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annotate PrivateQueue.c @ 50:93a5782d064b

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adding netbeans project directories to repository
author Sean Halle <seanhalle@yahoo.com>
date Fri, 14 Feb 2014 07:54:22 -0800
parents 1ea30ca7093c
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rev   line source
Me@19 1 /*
seanhalle@44 2 * Copyright 2009 OpenSourceResearchInstitute.org
Me@19 3 * Licensed under GNU General Public License version 2
Me@19 4 *
Me@19 5 * NOTE: this version of SRSW correct as of April 25, 2010
Me@19 6 *
Me@19 7 * Author: seanhalle@yahoo.com
Me@19 8 */
Me@19 9
Me@19 10
Me@19 11 #include <stdio.h>
Me@19 12 #include <string.h>
Me@19 13 #include <errno.h>
Me@19 14 #include <stdlib.h>
Me@19 15
Me@19 16 #include "PrivateQueue.h"
seanhalle@49 17 #include <PR__include/prqueue.h>
seanhalle@49 18 #include <PR__include/prmalloc.h>
Me@19 19
Me@19 20
Me@19 21
Me@19 22 //===========================================================================
Me@19 23
Me@19 24 /*This kind of queue is private to a single core at a time -- has no
Me@19 25 * synchronizations
Me@19 26 */
Me@19 27
Me@19 28 PrivQueueStruc* makePrivQ()
Me@19 29 {
Me@19 30 PrivQueueStruc* retQ;
seanhalle@32 31 //This malloc is not safe to use in wrapper lib nor app code!
seanhalle@48 32 retQ = (PrivQueueStruc *) PR__malloc( sizeof( PrivQueueStruc ) );
Me@19 33
seanhalle@32 34 //This malloc is not safe to use in wrapper lib nor app code!
seanhalle@48 35 retQ->startOfData = PR__malloc( 1024 * sizeof(void *) );
Me@19 36 memset( retQ->startOfData, 0, 1024 * sizeof(void *) );
Me@19 37 retQ->extractPos = &(retQ->startOfData[0]); //side by side == empty
Me@19 38 retQ->insertPos = &(retQ->startOfData[1]); // so start pos's have to be
Me@19 39 retQ->endOfData = &(retQ->startOfData[1023]);
Me@19 40
Me@19 41 return retQ;
Me@19 42 }
Me@19 43
Me@19 44
seanhalle@44 45 /*A bit tricky, 'cause have to copy in two halves, and be careful about case
seanhalle@44 46 * when insert is at top and extract at bottom..
seanhalle@44 47 */
Me@19 48 void
Me@19 49 enlargePrivQ( PrivQueueStruc *Q )
seanhalle@35 50 { int32 oldSize, newSize, topPartSize, bottPartSize;
seanhalle@32 51 int8 *insertPos, *extractPos;
seanhalle@32 52 int8 *oldStartOfData, *oldEndOfData, *newStartOfData, *newEndOfData;
seanhalle@35 53 int32 insertOffsetBytes, extractOffsetBytes;
seanhalle@35 54 int8 *copyStartAddr;
Me@19 55
seanhalle@32 56 oldStartOfData = (int8 *)Q->startOfData;
seanhalle@32 57 oldEndOfData = (int8 *)Q->endOfData;
seanhalle@32 58 insertPos = (int8 *)Q->insertPos;
seanhalle@32 59 extractPos = (int8 *)Q->extractPos;
Me@19 60
seanhalle@32 61 //TODO: verify these get number of bytes correct
seanhalle@35 62 insertOffsetBytes = (int32)(insertPos - oldStartOfData);
seanhalle@35 63 extractOffsetBytes = (int32)(extractPos - oldStartOfData);
seanhalle@32 64
seanhalle@35 65 oldSize = oldEndOfData - oldStartOfData + 1; //in bytes
seanhalle@32 66 newSize = 2 * oldSize;
seanhalle@32 67
seanhalle@32 68 //This malloc is not safe to use in wrapper lib nor app code!
