1 files changed, 74 insertions, 10 deletions

diff --git a/fork.c b/fork.c
index 0b27558..534effc 100644
--- a/fork.c
+++ b/fork.c
@@ -5,33 +5,73 @@
  * Implementation of fork() for POSIX threads.
  */
 
+#include "pthread.h"
+#include "implement.h"
+
 int
 pthread_atfork(void (*prepare)(void),
 	       void (*parent)(void),
 	       void (*child)(void))
 {
-  /* Push handlers (unless NULL) onto their respective stacks. */
+  /* Push handlers (unless NULL) onto their respective stacks. 
+
+     Local implementation semantics:
+     If we get an ENOMEM at any time in here then ALL handlers
+     (including those from previous pthread_atfork() calls) will be
+     popped off each of the three atfork stacks before we return. */
+
+  int ret = 0;
 
   if (prepare != NULL)
     {
       /* Push prepare. */
-      /* If push fails, return ENOMEM. */
+      if (_pthread_handler_push(_PTHREAD_FORKPREPARE_STACK,
+				_PTHREAD_HANDLER_POP_FIFO,
+				(void (*prepare)(void *)), NULL) == ENOMEM)
+	{
+	  ret = ENOMEM;
+	}
     }
 
-  if (parent != NULL)
+  if (parent != NULL &&
+      ret != ENOMEM)
     {
       /* Push parent. */
-      /* If push fails, return ENOMEM. */
+      if (_pthread_handler_push(_PTHREAD_FORKPARENT_STACK,
+				_PTHREAD_HANDLER_POP_LIFO,
+				(void (*parent)(void *)), NULL) == ENOMEM)
+	{
+	  ret = ENOMEM;
+	}
     }
 
-  if (child != NULL)
+  if (child != NULL &&
+      ret != ENOMEM)
     {
       /* Push child. */
-      /* If push fails, return ENOMEM. */
+      if (_pthread_handler_push(_PTHREAD_FORKCHILD_STACK,
+				_PTHREAD_HANDLER_POP_LIFO,
+				(void (*child)(void *)), arg) == ENOMEM)
+	{
+	  ret = ENOMEM;
+	}
+    }
+
+  if (ret == ENOMEM)
+    {
+      /* Pop all handlers without executing them before we return
+	 the error. */
+      _pthread_handler_pop_all(_PTHREAD_FORKPREPARE_STACK,
+			       _PTHREAD_HANDLER_NOEXECUTE);
+
+      _pthread_handler_pop_all(_PTHREAD_FORKPARENT_STACK,
+			       _PTHREAD_HANDLER_NOEXECUTE);
+
+      _pthread_handler_pop_all(_PTHREAD_FORKCHILD_STACK,
+			       _PTHREAD_HANDLER_NOEXECUTE);
     }
 
-  /* Everything is okay. */
-  return 0;
+  return ret;
 }
 
 /* It looks like the GNU linker is capable of selecting this version of
@@ -44,19 +84,43 @@ fork()
   pid_t pid;
 
   /* Pop prepare handlers here. */
+  _pthread_handler_pop_all(_PTHREAD_FORKPREPARE_STACK,
+			   _PTHREAD_HANDLER_EXECUTE);
 
   /* Now call Cygwin32's fork(). */
 
   if ((pid = _fork()) > 0)
     {
-      /* Pop parent handlers. */
+      /* PARENT */
+      /* Clear the child handler stack. */
+      _pthread_handler_pop_all(_PTHREAD_FORKCHILD_STACK,
+			       _PTHREAD_HANDLER_NOEXECUTE);
+
+      /* Pop parent handlers and execute them. */
+      _pthread_handler_pop_all(_PTHREAD_FORKPARENT_STACK,
+			       _PTHREAD_HANDLER_EXECUTE);
+
+      /* At this point all three atfork stacks are empty. */
       return pid;
     }
   else
     {
-      /* Pop child handlers. */
+      /* CHILD */
+      /* Clear the parent handler stack. */
+      _pthread_handler_pop_all(_PTHREAD_FORKPARENT_STACK,
+			       _PTHREAD_HANDLER_NOEXECUTE);
+
+      /* Pop child handlers and execute them. */
+      _pthread_handler_pop_all(_PTHREAD_FORKCHILD_STACK,
+			       _PTHREAD_HANDLER_EXECUTE);
+
+      /* At this point all three atfork stacks are empty. */
+
       /* Terminate all threads except pthread_self() using
 	 pthread_cancel(). */
+      _pthread_cancel_all_not_self();
+      _pthread_join_all_not_self();
+
       return 0;
     }