1998-07-22 Ben Elliston <bje@cygnus.com>

	* pthread.h (pthread_atfork): Add function prototype.

	* fork.c (pthread_atfork): Preliminary implementation.
	(_pthread_fork): Likewise.

3 files changed, 75 insertions, 0 deletions

diff --git a/ChangeLog b/ChangeLog
index ba6e725..35b3d82 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+1998-07-22  Ben Elliston  <bje@cygnus.com>
+
+	* pthread.h (pthread_atfork): Add function prototype.
+
+	* fork.c (pthread_atfork): Preliminary implementation.
+	(_pthread_fork): Likewise.
+
 Wed Jul 22 00:16:22 1998  Ross Johnson  <rpj@ixobrychus.canberra.edu.au>
 
 	* cleanup.c (_pthread_cleanup_push): Implement.
diff --git a/fork.c b/fork.c
new file mode 100644
index 0000000..0b27558
--- /dev/null
+++ b/fork.c
@@ -0,0 +1,64 @@
+/*
+ * fork.c
+ *
+ * Description:
+ * Implementation of fork() for POSIX threads.
+ */
+
+int
+pthread_atfork(void (*prepare)(void),
+	       void (*parent)(void),
+	       void (*child)(void))
+{
+  /* Push handlers (unless NULL) onto their respective stacks. */
+
+  if (prepare != NULL)
+    {
+      /* Push prepare. */
+      /* If push fails, return ENOMEM. */
+    }
+
+  if (parent != NULL)
+    {
+      /* Push parent. */
+      /* If push fails, return ENOMEM. */
+    }
+
+  if (child != NULL)
+    {
+      /* Push child. */
+      /* If push fails, return ENOMEM. */
+    }
+
+  /* Everything is okay. */
+  return 0;
+}
+
+/* It looks like the GNU linker is capable of selecting this version of
+   fork() over a version provided in more primitive libraries further down
+   the linker command line. */
+
+pid_t
+fork()
+{
+  pid_t pid;
+
+  /* Pop prepare handlers here. */
+
+  /* Now call Cygwin32's fork(). */
+
+  if ((pid = _fork()) > 0)
+    {
+      /* Pop parent handlers. */
+      return pid;
+    }
+  else
+    {
+      /* Pop child handlers. */
+      /* Terminate all threads except pthread_self() using
+	 pthread_cancel(). */
+      return 0;
+    }
+
+  /* Not reached. */
+}
diff --git a/pthread.h b/pthread.h
index bf9ff7b..82b1a93 100644
--- a/pthread.h
+++ b/pthread.h
@@ -51,6 +51,10 @@ typedef struct {
 extern "C" {
 #endif /* __cplusplus */
 
+int pthread_atfork (void (*prepare)(void),
+		    void (*parent)(void),
+		    void (*child)(void));
+
 int pthread_create(pthread_t *thread,
 		   const pthread_attr_t *attr,
 		   void * (*start_routine) (void *),