Bug 984196 - glxtest should use _exit instead of exit. r=bgirard

--HG--
extra : rebase_source : 3bba6badd7e5a4031ad402cf88f7e0a15f4ba386

build/valgrind/i386-redhat-linux-gnu.sup

@@ -49,3 +49,15 @@
    obj:/lib/libgobject-2.0.so.0.2200.5
    ...
 }
+
+###################################
+#  Leaks in short lived precesses #
+###################################
+
+{
+   Bug 984196
+   Memcheck:Leak
+   ...
+   fun:glxtest
+   ...
+}

build/valgrind/x86_64-redhat-linux-gnu.sup

@@ -71,3 +71,15 @@
    fun:gdk_display_open
    ...
 }
+
+###################################
+#  Leaks in short lived precesses #
+###################################
+
+{
+   Bug 984196
+   Memcheck:Leak
+   ...
+   fun:glxtest
+   ...
+}

toolkit/xre/glxtest.cpp

@@ -83,7 +83,7 @@ static void fatal_error(const char *str)
 {
   write(write_end_of_the_pipe, str, strlen(str));
   write(write_end_of_the_pipe, "\n", 1);
-  exit(EXIT_FAILURE);
+  _exit(EXIT_FAILURE);
 }
 
 static int
@@ -97,11 +97,18 @@ x_error_handler(Display *, XErrorEvent *ev)
                         ev->request_code,
                         ev->minor_code);
   write(write_end_of_the_pipe, buf, length);
-  exit(EXIT_FAILURE);
+  _exit(EXIT_FAILURE);
   return 0;
 }
 
-static void glxtest()
+
+// glxtest is declared inside extern "C" so that the name is not mangled.
+// The name is used in build/valgrind/x86_64-redhat-linux-gnu.sup to suppress
+// memory leak errors because we run it inside a short lived fork and we don't
+// care about leaking memory
+extern "C" {
+
+void glxtest()
 {
   // we want to redirect to /dev/null stdout, stderr, and while we're at it,
   // any PR logging file descriptors. To that effect, we redirect all positive
@@ -245,6 +252,8 @@ static void glxtest()
   write(write_end_of_the_pipe, buf, length);
 }
 
+}
+
 /** \returns true in the child glxtest process, false in the parent process */
 bool fire_glxtest_process()
 {
@@ -267,7 +276,7 @@ bool fire_glxtest_process()
       write_end_of_the_pipe = pfd[1];
       glxtest();
       close(pfd[1]);
-      exit(0);
+      _exit(0);
   }
 
   close(pfd[1]);