[omniORB] omnithread thread-local storage problem

[Luke Deller]

Just a follow-up to my last email... I don't believe that omnithread's 
thread-local storage can be implemented as a wrapper around win32 
thread-local storage calls, because win32 does not support destructors 
for thread-local values.

Also the diff I attached to my last email had an error in remove_value; 
the corrected patch is attached.

Luke.

Luke Deller wrote:
> 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 04:34:26 -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 04:34:26 -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 04:34:26 -0000
@@ -949,7 +949,44 @@
   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)
+{
+  value_t * v = (value_t*)pthread_getspecific(k);
+  pthread_key_delete(k);
+  return v;
+}
 
-#define INSIDE_THREAD_IMPL_CC
-#include "threaddata.cc"
-#undef INSIDE_THREAD_IMPL_CC