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rf_mcpair.c revision 1.7 
      1 /*	$NetBSD: rf_mcpair.c,v 1.7 2001/11/13 07:11:14 lukem 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 <sys/cdefs.h>
     35 __KERNEL_RCSID(0, "$NetBSD: rf_mcpair.c,v 1.7 2001/11/13 07:11:14 lukem Exp $");
     36 
     37 #include <dev/raidframe/raidframevar.h>
     38 
     39 #include "rf_archs.h"
     40 #include "rf_threadstuff.h"
     41 #include "rf_mcpair.h"
     42 #include "rf_debugMem.h"
     43 #include "rf_freelist.h"
     44 #include "rf_shutdown.h"
     45 
     46 #include <sys/proc.h>
     47 
     48 static RF_FreeList_t *rf_mcpair_freelist;
     49 
     50 #define RF_MAX_FREE_MCPAIR 128
     51 #define RF_MCPAIR_INC       16
     52 #define RF_MCPAIR_INITIAL   24
     53 
     54 static int init_mcpair(RF_MCPair_t *);
     55 static void clean_mcpair(RF_MCPair_t *);
     56 static void rf_ShutdownMCPair(void *);
     57 
     58 
     59 
     60 static int
     61 init_mcpair(t)
     62 	RF_MCPair_t *t;
     63 {
     64 	int     rc;
     65 
     66 	rc = rf_mutex_init(&t->mutex);
     67 	if (rc) {
     68 		RF_ERRORMSG3("Unable to init mutex file %s line %d rc=%d\n", __FILE__,
     69 		    __LINE__, rc);
     70 		return (rc);
     71 	}
     72 	rc = rf_cond_init(&t->cond);
     73 	if (rc) {
     74 		RF_ERRORMSG3("Unable to init cond file %s line %d rc=%d\n", __FILE__,
     75 		    __LINE__, rc);
     76 		rf_mutex_destroy(&t->mutex);
     77 		return (rc);
     78 	}
     79 	return (0);
     80 }
     81 
     82 static void
     83 clean_mcpair(t)
     84 	RF_MCPair_t *t;
     85 {
     86 	rf_mutex_destroy(&t->mutex);
     87 	rf_cond_destroy(&t->cond);
     88 }
     89 
     90 static void
     91 rf_ShutdownMCPair(ignored)
     92 	void   *ignored;
     93 {
     94 	RF_FREELIST_DESTROY_CLEAN(rf_mcpair_freelist, next, (RF_MCPair_t *), clean_mcpair);
     95 }
     96 
     97 int
     98 rf_ConfigureMCPair(listp)
     99 	RF_ShutdownList_t **listp;
    100 {
    101 	int     rc;
    102 
    103 	RF_FREELIST_CREATE(rf_mcpair_freelist, RF_MAX_FREE_MCPAIR,
    104 	    RF_MCPAIR_INC, sizeof(RF_MCPair_t));
    105 	rc = rf_ShutdownCreate(listp, rf_ShutdownMCPair, NULL);
    106 	if (rc) {
    107 		RF_ERRORMSG3("Unable to add to shutdown list file %s line %d rc=%d\n",
    108 		    __FILE__, __LINE__, rc);
    109 		rf_ShutdownMCPair(NULL);
    110 		return (rc);
    111 	}
    112 	RF_FREELIST_PRIME_INIT(rf_mcpair_freelist, RF_MCPAIR_INITIAL, next,
    113 	    (RF_MCPair_t *), init_mcpair);
    114 	return (0);
    115 }
    116 
    117 RF_MCPair_t *
    118 rf_AllocMCPair()
    119 {
    120 	RF_MCPair_t *t;
    121 
    122 	RF_FREELIST_GET_INIT(rf_mcpair_freelist, t, next, (RF_MCPair_t *), init_mcpair);
    123 	if (t) {
    124 		t->flag = 0;
    125 		t->next = NULL;
    126 	}
    127 	return (t);
    128 }
    129 
    130 void
    131 rf_FreeMCPair(t)
    132 	RF_MCPair_t *t;
    133 {
    134 	RF_FREELIST_FREE_CLEAN(rf_mcpair_freelist, t, next, clean_mcpair);
    135 }
    136 /* the callback function used to wake you up when you use an mcpair to wait for something */
    137 void
    138 rf_MCPairWakeupFunc(mcpair)
    139 	RF_MCPair_t *mcpair;
    140 {
    141 	RF_LOCK_MUTEX(mcpair->mutex);
    142 	mcpair->flag = 1;
    143 	wakeup(&(mcpair->cond));
    144 	RF_UNLOCK_MUTEX(mcpair->mutex);
    145 }
    146