Report exit status in debug stub, if tab is closed in chrome.

src/trusted/service_runtime/nacl_secure_service.c

Index: src/trusted/service_runtime/nacl_secure_service.c
===================================================================
--- src/trusted/service_runtime/nacl_secure_service.c	(revision 10072)
+++ src/trusted/service_runtime/nacl_secure_service.c	(working copy)
@@ -101,7 +101,7 @@
   }
   if (0 == --self->conn_count) {
     NaClLog(4, "NaClSecureServiceThread: all channels closed, exiting.\n");

[bsy, 2012/10/23 17:42:35]

please add a comment for why this is needed, since w/o debug stub this isn't.

also, this function name suggests that it reports an exit status but will
return.  (which is indeed what it does.)  maybe add a comment that this will
cause the service runtime's main thread to exit as a side-effect?

i don't think we should use 0 here as the "exit status", since it conflates the
NaCl module's use of the exit syscall with value 0 with the command channel
closure, which is more akin to a kill or sigpipe.  we should probably encode it
in the wait status the same way that posix does with 8 bit exit status and
termsig/stopsig etc.

[halyavin, 2012/10/23 18:42:42]

I added a comment.
This is normal scenario in browser. So I don't think we need to send non-zero
here.
 
FYI, debug stub sends only 8 bits of exit code.

-    NaClExit(0);
+    NaClReportExitStatus(self->nap, 0);
   }
   NaClXMutexUnlock(&self->mu);
 }