[Emacs-diffs] /srv/bzr/emacs/trunk r110059: Remove no-longer-needed Solaris 2.4 vfork bug workaround.

[Paul Eggert]

------------------------------------------------------------
revno: 110059
committer: Paul Eggert <address@hidden>
branch nick: trunk
timestamp: Sun 2012-09-16 18:02:11 -0700
message:
  Remove no-longer-needed Solaris 2.4 vfork bug workaround.
  
  The workaround was for improving performance on Solaris 2.4, but
  is getting in the way now.  Emacs will still work if someone is
  still running Solaris 2.4 in a museum somewhere; Sun dropped
  support for Solaris 2.4 in 2003.
  * configure.ac (ac_cv_func_vfork_works): Default to 'no' on
  Solaris 2.4, so that AC_FUNC_VFORK doesn't think vfork works.
  * src/callproc.c (Fcall_process) [HAVE_WORKING_VFORK]:
  * src/process.c (create_process) [HAVE_WORKING_VFORK]:
  Omit now-unnecessary workaround for the Solaris 2.4 vfork bug,
  since Emacs no longer uses vfork on that platform.
modified:
  ChangeLog
  configure.ac
  src/ChangeLog
  src/callproc.c
  src/process.c

=== modified file 'ChangeLog'
--- a/ChangeLog 2012-09-17 00:56:08 +0000
+++ b/ChangeLog 2012-09-17 01:02:11 +0000
@@ -1,3 +1,9 @@
+2012-09-17  Paul Eggert  <address@hidden>
+
+       Remove no-longer-needed Solaris 2.4 vfork bug workaround.
+       * configure.ac (ac_cv_func_vfork_works): Default to 'no' on
+       Solaris 2.4, so that AC_FUNC_VFORK doesn't think vfork works.
+
 2012-09-17  Glenn Morris  <address@hidden>
 
        * configure.ac (copyright): New output variable.

=== modified file 'configure.ac'
--- a/configure.ac      2012-09-17 00:56:08 +0000
+++ b/configure.ac      2012-09-17 01:02:11 +0000
@@ -3155,6 +3155,14 @@
   AC_MSG_RESULT(no)
 fi
 
+dnl Check for a Solaris 2.4 vfork bug that Autoconf misses (through 2.69).
+dnl This can be removed once we assume Autoconf 2.70.
+case $canonical in
+  *-solaris2.4 | *-solaris2.4.*)
+    dnl Disable the Autoconf-generated vfork test.
+    : ${ac_cv_func_vfork_works=no};;
+esac
+
 AC_FUNC_FORK
 
 AC_CHECK_FUNCS(snprintf)

=== modified file 'src/ChangeLog'
--- a/src/ChangeLog     2012-09-17 00:56:08 +0000
+++ b/src/ChangeLog     2012-09-17 01:02:11 +0000
@@ -1,3 +1,15 @@
+2012-09-17  Paul Eggert  <address@hidden>
+
+       Remove no-longer-needed Solaris 2.4 vfork bug workaround.
+       The workaround was for improving performance on Solaris 2.4, but
+       is getting in the way now.  Emacs will still work if someone is
+       still running Solaris 2.4 in a museum somewhere; Sun dropped
+       support for Solaris 2.4 in 2003.
+       * callproc.c (Fcall_process) [HAVE_WORKING_VFORK]:
+       * process.c (create_process) [HAVE_WORKING_VFORK]:
+       Omit now-unnecessary workaround for the Solaris 2.4 vfork bug,
+       since Emacs no longer uses vfork on that platform.
+
 2012-09-17  Glenn Morris  <address@hidden>
 
        * emacs.c: Use COPYRIGHT.

=== modified file 'src/callproc.c'
--- a/src/callproc.c    2012-09-15 07:06:56 +0000
+++ b/src/callproc.c    2012-09-17 01:02:11 +0000
@@ -496,11 +496,6 @@
     register char **save_environ = environ;
     register int fd1 = fd[1];
     int fd_error = fd1;
-#ifdef HAVE_WORKING_VFORK
-    sigset_t procmask;
-    sigset_t blocked;
-    struct sigaction sigpipe_action;
-#endif
 
     if (fd_output >= 0)
       fd1 = fd_output;
@@ -587,17 +582,6 @@
                       0, current_dir);
 #else  /* not WINDOWSNT */
 
-#ifdef HAVE_WORKING_VFORK
-    /* On many hosts (e.g. Solaris 2.4), if a vforked child calls `signal',
-       this sets the parent's signal handlers as well as the child's.
-       So delay all interrupts whose handlers the child might munge,
-       and record the current handlers so they can be restored later.  */
-    sigemptyset (&blocked);
-    sigaddset (&blocked, SIGPIPE);
-    sigaction (SIGPIPE, 0, &sigpipe_action);
-    pthread_sigmask (SIG_BLOCK, &blocked, &procmask);
-#endif
-
     BLOCK_INPUT;
 
