Fix gcconfig to turn on POSIX fork() support by default

(define HANDLE_FORK on Unix platforms with pthreads)

* doc/README.macros (HANDLE_FORK): Replace with NO_HANDLE_FORK; update
the documentation.
* include/private/gcconfig.h (HANDLE_FORK): Explicitly define if
GC_PTHREADS unless already defined or NO_HANDLE_FORK is defined, or
unsupported on the target.

diff --git a/doc/README.macros b/doc/README.macros
index 1136f3aa99b25234f73fc7d758b1e2ecceaa8de9..659e958c060cf9163addf50c9720b67c5b434bc0 100644 (file)
--- a/doc/README.macros
+++ b/doc/README.macros
@@ -435,9 +435,9 @@ STUBBORN_ALLOC  Allows allocation of "hard to change" objects, and thus
   makes incremental collection easier.  Was enabled by default until 6.0.
   Rarely used, to my knowledge.
 
-HANDLE_FORK     Attempts to make GC_malloc() work in a child process fork()'ed
-  from a multithreaded parent.  Currently only supported by pthread_support.c.
-  (Similar code should work on Solaris or Irix, but it hasn't been tried.)
+NO_HANDLE_FORK (Unix only)      Do not attempt to make GC_malloc() work in
+  a child process fork()'ed from a multi-threaded parent.  (Might be required
+  if pthread_atfork is missing.)
 
 TEST_WITH_SYSTEM_MALLOC         Causes gctest to allocate (and leak) large
   chunks of memory with the standard system malloc.  This will cause the root

diff --git a/include/private/gcconfig.h b/include/private/gcconfig.h
index d9c1d6375e49be127d28f7a2f09b8ba8a11e8628..a2ba20d3d39861eb19784c1c497123dce796bacc 100644 (file)
--- a/include/private/gcconfig.h
+++ b/include/private/gcconfig.h
@@ -2612,6 +2612,14 @@
 # define IF_CANCEL(x) /* empty */
 #endif
 
+#if defined(GC_PTHREADS) && !defined(GC_WIN32_THREADS) \
+    && !defined(HANDLE_FORK) && !defined(NO_HANDLE_FORK) \
+    && !defined(HURD) && !defined(NACL) && !defined(PLATFORM_ANDROID)
+  /* Attempts (where supported) to make GC_malloc work in a child       */
+  /* process fork'ed from a multi-threaded parent.                      */
+# define HANDLE_FORK
+#endif
+
 #if !defined(USE_MARK_BITS) && !defined(USE_MARK_BYTES) \
     && defined(PARALLEL_MARK)
    /* Minimize compare-and-swap usage.  */