seanhalle@48 69 Q->startOfData = (void **)PR__malloc( newSize );
seanhalle@32 70 newStartOfData = (int8 *)Q->startOfData;
seanhalle@32 71 newEndOfData = newStartOfData + newSize; //all calcs in Bytes
seanhalle@32 72 Q->endOfData = (void **)newEndOfData;
seanhalle@32 73
seanhalle@32 74 //TODO: test all of this, for both cases
seanhalle@32 75
seanhalle@32 76 //Moving the data and pointers to the new array is
seanhalle@32 77 //a little trickier than at first it seems.. the top part
seanhalle@32 78 // of old queue must be moved to the top part of new queue, while
seanhalle@32 79 // bottom part of old to bottom part of new, then the new insert
seanhalle@32 80 // and extract positions calculated by offset from top and bottom
seanhalle@32 81 //UNLESS the one case where old extract was at bottom and insert
seanhalle@32 82 // was at top.
seanhalle@32 83 //TODO: check that this is correct!
seanhalle@35 84 if( extractPos == oldStartOfData && insertPos == oldEndOfData )
seanhalle@32 85 {
seanhalle@32 86 memcpy( newStartOfData, oldStartOfData, oldSize ); //oldSize is bytes
seanhalle@32 87 Q->extractPos = Q->startOfData; //start of valid data
seanhalle@32 88 Q->insertPos = Q->startOfData + oldSize - 1; //end of valid data
seanhalle@32 89 }
seanhalle@32 90 else //have to copy two parts separately, then calc positions
seanhalle@32 91 { //TODO: check end-addr, sizes, and new positions carefully
seanhalle@35 92
seanhalle@32 93 //copy top part, starting at extract up until end of data,
seanhalle@35 94 // into top of new array
seanhalle@32 95 topPartSize = oldEndOfData - extractPos + 1; //+1 includes extractPos
seanhalle@35 96 copyStartAddr = newEndOfData - topPartSize + 1;//+1 cancels other
seanhalle@32 97 memcpy( copyStartAddr, Q->extractPos, topPartSize );
seanhalle@35 98 Q->extractPos = (void **)copyStartAddr; //extract just-copied data
seanhalle@35 99
seanhalle@32 100 //copy bottom part, from old start up to old insert,
seanhalle@35 101 // into bottom of new array
seanhalle@32 102 bottPartSize = oldSize - topPartSize - 1; //-1 for empty insertPos
seanhalle@32 103 memcpy( newStartOfData, oldStartOfData, bottPartSize );
seanhalle@32 104 Q->insertPos = (void **)(newStartOfData + bottPartSize);
seanhalle@32 105 }
seanhalle@32 106 //This free is not safe to use in wrapper lib nor app code!
seanhalle@48 107 PR__free(oldStartOfData);
Me@19 108 }
Me@19 109
Me@19 110
seanhalle@37 111 /*Returns TRUE when queue is empty
seanhalle@37 112 */
seanhalle@37 113 bool32 isEmptyPrivQ( PrivQueueStruc* Q )
seanhalle@37 114 { void *out = 0;
seanhalle@37 115 void **startOfData = Q->startOfData;
seanhalle@37 116 void **endOfData = Q->endOfData;
seanhalle@37 117
seanhalle@37 118 void **insertPos = Q->insertPos;
seanhalle@37 119 void **extractPos = Q->extractPos;
seanhalle@37 120
seanhalle@37 121 //if not empty -- (extract is just below insert when empty)
seanhalle@37 122 if( insertPos - extractPos != 1 &&
