%!PS-Adobe-3.0 %%Creator: Windows PSCRIPT %%Title: Microsoft Word - TWOSTUT.ORI %%BoundingBox: 18 19 593 774 %%DocumentNeededResources: (atend) %%DocumentSuppliedResources: (atend) %%Pages: (atend) %%BeginResource: procset Win35Dict 3 1 /Win35Dict 290 dict def Win35Dict begin/bd{bind def}bind def/in{72 mul}bd/ed{exch def}bd/ld{load def}bd/tr/translate ld/gs/gsave ld/gr /grestore ld/M/moveto ld/L/lineto ld/rmt/rmoveto ld/rlt/rlineto ld /rct/rcurveto ld/st/stroke ld/n/newpath ld/sm/setmatrix ld/cm/currentmatrix ld/cp/closepath ld/ARC/arcn ld/TR{65536 div}bd/lj/setlinejoin ld/lc /setlinecap ld/ml/setmiterlimit ld/sl/setlinewidth ld/scignore false def/sc{scignore{pop pop pop}{0 index 2 index eq 2 index 4 index eq and{pop pop 255 div setgray}{3{255 div 3 1 roll}repeat setrgbcolor}ifelse}ifelse}bd /FC{bR bG bB sc}bd/fC{/bB ed/bG ed/bR ed}bd/HC{hR hG hB sc}bd/hC{ /hB ed/hG ed/hR ed}bd/PC{pR pG pB sc}bd/pC{/pB ed/pG ed/pR ed}bd/sM matrix def/PenW 1 def/iPen 5 def/mxF matrix def/mxE matrix 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(previous ) 190 SB 1101 923 140 (events ) 145 SB 1246 923 107 (have ) 112 SB 1358 923 234 (completed. ) 239 SB 1597 923 13 ( ) 18 SB 1615 923 163 (Neither ) 168 SB 1783 923 155 (TWOS ) 160 SB 1943 923 80 (nor ) 85 SB 2028 923 72 (any) 72 SB 300 981 116 (other ) 147 SB 447 981 224 (simulation ) 255 SB 702 981 146 (engine ) 177 SB 879 981 88 (that ) 119 SB 998 981 168 (extracts ) 200 SB 1198 981 235 (parallelism ) 267 SB 1465 981 63 (by ) 95 SB 1560 981 169 (running ) 201 SB 1761 981 180 (multiple ) 212 SB 1973 981 127 (events) 127 SB 300 1039 1128 (simultaneously can possibly speed up such a simulation.) 1128 SB 392 1097 108 (Poor ) 125 SB 517 1097 235 (parallelism ) 252 SB 769 1097 46 (is ) 63 SB 832 1097 157 (usually ) 174 SB 1006 1097 124 (much ) 141 SB 1147 1097 87 (less ) 105 SB 1252 1097 171 (obvious ) 189 SB 1441 1097 99 (than ) 117 SB 1558 1097 52 (in ) 70 SB 1628 1097 85 (this ) 103 SB 1731 1097 195 (example, ) 213 SB 1944 1097 77 (but ) 95 SB 2039 1097 61 (the) 61 SB 300 1155 516 (simulation designer must ) 517 SB 817 1155 124 (strive ) 125 SB 942 1155 52 (to ) 53 SB 995 1155 166 (provide ) 167 SB 1162 1155 124 (many ) 125 SB 1287 1155 140 (events ) 141 SB 1428 1155 88 (that ) 89 SB 1517 1155 82 (can ) 83 SB 1600 1155 60 (be ) 61 SB 1661 1155 222 (performed ) 223 SB 1884 1155 52 (in ) 53 SB 1937 1155 163 (parallel.) 163 SB 300 1213 96 (One ) 99 SB 399 1213 163 (method ) 166 SB 565 1213 55 (of ) 58 SB 623 1213 183 (encourag) 183 SB 806 1213 77 (ing ) 80 SB 886 1213 235 (parallelism ) 238 SB 1124 1213 46 (is ) 49 SB 1173 1213 52 (to ) 55 SB 1228 1213 69 (try ) 72 SB 1300 1213 52 (to ) 55 SB 1355 1213 193 (decouple ) 196 SB 1551 1213 74 (the ) 77 SB 1628 1213 154 (actions ) 157 SB 1785 1213 55 (of ) 59 SB 1844 1213 154 (objects ) 158 SB 2002 1213 98 (from) 98 SB 300 1271 628 (each other as much as possible.) 628 SB 392 1329 91 (The ) 95 SB 487 1329 182 (designer ) 186 SB 673 1329 110 (must ) 114 SB 787 1329 93 (also ) 97 SB 884 1329 60 (be ) 64 SB 948 1329 132 (aware ) 136 SB 1084 1329 88 (that ) 92 SB 1176 1329 263 (parallelizing ) 267 SB 1443 1329 74 (the ) 78 SB 1521 1329 133 (simula) 133 SB 1654 1329 91 (tion ) 95 SB 1749 1329 113 (itself ) 118 SB 1867 1329 99 (may ) 104 SB 1971 1329 77 (not ) 82 SB 2053 1329 47 (be) 47 SB 300 1387 173 (enough. ) 180 SB 480 1387 13 ( ) 20 SB 500 1387 47 (If ) 54 SB 554 1387 74 (the ) 81 SB 635 1387 113 (body ) 120 SB 755 1387 55 (of ) 62 SB 817 1387 74 (the ) 81 SB 898 1387 224 (simulation ) 231 SB 1129 1387 46 (is ) 53 SB 1182 1387 100 (paral) 100 SB 1282 1387 159 (lelized, ) 166 SB 1448 1387 77 (but ) 84 SB 1532 1387 74 (the ) 81 SB 1613 1387 266 (initialization ) 274 SB 1887 1387 46 (is ) 