgbench.c    16 Nov 2003 11:44:39 -0000
***************
*** 28,33 ****
--- 28,34 ----
  #else
  #include <sys/time.h>
  #include <unistd.h>
+ #include <signal.h>

  #ifdef HAVE_GETOPT_H
  #include <getopt.h>
***************
*** 105,112 ****
  static void
  usage()
  {
!     fprintf(stderr, "usage: pgbench [-h hostname][-p port][-c nclients][-t ntransactions][-s
scaling_factor][-n][-C][-v][-S][-N][-l][-Ulogin][-P password][-d][dbname]\n"); 
!     fprintf(stderr, "(initialize mode): pgbench -i [-h hostname][-p port][-s scaling_factor][-U login][-P
password][-d][dbname]\n");
  }

  /* random number generator */
--- 106,113 ----
  static void
  usage()
  {
!     fprintf(stderr, "usage: pgbench [-h hostname][-p port][-c nclients][-t ntransactions][-s
scaling_factor][-n][-C][-v][-S][-N][-l][-a][-Ulogin][-P password][-d][dbname]\n"); 
!     fprintf(stderr, "(initialize mode): pgbench -i [-h hostname][-p port][-s scaling_factor][-U login][-P
password][-d][dbname][-a]\n");
  }

  /* random number generator */
***************
*** 703,712 ****
      else if ((env = getenv("PGUSER")) != NULL && *env != '\0')
          login = env;

!     while ((c = getopt(argc, argv, "ih:nvp:dc:t:s:U:P:CNSl")) != -1)
      {
          switch (c)
          {
              case 'i':
                  is_init_mode++;
                  break;
--- 704,718 ----
      else if ((env = getenv("PGUSER")) != NULL && *env != '\0')
          login = env;

!     while ((c = getopt(argc, argv, "aih:nvp:dc:t:s:U:P:CNSl")) != -1)
      {
          switch (c)
          {
+             case 'a':
+ #ifndef WIN32
+                 signal(SIGPIPE, SIG_IGN);
+ #endif
+                 break;
              case 'i':
                  is_init_mode++;
                  break;