2007-05-09 Joel Sherrill <joel.sherrill@OARcorp.com>

	* libcsupport/include/rtems/libcsupport.h, libcsupport/src/newlibc.c,
	sapi/Makefile.am, sapi/include/confdefs.h, sapi/src/exinit.c,
	score/Makefile.am, score/preinstall.am,
	score/include/rtems/score/userext.h, score/src/chain.c,
	score/src/userext.c: Switch to newlib reentrancy extension being
	installed in the initial set instead of using rtems_extension_create.
	While implementing this, noticed that user extensions and chain code
	had multiple functions in a single file which is not desirable in the
	SuperCore and API portions of RTEMS, so split these into multiple
	files with one function per file. Also noticed that some of user
	extension code was inlined for no particular reason so moved that to
	C bodies.  Split executive shutdown from initialization since not
	every application shuts down.  Moved __fini call to executive shutdown
	to be more symmetrical with where it is called at startup.
	* sapi/src/exshutdown.c, score/src/chainappend.c,
	score/src/chainextract.c, score/src/chainget.c,
	score/src/chaininsert.c, score/src/userextaddapiset.c,
	score/src/userextaddset.c, score/src/userextremoveset.c,
	score/src/userextthreadbegin.c, score/src/userextthreadcreate.c,
	score/src/userextthreaddelete.c, score/src/userextthreadrestart.c,
	score/src/userextthreadstart.c, score/src/userextthreadswitch.c: New
	files.
	* score/inline/rtems/score/userext.inl: Removed.

15 files changed, 642 insertions, 301 deletions

diff --git a/cpukit/score/src/chain.c b/cpukit/score/src/chain.c
index d9248ea794..c44d6201a3 100644
--- a/cpukit/score/src/chain.c
+++ b/cpukit/score/src/chain.c
@@ -1,12 +1,5 @@
 /*
- *  Chain Handler
- *
- *  NOTE:
- *
- *  The order of this file is to allow proper compilation due to the
- *  order of inlining required by the compiler.
- *
- *  COPYRIGHT (c) 1989-1999.
+ *  COPYRIGHT (c) 1989-2007.
  *  On-Line Applications Research Corporation (OAR).
  *
  *  The license and distribution terms for this file may be
@@ -65,119 +58,3 @@ void _Chain_Initialize(
   current->next    = _Chain_Tail( the_chain );
   the_chain->last  = current;
 }
-
-/*PAGE
- *
- *  _Chain_Get
- *
- *  This kernel routine returns a pointer to a node taken from the
- *  given chain.
- *
- *  Input parameters:
- *    the_chain - pointer to chain header
- *
- *  Output parameters:
- *    return_node - pointer to node in chain allocated
- *    CHAIN_END   - if no nodes available
- *
- *  INTERRUPT LATENCY:
- *    only case
- */
-
-Chain_Node *_Chain_Get(
-  Chain_Control *the_chain
-)
-{
-  ISR_Level          level;
-  Chain_Node *return_node;
-
-  return_node = NULL;
-  _ISR_Disable( level );
-    if ( !_Chain_Is_empty( the_chain ) )
-      return_node = _Chain_Get_first_unprotected( the_chain );
-  _ISR_Enable( level );
-  return return_node;
-}
-
-/*PAGE
- *
- *  _Chain_Append
- *
- *  This kernel routine puts a node on the end of the specified chain.
- *
- *  Input parameters:
- *    the_chain - pointer to chain header
- *    node      - address of node to put at rear of chain
- *
- *  Output parameters:  NONE
- *
- *  INTERRUPT LATENCY:
- *    only case
- */
-
-void _Chain_Append(
-  Chain_Control *the_chain,
-  Chain_Node    *node
-)
-{
-  ISR_Level level;
-
-  _ISR_Disable( level );
-    _Chain_Append_unprotected( the_chain, node );
-  _ISR_Enable( level );
-}
-
-/*PAGE
- *
- *  _Chain_Extract
- *
- *  This kernel routine deletes the given node from a chain.
