Implemented pthread_atfork()

Change-Id: Ie6c0bf593315d3507b3c4a6c8903a74a1fa053db
diff --git a/libc/bionic/fork.c b/libc/bionic/fork.c
index e20f548..8d3ea4b 100644
--- a/libc/bionic/fork.c
+++ b/libc/bionic/fork.c
@@ -40,9 +40,12 @@
      * of error, or in the parent process
      */
     __timer_table_start_stop(1);
+    __bionic_atfork_run_prepare();
+
     ret = __fork();
     if (ret != 0) {  /* not a child process */
         __timer_table_start_stop(0);
+        __bionic_atfork_run_parent();
     } else {
         /*
          * Newly created process must update cpu accounting.
@@ -51,6 +54,7 @@
          * as a parameter.
          */
         cpuacct_add(getuid());
+        __bionic_atfork_run_child();
     }
     return ret;
 }