Hello Ashi,
On 06/07/13 09:17, Ashi wrote:
Hi all,
this patch adds a data structure called freelist to score, there are no
test cases yet and should be added later.
I would appreciate to have the test for this new stuff included in the
patch.
Freelist is a structure, which contains a chain of nodes. It supports 2
operation:
- get node from freelist
- put node to freelist.
And when there is no enough node in freelist, it will automatically
increase itself's size by allocate more nodes from heap or workspace(which
is specified by user).
What can I do if I like to get the nodes from a magic space?
And the size of new allocated nodes is specified by
user when structure initialization. When initializing, freelist would
pre-allocate a bunch of nodes, which size is also can be specified by user.
By the way, the part of motivation of adding this data structure is to make
RTEMS POSIX Key(this patch will be posted later) unlimited mode more
efficient.
Thanks,
Zhongwei
add_freelist.patch
diff --git a/cpukit/score/Makefile.am b/cpukit/score/Makefile.am
index 3f6e686..092d983 100644
--- a/cpukit/score/Makefile.am
+++ b/cpukit/score/Makefile.am
@@ -30,6 +30,7 @@ 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/freelist.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
@@ -265,6 +266,9 @@ 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
+## FREELIST_C_FILES
+libscore_a_SOURCES += src/freelist.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/freelist.h
b/cpukit/score/include/rtems/score/freelist.h
new file mode 100644
index 0000000..c21a872
--- /dev/null
+++ b/cpukit/score/include/rtems/score/freelist.h
@@ -0,0 +1,138 @@
+/**
+ * @file
+ *
+ * @ingroup ScoreFreelist
+ *
+ * @brief Freelist 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 _FREELIST_H
+#define _FREELIST_H
+
+#include <rtems/score/chain.h>
+#include <rtems/rtems/types.h>
+#include <rtems/score/wkspace.h>
+
+/**
+ * @defgroup ScoreFreelist Freelist Handler API
+ *
+ * @ingroup Score
+ *
+ * The Freelist 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:
+ * Freelist_Control.
+ */
+/**@{*/
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * @typedef Freelist_Control
+ */
+typedef struct Freelist_Control_struct Freelist_Control;
You can also use
typedef struct Freelist_Control Freelist_Control;
+
+/**
+ * @typedef freelist_callout
+ */
+typedef void (*freelist_callout)(
+ Freelist_Control *fc,
+ void *nodes
+);
+
+/**
+ * @typedef Freelist_Control_struct
+ *
+ * This is used to manage each element.
+ */
+struct Freelist_Control_struct {
+ Chain_Control Freelist;
+ size_t free_count;
Why do we need the free_count?
+ size_t bump_count;
+ size_t node_size;
+ freelist_callout callout;
+ bool use_workspace;
+};
I would replace this with an extend handler.
/**
* @brief Extends the freelist.
*
* @param[in] freelist The freelist control.
*
* @return The count of new nodes.
*/
typedef size_t ( *Freelist_Extend )( Freelist_Control *freelist );
This is much more flexible since you only specify the interface and
don't limit this to heap/workspace.
You can provide a _Freelist_Extend_with_nothing() which simply returns 0.
+
+/**
+ * @brief Initialize a freelist
+ *
+ * This routine initializes @a the Freelist_Control structure to manage a
+ * chain of nodes, each node's size is @a node_size and the size of chain is
+ * initialized to @a bump_count and it also will increase with size of
+ * @a bump_count. @a callout is called on all the nodes after allocated from
+ * workspace.
+ *
+ * @param[in] fc is the freelist too initialize.
+ * @param[in] node_size is size of the elemment in this freelist.
+ * @param[in] bump_count is the size of chain increased when no free node left.
+ * @param[in] callout is the function called on all nodes in freelist_bump,
+ * if it's null, a default function is set.
+ * @param[in] use_workspace is used to determine whether heap or workspace is
+ * in for Freelist node.
+ */
+void _Freelist_Initialize(
+ Freelist_Control *fc,
I would use "freelist" instead of "fc". Maybe we should use "chain"
instead of "list.
[...]
--
Sebastian Huber, embedded brains GmbH
Address : Dornierstr. 4, D-82178 Puchheim, Germany
Phone : +49 89 189 47 41-16
Fax : +49 89 189 47 41-09
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Diese Nachricht ist keine geschäftliche Mitteilung im Sinne des EHUG.
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