- *
- *  Input parameters:
- *    node - pointer to node in chain to be deleted
- *
- *  Output parameters:  NONE
- *
- *  INTERRUPT LATENCY:
- *    only case
- */
-
-void _Chain_Extract(
-  Chain_Node *node
-)
-{
-  ISR_Level level;
-
-  _ISR_Disable( level );
-    _Chain_Extract_unprotected( node );
-  _ISR_Enable( level );
-}
-
-/*PAGE
- *
- *  _Chain_Insert
- *
- *  This kernel routine inserts a given node after a specified node
- *  a requested chain.
- *
- *  Input parameters:
- *    after_node - pointer to node in chain to be inserted after
- *    node       - pointer to node to be inserted
- *
- *  Output parameters:  NONE
- *
- *  INTERRUPT LATENCY:
- *    only case
- */
-
-void _Chain_Insert(
-  Chain_Node *after_node,
-  Chain_Node *node
-)
-{
-  ISR_Level level;
-
-  _ISR_Disable( level );
-    _Chain_Insert_unprotected( after_node, node );
-  _ISR_Enable( level );
-}
diff --git a/cpukit/score/src/chainappend.c b/cpukit/score/src/chainappend.c
new file mode 100644
index 0000000000..f5287a450f
--- /dev/null
+++ b/cpukit/score/src/chainappend.c
@@ -0,0 +1,46 @@
+/*
+ *  COPYRIGHT (c) 1989-2007.
+ *  On-Line Applications Research Corporation (OAR).
+ *
+ *  The license and distribution terms for this file may be
+ *  found in the file LICENSE in this distribution or at
+ *  http://www.rtems.com/license/LICENSE.
+ *
+ *  $Id$
+ */
+
+#if HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <rtems/system.h>
+#include <rtems/score/address.h>
+#include <rtems/score/chain.h>
+#include <rtems/score/isr.h>
+
+/*
+ *  _Chain_Append
+ *
+ *  This kernel routine puts a node on the end of the specified chain.
+ *
+ *  Input parameters:
+ *    the_chain - pointer to chain header
+ *    node      - address of node to put at rear of chain
+ *
+ *  Output parameters:  NONE
+ *
+ *  INTERRUPT LATENCY:
+ *    only case
+ */
+
+void _Chain_Append(
+  Chain_Control *the_chain,
+  Chain_Node    *node
+)
+{
+  ISR_Level level;
+
+  _ISR_Disable( level );
+    _Chain_Append_unprotected( the_chain, node );
+  _ISR_Enable( level );
+}
diff --git a/cpukit/score/src/chainextract.c b/cpukit/score/src/chainextract.c
new file mode 100644
index 0000000000..deb537ed85
--- /dev/null
+++ b/cpukit/score/src/chainextract.c
@@ -0,0 +1,44 @@
+/*
+ *  COPYRIGHT (c) 1989-2007.
+ *  On-Line Applications Research Corporation (OAR).
+ *
+ *  The license and distribution terms for this file may be
+ *  found in the file LICENSE in this distribution or at
+ *  http://www.rtems.com/license/LICENSE.
+ *
+ *  $Id$
+ */
+
+#if HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <rtems/system.h>
+#include <rtems/score/address.h>
+#include <rtems/score/chain.h>
+#include <rtems/score/isr.h>
+
+/*
+ *  _Chain_Extract
+ *
+ *  This kernel routine deletes the given node from a chain.
+ *
+ *  Input parameters:
+ *    node - pointer to node in chain to be deleted
+ *
+ *  Output parameters:  NONE
+ *
+ *  INTERRUPT LATENCY:
+ *    only case
+ */
+
+void _Chain_Extract(
+  Chain_Node *node
+)
+{
+  ISR_Level level;
+
+  _ISR_Disable( level );
+    _Chain_Extract_unprotected( node );
+  _ISR_Enable( level );
+}
diff --git a/cpukit/score/src/chainget.c b/cpukit/score/src/chainget.c
new file mode 100644
index 0000000000..4ec11c112e
--- /dev/null
+++ b/cpukit/score/src/chainget.c
@@ -0,0 +1,51 @@
+/*
+ *  COPYRIGHT (c) 1989-2007.