54 SB 1941 1387 90 (not, ) 98 SB 2039 1387 61 (the) 61 SB 300 1445 997 (early part of the simulation may run very slowly. ) 998 SB 1298 1445 13 ( ) 14 SB 1312 1445 47 (If ) 48 SB 1360 1445 63 (all ) 64 SB 1424 1445 80 (I/O ) 81 SB 1505 1445 139 (passes ) 140 SB 1645 1445 169 (through ) 170 SB 1815 1445 35 (a ) 36 SB 1851 1445 132 (single ) 133 SB 1984 1445 116 (point,) 116 SB 300 1503 74 (the ) 78 SB 378 1503 96 (lack ) 100 SB 478 1503 55 (of ) 59 SB 537 1503 299 (parallelization ) 303 SB 840 1503 55 (of ) 59 SB 899 1503 80 (I/O ) 84 SB 983 1503 99 (may ) 104 SB 1087 1503 107 (slow ) 112 SB 1199 1503 74 (the ) 79 SB 1278 1503 151 (system ) 156 SB 1434 1503 137 (down. ) 142 SB 1576 1503 13 ( ) 18 SB 1594 1503 47 (If ) 52 SB 1646 1503 63 (all ) 68 SB 1714 1503 210 (user-level ) 215 SB 1929 1503 171 (statistics) 171 SB 300 1561 1489 (are gathered at a single point, that bottleneck can cause poor performance.) 1489 SB 392 1619 223 (Generally, ) 234 SB 626 1619 240 (bottlenecks ) 251 SB 877 1619 74 (are ) 85 SB 962 1619 52 (to ) 63 SB 1025 1619 60 (be ) 71 SB 1096 1619 171 (avoided ) 182 SB 1278 1619 170 (because ) 181 SB 1459 1619 99 (they ) 111 SB 1570 1619 99 (tend ) 111 SB 1681 1619 52 (to ) 64 SB 1745 1619 243 (concentrate ) 255 SB 2000 1619 100 (large) 100 SB 300 1677 182 (amounts ) 189 SB 489 1677 55 (of ) 62 SB 551 1677 74 (the ) 81 SB 632 1677 263 (computation ) 270 SB 902 1677 91 (into ) 98 SB 1000 1677 121 (small ) 128 SB 1128 1677 182 (amounts ) 189 SB 1317 1677 55 (of ) 62 SB 1379 1677 226 (processing ) 234 SB 1613 1677 151 (power. ) 159 SB 1772 1677 13 ( ) 21 SB 1793 1677 91 (The ) 99 SB 1892 1677 208 (bottleneck) 208 SB 300 1735 172 (computa) 172 SB 472 1735 91 (tion ) 93 SB 565 1735 46 (is ) 49 SB 614 1735 110 (done ) 113 SB 727 1735 267 (sequentially, ) 270 SB 997 1735 130 (rather ) 133 SB 1130 1735 99 (than ) 102 SB 1232 1735 52 (in ) 55 SB 1287 1735 176 (parallel, ) 179 SB 1466 1735 85 (and ) 88 SB 1554 1735 85 (any ) 88 SB 1642 1735 135 (object ) 138 SB 1780 1735 88 (that ) 91 SB 1871 1735 176 (depends ) 179 SB 2050 1735 50 (on) 50 SB 300 1793 74 (the ) 90 SB 390 1793 143 (results ) 159 SB 549 1793 146 (cannot ) 162 SB 711 1793 165 (execute ) 181 SB 892 1793 191 (correctly ) 207 SB 1099 1793 52 (in ) 68 SB 1167 1793 163 (parallel ) 179 SB 1346 1793 105 (until ) 121 SB 1467 1793 74 (the ) 90 SB 1557 1793 215 (sequential ) 231 SB 1788 1793 263 (computation ) 279 SB 2067 1793 33 (is) 33 SB 300 1851 209 (complete. ) 219 SB 519 1851 13 ( ) 23 SB 542 1851 218 (Whenever ) 228 SB 770 1851 74 (the ) 84 SB 854 1851 182 (designer ) 192 SB 1046 1851 95 (sees ) 105 SB 1151 1851 60 (an ) 70 SB 1221 1851 135 (object ) 145 SB 1366 1851 88 (that ) 98 SB 1464 1851 110 (must ) 120 SB 1584 1851 146 (collect ) 157 SB 1741 1851 250 (information ) 261 SB 2002 1851 98 (from) 98 SB 300 1909 124 (many ) 139 SB 439 1909 154 (objects ) 169 SB 608 1909 141 (before ) 156 SB 764 1909 41 (it ) 56 SB 820 1909 82 (can ) 97 SB 917 1909 202 (distribute ) 217 SB 1134 1909 143 (results ) 158 SB 1292 1909 52 (to ) 68 SB 1360 1909 124 (many ) 140 SB 1500 1909 116 (other ) 132 SB 1632 1909 167 (objects, ) 183 SB 1815 1909 60 (he ) 76 SB 1891 1909 146 (should ) 162 SB 2053 1909 47 (be) 47 SB 300 1967 1045 (suspicious of a bottleneck. The designer should try ) 1046 SB 1346 1967 52 (to ) 53 SB 1399 1967 221 (parallelize ) 222 SB 1621 1967 104 (such ) 105 SB 1726 1967 240 (algorithms, ) 241 SB 1967 1967 57 (so ) 58 SB 2025 1967 75 (that) 75 SB 300 2025 124 (many ) 127 SB 427 2025 154 (objects ) 157 SB 584 2025 224 (participate ) 227 SB 811 2025 52 (in ) 55 SB 866 2025 226 (processing ) 229 SB 1095 2025 74 (the ) 78 SB 1173 2025 250 (information ) 254 SB 1427 2025 63 (on ) 67 SB 1494 2025 154 (several ) 158 SB 1652 2025 129 (nodes ) 133 SB 1785 2025 315 (simultaneously.) 