1 /* $NetBSD: rf_mcpair.c,v 1.3 1999/02/05 00:06:13 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@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 "rf_types.h" 35 #include "rf_threadstuff.h" 36 #include "rf_mcpair.h" 37 #include "rf_debugMem.h" 38 #include "rf_freelist.h" 39 #include "rf_shutdown.h" 40 41 #include <sys/proc.h> 42 43 static RF_FreeList_t *rf_mcpair_freelist; 44 45 #define RF_MAX_FREE_MCPAIR 128 46 #define RF_MCPAIR_INC 16 47 #define RF_MCPAIR_INITIAL 24 48 49 static int init_mcpair(RF_MCPair_t *); 50 static void clean_mcpair(RF_MCPair_t *); 51 static void rf_ShutdownMCPair(void *); 52 53 54 55 static int 56 init_mcpair(t) 57 RF_MCPair_t *t; 58 { 59 int rc; 60 61 rc = rf_mutex_init(&t->mutex); 62 if (rc) { 63 RF_ERRORMSG3("Unable to init mutex file %s line %d rc=%d\n", __FILE__, 64 __LINE__, rc); 65 return (rc); 66 } 67 rc = rf_cond_init(&t->cond); 68 if (rc) { 69 RF_ERRORMSG3("Unable to init cond file %s line %d rc=%d\n", __FILE__, 70 __LINE__, rc); 71 rf_mutex_destroy(&t->mutex); 72 return (rc); 73 } 74 return (0); 75 } 76 77 static void 78 clean_mcpair(t) 79 RF_MCPair_t *t; 80 { 81 rf_mutex_destroy(&t->mutex); 82 rf_cond_destroy(&t->cond); 83 } 84 85 static void 86 rf_ShutdownMCPair(ignored) 87 void *ignored; 88 { 89 RF_FREELIST_DESTROY_CLEAN(rf_mcpair_freelist, next, (RF_MCPair_t *), clean_mcpair); 90 } 91 92 int 93 rf_ConfigureMCPair(listp) 94 RF_ShutdownList_t **listp; 95 { 96 int rc; 97 98 RF_FREELIST_CREATE(rf_mcpair_freelist, RF_MAX_FREE_MCPAIR, 99 RF_MCPAIR_INC, sizeof(RF_MCPair_t)); 100 rc = rf_ShutdownCreate(listp, rf_ShutdownMCPair, NULL); 101 if (rc) { 102 RF_ERRORMSG3("Unable to add to shutdown list file %s line %d rc=%d\n", 103 __FILE__, __LINE__, rc); 104 rf_ShutdownMCPair(NULL); 105 return (rc); 106 } 107 RF_FREELIST_PRIME_INIT(rf_mcpair_freelist, RF_MCPAIR_INITIAL, next, 108 (RF_MCPair_t *), init_mcpair); 109 return (0); 110 } 111 112 RF_MCPair_t * 113 rf_AllocMCPair() 114 { 115 RF_MCPair_t *t; 116 117 RF_FREELIST_GET_INIT(rf_mcpair_freelist, t, next, (RF_MCPair_t *), init_mcpair); 118 if (t) { 119 t->flag = 0; 120 t->next = NULL; 121 } 122 return (t); 123 } 124 125 void 126 rf_FreeMCPair(t) 127 RF_MCPair_t *t; 128 { 129 RF_FREELIST_FREE_CLEAN(rf_mcpair_freelist, t, next, clean_mcpair); 130 } 131 /* the callback function used to wake you up when you use an mcpair to wait for something */ 132 void 133 rf_MCPairWakeupFunc(mcpair) 134 RF_MCPair_t *mcpair; 135 { 136 RF_LOCK_MUTEX(mcpair->mutex); 137 mcpair->flag = 1; 138 #if 0 139 printf("MCPairWakeupFunc called!\n"); 140 #endif 141 wakeup(&(mcpair->flag));/* XXX Does this do anything useful!! GO */ 142 /* XXX Looks like the following is needed to truly get the 143 * functionality they were looking for here... This could be a 144 * side-effect of my using a tsleep in the NetBSD port though... XXX */ 145 wakeup(&(mcpair->cond));/* XXX XXX XXX GO */ 146 RF_UNLOCK_MUTEX(mcpair->mutex); 147 } 148