+ *  On-Line Applications Research Corporation (OAR).
+ *
+ *  The license and distribution terms for this file may be
+ *  found in the file LICENSE in this distribution or at
+ *  http://www.rtems.com/license/LICENSE.
+ *
+ *  $Id$
+ */
+
+#if HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <rtems/system.h>
+#include <rtems/score/address.h>
+#include <rtems/score/chain.h>
+#include <rtems/score/isr.h>
+
+/*
+ *  _Chain_Get
+ *
+ *  This kernel routine returns a pointer to a node taken from the
+ *  given chain.
+ *
+ *  Input parameters:
+ *    the_chain - pointer to chain header
+ *
+ *  Output parameters:
+ *    return_node - pointer to node in chain allocated
+ *    CHAIN_END   - if no nodes available
+ *
+ *  INTERRUPT LATENCY:
+ *    only case
+ */
+
+Chain_Node *_Chain_Get(
+  Chain_Control *the_chain
+)
+{
+  ISR_Level          level;
+  Chain_Node *return_node;
+
+  return_node = NULL;
+  _ISR_Disable( level );
+    if ( !_Chain_Is_empty( the_chain ) )
+      return_node = _Chain_Get_first_unprotected( the_chain );
+  _ISR_Enable( level );
+  return return_node;
+}
diff --git a/cpukit/score/src/chaininsert.c b/cpukit/score/src/chaininsert.c
new file mode 100644
index 0000000000..0f5cdd25ab
--- /dev/null
+++ b/cpukit/score/src/chaininsert.c
@@ -0,0 +1,47 @@
+/*
+ *  COPYRIGHT (c) 1989-2007.
+ *  On-Line Applications Research Corporation (OAR).
+ *
+ *  The license and distribution terms for this file may be
+ *  found in the file LICENSE in this distribution or at
+ *  http://www.rtems.com/license/LICENSE.
+ *
+ *  $Id$
+ */
+
+#if HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <rtems/system.h>
+#include <rtems/score/address.h>
+#include <rtems/score/chain.h>
+#include <rtems/score/isr.h>
+
+/*
+ *  _Chain_Insert
+ *
+ *  This kernel routine inserts a given node after a specified node
+ *  a requested chain.
+ *
+ *  Input parameters:
+ *    after_node - pointer to node in chain to be inserted after
+ *    node       - pointer to node to be inserted
+ *
+ *  Output parameters:  NONE
+ *
+ *  INTERRUPT LATENCY:
+ *    only case
+ */
+
+void _Chain_Insert(
+  Chain_Node *after_node,
+  Chain_Node *node
+)
+{
+  ISR_Level level;
+
+  _ISR_Disable( level );
+    _Chain_Insert_unprotected( after_node, node );
+  _ISR_Enable( level );
+}
diff --git a/cpukit/score/src/userext.c b/cpukit/score/src/userext.c
index 469200ef76..c23e63f40d 100644
--- a/cpukit/score/src/userext.c
+++ b/cpukit/score/src/userext.c
@@ -1,9 +1,5 @@
 /*
- *  User Extension Handler
- *
- *  NOTE: XXX
- *
- *  COPYRIGHT (c) 1989-1999.
+ *  COPYRIGHT (c) 1989-2007.
  *  On-Line Applications Research Corporation (OAR).
  *
  *  The license and distribution terms for this file may be
@@ -19,187 +15,40 @@
 
 #include <rtems/system.h>
 #include <rtems/score/userext.h>
+#include <rtems/score/wkspace.h>
+#include <string.h>
 
-/*PAGE
- *
- *  _User_extensions_Thread_create
+/**
+ *  This routine performs the initialization necessary for this handler.