315 SB 300 2083 353 (Object behaviors ) 354 SB 654 2083 88 (that ) 89 SB 743 2083 130 (might ) 131 SB 874 2083 123 (cause ) 124 SB 998 2083 240 (bottlenecks ) 241 SB 1239 2083 160 (include ) 161 SB 1400 2083 127 (doing ) 128 SB 1528 2083 124 (much ) 125 SB 1653 2083 116 (more ) 117 SB 1770 2083 99 (than ) 100 SB 1870 2083 74 (the ) 75 SB 1945 2083 155 (average) 155 SB 300 2141 163 (amount ) 180 SB 480 2141 55 (of ) 72 SB 552 2141 276 (computation, ) 293 SB 845 2141 55 (or ) 73 SB 918 2141 152 (storing ) 170 SB 1088 2141 74 (the ) 92 SB 1180 2141 102 (only ) 120 SB 1300 2141 110 (copy ) 128 SB 1428 2141 55 (of ) 73 SB 1501 2141 113 (large ) 131 SB 1632 2141 182 (amounts ) 200 SB 1832 2141 55 (of ) 73 SB 1905 2141 195 (important) 195 SB 300 2199 1501 (information, or including lots of code that is expected to be run very often.) 1501 SB 392 2257 1040 (Another manifestation of poor parallelism is a long ) 1041 SB 1433 2257 152 (critical ) 153 SB 1586 2257 112 (path. ) 113 SB 1699 2257 13 ( ) 14 SB 1713 2257 91 (The ) 92 SB 1805 2257 152 (critical ) 153 SB 1958 2257 99 (path ) 100 SB 2058 2257 42 (of) 42 SB 300 2315 35 (a ) 48 SB 348 2315 224 (simulation ) 237 SB 585 2315 46 (is ) 59 SB 644 2315 74 (the ) 87 SB 731 2315 157 (longest ) 170 SB 901 2315 69 (\(in ) 82 SB 983 2315 207 (execution ) 220 SB 1203 2315 119 (time\) ) 132 SB 1335 2315 195 (sequence ) 208 SB 1543 2315 55 (of ) 68 SB 1611 2315 140 (events ) 153 SB 1764 2315 88 (that ) 102 SB 1866 2315 107 (have ) 121 SB 1987 2315 52 (to ) 66 SB 2053 2315 47 (be) 47 SB 300 2373 222 (performed ) 227 SB 527 2373 267 (sequentially. ) 272 SB 799 2373 13 ( ) 18 SB 817 2373 49 (A ) 54 SB 871 2373 97 (simu) 97 SB 968 2373 127 (lation ) 132 SB 1100 2373 99 (may ) 104 SB 1204 2373 60 (be ) 65 SB 1269 2373 109 (able, ) 115 SB 1384 2373 52 (in ) 58 SB 1442 2373 154 (theory, ) 160 SB 1602 2373 52 (to ) 58 SB 1660 2373 107 (have ) 113 SB 1773 2373 91 (half ) 97 SB 1870 2373 55 (of ) 61 SB 1931 2373 60 (its ) 66 SB 1997 2373 103 (work) 103 SB 300 2431 262 (done in paral) 262 SB 562 2431 1538 (lel, but if the critical path makes up the other half of the work, no simulation) 1538 SB 300 2489 146 (engine ) 148 SB 448 2489 82 (can ) 84 SB 532 2489 126 (speed ) 128 SB 660 2489 41 (it ) 43 SB 703 2489 63 (up ) 66 SB 769 2489 63 (by ) 66 SB 835 2489 116 (more ) 119 SB 954 2489 99 (than ) 102 SB 1056 2489 35 (a ) 38 SB 1094 2489 130 (factor ) 133 SB 1227 2489 55 (of ) 58 SB 1285 2489 101 (two. ) 104 SB 1389 2489 91 (The ) 94 SB 1483 2489 133 (simula) 133 SB 1616 2489 91 (tion ) 94 SB 1710 2489 130 (design) 130 SB 1840 2489 52 (er ) 55 SB 1895 2489 146 (should ) 149 SB 2044 2489 56 (try) 56 SB 300 2547 52 (to ) 62 SB 362 2547 190 (visualize ) 200 SB 562 2547 74 (the ) 84 SB 646 2547 105 (flow ) 115 SB 761 2547 55 (of ) 66 SB 827 2547 140 (events ) 151 SB 978 2547 52 (in ) 63 SB 1041 2547 71 (his ) 82 SB 1123 2547 97 (simu) 97 SB 1220 2547 127 (lation ) 138 SB 1358 2547 54 (as ) 65 SB 1423 2547 35 (a ) 46 SB 1469 2547 127 (graph ) 138 SB 1607 2547 55 (of ) 66 SB 1673 2547 140 (events ) 151 SB 1824 2547 215 (connected ) 226 SB 2050 2547 50 (by) 50 SB 300 2605 294 (dependencies. ) 301 SB 601 2605 13 ( ) 20 SB 621 2605 69 (To ) 76 SB 697 2605 74 (get ) 81 SB 778 2605 113 (good ) 120 SB 898 2605 100 (paral) 100 SB 998 2605 63 (lel ) 70 SB 1068 2605 279 (performance, ) 286 SB 1354 2605 35 (a ) 42 SB 1396 2605 140 (broad, ) 148 SB 1544 2605 113 (short ) 121 SB 1665 2605 127 (graph ) 135 SB 1800 2605 46 (is ) 54 SB 1854 2605 124 (much ) 132 SB 1986 2605 114 (better) 114 SB 300 2663 313 (than a long, nar) 313 SB 613 2663 218 (row graph.) 