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rf_alloclist.c revision 1.5 
      1 /*	$NetBSD: rf_alloclist.c,v 1.5 2001/07/18 06:45:33 thorpej Exp $	*/
      2 /*
      3  * Copyright (c) 1995 Carnegie-Mellon University.
      4  * All rights reserved.
      5  *
      6  * Author: Mark Holland
      7  *
      8  * Permission to use, copy, modify and distribute this software and
      9  * its documentation is hereby granted, provided that both the copyright
     10  * notice and this permission notice appear in all copies of the
     11  * software, derivative works or modified versions, and any portions
     12  * thereof, and that both notices appear in supporting documentation.
     13  *
     14  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
     15  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
     16  * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
     17  *
     18  * Carnegie Mellon requests users of this software to return to
     19  *
     20  *  Software Distribution Coordinator  or  Software.Distribution (at) CS.CMU.EDU
     21  *  School of Computer Science
     22  *  Carnegie Mellon University
     23  *  Pittsburgh PA 15213-3890
     24  *
     25  * any improvements or extensions that they make and grant Carnegie the
     26  * rights to redistribute these changes.
     27  */
     28 
     29 /****************************************************************************
     30  *
     31  * Alloclist.c -- code to manipulate allocation lists
     32  *
     33  * an allocation list is just a list of AllocListElem structures.  Each
     34  * such structure contains a fixed-size array of pointers.  Calling
     35  * FreeAList() causes each pointer to be freed.
     36  *
     37  ***************************************************************************/
     38 
     39 #include "rf_types.h"
     40 #include "rf_threadstuff.h"
     41 #include "rf_alloclist.h"
     42 #include "rf_debugMem.h"
     43 #include "rf_etimer.h"
     44 #include "rf_general.h"
     45 #include "rf_shutdown.h"
     46 
     47 RF_DECLARE_STATIC_MUTEX(alist_mutex)
     48 	static unsigned int fl_hit_count, fl_miss_count;
     49 
     50 	static RF_AllocListElem_t *al_free_list = NULL;
     51 	static int al_free_list_count;
     52 
     53 #define RF_AL_FREELIST_MAX 256
     54 
     55 #define DO_FREE(_p,_sz) RF_Free((_p),(_sz))
     56 
     57 	static void rf_ShutdownAllocList(void *);
     58 
     59 	static void rf_ShutdownAllocList(ignored)
     60 	void   *ignored;
     61 {
     62 	RF_AllocListElem_t *p, *pt;
     63 
     64 	for (p = al_free_list; p;) {
     65 		pt = p;
     66 		p = p->next;
     67 		DO_FREE(pt, sizeof(*pt));
     68 	}
     69 	rf_mutex_destroy(&alist_mutex);
     70 	/*
     71         printf("Alloclist: Free list hit count %lu (%lu %%) miss count %lu (%lu %%)\n",
     72 	       fl_hit_count, (100*fl_hit_count)/(fl_hit_count+fl_miss_count),
     73 	       fl_miss_count, (100*fl_miss_count)/(fl_hit_count+fl_miss_count));
     74         */
     75 }
     76 
     77 int
     78 rf_ConfigureAllocList(listp)
     79 	RF_ShutdownList_t **listp;
     80 {
     81 	int     rc;
     82 
     83 	rc = rf_mutex_init(&alist_mutex);
     84 	if (rc) {
     85 		RF_ERRORMSG3("Unable to init mutex file %s line %d rc=%d\n", __FILE__,
     86 		    __LINE__, rc);
     87 		return (rc);
     88 	}
     89 	al_free_list = NULL;
     90 	fl_hit_count = fl_miss_count = al_free_list_count = 0;
     91 	rc = rf_ShutdownCreate(listp, rf_ShutdownAllocList, NULL);
     92 	if (rc) {
     93 		RF_ERRORMSG3("Unable to add to shutdown list file %s line %d rc=%d\n",
     94 		    __FILE__, __LINE__, rc);
     95 		rf_mutex_destroy(&alist_mutex);
     96 		return (rc);
     97 	}
     98 	return (0);
     99 }
    100 
    101 
    102 /* we expect the lists to have at most one or two elements, so we're willing
    103  * to search for the end.  If you ever observe the lists growing longer,
    104  * increase POINTERS_PER_ALLOC_LIST_ELEMENT.
    105  */
    106 void
    107 rf_real_AddToAllocList(l, p, size, lockflag)
    108 	RF_AllocListElem_t *l;
    109 	void   *p;
    110 	int     size;
    111 	int     lockflag;
    112 {
    113 	RF_AllocListElem_t *newelem;
    114 
    115 	for (; l->next; l = l->next)
    116 		RF_ASSERT(l->numPointers == RF_POINTERS_PER_ALLOC_LIST_ELEMENT);	/* find end of list */
    117 
    118 	RF_ASSERT(l->numPointers >= 0 && l->numPointers <= RF_POINTERS_PER_ALLOC_LIST_ELEMENT);
    119 	if (l->numPointers == RF_POINTERS_PER_ALLOC_LIST_ELEMENT) {
    120 		newelem = rf_real_MakeAllocList(lockflag);
    121 		l->next = newelem;
    122 		l = newelem;
    123 	}
    124 	l->pointers[l->numPointers] = p;
    125 	l->sizes[l->numPointers] = size;
    126 	l->numPointers++;
    127 
    128 }
    129 
    130 
    131 /* we use the debug_mem_mutex here because we need to lock it anyway to call free.
    132  * this is probably a bug somewhere else in the code, but when I call malloc/free
    133  * outside of any lock I have endless trouble with malloc appearing to return the
    134  * same pointer twice.  Since we have to lock it anyway, we might as well use it
    135  * as the lock around the al_free_list.  Note that we can't call Free with the
    136  * debug_mem_mutex locked.
    137  */
    138 void
    139 rf_FreeAllocList(l)
    140 	RF_AllocListElem_t *l;
    141 {
    142 	int     i;
    143 	RF_AllocListElem_t *temp, *p;
    144 
    145 	for (p = l; p; p = p->next) {
    146 		RF_ASSERT(p->numPointers >= 0 && p->numPointers <= RF_POINTERS_PER_ALLOC_LIST_ELEMENT);
    147 		for (i = 0; i < p->numPointers; i++) {
    148 			RF_ASSERT(p->pointers[i]);
    149 			RF_Free(p->pointers[i], p->sizes[i]);
    150 		}
    151 	}
    152 	while (l) {
    153 		temp = l;
    154 		l = l->next;
    155 		if (al_free_list_count > RF_AL_FREELIST_MAX) {
    156 			DO_FREE(temp, sizeof(*temp));
    157 		} else {
    158 			temp->next = al_free_list;
    159 			al_free_list = temp;
    160 			al_free_list_count++;
    161 		}
    162 	}
    163 }
    164 
    165 RF_AllocListElem_t *
    166 rf_real_MakeAllocList(lockflag)
    167 	int     lockflag;
    168 {
    169 	RF_AllocListElem_t *p;
    170 
    171 	if (al_free_list) {
    172 		fl_hit_count++;
    173 		p = al_free_list;
    174 		al_free_list = p->next;
    175 		al_free_list_count--;
    176 	} else {
    177 		fl_miss_count++;
    178 		RF_Malloc(p, sizeof(RF_AllocListElem_t), (RF_AllocListElem_t *));	/* no allocation locking
    179 											 * in kernel, so this is
    180 											 * fine */
    181 	}
    182 	if (p == NULL) {
    183 		return (NULL);
    184 	}
    185 	memset((char *) p, 0, sizeof(RF_AllocListElem_t));
    186 	return (p);
    187 }
    188