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rf_mcpair.c revision 1.5 
      1 /*	$NetBSD: rf_mcpair.c,v 1.5 2001/09/26 02:52:57 oster Exp $	*/
      2 /*
      3  * Copyright (c) 1995 Carnegie-Mellon University.
      4  * All rights reserved.
      5  *
      6  * Author: Jim Zelenka
      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 /* rf_mcpair.c
     30  * an mcpair is a structure containing a mutex and a condition variable.
     31  * it's used to block the current thread until some event occurs.
     32  */
     33 
     34 #include "rf_types.h"
     35 #include "rf_archs.h"
     36 #include "rf_threadstuff.h"
     37 #include "rf_mcpair.h"
     38 #include "rf_debugMem.h"
     39 #include "rf_freelist.h"
     40 #include "rf_shutdown.h"
     41 
     42 #include <sys/proc.h>
     43 
     44 static RF_FreeList_t *rf_mcpair_freelist;
     45 
     46 #define RF_MAX_FREE_MCPAIR 128
     47 #define RF_MCPAIR_INC       16
     48 #define RF_MCPAIR_INITIAL   24
     49 
     50 static int init_mcpair(RF_MCPair_t *);
     51 static void clean_mcpair(RF_MCPair_t *);
     52 static void rf_ShutdownMCPair(void *);
     53 
     54 
     55 
     56 static int
     57 init_mcpair(t)
     58 	RF_MCPair_t *t;
     59 {
     60 	int     rc;
     61 
     62 	rc = rf_mutex_init(&t->mutex);
     63 	if (rc) {
     64 		RF_ERRORMSG3("Unable to init mutex file %s line %d rc=%d\n", __FILE__,
     65 		    __LINE__, rc);
     66 		return (rc);
     67 	}
     68 	rc = rf_cond_init(&t->cond);
     69 	if (rc) {
     70 		RF_ERRORMSG3("Unable to init cond file %s line %d rc=%d\n", __FILE__,
     71 		    __LINE__, rc);
     72 		rf_mutex_destroy(&t->mutex);
     73 		return (rc);
     74 	}
     75 	return (0);
     76 }
     77 
     78 static void
     79 clean_mcpair(t)
     80 	RF_MCPair_t *t;
     81 {
     82 	rf_mutex_destroy(&t->mutex);
     83 	rf_cond_destroy(&t->cond);
     84 }
     85 
     86 static void
     87 rf_ShutdownMCPair(ignored)
     88 	void   *ignored;
     89 {
     90 	RF_FREELIST_DESTROY_CLEAN(rf_mcpair_freelist, next, (RF_MCPair_t *), clean_mcpair);
     91 }
     92 
     93 int
     94 rf_ConfigureMCPair(listp)
     95 	RF_ShutdownList_t **listp;
     96 {
     97 	int     rc;
     98 
     99 	RF_FREELIST_CREATE(rf_mcpair_freelist, RF_MAX_FREE_MCPAIR,
    100 	    RF_MCPAIR_INC, sizeof(RF_MCPair_t));
    101 	rc = rf_ShutdownCreate(listp, rf_ShutdownMCPair, NULL);
    102 	if (rc) {
    103 		RF_ERRORMSG3("Unable to add to shutdown list file %s line %d rc=%d\n",
    104 		    __FILE__, __LINE__, rc);
    105 		rf_ShutdownMCPair(NULL);
    106 		return (rc);
    107 	}
    108 	RF_FREELIST_PRIME_INIT(rf_mcpair_freelist, RF_MCPAIR_INITIAL, next,
    109 	    (RF_MCPair_t *), init_mcpair);
    110 	return (0);
    111 }
    112 
    113 RF_MCPair_t *
    114 rf_AllocMCPair()
    115 {
    116 	RF_MCPair_t *t;
    117 
    118 	RF_FREELIST_GET_INIT(rf_mcpair_freelist, t, next, (RF_MCPair_t *), init_mcpair);
    119 	if (t) {
    120 		t->flag = 0;
    121 		t->next = NULL;
    122 	}
    123 	return (t);
    124 }
    125 
    126 void
    127 rf_FreeMCPair(t)
    128 	RF_MCPair_t *t;
    129 {
    130 	RF_FREELIST_FREE_CLEAN(rf_mcpair_freelist, t, next, clean_mcpair);
    131 }
    132 /* the callback function used to wake you up when you use an mcpair to wait for something */
    133 void
    134 rf_MCPairWakeupFunc(mcpair)
    135 	RF_MCPair_t *mcpair;
    136 {
    137 	RF_LOCK_MUTEX(mcpair->mutex);
    138 	mcpair->flag = 1;
    139 	wakeup(&(mcpair->cond));
    140 	RF_UNLOCK_MUTEX(mcpair->mutex);
    141 }
    142