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rf_mcpair.c revision 1.16 
      1 /*	$NetBSD: rf_mcpair.c,v 1.16 2004/03/05 02:53:58 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 1.16 2004/03/05 02:53:58 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_MIN_FREE_MCPAIR  24
     52 
     53 static void rf_ShutdownMCPair(void *);
     54 
     55 static void
     56 rf_ShutdownMCPair(void *ignored)
     57 {
     58 	pool_destroy(&rf_mcpair_pool);
     59 }
     60 
     61 int
     62 rf_ConfigureMCPair(RF_ShutdownList_t **listp)
     63 {
     64 
     65 	pool_init(&rf_mcpair_pool, sizeof(RF_MCPair_t), 0, 0, 0,
     66 		  "rf_mcpair_pl", NULL);
     67 	pool_sethiwat(&rf_mcpair_pool, RF_MAX_FREE_MCPAIR);
     68 	pool_prime(&rf_mcpair_pool, RF_MIN_FREE_MCPAIR);
     69 	pool_setlowat(&rf_mcpair_pool, RF_MIN_FREE_MCPAIR);
     70 
     71 	rf_ShutdownCreate(listp, rf_ShutdownMCPair, NULL);
     72 
     73 	return (0);
     74 }
     75 
     76 RF_MCPair_t *
     77 rf_AllocMCPair()
     78 {
     79 	RF_MCPair_t *t;
     80 
     81 	t = pool_get(&rf_mcpair_pool, PR_WAITOK);
     82 	simple_lock_init(&t->mutex);
     83 	t->cond = 0;
     84 	t->flag = 0;
     85 
     86 	return (t);
     87 }
     88 
     89 void
     90 rf_FreeMCPair(RF_MCPair_t *t)
     91 {
     92 	pool_put(&rf_mcpair_pool, t);
     93 }
     94 
     95 /* the callback function used to wake you up when you use an mcpair to
     96    wait for something */
     97 void
     98 rf_MCPairWakeupFunc(RF_MCPair_t *mcpair)
     99 {
    100 	RF_LOCK_MUTEX(mcpair->mutex);
    101 	mcpair->flag = 1;
    102 	wakeup(&(mcpair->cond));
    103 	RF_UNLOCK_MUTEX(mcpair->mutex);
    104 }
    105