thread patch - Mailing list pgsql-patches

Here is the thread patch.

--
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 359-1001
  +  If your life is a hard drive,     |  13 Roberts Road
  +  Christ can be your backup.        |  Newtown Square, Pennsylvania 19073
Index: configure.in
===================================================================
RCS file: /cvsroot/pgsql-server/configure.in,v
retrieving revision 1.287
diff -c -c -r1.287 configure.in
*** configure.in    12 Sep 2003 16:10:26 -0000    1.287
--- configure.in    13 Sep 2003 14:47:43 -0000
***************
*** 1031,1047 ****
  # One trick here is that if we don't call AC_CHECK_FUNCS, the
  # functions are marked "not found", which is perfect.
  #
! if test "$enable_thread_safety" = yes -a "$NEED_REENTRANT_FUNC_NAMES" = yes ; then
  _CFLAGS="$CFLAGS"
  _LIBS="$LIBS"
  CFLAGS="$CFLAGS $THREAD_CFLAGS"
  LIBS="$LIBS $THREAD_LIBS"
! AC_CHECK_FUNC(strerror_r,
!     [], [AC_MSG_ERROR([strerror_r not found, required on this platform for --enable-thread-safety])])
! AC_CHECK_FUNC(getpwuid_r,
!     [], [AC_MSG_ERROR([getpwuid_r not found, required on this platform for --enable-thread-safety])])
! AC_CHECK_FUNC(gethostbyname_r,
!     [], [AC_MSG_ERROR([gethostbyname_r not found, required on this platform for --enable-thread-safety])])
  CFLAGS="$_CFLAGS"
  LIBS="$_LIBS"
  fi
--- 1031,1042 ----
  # One trick here is that if we don't call AC_CHECK_FUNCS, the
  # functions are marked "not found", which is perfect.
  #
! if test "$enable_thread_safety" = yes -a "$NEED_REENTRANT_FUNCS" = yes ; then
  _CFLAGS="$CFLAGS"
  _LIBS="$LIBS"
  CFLAGS="$CFLAGS $THREAD_CFLAGS"
  LIBS="$LIBS $THREAD_LIBS"
! AC_CHECK_FUNCS([strerror_r getpwuid_r gethostbyname_r])
  CFLAGS="$_CFLAGS"
  LIBS="$_LIBS"
  fi
Index: src/include/port.h
===================================================================
RCS file: /cvsroot/pgsql-server/src/include/port.h,v
retrieving revision 1.13
diff -c -c -r1.13 port.h
*** src/include/port.h    5 Sep 2003 17:43:39 -0000    1.13
--- src/include/port.h    13 Sep 2003 14:47:46 -0000
***************
*** 114,124 ****

  #ifndef WIN32
  extern int pqGetpwuid(uid_t uid, struct passwd * resultbuf, char *buffer,
!            size_t buflen, struct passwd ** result);
  #endif

  extern int pqGethostbyname(const char *name,
!                 struct hostent * resbuf,
!                 char *buf, size_t buflen,
!                 struct hostent ** result,
                  int *herrno);
--- 114,124 ----

  #ifndef WIN32
  extern int pqGetpwuid(uid_t uid, struct passwd * resultbuf, char *buffer,
!            size_t buflen, struct passwd **result);
  #endif

  extern int pqGethostbyname(const char *name,
!                 struct hostent *resultbuf,
!                 char *buffer, size_t buflen,
!                 struct hostent **result,
                  int *herrno);
Index: src/port/thread.c
===================================================================
RCS file: /cvsroot/pgsql-server/src/port/thread.c,v
retrieving revision 1.6
diff -c -c -r1.6 thread.c
*** src/port/thread.c    5 Sep 2003 17:43:40 -0000    1.6
--- src/port/thread.c    13 Sep 2003 14:47:47 -0000
***************
*** 14,25 ****

  #include "postgres.h"

  /*
   *    Threading sometimes requires specially-named versions of functions
   *    that return data in static buffers, like strerror_r() instead of
   *    strerror().  Other operating systems use pthread_setspecific()
   *    and pthread_getspecific() internally to allow standard library
!  *    functions to return static data to threaded applications.
   *
   *    Additional confusion exists because many operating systems that
   *    use pthread_setspecific/pthread_getspecific() also have *_r versions
--- 14,30 ----

  #include "postgres.h"