  */
 
-boolean _User_extensions_Thread_create (
-  Thread_Control *the_thread
+void _User_extensions_Handler_initialization (
+  uint32_t                number_of_extensions,
+  User_extensions_Table  *initial_extensions
 )
 {
-  Chain_Node              *the_node;
-  User_extensions_Control *the_extension;
-  boolean                  status;
+  User_extensions_Control *extension;
+  uint32_t                 i;
 
-  for ( the_node = _User_extensions_List.first ;
-        !_Chain_Is_tail( &_User_extensions_List, the_node ) ;
-        the_node = the_node->next ) {
+  _Chain_Initialize_empty( &_User_extensions_List );
+  _Chain_Initialize_empty( &_User_extensions_Switches_list );
 
-    the_extension = (User_extensions_Control *) the_node;
-
-    if ( the_extension->Callouts.thread_create != NULL ) {
-      status = (*the_extension->Callouts.thread_create)(
-        _Thread_Executing,
-        the_thread
+  if ( initial_extensions ) {
+    extension = (User_extensions_Control *)
+      _Workspace_Allocate_or_fatal_error(
+        number_of_extensions * sizeof( User_extensions_Control )
       );
-      if ( !status )
-        return FALSE;
+  
+    memset (
+      extension,
+      0,
+      number_of_extensions * sizeof( User_extensions_Control )
+    );
+  
+    for ( i = 0 ; i < number_of_extensions ; i++ ) {
+      _User_extensions_Add_set (extension, &initial_extensions[i]);
+      extension++;
     }
   }
-
-  return TRUE;
-}
-
-/*PAGE
- *
- *  _User_extensions_Thread_delete
- */
-
-void _User_extensions_Thread_delete (
-  Thread_Control *the_thread
-)
-{
-  Chain_Node              *the_node;
-  User_extensions_Control *the_extension;
-
-  for ( the_node = _User_extensions_List.last ;
-        !_Chain_Is_head( &_User_extensions_List, the_node ) ;
-        the_node = the_node->previous ) {
-
-    the_extension = (User_extensions_Control *) the_node;
-
-    if ( the_extension->Callouts.thread_delete != NULL )
-      (*the_extension->Callouts.thread_delete)(
-        _Thread_Executing,
-        the_thread
-      );
-  }
-}
-
-/*PAGE
- *
- *  _User_extensions_Thread_start
- *
- */
-
-void _User_extensions_Thread_start (
-  Thread_Control *the_thread
-)
-{
-  Chain_Node              *the_node;
-  User_extensions_Control *the_extension;
-
-  for ( the_node = _User_extensions_List.first ;
-        !_Chain_Is_tail( &_User_extensions_List, the_node ) ;
-        the_node = the_node->next ) {
-
-    the_extension = (User_extensions_Control *) the_node;
-
-    if ( the_extension->Callouts.thread_start != NULL )
-      (*the_extension->Callouts.thread_start)(
-        _Thread_Executing,
-        the_thread
-      );
-  }
-}
-
-/*PAGE
- *
- *  _User_extensions_Thread_restart
- *
- */
-
-void _User_extensions_Thread_restart (
-  Thread_Control *the_thread
-)
-{
-  Chain_Node              *the_node;
-  User_extensions_Control *the_extension;
-
-  for ( the_node = _User_extensions_List.first ;
-        !_Chain_Is_tail( &_User_extensions_List, the_node ) ;
-        the_node = the_node->next ) {
-
-    the_extension = (User_extensions_Control *) the_node;
-
-    if ( the_extension->Callouts.thread_restart != NULL )
-      (*the_extension->Callouts.thread_restart)(
-        _Thread_Executing,
-        the_thread
-      );
-  }
-}
-
-/*PAGE
- *
- *  _User_extensions_Thread_begin
- *
- */
-
-void _User_extensions_Thread_begin (
-  Thread_Control *executing
-)
-{
-  Chain_Node              *the_node;
-  User_extensions_Control *the_extension;