218 SB 392 2721 138 (Under ) 139 SB 531 2721 149 (certain ) 150 SB 681 2721 308 (circumstances, ) 309 SB 990 2721 155 (TWOS ) 157 SB 1147 2721 82 (can ) 84 SB 1231 2721 96 (beat ) 98 SB 1329 2721 74 (the ) 76 SB 1405 2721 152 (critical ) 154 SB 1559 2721 99 (path ) 101 SB 1660 2721 189 (speedup. ) 191 SB 1851 2721 13 ( ) 15 SB 1866 2721 74 (No ) 76 SB 1942 2721 158 (realistic) 158 SB 300 2779 235 (application ) 237 SB 537 2779 80 (run ) 82 SB 619 2779 63 (on ) 66 SB 685 2779 155 (TWOS ) 158 SB 843 2779 79 (has ) 82 SB 925 2779 99 (ever ) 102 SB 1027 2779 110 (done ) 113 SB 1140 2779 70 (so, ) 73 SB 1213 2779 85 (and ) 88 SB 1301 2779 74 (the ) 77 SB 1378 2779 295 (circumstances ) 298 SB 1676 2779 206 (necessary ) 209 SB 1885 2779 52 (to ) 55 SB 1940 2779 96 (beat ) 99 SB 2039 2779 61 (the) 61 SB 300 2837 402 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1316 401 104 (does ) 107 SB 1423 401 77 (not ) 80 SB 1503 401 157 (depend ) 160 SB 1663 401 63 (on ) 66 SB 1729 401 163 (explicit ) 166 SB 1895 401 205 (lookahead) 205 SB 300 459 1154 (information either for correctness or performance. None ) 1155 SB 1455 459 74 (the ) 75 SB 1530 459 100 (less, ) 101 SB 1631 459 149 (having ) 150 SB 1781 459 113 (good ) 114 SB 1895 459 205 (lookahead) 205 SB 300 517 213 (properties ) 225 SB 525 517 91 (will ) 103 SB 628 517 216 (contribute ) 228 SB 856 517 52 (to ) 64 SB 920 517 74 (the ) 86 SB 1006 517 266 (performance ) 278 SB 1284 517 55 (of ) 68 SB 1352 517 35 (a ) 48 SB 1400 517 155 (TWOS ) 168 SB 1568 517 248 (application. ) 261 SB 1829 517 13 ( ) 26 SB 1855 517 146 (Rather ) 159 SB 2014 517 86 (than) 86 SB 300 575 202 (explicitly ) 205 SB 505 575 244 (quantifying ) 247 SB 752 575 74 (the ) 77 SB 829 575 118 (exact ) 122 SB 951 575 163 (amount ) 167 SB 1118 575 55 (of ) 59 SB 1177 575 231 (lookahead, ) 235 SB 1412 575 198 (however, ) 202 SB 1614 575 74 (the ) 78 SB 1692 575 235 (application ) 239 SB 1931 575 169 (designer) 169 SB 300 633 146 (should ) 157 SB 457 633 85 (just ) 96 SB 553 633 99 (bear ) 110 SB 663 633 52 (in ) 63 SB 726 633 116 (mind ) 127 SB 853 633 88 (that ) 99 SB 952 633 218 (lookahead ) 229 SB 1181 633 46 (is ) 57 SB 1238 633 97 (desir) 97 SB 1335 633 96 (able ) 107 SB 1442 633 85 (and ) 96 SB 1538 633 69 (try ) 80 SB 1618 633 52 (to ) 64 SB 1682 633 121 (make ) 133 SB 1815 633 198 (decisions ) 210 SB 2025 633 75 (that) 75 SB 300 691 210 (maximize ) 231 SB 531 691 231 (lookahead. ) 252 SB 783 691 13 ( ) 35 SB 818 691 155 (TWOS ) 177 SB 995 691 91 (will ) 113 SB 1108 691 285 (automatically ) 307 SB 1415 691 149 (extract ) 171 SB 1586 691 176 (speedup ) 198 SB 1784 691 111 (from ) 133 SB 1917 691 183 (whatever) 183 SB 300 749 659 (lookahead the designer included.) 659 SB 392 807 160 (Certain ) 174 SB 566 807 118 (types ) 132 SB 698 807 55 (of ) 69 SB 767 807 188 (behavior ) 202 SB 969 807 74 (are ) 88 SB 1057 807 216 (inherently ) 230 SB 1287 807 228 (sequential, ) 242 SB 1529 807 85 (and ) 99 SB 1628 807 216 (contribute ) 230 SB 1858 807 52 (to ) 67 SB 1925 807 175 (reducing) 175 SB 300 865 764 (parallelism. For instance, queries are ) 765 SB 1065 865 103 (inher) 103 SB 1168 865 113 (ently ) 114 SB 1282 865 228 (sequential. ) 229 SB 1511 865 13 ( ) 14 SB 1525 865 47 (If ) 48 SB 1573 865 135 (object ) 136 SB 1709 865 49 (A ) 50 SB 1759 865 98 (asks ) 99 SB 1858 865 135 (object ) 136 SB 1994 865 46 (B ) 47 SB 2041 865 59 (for) 59 SB 300 923 35 (a ) 38 SB 338 923 118 (piece ) 121 SB 459 923 55 (of ) 58 SB 517 923 159 (informa) 159 SB 676 923 104 (tion, ) 107 SB 783 923 85 (and ) 89 SB 872 923 135 (object ) 139 SB 1011 923 49 (A ) 53 SB 1064 923 146 (cannot ) 150 SB 1214 923 63 (do ) 67 SB 1281 923 85 (any ) 89 SB 1370 923 135 (useful ) 139 SB 1509 923 61 (wo) 61 SB 1570 923 55 (rk ) 