Correction de race conditions entre I/O, GC, et marshaling (PR #24 et #25)

git-svn-id: http://caml.inria.fr/svn/ocaml/trunk@2794 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02

1 files changed, 7 insertions, 1 deletions

diff --git a/byterun/extern.c b/byterun/extern.c
index d0c7c4c4fc..8ad3a76ef3 100644
--- a/byterun/extern.c
+++ b/byterun/extern.c
@@ -391,12 +391,18 @@ static long extern_value(value v, value flags)
 void output_val(struct channel *chan, value v, value flags)
 {
   long len;
+  char * block;
+
   if (! channel_binary_mode(chan))
     failwith("output_value: not a binary channel");
   alloc_extern_block();
   len = extern_value(v, flags);
+  /* During really_putblock, concurrent output_val operations can take
+     place (via signal handlers or context switching in systhreads),
+     and extern_block may change.  So, save the pointer in a local variable. */
+  block = extern_block;
   really_putblock(chan, extern_block, len);
-  stat_free(extern_block);
+  stat_free(block);
 }
 
 value output_value(value vchan, value v, value flags) /* ML */