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rf_mcpair.c revision 1.6 
      1 /*	$NetBSD: rf_mcpair.c,v 1.6 2001/10/04 15:58:54 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 <dev/raidframe/raidframevar.h>
     35 
     36 #include "rf_archs.h"
     37 #include "rf_threadstuff.h"
     38 #include "rf_mcpair.h"
     39 #include "rf_debugMem.h"
     40 #include "rf_freelist.h"
     41 #include "rf_shutdown.h"
     42 
     43 #include <sys/proc.h>
     44 
     45 static RF_FreeList_t *rf_mcpair_freelist;
     46 
     47 #define RF_MAX_FREE_MCPAIR 128
     48 #define RF_MCPAIR_INC       16
     49 #define RF_MCPAIR_INITIAL   24
     50 
     51 static int init_mcpair(RF_MCPair_t *);
     52 static void clean_mcpair(RF_MCPair_t *);
     53 static void rf_ShutdownMCPair(void *);
     54 
     55 
     56 
     57 static int
     58 init_mcpair(t)
     59 	RF_MCPair_t *t;
     60 {
     61 	int     rc;
     62 
     63 	rc = rf_mutex_init(&t->mutex);
     64 	if (rc) {
     65 		RF_ERRORMSG3("Unable to init mutex file %s line %d rc=%d\n", __FILE__,
     66 		    __LINE__, rc);
     67 		return (rc);
     68 	}
     69 	rc = rf_cond_init(&t->cond);
     70 	if (rc) {
     71 		RF_ERRORMSG3("Unable to init cond file %s line %d rc=%d\n", __FILE__,
     72 		    __LINE__, rc);
     73 		rf_mutex_destroy(&t->mutex);
     74 		return (rc);
     75 	}
     76 	return (0);
     77 }
     78 
     79 static void
     80 clean_mcpair(t)
     81 	RF_MCPair_t *t;
     82 {
     83 	rf_mutex_destroy(&t->mutex);
     84 	rf_cond_destroy(&t->cond);
     85 }
     86 
     87 static void
     88 rf_ShutdownMCPair(ignored)
     89 	void   *ignored;
     90 {
     91 	RF_FREELIST_DESTROY_CLEAN(rf_mcpair_freelist, next, (RF_MCPair_t *), clean_mcpair);
     92 }
     93 
     94 int
     95 rf_ConfigureMCPair(listp)
     96 	RF_ShutdownList_t **listp;
     97 {
     98 	int     rc;
     99 
    100 	RF_FREELIST_CREATE(rf_mcpair_freelist, RF_MAX_FREE_MCPAIR,
    101 	    RF_MCPAIR_INC, sizeof(RF_MCPair_t));
    102 	rc = rf_ShutdownCreate(listp, rf_ShutdownMCPair, NULL);
    103 	if (rc) {
    104 		RF_ERRORMSG3("Unable to add to shutdown list file %s line %d rc=%d\n",
    105 		    __FILE__, __LINE__, rc);
    106 		rf_ShutdownMCPair(NULL);
    107 		return (rc);
    108 	}
    109 	RF_FREELIST_PRIME_INIT(rf_mcpair_freelist, RF_MCPAIR_INITIAL, next,
    110 	    (RF_MCPair_t *), init_mcpair);
    111 	return (0);
    112 }
    113 
    114 RF_MCPair_t *
    115 rf_AllocMCPair()
    116 {
    117 	RF_MCPair_t *t;
    118 
    119 	RF_FREELIST_GET_INIT(rf_mcpair_freelist, t, next, (RF_MCPair_t *), init_mcpair);
    120 	if (t) {
    121 		t->flag = 0;
    122 		t->next = NULL;
    123 	}
    124 	return (t);
    125 }
    126 
    127 void
    128 rf_FreeMCPair(t)
    129 	RF_MCPair_t *t;
    130 {
    131 	RF_FREELIST_FREE_CLEAN(rf_mcpair_freelist, t, next, clean_mcpair);
    132 }
    133 /* the callback function used to wake you up when you use an mcpair to wait for something */
    134 void
    135 rf_MCPairWakeupFunc(mcpair)
    136 	RF_MCPair_t *mcpair;
    137 {
    138 	RF_LOCK_MUTEX(mcpair->mutex);
    139 	mcpair->flag = 1;
    140 	wakeup(&(mcpair->cond));
    141 	RF_UNLOCK_MUTEX(mcpair->mutex);
    142 }
    143