Solaris: various repairs

Fix threading, including SIGCHLD mask.

racket/collects/compiler/private/xform.rkt

@@ -895,7 +895,7 @@
                __builtin_next_arg __builtin_saveregs 
                __builtin_constant_p
                __builtin___CFStringMakeConstantString
-               __error __errno_location __toupper __tolower
+               __error __errno_location __toupper __tolower ___errno
                __attribute__ __mode__ ; not really functions in gcc
                __iob_func ; VC 8
                |GetStdHandle| |__CFStringMakeConstantString|

racket/src/configure

@@ -8814,7 +8814,7 @@ if test "${enable_pthread}" = "yes" ; then
     LDFLAGS="$LDFLAGS -pthread"
   fi
   if test "${use_flag_posix_pthread}" = "yes" ; then
-    PREFLAGS="$PREFLAGS -D_POSIX_PTHREAD_SEMANTICS"
+    PREFLAGS="$PREFLAGS -D_POSIX_PTHREAD_SEMANTICS -D_REENTRANT"
   fi
 
 cat >>confdefs.h <<\_ACEOF

racket/src/racket/configure.ac

@@ -1215,7 +1215,7 @@ if test "${enable_pthread}" = "yes" ; then
     LDFLAGS="$LDFLAGS -pthread"
   fi
   if test "${use_flag_posix_pthread}" = "yes" ; then
-    PREFLAGS="$PREFLAGS -D_POSIX_PTHREAD_SEMANTICS"
+    PREFLAGS="$PREFLAGS -D_POSIX_PTHREAD_SEMANTICS -D_REENTRANT"
   fi
   AC_DEFINE(USE_PTHREAD_INSTEAD_OF_ITIMER, 1, [Pthread timer enabled])
 

racket/src/racket/sconfig.h

@@ -118,6 +118,10 @@
 
 # define FMOD_CAN_RETURN_POS_ZERO
 
+# ifdef _POSIX_PTHREAD_SEMANTICS
+#  define SUBPROCESS_USE_FORK1
+# endif
+
 # ifdef i386
 #  define MZ_USE_JIT_I386
 #  define MZ_JIT_USE_MPROTECT
@@ -1236,6 +1240,8 @@
     should be closed after performing a fork() for `process'
     and `system' calls. */
 
+ /* SUBPROCESS_USE_FORK1 uses fork1() instead of fork(). */
+
  /* USE_UNIX_SOCKETS_TCP means that the tcp- procedures can be implemented
     with the standard Unix socket functions. */
 

racket/src/racket/src/place.c

@@ -995,15 +995,18 @@ static void got_sigchld() XFORM_SKIP_PROC
 void scheme_places_block_child_signal() XFORM_SKIP_PROC
 {
   sigset_t set;
-  sigemptyset(&set);
-  sigaddset(&set, SIGCHLD);
-  sigprocmask(SIG_BLOCK, &set, NULL);
 
   /* Mac OS X seems to need a handler installed for SIGCHLD to be
      delivered, since the default is to drop the signal. Also, this
      handler serves as a back-up alert if some thread is created that
-     does not block SIGCHLD. */
+     does not block SIGCHLD.
+     Solaris, meanwhile, seems to unmask SIGCHLD as a result of
+     setting a handler, so do this before masking the signal. */
   MZ_SIGSET(SIGCHLD, got_sigchld);
+
+  sigemptyset(&set);
+  sigaddset(&set, SIGCHLD);
+  sigprocmask(SIG_BLOCK, &set, NULL);
 }
 
 void scheme_places_unblock_child_signal() XFORM_SKIP_PROC

racket/src/racket/src/port.c

@@ -5695,7 +5695,11 @@ static int try_lock(intptr_t fd, int writer, int *_errid)
       if (!pipe(ofds)) {
         int pid;
 
+#ifdef SUBPROCESS_USE_FORK1
+        pid = fork1();
+#else
         pid = fork();
+#endif
         
         if (pid > 0) {
           /* Original process: */
@@ -9814,10 +9818,12 @@ static Scheme_Object *subprocess(int c, Scheme_Object *args[])
     scheme_starting_child();
 #endif
 
-#if !defined(__QNX__)
-    pid = fork();
-#else
+#if defined(__QNX__)
     pid = vfork();
+#elif defined(SUBPROCESS_USE_FORK1)
+    pid = fork1();
+#else
+    pid = fork();
 #endif
 
     if (pid > 0) {