-
-  for ( the_node = _User_extensions_List.first ;
-        !_Chain_Is_tail( &_User_extensions_List, the_node ) ;
-        the_node = the_node->next ) {
-
-    the_extension = (User_extensions_Control *) the_node;
-
-    if ( the_extension->Callouts.thread_begin != NULL )
-      (*the_extension->Callouts.thread_begin)( executing );
-  }
-}
-
-/*PAGE
- *
- *  _User_extensions_Thread_exitted
- */
-
-void _User_extensions_Thread_exitted (
-  Thread_Control *executing
-)
-{
-  Chain_Node              *the_node;
-  User_extensions_Control *the_extension;
-
-  for ( the_node = _User_extensions_List.last ;
-        !_Chain_Is_head( &_User_extensions_List, the_node ) ;
-        the_node = the_node->previous ) {
-
-    the_extension = (User_extensions_Control *) the_node;
-
-    if ( the_extension->Callouts.thread_exitted != NULL )
-      (*the_extension->Callouts.thread_exitted)( executing );
-  }
 }
 
-/*PAGE
- *
- *  _User_extensions_Fatal
- */
-
-void _User_extensions_Fatal (
-  Internal_errors_Source  the_source,
-  boolean                 is_internal,
-  uint32_t                the_error
-)
-{
-  Chain_Node              *the_node;
-  User_extensions_Control *the_extension;
-
-  for ( the_node = _User_extensions_List.last ;
-        !_Chain_Is_head( &_User_extensions_List, the_node ) ;
-        the_node = the_node->previous ) {
-
-    the_extension = (User_extensions_Control *) the_node;
-
-    if ( the_extension->Callouts.fatal != NULL )
-      (*the_extension->Callouts.fatal)( the_source, is_internal, the_error );
-  }
-}
diff --git a/cpukit/score/src/userextaddapiset.c b/cpukit/score/src/userextaddapiset.c
new file mode 100644
index 0000000000..db2670f5e0
--- /dev/null
+++ b/cpukit/score/src/userextaddapiset.c
@@ -0,0 +1,38 @@
+/*
+ *  COPYRIGHT (c) 1989-2007.
+ *  On-Line Applications Research Corporation (OAR).
+ *
+ *  The license and distribution terms for this file may be
+ *  found in the file LICENSE in this distribution or at
+ *  http://www.rtems.com/license/LICENSE.
+ *
+ *  $Id$
+ */
+
+#if HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <rtems/system.h>
+#include <rtems/score/userext.h>
+
+/**
+ *  This routine is used to add an API extension set to the active list.
+ */
+ 
+void _User_extensions_Add_API_set (
+  User_extensions_Control *the_extension
+)
+{
+  _Chain_Append( &_User_extensions_List, &the_extension->Node );
+
+  /*
+   *  If a switch handler is present, append it to the switch chain.
+   */
+
+  if ( the_extension->Callouts.thread_switch != NULL ) {
+    the_extension->Switch.thread_switch = the_extension->Callouts.thread_switch;
+    _Chain_Append( 
+      &_User_extensions_Switches_list, &the_extension->Switch.Node );
+  }
+}
diff --git a/cpukit/score/src/userextaddset.c b/cpukit/score/src/userextaddset.c
new file mode 100644
index 0000000000..516477a50e
--- /dev/null
+++ b/cpukit/score/src/userextaddset.c
@@ -0,0 +1,46 @@
+/*
+ *  COPYRIGHT (c) 1989-2007.
+ *  On-Line Applications Research Corporation (OAR).
+ *
+ *  The license and distribution terms for this file may be
+ *  found in the file LICENSE in this distribution or at
+ *  http://www.rtems.com/license/LICENSE.
+ *
+ *  $Id$
+ */
+
+#if HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <rtems/system.h>
+#include <rtems/score/userext.h>
+
+/**
+ *  This routine is used to add a user extension set to the active list.
+ *
+ *  @note Must be before _User_extensions_Handler_initialization to
+ *        ensure proper inlining.