seanhalle@37 123 !(extractPos == endOfData && insertPos == startOfData))
seanhalle@37 124 {
seanhalle@37 125 return FALSE;
seanhalle@37 126 }
seanhalle@37 127 //Q is empty
seanhalle@37 128 return TRUE;
seanhalle@37 129 }
seanhalle@37 130
seanhalle@37 131 /*Returns NULL when queue is empty
seanhalle@37 132 */
seanhalle@37 133 void* peekPrivQ( PrivQueueStruc* Q )
seanhalle@37 134 { void *out = 0;
seanhalle@37 135 void **startOfData = Q->startOfData;
seanhalle@37 136 void **endOfData = Q->endOfData;
seanhalle@37 137
seanhalle@37 138 void **insertPos = Q->insertPos;
seanhalle@37 139 void **extractPos = Q->extractPos;
seanhalle@37 140
seanhalle@37 141 //if not empty -- (extract is just below insert when empty)
seanhalle@37 142 if( insertPos - extractPos != 1 &&
seanhalle@37 143 !(extractPos == endOfData && insertPos == startOfData))
seanhalle@37 144 {
seanhalle@37 145 out = *(Q->extractPos);
seanhalle@37 146 return out;
seanhalle@37 147 }
seanhalle@37 148 //Q is empty
seanhalle@37 149 return NULL;
seanhalle@37 150 }
seanhalle@37 151
seanhalle@37 152
Me@19 153 /*Returns NULL when queue is empty
Me@19 154 */
Me@19 155 void* readPrivQ( PrivQueueStruc* Q )
Me@19 156 { void *out = 0;
Me@19 157 void **startOfData = Q->startOfData;
Me@19 158 void **endOfData = Q->endOfData;
Me@19 159
Me@19 160 void **insertPos = Q->insertPos;
Me@19 161 void **extractPos = Q->extractPos;
Me@19 162
Me@19 163 //if not empty -- (extract is just below insert when empty)
Me@19 164 if( insertPos - extractPos != 1 &&
Me@19 165 !(extractPos == endOfData && insertPos == startOfData))
Me@19 166 { //move before read
Me@19 167 if( extractPos == endOfData ) //write new pos exactly once, correctly
Me@19 168 { Q->extractPos = startOfData; //can't overrun then fix it 'cause
Me@19 169 } // other thread might read bad pos
Me@19 170 else
Me@19 171 { Q->extractPos++;
Me@19 172 }
Me@19 173 out = *(Q->extractPos);
Me@19 174 return out;
Me@19 175 }
Me@19 176 //Q is empty
Me@19 177 return NULL;
Me@19 178 }
Me@19 179
Me@19 180
Me@19 181 /*Expands the queue size automatically when it's full
Me@19 182 */
Me@19 183 void
Me@19 184 writePrivQ( void * in, PrivQueueStruc* Q )
Me@19 185 {
Me@19 186 void **startOfData = Q->startOfData;
Me@19 187 void **endOfData = Q->endOfData;
Me@19 188
Me@19 189 void **insertPos = Q->insertPos;
Me@19 190 void **extractPos = Q->extractPos;
Me@19 191
Me@19 192 tryAgain:
Me@19 193 //Full? (insert is just below extract when full)
Me@19 194 if( extractPos - insertPos != 1 &&
Me@19 195 !(insertPos == endOfData && extractPos == startOfData))
Me@19 196 { *(Q->insertPos) = in; //insert before move
Me@19 197 if( insertPos == endOfData ) //write new pos exactly once, correctly
Me@19 198 { Q->insertPos = startOfData;
Me@19 199 }
Me@19 200 else
Me@19 201 { Q->insertPos++;
Me@19 202 }
Me@19 203 return;
Me@19 204 }
Me@19 205 //Q is full
Me@19 206 enlargePrivQ( Q );
Me@19 207 goto tryAgain;
Me@19 208 }
Me@19 209
Me@19 210
Me@19 211 /*Returns false when the queue was full.