+ #include <pthread.h>
+ #include <sys/types.h>
+ #include <pwd.h>
+
  /*
   *    Threading sometimes requires specially-named versions of functions
   *    that return data in static buffers, like strerror_r() instead of
   *    strerror().  Other operating systems use pthread_setspecific()
   *    and pthread_getspecific() internally to allow standard library
!  *    functions to return static data to threaded applications. And some
!  *    operating systems have neither, meaning we have to do our own locking.
   *
   *    Additional confusion exists because many operating systems that
   *    use pthread_setspecific/pthread_getspecific() also have *_r versions
***************
*** 36,46 ****
   *    doesn't have strerror_r(), so we can't fall back to only using *_r
   *    functions for threaded programs.
   *
!  *    The current setup is to assume either all standard functions are
!  *    thread-safe (NEED_REENTRANT_FUNC_NAMES=no), or the operating system
!  *    requires reentrant function names (NEED_REENTRANT_FUNC_NAMES=yes).
   *    Compile and run src/tools/test_thread_funcs.c to see if your operating
!  *    system requires reentrant function names.
   */


--- 41,55 ----
   *    doesn't have strerror_r(), so we can't fall back to only using *_r
   *    functions for threaded programs.
   *
!  *    The current setup is to try threading in this order:
!  *
!  *        use non-*_r function names if they are all thread-safe
!  *            (NEED_REENTRANT_FUNCS=no)
!  *        use *_r functions if they exist (configure test)
!  *        do our own locking and copying of non-threadsafe functions
!  *
   *    Compile and run src/tools/test_thread_funcs.c to see if your operating
!  *    system has thread-safe non-*_r functions.
   */


***************
*** 51,64 ****
  char *
  pqStrerror(int errnum, char *strerrbuf, size_t buflen)
  {
! #if defined(USE_THREADS) && defined(NEED_REENTRANT_FUNC_NAMES)
      /* reentrant strerror_r is available */
      /* some early standards had strerror_r returning char * */
      strerror_r(errnum, strerrbuf, buflen);
!     return (strerrbuf);
  #else
      /* no strerror_r() available, just use strerror */
!     return strerror(errnum);
  #endif
  }

--- 60,86 ----
  char *
  pqStrerror(int errnum, char *strerrbuf, size_t buflen)
  {
! #if defined(FRONTEND) && defined(USE_THREADS) && defined(NEED_REENTRANT_FUNCS) && defined(HAVE_STRERROR_R)
      /* reentrant strerror_r is available */
      /* some early standards had strerror_r returning char * */
      strerror_r(errnum, strerrbuf, buflen);
!     return strerrbuf;
!
  #else
+
+ #if defined(FRONTEND) && defined(USE_THREADS) && defined(NEED_REENTRANT_FUNCS) && !defined(HAVE_STRERROR_R)
+     static pthread_mutex_t strerror_lock = PTHREAD_MUTEX_INITIALIZER;
+     pthread_mutex_lock(&strerror_lock);
+ #endif
+
      /* no strerror_r() available, just use strerror */
!     StrNCpy(strerrbuf, strerror(errnum), buflen);
!
! #if defined(FRONTEND) && defined(USE_THREADS) && defined(NEED_REENTRANT_FUNCS) && !defined(HAVE_STRERROR_R)
!     pthread_mutex_unlock(&strerror_lock);
! #endif
!
!     return strerrbuf;
  #endif
  }