+ */
+
+void _User_extensions_Add_set (
+  User_extensions_Control *the_extension,
+  User_extensions_Table   *extension_table
+)
+{
+  the_extension->Callouts = *extension_table;
+
+  _Chain_Append( &_User_extensions_List, &the_extension->Node );
+
+  /*
+   * If a switch handler is present, append it to the switch chain.
+   */
+
+  if ( extension_table->thread_switch != NULL ) {
+    the_extension->Switch.thread_switch = extension_table->thread_switch;
+    _Chain_Append(
+      &_User_extensions_Switches_list,
+      &the_extension->Switch.Node
+    );
+  }
+}
diff --git a/cpukit/score/src/userextremoveset.c b/cpukit/score/src/userextremoveset.c
new file mode 100644
index 0000000000..dcff2ef626
--- /dev/null
+++ b/cpukit/score/src/userextremoveset.c
@@ -0,0 +1,35 @@
+/*
+ *  COPYRIGHT (c) 1989-2007.
+ *  On-Line Applications Research Corporation (OAR).
+ *
+ *  The license and distribution terms for this file may be
+ *  found in the file LICENSE in this distribution or at
+ *  http://www.rtems.com/license/LICENSE.
+ *
+ *  $Id$
+ */
+
+#if HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <rtems/system.h>
+#include <rtems/score/userext.h>
+
+/**
+ *  This routine is used to remove a user extension set from the active list.
+ */
+
+void _User_extensions_Remove_set (
+  User_extensions_Control  *the_extension
+)
+{
+  _Chain_Extract( &the_extension->Node );
+  
+  /*
+   * If a switch handler is present, remove it.
+   */
+
+  if ( the_extension->Callouts.thread_switch != NULL )
+    _Chain_Extract( &the_extension->Switch.Node );
+}
diff --git a/cpukit/score/src/userextthreadbegin.c b/cpukit/score/src/userextthreadbegin.c
new file mode 100644
index 0000000000..bf2cc1a1af
--- /dev/null
+++ b/cpukit/score/src/userextthreadbegin.c
@@ -0,0 +1,89 @@
+/*
+ *  COPYRIGHT (c) 1989-2007.
+ *  On-Line Applications Research Corporation (OAR).
+ *
+ *  The license and distribution terms for this file may be
+ *  found in the file LICENSE in this distribution or at
+ *  http://www.rtems.com/license/LICENSE.
+ *
+ *  $Id$
+ */
+
+#if HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <rtems/system.h>
+#include <rtems/score/userext.h>
+
+/*PAGE
+ *
+ *  _User_extensions_Thread_begin
+ *
+ */
+
+void _User_extensions_Thread_begin (
+  Thread_Control *executing
+)
+{
+  Chain_Node              *the_node;
+  User_extensions_Control *the_extension;
+
+  for ( the_node = _User_extensions_List.first ;
+        !_Chain_Is_tail( &_User_extensions_List, the_node ) ;
+        the_node = the_node->next ) {
+
+    the_extension = (User_extensions_Control *) the_node;
+
+    if ( the_extension->Callouts.thread_begin != NULL )
+      (*the_extension->Callouts.thread_begin)( executing );
+  }
+}
+
+/*PAGE
+ *
+ *  _User_extensions_Thread_exitted
+ */
+
+void _User_extensions_Thread_exitted (
+  Thread_Control *executing
+)
+{
+  Chain_Node              *the_node;
+  User_extensions_Control *the_extension;
+
+  for ( the_node = _User_extensions_List.last ;
+        !_Chain_Is_head( &_User_extensions_List, the_node ) ;
+        the_node = the_node->previous ) {
+
+    the_extension = (User_extensions_Control *) the_node;
+
+    if ( the_extension->Callouts.thread_exitted != NULL )
+      (*the_extension->Callouts.thread_exitted)( executing );
+  }
+}
+
+/*PAGE
+ *
+ *  _User_extensions_Fatal
+ */
+
+void _User_extensions_Fatal (
+  Internal_errors_Source  the_source,
+  boolean                 is_internal,
+  uint32_t                the_error
+)
+{
+  Chain_Node              *the_node;
+  User_extensions_Control *the_extension;
+
+  for ( the_node = _User_extensions_List.last ;
+        !_Chain_Is_head( &_User_extensions_List, the_node ) ;
+        the_node = the_node->previous ) {
+
+    the_extension = (User_extensions_Control *) the_node;
+
+    if ( the_extension->Callouts.fatal != NULL )
+      (*the_extension->Callouts.fatal)( the_source, is_internal, the_error );
+  }
+}
diff --git a/cpukit/score/src/userextthreadcreate.c b/cpukit/score/src/userextthreadcreate.c
new file mode 100644
index 0000000000..3d9caca174
--- /dev/null
+++ b/cpukit/score/src/userextthreadcreate.c
@@ -0,0 +1,49 @@
+/*
+ *  COPYRIGHT (c) 1989-2007.
