usr/src/lib/libtnfprobe/probe_mem.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License, Version 1.0 only
   6  * (the "License").  You may not use this file except in compliance
   7  * with the License.
   8  *
   9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10  * or http://www.opensolaris.org/os/licensing.
  11  * See the License for the specific language governing permissions
  12  * and limitations under the License.
  13  *
  14  * When distributing Covered Code, include this CDDL HEADER in each
  15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16  * If applicable, add the following below this CDDL HEADER, with the
  17  * fields enclosed by brackets "[]" replaced with your own identifying
  18  * information: Portions Copyright [yyyy] [name of copyright owner]
  19  *
  20  * CDDL HEADER END
  21  */
  22 /*
  23  *      Copyright (c) 1994, by Sun Microsytems, Inc.
  24  */
  25
  26 #pragma ident   "%Z%%M% %I%     %E% SMI"
  27
  28 /*
  29  * Includes
  30  */
  31
  32 #include "prb_internals.h"
  33
  34
  35 /*
  36  * Globals
  37  *      Memory that prex uses to store combinations in target process
  38  */
  39
  40 #define INITMEMSZ 2048
  41
  42 static char     initial_memory[INITMEMSZ];
  43 static tnf_memseg_t     initial_memseg = {
  44                                         initial_memory,
  45                                         initial_memory + INITMEMSZ,
  46                                         DEFAULTMUTEX,
  47                                         0
  48                                 };
  49
  50 tnf_memseg_t *  __tnf_probe_memseg_p = &initial_memseg;
  51
  52
  53 /*
  54  * __tnf_probe_alloc() - allocates memory from the global pool
  55  */
  56
  57 char *
  58 __tnf_probe_alloc(size_t size)
  59 {
  60         tnf_memseg_t *  memseg_p = __tnf_probe_memseg_p;
  61         char *          ptr;
  62
  63         ptr = NULL;
  64
  65         mutex_lock(&memseg_p->i_lock);
  66
  67         memseg_p->i_reqsz = size;
  68
  69         if ((memseg_p->min_p + size) <= memseg_p->max_p) {
  70             ptr = memseg_p->min_p;
  71             memseg_p->min_p += size;
  72         }
  73
  74         memseg_p->i_reqsz = 0;
  75
  76         mutex_unlock(&memseg_p->i_lock);
  77
  78         return (ptr);
  79
  80 }   /* end __tnf_probe_alloc */