***************
*** 71,77 ****
  pqGetpwuid(uid_t uid, struct passwd *resultbuf, char *buffer,
             size_t buflen, struct passwd **result)
  {
! #if defined(USE_THREADS) && defined(NEED_REENTRANT_FUNC_NAMES)
      /*
       * Early POSIX draft of getpwuid_r() returns 'struct passwd *'.
       *    getpwuid_r(uid, resultbuf, buffer, buflen)
--- 93,99 ----
  pqGetpwuid(uid_t uid, struct passwd *resultbuf, char *buffer,
             size_t buflen, struct passwd **result)
  {
! #if defined(FRONTEND) && defined(USE_THREADS) && defined(NEED_REENTRANT_FUNCS) && defined(HAVE_GETPWUID_R)
      /*
       * Early POSIX draft of getpwuid_r() returns 'struct passwd *'.
       *    getpwuid_r(uid, resultbuf, buffer, buflen)
***************
*** 79,87 ****
--- 101,152 ----
       */
      /* POSIX version */
      getpwuid_r(uid, resultbuf, buffer, buflen, result);
+
  #else
+
+ #if defined(FRONTEND) && defined(USE_THREADS) && defined(NEED_REENTRANT_FUNCS) && !defined(HAVE_GETPWUID_R)
+     static pthread_mutex_t getpwuid_lock = PTHREAD_MUTEX_INITIALIZER;
+     pthread_mutex_lock(&getpwuid_lock);
+ #endif
+
      /* no getpwuid_r() available, just use getpwuid() */
      *result = getpwuid(uid);
+
+ #if defined(FRONTEND) && defined(USE_THREADS) && defined(NEED_REENTRANT_FUNCS) && !defined(HAVE_GETPWUID_R)
+
+     /* Use 'buffer' memory for storage of strings used by struct passwd */
+     if (*result &&
+         strlen((*result)->pw_name) + 1 +
+         strlen((*result)->pw_passwd) + 1 +
+         strlen((*result)->pw_gecos) + 1 +
+         /* skip class if it exists */
+         strlen((*result)->pw_dir) + 1 +
+         strlen((*result)->pw_shell) + 1 <= buflen)
+     {
+         memcpy(resultbuf, *result, sizeof(struct passwd));
+         strcpy(buffer, (*result)->pw_name);
+         resultbuf->pw_name = buffer;
+         buffer += strlen(resultbuf->pw_name) + 1;
+         strcpy(buffer, (*result)->pw_passwd);
+         resultbuf->pw_passwd = buffer;
+         buffer += strlen(resultbuf->pw_passwd) + 1;
+         strcpy(buffer, (*result)->pw_gecos);
+         resultbuf->pw_gecos = buffer;
+         buffer += strlen(resultbuf->pw_gecos) + 1;
+         strcpy(buffer, (*result)->pw_dir);
+         resultbuf->pw_dir = buffer;
+         buffer += strlen(resultbuf->pw_dir) + 1;
+         strcpy(buffer, (*result)->pw_shell);
+         resultbuf->pw_shell = buffer;
+         buffer += strlen(resultbuf->pw_shell) + 1;
+
+         *result = resultbuf;
+     }
+     else
+         *result = NULL;
+
+     pthread_mutex_unlock(&getpwuid_lock);
+ #endif
  #endif
      return (*result == NULL) ? -1 : 0;
  }
***************
*** 93,119 ****
   */
  int
  pqGethostbyname(const char *name,
!                 struct hostent *resbuf,
!                 char *buf, size_t buflen,
                  struct hostent **result,
                  int *herrno)
  {
! #if defined(USE_THREADS) && defined(NEED_REENTRANT_FUNC_NAMES)
      /*
       * broken (well early POSIX draft) gethostbyname_r() which returns
       * 'struct hostent *'
       */
!     *result = gethostbyname_r(name, resbuf, buf, buflen, herrno);
      return (*result == NULL) ? -1 : 0;
  #else
      /* no gethostbyname_r(), just use gethostbyname() */
      *result = gethostbyname(name);
      if (*result != NULL)
          return 0;
      else
-     {
-         *herrno = h_errno;
          return -1;
-     }
  #endif
  }
--- 158,258 ----
   */
  int
  pqGethostbyname(const char *name,
!                 struct hostent *resultbuf,
!                 char *buffer, size_t buflen,
