OpenModem/bertos/struct/pool.h

178 lines
5.1 KiB
C

/**
* \file
* <!--
* This file is part of BeRTOS.
*
* Bertos is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
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*
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
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* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* As a special exception, you may use this file as part of a free software
* library without restriction. Specifically, if other files instantiate
* templates or use macros or inline functions from this file, or you compile
* this file and link it with other files to produce an executable, this
* file does not by itself cause the resulting executable to be covered by
* the GNU General Public License. This exception does not however
* invalidate any other reasons why the executable file might be covered by
* the GNU General Public License.
*
* Copyright 2004, 2008, 2011 Develer S.r.l. (http://www.develer.com/)
* -->
*
* \defgroup pool Pool memory allocator
* \ingroup struct
* \{
*
* \brief Pool macros.
*
* The pool module provides the boilerplate code to create a set of objects
* of the same type.
* It provides an interface similar to the heap module, with pool_alloc() and
* pool_free() functions that allocate and free an element respectively.
* In contrast with the heap module, you can specify exactly the number of
* items that you want to be in the pool.
*
* Items in the pool must be a derived class of <tt>Node *</tt>, which also
* means that they can be used as-is with list containers, eg. MsgPort.
*
* Example code:
* \code
* typedef struct MyType
* {
* Node *n;
* uint16_t *buf;
* // other members here...
* } MyType;
*
* DECLARE_POOL(mypool, MyType, POOL_SIZE);
*
* static void elem_init(MyType *e)
* {
* e->buf = NULL;
* // other initializations here
* }
*
* int main(void)
* {
* pool_init(&mypool, elem_init);
*
* MyType *foo = pool_alloc(&mypool);
* // do stuff with foo
* pool_free(&mypool, foo);
* }
* \endcode
*
* \author Giovanni Bajo <rasky@develer.com>
* \author Luca Ottaviano <lottaviano@develer.com>
*/
#ifndef STRUCT_POOL_H
#define STRUCT_POOL_H
#include <cfg/macros.h>
#include <struct/list.h>
/**
* \brief Extern pool declaration
*/
#define EXTERN_POOL(name) \
extern List name
#define DECLARE_POOL_WITH_STORAGE(name, type, num, storage) \
static type name##_items[num]; \
storage name; \
INLINE void name##_init(void (*init_func)(type*)) \
{ \
size_t i; \
LIST_INIT(&name); \
for (i=0;i<countof(name##_items);++i) \
{ \
if (init_func) init_func(&name##_items[i]); \
ADDTAIL(&name, (Node*)&name##_items[i]); \
} \
} \
INLINE void name##_init(void (*init_func)(type*)) \
/**/
/**
* \brief Helper macro to declare a Pool data type.
*
* Data type inserted into the pool must be a <tt>Node *</tt>
* type.
*
* \param name Variable name of the pool.
* \param type Data type held by the pool.
* \param num Number of elements in pool.
*/
#define DECLARE_POOL(name, type, num) \
DECLARE_POOL_WITH_STORAGE(name, type, num, List)
/**
* \brief Static Pool declaration
*
* \sa DECLARE_POOL
*/
#define DECLARE_POOL_STATIC(name, type, num) \
DECLARE_POOL_WITH_STORAGE(name, type, num, static List)
/**
* Initialize the pool \a name, calling \a init_func on each element.
*
* The init function must have the following prototype:
* \code
* void init_func(type *)
* \endcode
* where \a type is the type of objects held in the pool.
*
* \param name Pool to initialize
* \param init_func Init function to be called on each element
*/
#define pool_init(name, init_func) (*(name##_init))(init_func)
/**
* \brief Allocate an element from the pool.
*
* The returned element is of type <tt>Node *</tt>, it's safe to
* cast it to the type contained in the pool.
*
* \note If the element was recycled with pool_free(), it will not be reset,
* so don't assume that the element has specific values.
*
* \param name Pointer to pool to alloc from.
* \return Element of the type present in the pool.
*/
#define pool_alloc(name) list_remHead(name)
/**
* \brief Recycle an element into the pool
*
* \note Element fields are not reset to its original values, keep that in
* mind when you alloc nodes.
*
* \param name Pointer to pool where the node should be recycled.
* \param elem Element to be recycled.
*/
#define pool_free(name, elem) ADDHEAD(name, (Node*)elem)
/**
* \brief Test if the pool is empty
*
* \param name Pointer to pool.
* \return True if the pool is empty, false otherwise.
*/
#define pool_empty(name) LIST_EMPTY(name)
/** \} */ /* defgroup pool */
#endif /* STRUCT_POOL_H */