[omniORB] omnithread thread-local storage problem

[Luke Deller]

Hi,

I encountered a problem with using omni_thread::get_value when I tried 
moving to the native posix thread library (NPTL) supported by the 2.6 
kernel series.

I'm working with an application which provides its own replacement for 
malloc and new.  It seems that with nptl, malloc is being called by a 
thread after the corresponding omni_thread has been deleted.  Thus when 
malloc calls omni_thread::self()->get_value(..), it can get a rubbish value.

This led me to wonder: why does omnithread use its own implementation of 
  thread-local storage?  Why doesn't it simply wrap the system thread 
library's implementation?

(I tried doing this myself for posix threads, and it fixes my problem 
because omni_thread::get_value no longer depends upon omni_thread 
instance data.  The cvs diff is attached if you're interested.  It 
should be easy enough to do the same thing for win32 thread calls).

Regards,
Luke.
-------------- next part --------------
Index: include/omnithread.h
===================================================================
RCS file: /cvsroot/omniorb/omni/include/Attic/omnithread.h,v
retrieving revision 1.21.2.17
diff -u -r1.21.2.17 omnithread.h
--- include/omnithread.h	6 Feb 2004 16:16:29 -0000	1.21.2.17
+++ include/omnithread.h	1 Apr 2004 04:16:34 -0000
@@ -182,6 +182,10 @@
 #error "Implementation header file incomplete"
 #endif
 
+#ifndef OMNI_THREAD_KEY_T
+#    define OMNI_THREAD_KEY_T unsigned int
+#endif
+
 
 //
 // This exception is thrown in the event of a fatal error.
@@ -488,7 +492,7 @@
     // careful about setting/getting data in a different thread to the
     // current thread.
 
-    typedef unsigned int key_t;
+    typedef OMNI_THREAD_KEY_T key_t;
     static key_t allocate_key();
 
     class value_t {
Index: include/omnithread/posix.h
===================================================================
RCS file: /cvsroot/omniorb/omni/include/omnithread/Attic/posix.h,v
retrieving revision 1.7.2.2
diff -u -r1.7.2.2 posix.h
--- include/omnithread/posix.h	8 Sep 2002 21:58:54 -0000	1.7.2.2
+++ include/omnithread/posix.h	1 Apr 2004 04:16:34 -0000
@@ -73,4 +73,6 @@
     static int posix_priority(priority_t);		\
     friend void* omni_thread_wrapper(void* ptr);
 
+#define OMNI_THREAD_KEY_T pthread_key_t
+
 #endif
Index: src/lib/omnithread/posix.cc
===================================================================
RCS file: /cvsroot/omniorb/omni/src/lib/omnithread/Attic/posix.cc,v
retrieving revision 1.27.2.11
diff -u -r1.27.2.11 posix.cc
--- src/lib/omnithread/posix.cc	9 Jun 2003 11:59:26 -0000	1.27.2.11
+++ src/lib/omnithread/posix.cc	1 Apr 2004 04:16:35 -0000
@@ -949,7 +949,43 @@
   delete dummy;
 }
 
+static void
+value_destructor(void *value)
+{
+  delete (omni_thread::value_t*)value;
+}
+
+omni_thread::key_t
+omni_thread::allocate_key()
+{
+  pthread_key_t key;
+  THROW_ERRORS(pthread_key_create(&key, value_destructor));
+  return key;
+}
+
+omni_thread::value_t*
+omni_thread::set_value(key_t k, value_t* v)
+{
+  int err;
+  err = pthread_setspecific(k, v);
+  if (err==0)
+    return v;
+  else if (err==EINVAL)
+    return 0; /* invalid key */
+  else
+    throw omni_thread_fatal(err);
+}
+
+omni_thread::value_t*
+omni_thread::get_value(key_t k)
+{
+  return (value_t*)pthread_getspecific(k);
+}
+
+omni_thread::value_t*
+omni_thread::remove_value(key_t k)
+{
+  delete (value_t*)pthread_getspecific(k);
+  pthread_key_delete(k);
+}
 
-#define INSIDE_THREAD_IMPL_CC
-#include "threaddata.cc"
-#undef INSIDE_THREAD_IMPL_CC