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rf_mcpair.c revision 1.18 
      1 /*	$NetBSD: rf_mcpair.c,v 1.18 2005/02/27 00:27:45 perry 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 1.18 2005/02/27 00:27:45 perry 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 #include "rf_netbsd.h"
     46 
     47 #include <sys/pool.h>
     48 #include <sys/proc.h>
     49 
     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_pools.mcpair);
     59 }
     60 
     61 int
     62 rf_ConfigureMCPair(RF_ShutdownList_t **listp)
     63 {
     64 
     65 	rf_pool_init(&rf_pools.mcpair, sizeof(RF_MCPair_t),
     66 		     "rf_mcpair_pl", RF_MIN_FREE_MCPAIR, RF_MAX_FREE_MCPAIR);
     67 	rf_ShutdownCreate(listp, rf_ShutdownMCPair, NULL);
     68 
     69 	return (0);
     70 }
     71 
     72 RF_MCPair_t *
     73 rf_AllocMCPair()
     74 {
     75 	RF_MCPair_t *t;
     76 
     77 	t = pool_get(&rf_pools.mcpair, PR_WAITOK);
     78 	simple_lock_init(&t->mutex);
     79 	t->cond = 0;
     80 	t->flag = 0;
     81 
     82 	return (t);
     83 }
     84 
     85 void
     86 rf_FreeMCPair(RF_MCPair_t *t)
     87 {
     88 	pool_put(&rf_pools.mcpair, t);
     89 }
     90 
     91 /* the callback function used to wake you up when you use an mcpair to
     92    wait for something */
     93 void
     94 rf_MCPairWakeupFunc(RF_MCPair_t *mcpair)
     95 {
     96 	RF_LOCK_MUTEX(mcpair->mutex);
     97 	mcpair->flag = 1;
     98 	wakeup(&(mcpair->cond));
     99 	RF_UNLOCK_MUTEX(mcpair->mutex);
    100 }
    101