                  struct hostent **result,
                  int *herrno)
  {
! #if defined(FRONTEND) && defined(USE_THREADS) && defined(NEED_REENTRANT_FUNCS) && defined(HAVE_GETHOSTBYNAME_R)
      /*
       * broken (well early POSIX draft) gethostbyname_r() which returns
       * 'struct hostent *'
       */
!     *result = gethostbyname_r(name, resbuf, buffer, buflen, herrno);
      return (*result == NULL) ? -1 : 0;
+
  #else
+
+ #if defined(FRONTEND) && defined(USE_THREADS) && defined(NEED_REENTRANT_FUNCS) && !defined(HAVE_GETHOSTBYNAME_R)
+     static pthread_mutex_t gethostbyname_lock = PTHREAD_MUTEX_INITIALIZER;
+     pthread_mutex_lock(&gethostbyname_lock);
+ #endif
+
      /* no gethostbyname_r(), just use gethostbyname() */
      *result = gethostbyname(name);
+
+ #if defined(FRONTEND) && defined(USE_THREADS) && defined(NEED_REENTRANT_FUNCS) && !defined(HAVE_GETHOSTBYNAME_R)
+
+     /*
+      *    Use 'buffer' memory for storage of structures used by struct hostent.
+      *    The layout is:
+      *
+      *        addr pointers
+      *        alias pointers
+      *        addr structures
+      *        alias structures
+      *        name
+      */
+     if (*result)
+     {
+         int        i, pointers = 2 /* for nulls */, len = 0;
+         char    **pbuffer;
+
+         for (i = 0; (*result)->h_addr_list[i]; i++, pointers++)
+             len += (*result)->h_length;
+         for (i = 0; (*result)->h_aliases[i]; i++, pointers++)
+             len += (*result)->h_length;
+
+         if (MAXALIGN(len) + pointers * sizeof(char *) + strlen((*result)->h_name) + 1 <= buflen)
+         {
+             memcpy(resultbuf, *result, sizeof(struct hostent));
+
+             pbuffer = (char **)buffer;
+             resultbuf->h_addr_list = pbuffer;
+             buffer += pointers * sizeof(char *);
+
+             for (i = 0; (*result)->h_addr_list[i]; i++, pbuffer++)
+             {
+                 memcpy(buffer, (*result)->h_addr_list[i], (*result)->h_length);
+                 resultbuf->h_addr_list[i] = buffer;
+                 buffer += (*result)->h_length;
+             }
+             resultbuf->h_addr_list[i] = NULL;
+             pbuffer++;
+
+             resultbuf->h_aliases = pbuffer;
+
+             for (i = 0; (*result)->h_aliases[i]; i++, pbuffer++)
+             {
+                 memcpy(buffer, (*result)->h_aliases[i], (*result)->h_length);
+                 resultbuf->h_aliases[i] = buffer;
+                 buffer += (*result)->h_length;
+             }
+             resultbuf->h_aliases[i] = NULL;
+             pbuffer++;
+
+             /* Place at end for cleaner alignment */
+             strcpy(buffer, (*result)->h_name);
+             resultbuf->h_name = buffer;
+             buffer += strlen(resultbuf->h_name) + 1;
+
+             *result = resultbuf;
+         }
+         else
+             *result = NULL;
+     }
+ #endif
+
+     if (*result != NULL)
+         *herrno = h_errno;
+
+ #if defined(FRONTEND) && defined(USE_THREADS) && defined(NEED_REENTRANT_FUNCS) && !defined(HAVE_GETHOSTBYNAME_R)
+     pthread_mutex_unlock(&gethostbyname_lock);
+ #endif
+
      if (*result != NULL)
          return 0;
      else
          return -1;
  #endif
  }
Index: src/template/bsdi
===================================================================
RCS file: /cvsroot/pgsql-server/src/template/bsdi,v
retrieving revision 1.13
diff -c -c -r1.13 bsdi
*** src/template/bsdi    3 Sep 2003 20:54:20 -0000    1.13
--- src/template/bsdi    13 Sep 2003 14:47:47 -0000
***************
*** 11,14 ****
  esac