59 SB 1629 923 105 (until ) 109 SB 1738 923 135 (object ) 139 SB 1877 923 46 (B ) 50 SB 1927 923 173 (answers,) 173 SB 300 981 113 (there ) 115 SB 415 981 46 (is ) 48 SB 463 981 63 (no ) 65 SB 528 981 151 (chance ) 153 SB 681 981 55 (of ) 57 SB 738 981 49 (A ) 51 SB 789 981 85 (and ) 87 SB 876 981 46 (B ) 48 SB 924 981 207 (executing ) 209 SB 1133 981 52 (in ) 55 SB 1188 981 163 (parallel ) 166 SB 1354 981 105 (until ) 108 SB 1462 981 74 (the ) 77 SB 1539 981 127 (query ) 130 SB 1669 981 116 (reply ) 119 SB 1788 981 140 (comes ) 143 SB 1931 981 169 (through.) 169 SB 300 1039 91 (The ) 95 SB 395 1039 127 (query ) 131 SB 526 1039 46 (is ) 50 SB 576 1039 35 (a ) 39 SB 615 1039 102 (very ) 106 SB 721 1039 191 (tempting ) 196 SB 917 1039 209 (construct, ) 214 SB 1131 1039 54 (as ) 59 SB 1190 1039 41 (it ) 46 SB 1236 1039 46 (is ) 51 SB 1287 1039 149 (widely ) 154 SB 1441 1039 104 (used ) 109 SB 1550 1039 52 (in ) 57 SB 1607 1039 215 (sequential ) 220 SB 1827 1039 273 (programming) 273 SB 300 1097 85 (and ) 86 SB 386 1097 162 (appeals ) 163 SB 549 1097 52 (to ) 53 SB 602 1097 132 (users\222 ) 133 SB 735 1097 78 (intu) 78 SB 813 1097 137 (itions. ) 138 SB 951 1097 13 ( ) 15 SB 966 1097 55 (In ) 57 SB 1023 1097 118 (some ) 120 SB 1143 1097 130 (cases, ) 132 SB 1275 1097 41 (it ) 43 SB 1318 1097 46 (is ) 48 SB 1366 1097 74 (the ) 76 SB 1442 1097 102 (only ) 104 SB 1546 1097 152 (natural ) 154 SB 1700 1097 154 (option. ) 156 SB 1856 1097 13 ( ) 15 SB 1871 1097 85 (But ) 87 SB 1958 1097 142 (TWOS) 142 SB 300 1155 403 (designers \(and paral) 403 SB 703 1155 1331 (lel designers, in general\) should take care to use queries sparingly.) 1331 SB 392 1213 212 (Designers ) 216 SB 608 1213 146 (should ) 150 SB 758 1213 93 (also ) 98 SB 856 1213 182 (consider ) 187 SB 1043 1213 196 (changing ) 201 SB 1244 1213 227 (algorithms ) 232 SB 1476 1213 88 (that ) 93 SB 1569 1213 155 (require ) 160 SB 1729 1213 35 (a ) 40 SB 1769 1213 113 (large ) 118 SB 1887 1213 166 (number ) 171 SB 2058 1213 42 (of) 42 SB 300 1271 1265 (objects to be consulted before a decision can be made. If each ) 1266 SB 1566 1271 135 (object ) 136 SB 1702 1271 46 (is ) 47 SB 1749 1271 93 (sent ) 94 SB 1843 1271 35 (a ) 36 SB 1879 1271 181 (message ) 182 SB 2061 1271 39 (in) 39 SB 300 1329 107 (turn, ) 108 SB 408 1329 127 (doing ) 128 SB 536 1329 60 (its ) 61 SB 597 1329 116 (work ) 117 SB 714 1329 85 (and ) 87 SB 801 1329 168 (sending ) 170 SB 971 1329 74 (the ) 76 SB 1047 1329 181 (message ) 183 SB 1230 1329 63 (on ) 65 SB 1295 1329 52 (to ) 54 SB 1349 1329 74 (the ) 76 SB 1425 1329 99 (next ) 101 SB 1526 1329 135 (object ) 137 SB 1663 1329 52 (in ) 54 SB 1717 1329 208 (sequence, ) 210 SB 1927 1329 99 (then ) 101 SB 2028 1329 72 (this) 72 SB 300 1387 158 (portion ) 164 SB 464 1387 55 (of ) 61 SB 525 1387 74 (the ) 81 SB 606 1387 152 (overall ) 159 SB 765 1387 263 (computation ) 270 SB 1035 1387 46 (is ) 53 SB 1088 1387 141 (highly ) 148 SB 1236 1387 228 (sequential. ) 235 SB 1471 1387 13 ( ) 20 SB 1491 1387 91 (The ) 98 SB 1589 1387 182 (designer ) 189 SB 1778 1387 146 (should ) 153 SB 1931 1387 169 (examine) 169 SB 300 1445 174 (whether ) 179 SB 479 1445 154 (several ) 159 SB 638 1445 55 (of ) 60 SB 698 1445 74 (the ) 79 SB 777 1445 154 (objects ) 159 SB 936 1445 82 (can ) 88 SB 1024 1445 63 (do ) 69 SB 1093 1445 105 (their ) 111 SB 1204 1445 181 (subtasks ) 187 SB 1391 1445 52 (in ) 58 SB 1449 1445 176 (parallel, ) 182 SB 1631 1445 166 (without ) 172 SB 1803 1445 163 (waiting ) 169 SB 1972 1445 72 (for ) 78 SB 2050 1445 50 (all) 50 SB 300 1503 988 (previous stages of the algorithm completing first.) 