/* glpenv05.c (memory allocation) */

 /***********************************************************************

 *  This code is part of GLPK (GNU Linear Programming Kit).

 *

 *  Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008,

 *  2009, 2010 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 "glpapi.h"

 /* some processors need data to be properly aligned; the macro

    align_datasize enlarges the specified size of a data item to provide

    a proper alignment of immediately following data */

 #define align_datasize(size) ((((size) + 15) / 16) * 16)

 /* 16 bytes is sufficient in both 32- and 64-bit environments

    (8 bytes is not sufficient in 64-bit environment due to jmp_buf) */

 /***********************************************************************

 *  NAME

 *

 *  glp_malloc - allocate memory block

 *

 *  SYNOPSIS

 *

 *  void *glp_malloc(int size);

 *

 *  DESCRIPTION

 *

 *  The routine glp_malloc allocates a memory block of size bytes long.

 *

 *  Note that being allocated the memory block contains arbitrary data

 *  (not binary zeros).

 *

 *  RETURNS

 *

 *  The routine glp_malloc returns a pointer to the allocated block.

 *  To free this block the routine glp_free (not free!) must be used. */

 void *glp_malloc(int size)

 {     ENV *env = get_env_ptr();

       MEM *desc;

       int size_of_desc = align_datasize(sizeof(MEM));

       if (size < 1 || size > INT_MAX - size_of_desc)

          xerror("glp_malloc: size = %d; invalid parameter\n", size);

       size += size_of_desc;

       if (xlcmp(xlset(size),

           xlsub(env->mem_limit, env->mem_total)) > 0)

          xerror("glp_malloc: memory limit exceeded\n");

       if (env->mem_count == INT_MAX)

          xerror("glp_malloc: too many memory blocks allocated\n");

       desc = malloc(size);

       if (desc == NULL)

          xerror("glp_malloc: no memory available\n");

       memset(desc, '?', size);

       desc->flag = MEM_MAGIC;

       desc->size = size;

       desc->prev = NULL;

       desc->next = env->mem_ptr;

       if (desc->next != NULL) desc->next->prev = desc;

       env->mem_ptr = desc;

       env->mem_count++;

       if (env->mem_cpeak < env->mem_count)

          env->mem_cpeak = env->mem_count;

       env->mem_total = xladd(env->mem_total, xlset(size));

       if (xlcmp(env->mem_tpeak, env->mem_total) < 0)

          env->mem_tpeak = env->mem_total;

       return (void *)((char *)desc + size_of_desc);

 }

 /***********************************************************************

 *  NAME

 *

 *  glp_calloc - allocate memory block

 *

 *  SYNOPSIS

 *

 *  void *glp_calloc(int n, int size);

 *

 *  DESCRIPTION

 *

 *  The routine glp_calloc allocates a memory block of (n*size) bytes

 *  long.

 *

 *  Note that being allocated the memory block contains arbitrary data

 *  (not binary zeros).

 *

 *  RETURNS

 *

 *  The routine glp_calloc returns a pointer to the allocated block.

 *  To free this block the routine glp_free (not free!) must be used. */

 void *glp_calloc(int n, int size)

 {     if (n < 1)

          xerror("glp_calloc: n = %d; invalid parameter\n", n);

       if (size < 1)

          xerror("glp_calloc: size = %d; invalid parameter\n", size);

       if (n > INT_MAX / size)

          xerror("glp_calloc: n = %d; size = %d; array too big\n", n,

             size);

       return xmalloc(n * size);

 }

 /***********************************************************************

 *  NAME

 *

 *  glp_free - free memory block

 *

 *  SYNOPSIS

 *

 *  void glp_free(void *ptr);

 *

 *  DESCRIPTION

 *

 *  The routine glp_free frees a memory block pointed to by ptr, which

 *  was previuosly allocated by the routine glp_malloc or glp_calloc. */

 void glp_free(void *ptr)

 {     ENV *env = get_env_ptr();

       MEM *desc;

       int size_of_desc = align_datasize(sizeof(MEM));

       if (ptr == NULL)

          xerror("glp_free: ptr = %p; null pointer\n", ptr);

       desc = (void *)((char *)ptr - size_of_desc);

       if (desc->flag != MEM_MAGIC)

          xerror("glp_free: ptr = %p; invalid pointer\n", ptr);

       if (env->mem_count == 0 ||

           xlcmp(env->mem_total, xlset(desc->size)) < 0)

          xerror("glp_free: memory allocation error\n");

       if (desc->prev == NULL)

          env->mem_ptr = desc->next;

       else

          desc->prev->next = desc->next;

       if (desc->next == NULL)

          ;

       else

          desc->next->prev = desc->prev;

       env->mem_count--;

       env->mem_total = xlsub(env->mem_total, xlset(desc->size));

       memset(desc, '?', size_of_desc);

       free(desc);

       return;

 }

 /***********************************************************************

 *  NAME

 *

 *  glp_mem_limit - set memory usage limit

 *

 *  SYNOPSIS

 *

 *  void glp_mem_limit(int limit);

 *

 *  DESCRIPTION

 *

 *  The routine glp_mem_limit limits the amount of memory available for

 *  dynamic allocation (in GLPK routines) to limit megabytes. */

 void glp_mem_limit(int limit)

 {     ENV *env = get_env_ptr();

       if (limit < 0)

          xerror("glp_mem_limit: limit = %d; invalid parameter\n",

             limit);

       env->mem_limit = xlmul(xlset(limit), xlset(1 << 20));

       return;

 }

 /***********************************************************************

 *  NAME

 *

 *  glp_mem_usage - get memory usage information

 *

 *  SYNOPSIS

 *

 *  void glp_mem_usage(int *count, int *cpeak, glp_long *total,

 *     glp_long *tpeak);

 *

 *  DESCRIPTION

 *

 *  The routine glp_mem_usage reports some information about utilization

 *  of the memory by GLPK routines. Information is stored to locations

 *  specified by corresponding parameters (see below). Any parameter can

 *  be specified as NULL, in which case corresponding information is not

 *  stored.

 *

 *  *count is the number of the memory blocks currently allocated by the

 *  routines xmalloc and xcalloc (one call to xmalloc or xcalloc results

 *  in allocating one memory block).

 *

 *  *cpeak is the peak value of *count reached since the initialization

 *  of the GLPK library environment.

 *

 *  *total is the total amount, in bytes, of the memory blocks currently

 *  allocated by the routines xmalloc and xcalloc.

 *

 *  *tpeak is the peak value of *total reached since the initialization

 *  of the GLPK library envirionment. */

 void glp_mem_usage(int *count, int *cpeak, glp_long *total,

       glp_long *tpeak)

 {     ENV *env = get_env_ptr();

       if (count != NULL) *count = env->mem_count;

       if (cpeak != NULL) *cpeak = env->mem_cpeak;

       if (total != NULL) *total = env->mem_total;

       if (tpeak != NULL) *tpeak = env->mem_tpeak;

       return;

 }

 /* eof */