  SUPPORTS_THREADS=yes
! NEED_REENTRANT_FUNC_NAMES=no    # verified 4.3 2003-09-03
--- 11,14 ----
  esac

  SUPPORTS_THREADS=yes
! NEED_REENTRANT_FUNCS=no    # verified 4.3 2003-09-03
Index: src/template/freebsd
===================================================================
RCS file: /cvsroot/pgsql-server/src/template/freebsd,v
retrieving revision 1.20
diff -c -c -r1.20 freebsd
*** src/template/freebsd    12 Sep 2003 16:49:34 -0000    1.20
--- src/template/freebsd    13 Sep 2003 14:47:47 -0000
***************
*** 4,11 ****
    alpha*)   CFLAGS="$CFLAGS -O" ;;
  esac

! SUPPORTS_THREADS=no     # 4.8, 5.1  2003-09-12
! NEED_REENTRANT_FUNC_NAMES=no

  case $host_os in
          freebsd2*|freebsd3*|freebsd4*)
--- 4,11 ----
    alpha*)   CFLAGS="$CFLAGS -O" ;;
  esac

! SUPPORTS_THREADS=yes
! NEED_REENTRANT_FUNCS=yes     # 4.8, 5.1  2003-09-12

  case $host_os in
          freebsd2*|freebsd3*|freebsd4*)
Index: src/template/linux
===================================================================
RCS file: /cvsroot/pgsql-server/src/template/linux,v
retrieving revision 1.13
diff -c -c -r1.13 linux
*** src/template/linux    3 Sep 2003 22:34:08 -0000    1.13
--- src/template/linux    13 Sep 2003 14:47:47 -0000
***************
*** 1,7 ****
  CFLAGS=-O2

  SUPPORTS_THREADS=yes
! NEED_REENTRANT_FUNC_NAMES=yes    # verified glibc 2.1 2003-09-03
  THREAD_CFLAGS="-D_REENTRANT -D_THREAD_SAFE -D_POSIX_PTHREAD_SEMANTICS"
  THREAD_LIBS="-lpthread"

--- 1,7 ----
  CFLAGS=-O2

  SUPPORTS_THREADS=yes
! NEED_REENTRANT_FUNCS=yes    # verified glibc 2.1 2003-09-03
  THREAD_CFLAGS="-D_REENTRANT -D_THREAD_SAFE -D_POSIX_PTHREAD_SEMANTICS"
  THREAD_LIBS="-lpthread"

Index: src/template/netbsd
===================================================================
RCS file: /cvsroot/pgsql-server/src/template/netbsd,v
retrieving revision 1.10
diff -c -c -r1.10 netbsd
*** src/template/netbsd    16 Aug 2003 15:35:51 -0000    1.10
--- src/template/netbsd    13 Sep 2003 14:47:47 -0000
***************
*** 1,4 ****
  CFLAGS='-O2 -pipe'

  SUPPORTS_THREADS=yes
! NEED_REENTRANT_FUNC_NAMES=no
--- 1,4 ----
  CFLAGS='-O2 -pipe'

  SUPPORTS_THREADS=yes
! NEED_REENTRANT_FUNCS=no
Index: src/template/osf
===================================================================
RCS file: /cvsroot/pgsql-server/src/template/osf,v
retrieving revision 1.7
diff -c -c -r1.7 osf
*** src/template/osf    16 Aug 2003 15:35:51 -0000    1.7
--- src/template/osf    13 Sep 2003 14:47:47 -0000
***************
*** 6,10 ****
  fi

  SUPPORTS_THREADS=yes
! NEED_REENTRANT_FUNC_NAMES=no
  THREAD_CFLAGS="-pthread"
--- 6,10 ----
  fi

  SUPPORTS_THREADS=yes
! NEED_REENTRANT_FUNCS=no        # 4.0 2003-09-13
  THREAD_CFLAGS="-pthread"
Index: src/template/solaris
===================================================================
RCS file: /cvsroot/pgsql-server/src/template/solaris,v
retrieving revision 1.2
diff -c -c -r1.2 solaris
*** src/template/solaris    21 Oct 2000 22:36:14 -0000    1.2
--- src/template/solaris    13 Sep 2003 14:47:47 -0000
***************
*** 4,6 ****
--- 4,11 ----
    CC="$CC -Xa"            # relaxed ISO C mode
    CFLAGS=-v            # -v is like gcc -Wall
  fi
+
+ SUPPORTS_THREADS=yes
+ NEED_REENTRANT_FUNCS=yes    # 5.6 2003-09-13
+ THREAD_CFLAGS="-pthread"
+
Index: src/template/unixware
===================================================================
RCS file: /cvsroot/pgsql-server/src/template/unixware,v
retrieving revision 1.21
diff -c -c -r1.21 unixware
*** src/template/unixware    3 Sep 2003 20:54:21 -0000    1.21
--- src/template/unixware    13 Sep 2003 14:47:47 -0000
***************
*** 10,14 ****
  fi

  SUPPORTS_THREADS=yes
! NEED_REENTRANT_FUNC_NAMES=no    # verified 7.1.3 2003-09-03
  THREAD_CFLAGS="$THREAD_CFLAGS -D_REENTRANT"
--- 10,14 ----
  fi

  SUPPORTS_THREADS=yes
! NEED_REENTRANT_FUNCS=no        # verified 7.1.3 2003-09-03
  THREAD_CFLAGS="$THREAD_CFLAGS -D_REENTRANT"