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rf_mcpair.c revision 1.9 
      1 /*	$NetBSD: rf_mcpair.c,v 1.9 2003/12/29 03:33:48 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 <sys/cdefs.h>
     35 __KERNEL_RCSID(0, "$NetBSD: rf_mcpair.c,v 1.9 2003/12/29 03:33:48 oster 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_general.h"
     44 #include "rf_shutdown.h"
     45 
     46 #include <sys/pool.h>
     47 #include <sys/proc.h>
     48 
     49 static struct pool rf_mcpair_pool;
     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_print_unable_to_init_mutex(__FILE__, __LINE__, rc);
     69 		return (rc);
     70 	}
     71 	rc = rf_cond_init(&t->cond);
     72 	if (rc) {
     73 		rf_print_unable_to_init_cond(__FILE__, __LINE__, rc);
     74 		rf_mutex_destroy(&t->mutex);
     75 		return (rc);
     76 	}
     77 	return (0);
     78 }
     79 
     80 static void
     81 clean_mcpair(t)
     82 	RF_MCPair_t *t;
     83 {
     84 	rf_mutex_destroy(&t->mutex);
     85 	rf_cond_destroy(&t->cond);
     86 }
     87 
     88 static void
     89 rf_ShutdownMCPair(ignored)
     90 	void   *ignored;
     91 {
     92 	/* XXX what about the "cleaning" stuff???  Is it even necessary */
     93 	pool_destroy(&rf_mcpair_pool);
     94 }
     95 
     96 int
     97 rf_ConfigureMCPair(listp)
     98 	RF_ShutdownList_t **listp;
     99 {
    100 	int     rc;
    101 
    102 	pool_init(&rf_mcpair_pool, sizeof(RF_MCPair_t), 0, 0, 0,
    103 		  "rf_mcpair_pl", NULL);
    104 	pool_sethiwat(&rf_mcpair_pool, RF_MAX_FREE_MCPAIR);
    105 	pool_prime(&rf_mcpair_pool, RF_MCPAIR_INITIAL);
    106 
    107 	rc = rf_ShutdownCreate(listp, rf_ShutdownMCPair, NULL);
    108 	if (rc) {
    109 		rf_print_unable_to_add_shutdown(__FILE__, __LINE__, rc);
    110 		rf_ShutdownMCPair(NULL);
    111 		return (rc);
    112 	}
    113 
    114 	return (0);
    115 }
    116 
    117 RF_MCPair_t *
    118 rf_AllocMCPair()
    119 {
    120 	RF_MCPair_t *t;
    121 
    122 	t = pool_get(&rf_mcpair_pool, PR_WAITOK);
    123 	if (init_mcpair(t)) {
    124 		/* some sort of error... */
    125 		pool_put(&rf_mcpair_pool, t);
    126 		t = NULL;
    127 	}
    128 	if (t) {
    129 		t->flag = 0;
    130 		t->next = NULL;
    131 	}
    132 	return (t);
    133 }
    134 
    135 void
    136 rf_FreeMCPair(t)
    137 	RF_MCPair_t *t;
    138 {
    139 	clean_mcpair(t);
    140 	pool_put(&rf_mcpair_pool, t);
    141 }
    142 /* the callback function used to wake you up when you use an mcpair to wait for something */
    143 void
    144 rf_MCPairWakeupFunc(mcpair)
    145 	RF_MCPair_t *mcpair;
    146 {
    147 	RF_LOCK_MUTEX(mcpair->mutex);
    148 	mcpair->flag = 1;
    149 	wakeup(&(mcpair->cond));
    150 	RF_UNLOCK_MUTEX(mcpair->mutex);
    151 }
    152