/* alloc.c (dynamic memory allocation) */ /*********************************************************************** * 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: . * * 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 . ***********************************************************************/ #include "glpenv.h" #ifdef HAVE_ENV #define ALIGN 16 /* some processors need data to be properly aligned, so this macro * defines the alignment boundary, in bytes, provided by glpk memory * allocation routines; looks like 16-byte alignment boundary is * sufficient for all 32- and 64-bit platforms (8-byte boundary is not * sufficient for some 64-bit platforms because of jmp_buf) */ #define MBD_SIZE (((sizeof(MBD) + (ALIGN - 1)) / ALIGN) * ALIGN) /* size of memory block descriptor, in bytes, rounded up to multiple * of the alignment boundary */ /*********************************************************************** * dma - dynamic memory allocation (basic routine) * * This routine performs dynamic memory allocation. It is similar to * the standard realloc function, however, it provides every allocated * memory block with a descriptor, which is used for sanity checks on * reallocating/freeing previously allocated memory blocks as well as * for book-keeping the memory usage statistics. */ static void *dma(const char *func, void *ptr, size_t size) { ENV *env = get_env_ptr(); MBD *mbd; if (ptr == NULL) { /* new memory block will be allocated */ mbd = NULL; } else { /* allocated memory block will be reallocated or freed */ /* get pointer to the block descriptor */ mbd = (MBD *)((char *)ptr - MBD_SIZE); /* make sure that the block descriptor is valid */ if (mbd->self != mbd) xerror("%s: ptr = %p; invalid pointer\n", func, ptr); /* remove the block from the linked list */ mbd->self = NULL; if (mbd->prev == NULL) env->mem_ptr = mbd->next; else mbd->prev->next = mbd->next; if (mbd->next == NULL) ; else mbd->next->prev = mbd->prev; /* decrease usage counts */ if (!(env->mem_count >= 1 && env->mem_total >= mbd->size)) xerror("%s: memory allocation error\n", func); env->mem_count--; env->mem_total -= mbd->size; if (size == 0) { /* free the memory block */ free(mbd); return NULL; } } /* allocate/reallocate memory block */ if (size > SIZE_T_MAX - MBD_SIZE) xerror("%s: block too large\n", func); size += MBD_SIZE; if (size > env->mem_limit - env->mem_total) xerror("%s: memory allocation limit exceeded\n", func); if (env->mem_count == INT_MAX) xerror("%s: too many memory blocks allocated\n", func); mbd = (mbd == NULL ? malloc(size) : realloc(mbd, size)); if (mbd == NULL) xerror("%s: no memory available\n", func); /* setup the block descriptor */ mbd->size = size; mbd->self = mbd; mbd->prev = NULL; mbd->next = env->mem_ptr; /* add the block to the beginning of the linked list */ if (mbd->next != NULL) mbd->next->prev = mbd; env->mem_ptr = mbd; /* increase usage counts */ env->mem_count++; if (env->mem_cpeak < env->mem_count) env->mem_cpeak = env->mem_count; env->mem_total += size; if (env->mem_tpeak < env->mem_total) env->mem_tpeak = env->mem_total; return (char *)mbd + MBD_SIZE; } /*********************************************************************** * NAME * * glp_alloc - allocate memory block * * SYNOPSIS * * void *glp_alloc(int n, int size); * * DESCRIPTION * * The routine glp_alloc 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_alloc returns a pointer to the block allocated. * To free this block the routine glp_free (not free!) must be used. */ void *glp_alloc(int n, int size) { if (n < 1) xerror("glp_alloc: n = %d; invalid parameter\n", n); if (size < 1) xerror("glp_alloc: size = %d; invalid parameter\n", size); if ((size_t)n > SIZE_T_MAX / (size_t)size) xerror("glp_alloc: n = %d, size = %d; block too large\n", n, size); return dma("glp_alloc", NULL, (size_t)n * (size_t)size); } /**********************************************************************/ void *glp_realloc(void *ptr, int n, int size) { /* reallocate memory block */ if (ptr == NULL) xerror("glp_realloc: ptr = %p; invalid pointer\n", ptr); if (n < 1) xerror("glp_realloc: n = %d; invalid parameter\n", n); if (size < 1) xerror("glp_realloc: size = %d; invalid parameter\n", size); if ((size_t)n > SIZE_T_MAX / (size_t)size) xerror("glp_realloc: n = %d, size = %d; block too large\n", n, size); return dma("glp_realloc", ptr, (size_t)n * (size_t)size); } /*********************************************************************** * NAME * * glp_free - free (deallocate) memory block * * SYNOPSIS * * void glp_free(void *ptr); * * DESCRIPTION * * The routine glp_free frees (deallocates) a memory block pointed to * by ptr, which was previuosly allocated by the routine glp_alloc or * reallocated by the routine glp_realloc. */ void glp_free(void *ptr) { if (ptr == NULL) xerror("glp_free: ptr = %p; invalid pointer\n", ptr); dma("glp_free", ptr, 0); 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 < 1) xerror("glp_mem_limit: limit = %d; invalid parameter\n", limit); if ((size_t)limit <= (SIZE_T_MAX >> 20)) env->mem_limit = (size_t)limit << 20; else env->mem_limit = SIZE_T_MAX; return; } /*********************************************************************** * NAME * * glp_mem_usage - get memory usage information * * SYNOPSIS * * void glp_mem_usage(int *count, int *cpeak, size_t *total, * size_t *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 its value is not stored. * * *count is the number of the memory blocks currently allocated by the * routines glp_malloc and glp_calloc (one call to glp_malloc or * glp_calloc 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 glp_malloc and glp_calloc. * * *tpeak is the peak value of *total reached since the initialization * of the GLPK library envirionment. */ void glp_mem_usage(int *count, int *cpeak, size_t *total, size_t *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; } #else void *glp_alloc(int n, int size) { return calloc((size_t)n, (size_t)size); } void *glp_realloc(void *ptr, int n, int size) { return realloc(ptr, (size_t)n * (size_t)size); } void glp_free(void *ptr) { free(ptr); } void glp_mem_limit(int limit) { } void glp_mem_usage(int *count, int *cpeak, size_t *total, size_t *tpeak) { if (count != NULL) *count = 0; if (cpeak != NULL) *cpeak = 0; if (total != NULL) *total = 0; if (tpeak != NULL) *tpeak = 0; return; } #endif /* eof */