     /* vfork, and prevent local vars from being clobbered by the vfork.  */
@@ -645,9 +629,6 @@
        /* GConf causes us to ignore SIGPIPE, make sure it is restored
           in the child.  */
        signal (SIGPIPE, SIG_DFL);
-#ifdef HAVE_WORKING_VFORK
-       pthread_sigmask (SIG_SETMASK, &procmask, 0);
-#endif
 
        child_setup (filefd, fd1, fd_error, (char **) new_argv,
                     0, current_dir);
@@ -655,12 +636,6 @@
 
     UNBLOCK_INPUT;
 
-#ifdef HAVE_WORKING_VFORK
-    /* Restore the signal state.  */
-    sigaction (SIGPIPE, &sigpipe_action, 0);
-    pthread_sigmask (SIG_SETMASK, &procmask, 0);
-#endif
-
 #endif /* not WINDOWSNT */
 
     /* The MSDOS case did this already.  */

=== modified file 'src/process.c'
--- a/src/process.c     2012-09-16 21:43:55 +0000
+++ b/src/process.c     2012-09-17 01:02:11 +0000
@@ -1609,14 +1609,10 @@
 #if !defined (WINDOWSNT) && defined (FD_CLOEXEC)
   int wait_child_setup[2];
 #endif
+#ifdef SIGCHLD
   sigset_t blocked, procmask;
-  struct sigaction sigint_action;
-  struct sigaction sigquit_action;
-  struct sigaction sigpipe_action;
-#ifdef AIX
-  struct sigaction sighup_action;
 #endif
-  /* Use volatile to protect variables from being clobbered by longjmp.  */
+  /* Use volatile to protect variables from being clobbered by vfork.  */
   volatile int forkin, forkout;
   volatile int pty_flag = 0;
 
@@ -1708,25 +1704,13 @@
   XPROCESS (process)->pty_flag = pty_flag;
   pset_status (XPROCESS (process), Qrun);
 
+#ifdef SIGCHLD
   /* Delay interrupts until we have a chance to store
      the new fork's pid in its process structure */
   sigemptyset (&blocked);
-#ifdef SIGCHLD
   sigaddset (&blocked, SIGCHLD);
-#endif
-#ifdef HAVE_WORKING_VFORK
-  /* On many hosts (e.g. Solaris 2.4), if a vforked child calls `signal',
-     this sets the parent's signal handlers as well as the child's.
-     So delay all interrupts whose handlers the child might munge,
-     and record the current handlers so they can be restored later.  */
-  sigaddset (&blocked, SIGINT );  sigaction (SIGINT , 0, &sigint_action );
-  sigaddset (&blocked, SIGQUIT);  sigaction (SIGQUIT, 0, &sigquit_action);
-  sigaddset (&blocked, SIGPIPE);  sigaction (SIGPIPE, 0, &sigpipe_action);
-#ifdef AIX
-  sigaddset (&blocked, SIGHUP );  sigaction (SIGHUP , 0, &sighup_action );
-#endif
-#endif /* HAVE_WORKING_VFORK */
   pthread_sigmask (SIG_BLOCK, &blocked, &procmask);
+#endif
 
   FD_SET (inchannel, &input_wait_mask);
   FD_SET (inchannel, &non_keyboard_wait_mask);
@@ -1879,8 +1863,10 @@
           in the child.  */
        signal (SIGPIPE, SIG_DFL);
 
+#ifdef SIGCHLD
        /* Stop blocking signals in the child.  */
        pthread_sigmask (SIG_SETMASK, &procmask, 0);
+#endif
 
        if (pty_flag)
          child_setup_tty (xforkout);
@@ -1959,19 +1945,10 @@
 #endif
     }
 
-  /* Restore the signal state whether vfork succeeded or not.
-     (We will signal an error, below, if it failed.)  */
-#ifdef HAVE_WORKING_VFORK
-  /* Restore the parent's signal handlers.  */
-  sigaction (SIGINT, &sigint_action, 0);
-  sigaction (SIGQUIT, &sigquit_action, 0);
-  sigaction (SIGPIPE, &sigpipe_action, 0);
-#ifdef AIX
-  sigaction (SIGHUP, &sighup_action, 0);
-#endif
-#endif /* HAVE_WORKING_VFORK */
+#ifdef SIGCHLD
   /* Stop blocking signals in the parent.  */
   pthread_sigmask (SIG_SETMASK, &procmask, 0);
+#endif
 
   /* Now generate the error if vfork failed.  */
   if (pid < 0)