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Diffstat (limited to 'test/monniaux/glpk-4.65/src/misc/dmp.c')
| -rw-r--r-- | test/monniaux/glpk-4.65/src/misc/dmp.c | 243 |
1 files changed, 243 insertions, 0 deletions
diff --git a/test/monniaux/glpk-4.65/src/misc/dmp.c b/test/monniaux/glpk-4.65/src/misc/dmp.c new file mode 100644 index 00000000..a4882c86 --- /dev/null +++ b/test/monniaux/glpk-4.65/src/misc/dmp.c @@ -0,0 +1,243 @@ +/* dmp.c (dynamic memory pool) */ + +/*********************************************************************** +* This code is part of GLPK (GNU Linear Programming Kit). +* +* Copyright (C) 2000-2013 Andrew Makhorin, Department for Applied +* Informatics, Moscow Aviation Institute, Moscow, Russia. All rights +* reserved. E-mail: <mao@gnu.org>. +* +* GLPK 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 3 of the License, or +* (at your option) any later version. +* +* GLPK is distributed in the hope that it will be useful, but WITHOUT +* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY +* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public +* License for more details. +* +* You should have received a copy of the GNU General Public License +* along with GLPK. If not, see <http://www.gnu.org/licenses/>. +***********************************************************************/ + +#include "env.h" +#include "dmp.h" + +struct DMP +{ /* dynamic memory pool */ + void *avail[32]; + /* avail[k], 0 <= k <= 31, is a pointer to first available (free) + * atom of (k+1)*8 bytes long; at the beginning of each free atom + * there is a pointer to another free atom of the same size */ + void *block; + /* pointer to most recently allocated memory block; at the + * beginning of each allocated memory block there is a pointer to + * previously allocated memory block */ + int used; + /* number of bytes used in most recently allocated memory block */ + size_t count; + /* number of atoms which are currently in use */ +}; + +#define DMP_BLK_SIZE 8000 +/* size of memory blocks, in bytes, allocated for memory pools */ + +struct prefix +{ /* atom prefix (for debugging only) */ + DMP *pool; + /* dynamic memory pool */ + int size; + /* original atom size, in bytes */ +}; + +#define prefix_size ((sizeof(struct prefix) + 7) & ~7) +/* size of atom prefix rounded up to multiple of 8 bytes */ + +int dmp_debug; +/* debug mode flag */ + +/*********************************************************************** +* NAME +* +* dmp_create_pool - create dynamic memory pool +* +* SYNOPSIS +* +* #include "dmp.h" +* DMP *dmp_create_pool(void); +* +* DESCRIPTION +* +* The routine dmp_create_pool creates a dynamic memory pool. +* +* RETURNS +* +* The routine returns a pointer to the memory pool created. */ + +DMP *dmp_create_pool(void) +{ DMP *pool; + int k; + xassert(sizeof(void *) <= 8); + if (dmp_debug) + xprintf("dmp_create_pool: warning: debug mode is on\n"); + pool = talloc(1, DMP); + for (k = 0; k <= 31; k++) + pool->avail[k] = NULL; + pool->block = NULL; + pool->used = DMP_BLK_SIZE; + pool->count = 0; + return pool; +} + +/*********************************************************************** +* NAME +* +* dmp_get_atom - get free atom from dynamic memory pool +* +* SYNOPSIS +* +* #include "dmp.h" +* void *dmp_get_atom(DMP *pool, int size); +* +* DESCRIPTION +* +* The routine dmp_get_atom obtains a free atom (memory space) from the +* specified memory pool. +* +* The parameter size is the atom size, in bytes, 1 <= size <= 256. +* +* Note that the free atom contains arbitrary data, not binary zeros. +* +* RETURNS +* +* The routine returns a pointer to the free atom obtained. */ + +void *dmp_get_atom(DMP *pool, int size) +{ void *atom; + int k, need; + xassert(1 <= size && size <= 256); + /* round up atom size to multiple of 8 bytes */ + need = (size + 7) & ~7; + /* determine number of corresponding list of free atoms */ + k = (need >> 3) - 1; + /* obtain free atom */ + if (pool->avail[k] == NULL) + { /* corresponding list of free atoms is empty */ + /* if debug mode is on, add atom prefix size */ + if (dmp_debug) + need += prefix_size; + if (pool->used + need > DMP_BLK_SIZE) + { /* allocate new memory block */ + void *block = talloc(DMP_BLK_SIZE, char); + *(void **)block = pool->block; + pool->block = block; + pool->used = 8; /* sufficient to store pointer */ + } + /* allocate new atom in current memory block */ + atom = (char *)pool->block + pool->used; + pool->used += need; + } + else + { /* obtain atom from corresponding list of free atoms */ + atom = pool->avail[k]; + pool->avail[k] = *(void **)atom; + } + /* if debug mode is on, fill atom prefix */ + if (dmp_debug) + { ((struct prefix *)atom)->pool = pool; + ((struct prefix *)atom)->size = size; + atom = (char *)atom + prefix_size; + } + /* increase number of allocated atoms */ + pool->count++; + return atom; +} + +/*********************************************************************** +* NAME +* +* dmp_free_atom - return atom to dynamic memory pool +* +* SYNOPSIS +* +* #include "dmp.h" +* void dmp_free_atom(DMP *pool, void *atom, int size); +* +* DESCRIPTION +* +* The routine dmp_free_atom returns the specified atom (memory space) +* to the specified memory pool, making the atom free. +* +* The parameter size is the atom size, in bytes, 1 <= size <= 256. +* +* Note that the atom can be returned only to the pool, from which it +* was obtained, and its size must be exactly the same as on obtaining +* it from the pool. */ + +void dmp_free_atom(DMP *pool, void *atom, int size) +{ int k; + xassert(1 <= size && size <= 256); + /* determine number of corresponding list of free atoms */ + k = ((size + 7) >> 3) - 1; + /* if debug mode is on, check atom prefix */ + if (dmp_debug) + { atom = (char *)atom - prefix_size; + xassert(((struct prefix *)atom)->pool == pool); + xassert(((struct prefix *)atom)->size == size); + } + /* return atom to corresponding list of free atoms */ + *(void **)atom = pool->avail[k]; + pool->avail[k] = atom; + /* decrease number of allocated atoms */ + xassert(pool->count > 0); + pool->count--; + return; +} + +/*********************************************************************** +* NAME +* +* dmp_in_use - determine how many atoms are still in use +* +* SYNOPSIS +* +* #include "dmp.h" +* size_t dmp_in_use(DMP *pool); +* +* RETURNS +* +* The routine returns the number of atoms of the specified memory pool +* which are still in use. */ + +size_t dmp_in_use(DMP *pool) +{ return + pool->count; +} + +/*********************************************************************** +* NAME +* +* dmp_delete_pool - delete dynamic memory pool +* +* SYNOPSIS +* +* #include "dmp.h" +* void dmp_delete_pool(DMP *pool); +* +* DESCRIPTION +* +* The routine dmp_delete_pool deletes the specified dynamic memory +* pool freeing all the memory allocated to this object. */ + +void dmp_delete_pool(DMP *pool) +{ while (pool->block != NULL) + { void *block = pool->block; + pool->block = *(void **)block; + tfree(block); + } + tfree(pool); + return; +} + +/* eof */ |