Me@19 212 * have option of calling make_larger_PrivQ to make more room, then try again
Me@19 213 */
seanhalle@35 214 bool32
seanhalle@35 215 writeIfSpacePrivQ( void * in, PrivQueueStruc* Q )
Me@19 216 {
Me@19 217 void **startOfData = Q->startOfData;
Me@19 218 void **endOfData = Q->endOfData;
Me@19 219
Me@19 220 void **insertPos = Q->insertPos;
Me@19 221 void **extractPos = Q->extractPos;
Me@19 222
Me@19 223 if( extractPos - insertPos != 1 &&
Me@19 224 !(insertPos == endOfData && extractPos == startOfData))
Me@19 225 { *(Q->insertPos) = in; //insert before move
Me@19 226 if( insertPos == endOfData ) //write new pos exactly once, correctly
Me@19 227 { Q->insertPos = startOfData;
Me@19 228 }
Me@19 229 else
Me@19 230 { Q->insertPos++;
Me@19 231 }
Me@19 232 return TRUE;
Me@19 233 }
Me@19 234 //Q is full
Me@19 235 return FALSE;
Me@19 236 }
seanhalle@27 237
seanhalle@32 238 int32
seanhalle@32 239 numInPrivQ( PrivQueueStruc *Q )
seanhalle@32 240 { int32 size, numIn;
seanhalle@32 241
seanhalle@32 242 if( Q->insertPos < Q->extractPos )
seanhalle@32 243 { //insert has wrapped around so numIn is:
seanhalle@32 244 // insertPos + size - extractPos -- Consider, is empty when
seanhalle@32 245 // extractPos = endOfData and insert = start -- correctly get zero
seanhalle@33 246 size = Q->endOfData - Q->startOfData + 1; //sz of 10 is 0..9
seanhalle@33 247 numIn = Q->insertPos - Q->extractPos + size - 1; //-1 bec insrt empty
seanhalle@32 248 }
seanhalle@32 249 else
seanhalle@32 250 {
seanhalle@33 251 numIn = Q->insertPos - Q->extractPos -1;//-1 bec insertPos empty
seanhalle@32 252 }
seanhalle@32 253 return numIn;
seanhalle@32 254 }
seanhalle@32 255
seanhalle@32 256
seanhalle@32 257 /*Treats queue as a stack -- no matter contents, if read done right after
seanhalle@32 258 * a push, then the pushed item is what comes out.
seanhalle@32 259 * Expands the queue size automatically when it's full.
seanhalle@32 260 */
seanhalle@32 261 void
seanhalle@32 262 pushPrivQ( void * in, PrivQueueStruc* Q )
seanhalle@32 263 {
seanhalle@32 264 while(1){
seanhalle@32 265 void **startOfData = Q->startOfData;
seanhalle@32 266 void **endOfData = Q->endOfData;
seanhalle@32 267
seanhalle@32 268 void **insertPos = Q->insertPos;
seanhalle@32 269 void **extractPos = Q->extractPos;
seanhalle@32 270
seanhalle@32 271 //Full? (insert is just below extract when full)
seanhalle@32 272 if( extractPos - insertPos != 1 &&
seanhalle@32 273 !(insertPos == endOfData && extractPos == startOfData))
seanhalle@32 274 { //insert -- but go backwards, inserting at read position then
seanhalle@32 275 // move read pos backwards
seanhalle@32 276 *(Q->extractPos) = in;
seanhalle@32 277 if( extractPos == startOfData ) //write new pos exactly once, correctly
seanhalle@32 278 { Q->extractPos = endOfData; //can't overrun then fix it 'cause
seanhalle@32 279 } // other thread might read bad pos
seanhalle@32 280 else
seanhalle@32 281 { Q->extractPos--;
seanhalle@32 282 }
seanhalle@32 283 return;
seanhalle@32 284 }
seanhalle@32 285 //Q is full
seanhalle@32 286 enlargePrivQ( Q );
seanhalle@32 287 }
seanhalle@32 288 }
seanhalle@32 289
seanhalle@32 290
seanhalle@44 291 /*NOTE: This free is not safe to use in wrapper lib nor app code
seanhalle@44 292 */
seanhalle@44 293 void
seanhalle@44 294 freePrivQ( PrivQueueStruc *Q )
seanhalle@44 295 {
seanhalle@44 296 //This free is not safe to use in wrapper lib nor app code!
seanhalle@48 297 PR__free( Q->startOfData );
seanhalle@48 298 PR__free( Q );
seanhalle@44 299 }