score: Add freechain

4 files changed, 163 insertions, 0 deletions

diff --git a/cpukit/score/Makefile.am b/cpukit/score/Makefile.am
index 817ad886e3..06b6f11c23 100644
--- a/cpukit/score/Makefile.am
+++ b/cpukit/score/Makefile.am
@@ -36,6 +36,7 @@ include_rtems_score_HEADERS += include/rtems/score/protectedheap.h
 include_rtems_score_HEADERS += include/rtems/score/interr.h
 include_rtems_score_HEADERS += include/rtems/score/isr.h
 include_rtems_score_HEADERS += include/rtems/score/isrlevel.h
+include_rtems_score_HEADERS += include/rtems/score/freechain.h
 include_rtems_score_HEADERS += include/rtems/score/object.h
 include_rtems_score_HEADERS += include/rtems/score/percpu.h
 include_rtems_score_HEADERS += include/rtems/score/priority.h
@@ -257,6 +258,9 @@ libscore_a_SOURCES += src/pheapallocate.c \
     src/pheapgetblocksize.c src/pheapgetfreeinfo.c src/pheapgetinfo.c \
     src/pheapinit.c src/pheapresizeblock.c src/pheapwalk.c src/pheapiterate.c
 
+## FREECHAIN_C_FILES
+libscore_a_SOURCES += src/freechain.c
+
 ## RBTREE_C_FILES
 libscore_a_SOURCES += src/rbtree.c \
     src/rbtreeextract.c src/rbtreefind.c src/rbtreefindheader.c \
diff --git a/cpukit/score/include/rtems/score/freechain.h b/cpukit/score/include/rtems/score/freechain.h
new file mode 100644
index 0000000000..d59de06319
--- /dev/null
+++ b/cpukit/score/include/rtems/score/freechain.h
@@ -0,0 +1,108 @@
+/**
+ * @file
+ *
+ * @ingroup ScoreFreechain
+ *
+ * @brief Freechain Handler API
+ */
+/*
+ * Copyright (c) 2013 Gedare Bloom.
+ *
+ * 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.
+ */
+
+#ifndef _RTEMS_SCORE_FREECHAIN_H
+#define _RTEMS_SCORE_FREECHAIN_H
+
+#include <stdbool.h>
+
+#include <rtems/score/chain.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * @defgroup ScoreFreechain Freechain Handler
+ *
+ * @ingroup Score
+ *
+ * The Freechain Handler is used to manage a chain of nodes, of which size can
+ * automatically increase when there is no free node left. This handler
+ * provides one data structure: Freechain_Control.
+ *
+ * @{
+ */
+
+typedef struct Freechain_Control Freechain_Control;
+
+/**
+ * @brief Extends the freechain.
+ *
+ * @param[in] freechain The freechain control.
+ *
+ * @retval true The freechain contains now at least one node.
+ * @retval false Otherwise.
+ */
+typedef bool ( *Freechain_Extend )( Freechain_Control *freechain );
+
+/**
+ * @typedef Freechain_Control
+ *
+ * This is used to manage freechain's nodes.
+ */
+struct Freechain_Control {
+  Chain_Control     Freechain;
+  Freechain_Extend  extend;
+};
+
+/**
+ * @brief Initializes a freechain.
+ *
+ * This routine initializes the freechain control structure to manage a chain
+ * of nodes.  In case the freechain is empty the extend handler is called to
+ * get more nodes.
+ *
+ * @param[in,out] freechain The freechain control to initialize.
+ * @param[in] extend The extend handler.  It is called by _Freechain_Get() in
+ * case the freechain is empty.
+ */
+void _Freechain_Initialize(
+  Freechain_Control *freechain,
+  Freechain_Extend   extend
+);
+
+/**
+ * @brief Gets a node from the freechain.
+ *
+ * @param[in,out] freechain The freechain control.
+ *
+ * @retval NULL The freechain is empty and the extend operation failed.
+ * @retval otherwise Pointer to a node.  The node ownership passes to the
+ * caller.
+ */
+void *_Freechain_Get(
+  Freechain_Control *freechain
+);
+
+/**
+ * @brief Puts a node back onto the freechain.
+ *
+ * @param[in,out] freechain The freechain control.
+ * @param[in] node The node to put back.
+ */
+void _Freechain_Put(
+  Freechain_Control *freechain,
+  void              *node
+);
+
+/**@}*/
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
+/* end of include file */
diff --git a/cpukit/score/preinstall.am b/cpukit/score/preinstall.am
index 740e58e014..3bfc582830 100644
--- a/cpukit/score/preinstall.am
+++ b/cpukit/score/preinstall.am
@@ -127,6 +127,10 @@ $(PROJECT_INCLUDE)/rtems/score/isrlevel.h: include/rtems/score/isrlevel.h $(PROJ
 	$(INSTALL_DATA) $< $(PROJECT_INCLUDE)/rtems/score/isrlevel.h
 PREINSTALL_FILES += $(PROJECT_INCLUDE)/rtems/score/isrlevel.h
 
+$(PROJECT_INCLUDE)/rtems/score/freechain.h: include/rtems/score/freechain.h $(PROJECT_INCLUDE)/rtems/score/$(dirstamp)
+	$(INSTALL_DATA) $< $(PROJECT_INCLUDE)/rtems/score/freechain.h
+PREINSTALL_FILES += $(PROJECT_INCLUDE)/rtems/score/freechain.h
+
 $(PROJECT_INCLUDE)/rtems/score/object.h: include/rtems/score/object.h $(PROJECT_INCLUDE)/rtems/score/$(dirstamp)
 	$(INSTALL_DATA) $< $(PROJECT_INCLUDE)/rtems/score/object.h
 PREINSTALL_FILES += $(PROJECT_INCLUDE)/rtems/score/object.h
diff --git a/cpukit/score/src/freechain.c b/cpukit/score/src/freechain.c
new file mode 100644
index 0000000000..101a11e001
--- /dev/null
+++ b/cpukit/score/src/freechain.c
@@ -0,0 +1,47 @@
+/**
+ * @file
+ *
+ * @ingroup ScoreFreechain
+ *
+ * @brief Freechain Handler Implementation
+ */
+
+/*
+ * Copyright (c) 2013 Gedare Bloom.
+ *
+ * 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.
+ */
+
+#if HAVE_CONFIG_H
+  #include "config.h"
+#endif
+
+#include <rtems/score/freechain.h>
+#include <rtems/score/chainimpl.h>
+
+void _Freechain_Initialize(
+    Freechain_Control *freechain,
+    Freechain_Extend   extend
+)
+{
+  _Chain_Initialize_empty( &freechain->Freechain );
+  freechain->extend = extend;
+}
+
+void *_Freechain_Get(Freechain_Control *freechain)
+{
+  if ( _Chain_Is_empty( &freechain->Freechain ) ) {
+    if ( !( *freechain->extend )( freechain ) ) {
+      return NULL;
+    }
+  }
+
+  return _Chain_Get_first_unprotected( &freechain->Freechain );
+}
+
+void _Freechain_Put( Freechain_Control *freechain, void *node )
+{
+  _Chain_Prepend_unprotected( &freechain->Freechain, node );
+}