+ *  On-Line Applications Research Corporation (OAR).
+ *
+ *  The license and distribution terms for this file may be
+ *  found in the file LICENSE in this distribution or at
+ *  http://www.rtems.com/license/LICENSE.
+ *
+ *  $Id$
+ */
+
+#if HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <rtems/system.h>
+#include <rtems/score/userext.h>
+
+/*PAGE
+ *
+ *  _User_extensions_Thread_create
+ */
+
+boolean _User_extensions_Thread_create (
+  Thread_Control *the_thread
+)
+{
+  Chain_Node              *the_node;
+  User_extensions_Control *the_extension;
+  boolean                  status;
+
+  for ( the_node = _User_extensions_List.first ;
+        !_Chain_Is_tail( &_User_extensions_List, the_node ) ;
+        the_node = the_node->next ) {
+
+    the_extension = (User_extensions_Control *) the_node;
+
+    if ( the_extension->Callouts.thread_create != NULL ) {
+      status = (*the_extension->Callouts.thread_create)(
+        _Thread_Executing,
+        the_thread
+      );
+      if ( !status )
+        return FALSE;
+    }
+  }
+
+  return TRUE;
+}
diff --git a/cpukit/score/src/userextthreaddelete.c b/cpukit/score/src/userextthreaddelete.c
new file mode 100644
index 0000000000..4f7214805b
--- /dev/null
+++ b/cpukit/score/src/userextthreaddelete.c
@@ -0,0 +1,43 @@
+/*
+ *  COPYRIGHT (c) 1989-2007.
+ *  On-Line Applications Research Corporation (OAR).
+ *
+ *  The license and distribution terms for this file may be
+ *  found in the file LICENSE in this distribution or at
+ *  http://www.rtems.com/license/LICENSE.
+ *
+ *  $Id$
+ */
+
+#if HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <rtems/system.h>
+#include <rtems/score/userext.h>
+
+/*PAGE
+ *
+ *  _User_extensions_Thread_delete
+ */
+
+void _User_extensions_Thread_delete (
+  Thread_Control *the_thread
+)
+{
+  Chain_Node              *the_node;
+  User_extensions_Control *the_extension;
+
+  for ( the_node = _User_extensions_List.last ;
+        !_Chain_Is_head( &_User_extensions_List, the_node ) ;
+        the_node = the_node->previous ) {
+
+    the_extension = (User_extensions_Control *) the_node;
+
+    if ( the_extension->Callouts.thread_delete != NULL )
+      (*the_extension->Callouts.thread_delete)(
+        _Thread_Executing,
+        the_thread
+      );
+  }
+}
diff --git a/cpukit/score/src/userextthreadrestart.c b/cpukit/score/src/userextthreadrestart.c
new file mode 100644
index 0000000000..d8af932cf2
--- /dev/null
+++ b/cpukit/score/src/userextthreadrestart.c
@@ -0,0 +1,44 @@
+/*
+ *  COPYRIGHT (c) 1989-2007.
+ *  On-Line Applications Research Corporation (OAR).
+ *
+ *  The license and distribution terms for this file may be
+ *  found in the file LICENSE in this distribution or at
+ *  http://www.rtems.com/license/LICENSE.
+ *
+ *  $Id$
+ */
+
+#if HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <rtems/system.h>
+#include <rtems/score/userext.h>
+
+/*PAGE
+ *
+ *  _User_extensions_Thread_restart
+ *
+ */
+
+void _User_extensions_Thread_restart (
+  Thread_Control *the_thread
+)
+{
+  Chain_Node              *the_node;
+  User_extensions_Control *the_extension;
+
+  for ( the_node = _User_extensions_List.first ;
+        !_Chain_Is_tail( &_User_extensions_List, the_node ) ;
+        the_node = the_node->next ) {
+
+    the_extension = (User_extensions_Control *) the_node;
+
+    if ( the_extension->Callouts.thread_restart != NULL )
+      (*the_extension->Callouts.thread_restart)(
+        _Thread_Executing,
+        the_thread
+      );
+  }
+}
diff --git a/cpukit/score/src/userextthreadstart.c b/cpukit/score/src/userextthreadstart.c
new file mode 100644
index 0000000000..1534571344
--- /dev/null
+++ b/cpukit/score/src/userextthreadstart.c
@@ -0,0 +1,44 @@
+/*
+ *  COPYRIGHT (c) 1989-2007.
+ *  On-Line Applications Research Corporation (OAR).
+ *
+ *  The license and distribution terms for this file may be
+ *  found in the file LICENSE in this distribution or at
+ *  http://www.rtems.com/license/LICENSE.
+ *
+ *  $Id$
+ */
+
+#if HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <rtems/system.h>
+#include <rtems/score/userext.h>
+
+/*PAGE
+ *
+ *  _User_extensions_Thread_start
+ *
+ */
+
+void _User_extensions_Thread_start (
+  Thread_Control *the_thread
+)
+{
+  Chain_Node              *the_node;
+  User_extensions_Control *the_extension;
+
+  for ( the_node = _User_extensions_List.first ;
+        !_Chain_Is_tail( &_User_extensions_List, the_node ) ;
+        the_node = the_node->next ) {
+
+    the_extension = (User_extensions_Control *) the_node;
+
+    if ( the_extension->Callouts.thread_start != NULL )
+      (*the_extension->Callouts.thread_start)(
+        _Thread_Executing,
+        the_thread
+      );
+  }
+}
diff --git a/cpukit/score/src/userextthreadswitch.c b/cpukit/score/src/userextthreadswitch.c
new file mode 100644
index 0000000000..2a88c9f4f9
--- /dev/null
+++ b/cpukit/score/src/userextthreadswitch.c
@@ -0,0 +1,39 @@
+/*
+ *  COPYRIGHT (c) 1989-2007.
+ *  On-Line Applications Research Corporation (OAR).
+ *
+ *  The license and distribution terms for this file may be
+ *  found in the file LICENSE in this distribution or at
+ *  http://www.rtems.com/license/LICENSE.
+ *
+ *  $Id$
+ */
+
+#if HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <rtems/system.h>
+#include <rtems/score/userext.h>
+
+/**
+ *  This routine is used to invoke the user extension which
+ *  is invoked when a context switch occurs.
+ */
+void _User_extensions_Thread_switch (
+  Thread_Control *executing,
+  Thread_Control *heir
+)
+{
+  Chain_Node                     *the_node;
+  User_extensions_Switch_control *the_extension_switch;
+  
+  for ( the_node = _User_extensions_Switches_list.first ;
+        !_Chain_Is_tail( &_User_extensions_Switches_list, the_node ) ;
+        the_node = the_node->next ) {
+
+    the_extension_switch = (User_extensions_Switch_control *) the_node;
+
+    (*the_extension_switch->thread_switch)( executing, heir );
+  }
+}