988 SB 392 1561 47 (If ) 51 SB 443 1561 35 (a ) 39 SB 482 1561 149 (certain ) 153 SB 635 1561 118 (piece ) 122 SB 757 1561 55 (of ) 59 SB 816 1561 96 (data ) 100 SB 916 1561 46 (is ) 50 SB 966 1561 127 (likely ) 131 SB 1097 1561 52 (to ) 56 SB 1153 1561 60 (be ) 64 SB 1217 1561 204 (consulted ) 208 SB 1425 1561 124 (many ) 128 SB 1553 1561 134 (times, ) 138 SB 1691 1561 55 (or ) 59 SB 1750 1561 63 (by ) 67 SB 1817 1561 124 (many ) 129 SB 1946 1561 154 (objects,) 154 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(machines\) ) 227 SB 1144 923 85 (and ) 94 SB 1238 923 154 (several ) 163 SB 1401 923 135 (useful ) 144 SB 1545 923 185 (software ) 194 SB 1739 923 110 (tools ) 119 SB 1858 923 72 (for ) 81 SB 1939 923 161 (creating) 161 SB 300 981 190 (balanced ) 200 SB 500 981 283 (configuration ) 293 SB 793 981 99 (files ) 110 SB 903 981 85 (and ) 96 SB 999 981 146 (testing ) 157 SB 1156 981 85 (and ) 96 SB 1252 981 265 (compressing ) 276 SB 1528 981 74 (the ) 85 SB 1613 981 143 (results ) 154 SB 1767 981 55 (of ) 66 SB 1833 981 35 (a ) 46 SB 1879 981 93 (run. ) 104 SB 1983 981 117 (Three) 117 SB 300 1039 144 (applica) 144 SB 444 1039 110 (tions ) 119 SB 563 1039 74 (are ) 83 SB 646 1039 93 (also ) 102 SB 748 1039 198 (included. ) 207 SB 955 1039 13 ( ) 23 SB 978 1039 96 (One ) 106 SB 1084 1039 46 (is ) 56 SB 1140 1039 35 (a ) 45 SB 1185 1039 163 (slightly ) 173 SB 1358 1039 116 (more ) 126 SB 1484 1039 185 (complex ) 195 SB 1679 1039 160 (version ) 170 SB 1849 1039 55 (of ) 65 SB 1914 1039 115 (ping, ) 125 SB 2039 1039 61 (the) 61 SB 300 1097 1275 (application shown in figure 2. The second is the game of Life. ) 1276 SB 1576 1097 13 ( ) 14 SB 1590 1097 91 (The ) 92 SB 1682 1097 108 (third ) 109 SB 1791 1097 46 (is ) 47 SB 1838 1097 132 (called ) 133 SB 1971 1097 129 (pucks,) 129 SB 300 1155 263 (and is a simu) 263 SB 563 1155 270 (lation of two ) 271 SB 834 1155 125 (dimen) 125 SB 959 1155 132 (sional ) 133 SB 1092 1155 235 (frictionless ) 236 SB 1328 1155 129 (pucks ) 130 SB 1458 1155 166 (moving ) 167 SB 1625 1155 85 (and ) 86 SB 1711 1155 191 (colliding ) 192 SB 1903 1155 63 (on ) 64 SB 1967 1155 35 (a ) 36 SB 2003 1155 97 (table) 97 SB 300 1213 193 (with cush) 193 SB 493 1213 877 (ions [Hontalas and Beckman 1989]. 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Each node only hosts some of the components of the simulation, however.) 1722 SB 392 2147 126 (Users ) 136 SB 528 2147 207 (designing ) 217 SB 745 2147 243 (simulations ) 253 SB 998 2147 72 (for ) 82 SB 1080 2147 155 (TWOS ) 165 SB 1245 2147 237 (decompose ) 247 SB 1492 2147 113 (them ) 124 SB 1616 2147 91 (into ) 102 SB 1718 2147 167 (objects. ) 178 SB 1896 2147 13 ( ) 24 SB 1920 2147 144 (Figure ) 155 SB 2075 2147 25 (3) 25 SB 300 2205 945 (shows a TWOS object in its internal representa) 945 SB 1245 2205 104 (tion. ) 105 SB 1350 2205 13 ( ) 14 SB 1364 2205 44 (It ) 45 SB 1409 2205 170 (consists ) 171 SB 1580 2205 55 (of ) 56 SB 1636 2205 60 (an ) 61 SB 1697 2205 135 (object ) 136 SB 1833 2205 155 (control ) 156 SB 1989 2205 111 (block) 111 SB 300 2263 162 (\(OCB\), ) 168 SB 468 2263 35 (a ) 41 SB 509 2263 132 (queue ) 138 SB 647 2263 55 (of ) 61 SB 708 2263 116 (input ) 122 SB 830 2263 213 (messages, ) 219 SB 1049 2263 35 (a ) 41 SB 1090 2263 132 (queue ) 138 SB 1228 2263 55 (of ) 61 SB 1289 2263 141 (output ) 147 SB 1436 2263 213 (messages, ) 219 SB 1655 2263 85 (and ) 91 SB 1746 2263 35 (a ) 41 SB 1787 2263 132 (queue ) 138 SB 1925 2263 55 (of ) 62 SB 1987 2263 113 (saved) 113 SB 300 2321 136 (states. ) 138 SB 438 2321 13 ( ) 15 SB 453 2321 91 (The ) 93 SB 546 2321 155 (control ) 157 SB 703 2321 124 (block ) 126 SB 829 2321 129 (stores ) 131 SB 960 2321 250 (information ) 252 SB 1212 2321 124 (about ) 126 SB 1338 2321 74 (the ) 76 SB 1414 2321 148 (object, ) 150 SB 1564 2321 104 (such ) 106 SB 1670 2321 54 (as ) 56 SB 1726 2321 60 (its ) 63 SB 1789 2321 121 (name ) 124 SB 1913 2321 85 (and ) 88 SB 2001 2321 99 (type,) 99 SB 300 2379 85 (and ) 87 SB 387 2379 174 (pointers ) 176 SB 563 2379 52 (to ) 54 SB 617 2379 74 (the ) 76 SB 693 2379 116 (other ) 118 SB 811 2379 164 (queues. ) 166 SB 977 2379 13 ( ) 16 SB 993 2379 91 (The ) 94 SB 1087 2379 116 (input ) 119 SB 1206 2379 132 (queue ) 135 SB 1341 2379 179 (contains ) 182 SB 1523 2379 200 (messages ) 203 SB 1726 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55 (of ) 59 SB 359 2553 74 (the ) 78 SB 437 2553 166 (internal ) 170 SB 607 2553 104 (state ) 108 SB 715 2553 193 (variables ) 197 SB 912 2553 55 (of ) 59 SB 971 2553 74 (the ) 78 SB 1049 2553 148 (object, ) 152 SB 1201 2553 102 (with ) 106 SB 1307 2553 85 (one ) 89 SB 1396 2553 110 (copy ) 114 SB 1510 2553 77 (per ) 81 SB 1591 2553 121 (event ) 126 SB 1717 2553 74 (the ) 79 SB 1796 2553 135 (object ) 140 SB 1936 2553 79 (has ) 84 SB 2020 2553 80 (run,) 80 SB 300 2611 655 (ordered by the time of the event.) 655 SB 1 #C statusdict begin /manualfeed false store end EJ RS %%PageTrailer %%PageResources: font Times-Bold %%+ font Times-Roman %%Page: 11 11 %%PageResources: (atend) SS 0 0 25 25 798 1100 300 SM 1 lc 1 lj 0 0 0 pC 6 4 SP 255 255 255 fC /fm 256 def 1141 315 1432 606 56 56 RR 1 F S n 0 lc 0 lj /fm 256 def 132 145 1008 373 B 1 F S n /fm 256 def 132 57 1008 373 B 1 F S n /fm 256 def 129 145 749 373 B 1 F S n /fm 256 def 129 57 749 373 B 1 F S n /fm 256 def 128 145 879 373 B 1 F S n /fm 256 def 128 57 879 373 B 1 F S n /fm 256 def 195 146 1170 606 B 1 F S n /fm 256 def 133 58 1170 606 B 1 F S n /fm 256 def 195 146 1366 606 B 1 F S n /fm 256 def 133 58 1366 606 B 1 F S n /fm 256 def 196 146 974 606 B 1 F S n /fm 256 def 133 58 974 606 B 1 F S n /fm 256 def 129 145 1566 373 B 1 F S n /fm 256 def 129 57 1566 373 B 1 F S n /fm 256 def 133 145 1433 373 B 1 F S n /fm 256 def 133 57 1433 373 B 1 F S n 32 0 0 50 50 0 0 0 45 /Times-Roman /font32 ANSIFont font 0 0 0 fC gs 1013 713 739 225 CB 1581 371 100 (1800) 100 SB gr gs 1013 713 739 225 CB 1452 371 100 (1800) 100 SB gr gs 1013 713 739 225 CB 1031 371 100 (2209) 100 SB gr gs 1013 713 739 225 CB 893 371 100 (1800) 100 SB gr gs 1013 713 739 225 CB 764 371 100 (1500) 100 SB gr gs 1013 713 739 225 CB 1393 604 100 (1800) 100 SB gr gs 1013 713 739 225 CB 1198 604 100 (1500) 100 SB gr gs 1013 713 739 225 CB 993 604 100 (1200) 100 SB gr 32 0 0 50 50 0 0 0 46 /Times-Bold /font29 ANSIFont font gs 1013 713 739 225 CB 797 271 272 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SB 427 1413 105 (field ) 109 SB 536 1413 52 (in ) 56 SB 592 1413 74 (the ) 78 SB 670 1413 171 (object\222s ) 175 SB 845 1413 155 (control ) 159 SB 1004 1413 124 (block ) 128 SB 1132 1413 46 (is ) 50 SB 1182 1413 68 (set ) 72 SB 1254 1413 52 (to ) 56 SB 1310 1413 171 (indicate ) 175 SB 1485 1413 88 (that ) 92 SB 1577 1413 74 (the ) 78 SB 1655 1413 135 (object ) 139 SB 1794 1413 126 (needs ) 130 SB 1924 1413 52 (to ) 56 SB 1980 1413 80 (run ) 84 SB 2064 1413 36 (at) 36 SB 300 1471 102 (time ) 105 SB 405 1471 126 (2209. ) 129 SB 534 1471 13 ( ) 16 SB 550 1471 243 (Eventually, ) 246 SB 796 1471 74 (the ) 77 SB 873 1471 204 (scheduler ) 207 SB 1080 1471 72 (for ) 75 SB 1155 1471 74 (the ) 77 SB 1232 1471 110 (local ) 113 SB 1345 1471 110 (node ) 113 SB 1458 1471 91 (will ) 94 SB 1552 1471 213 (determine ) 217 SB 1769 1471 88 (that ) 92 SB 1861 1471 74 (the ) 78 SB 1939 1471 121 (event ) 125 SB 2064 1471 36 (at) 36 SB 300 1529 1136 (time 2209 is the earliest piece of work for any object on ) 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(events ) 142 SB 1753 1645 91 (will ) 93 SB 1846 1645 107 (need ) 109 SB 1955 1645 52 (to ) 54 SB 2009 1645 91 (send) 91 SB 300 1703 213 (messages. ) 215 SB 515 1703 13 ( ) 15 SB 530 1703 47 (If ) 49 SB 579 1703 85 (this ) 88 SB 667 1703 121 (event ) 124 SB 791 1703 46 (is ) 49 SB 840 1703 52 (to ) 55 SB 895 1703 104 (send ) 107 SB 1002 1703 35 (a ) 38 SB 1040 1703 194 (message, ) 197 SB 1237 1703 41 (it ) 44 SB 1281 1703 140 (makes ) 143 SB 1424 1703 35 (a ) 38 SB 1462 1703 157 (request ) 160 SB 1622 1703 52 (to ) 55 SB 1677 1703 168 (TWOS. ) 171 SB 1848 1703 13 ( ) 16 SB 1864 1703 155 (TWOS ) 158 SB 2022 1703 78 (will) 78 SB 300 1761 121 (make ) 124 SB 424 1761 88 (two ) 91 SB 515 1761 140 (copies ) 143 SB 658 1761 55 (of ) 59 SB 717 1761 74 (the ) 78 SB 795 1761 194 (message, ) 198 SB 993 1761 185 (identical ) 189 SB 1182 1761 52 (in ) 56 SB 1238 1761 63 (all ) 67 SB 1305 1761 115 (ways ) 119 SB 1424 1761 143 (except ) 147 SB 1571 1761 72 (for ) 76 SB 1647 1761 35 (a ) 39 SB 1686 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(is) 33 SB 300 2051 240 (no rollback.) 240 SB 392 2109 178 (Because ) 180 SB 572 2109 155 (TWOS ) 157 SB 729 2109 184 (executes ) 186 SB 915 2109 301 (optimistically, ) 303 SB 1218 2109 60 (its ) 62 SB 1280 2109 154 (objects ) 156 SB 1436 2109 99 (may ) 101 SB 1537 2109 185 (compute ) 187 SB 1724 2109 52 (in ) 54 SB 1778 2109 124 (error. ) 126 SB 1904 2109 13 ( ) 15 SB 1919 2109 118 (Once ) 120 SB 2039 2109 61 (the) 61 SB 300 2167 111 (error ) 113 SB 413 2167 46 (is ) 48 SB 461 2167 242 (discovered, ) 244 SB 705 2167 155 (TWOS ) 157 SB 862 2167 110 (must ) 112 SB 974 2167 83 (roll ) 85 SB 1059 2167 107 (back ) 109 SB 1168 2167 52 (to ) 54 SB 1222 2167 35 (a ) 37 SB 1259 2167 97 (simu) 97 SB 1356 2167 127 (lation ) 129 SB 1485 2167 102 (time ) 105 SB 1590 2167 141 (before ) 144 SB 1734 2167 74 (the ) 77 SB 1811 2167 111 (error ) 114 SB 1925 2167 175 (occurred) 175 SB 300 2225 1570 (and re-execute, correcting any mistakes made. 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2003 2341 97 (must) 97 SB 300 2399 160 (contain ) 163 SB 463 2399 77 (not ) 80 SB 543 2399 85 (just ) 88 SB 631 2399 117 (unpro) 117 SB 748 2399 142 (cessed ) 146 SB 894 2399 213 (messages, ) 217 SB 1111 2399 77 (but ) 81 SB 1192 2399 93 (also ) 97 SB 1289 2399 118 (some ) 122 SB 1411 2399 200 (messages ) 204 SB 1615 2399 88 (that ) 92 SB 1707 2399 107 (have ) 111 SB 1818 2399 107 (been ) 111 SB 1929 2399 171 (handled,) 171 SB 300 2457 115 (since ) 116 SB 416 2457 196 (rollbacks ) 197 SB 613 2457 99 (may ) 100 SB 713 2457 155 (require ) 156 SB 869 2457 106 (repro) 106 SB 975 2457 159 (cessing ) 160 SB 1135 2457 126 (them. ) 127 SB 1262 2457 13 ( ) 14 SB 1276 2457 199 (Handling ) 200 SB 1476 2457 196 (rollbacks ) 197 SB 1673 2457 93 (also ) 94 SB 1767 2457 174 (requires ) 175 SB 1942 2457 158 (keeping) 158 SB 300 2515 140 (copies ) 141 SB 441 2515 55 (of ) 56 SB 497 2515 200 (messages ) 201 SB 698 2515 85 (this ) 86 SB 784 2515 135 (object ) 136 SB 920 2515 79 (has ) 80 SB 1000 2515 106 (sent, ) 107 SB 1107 2515 135 (which ) 137 SB 1244 2515 46 (is ) 48 SB 1292 2515 74 (the ) 76 SB 1368 2515 171 (purpose ) 173 SB 1541 2515 55 (of ) 57 SB 1598 2515 74 (the ) 76 SB 1674 2515 141 (output ) 143 SB 1817 2515 145 (queue. ) 147 SB 1964 2515 13 ( ) 15 SB 1979 2515 47 (If ) 49 SB 2028 2515 72 (any) 72 SB 300 2573 55 (of ) 57 SB 357 2573 115 (these ) 117 SB 474 2573 200 (messages ) 202 SB 676 2573 110 (were ) 112 SB 788 2573 93 (sent ) 95 SB 883 2573 52 (in ) 54 SB 937 2573 124 (error, ) 127 SB 1064 2573 91 (part ) 94 SB 1158 2573 55 (of ) 58 SB 1216 2573 74 (the ) 77 SB 1293 2573 162 (process ) 165 SB 1458 2573 55 (of ) 58 SB 1516 2573 177 (rollback ) 180 SB 1696 2573 91 (will ) 94 SB 1790 2573 132 (detect ) 135 SB 1925 2573 74 (the ) 77 SB 2002 2573 98 (error) 98 SB 300 2631 85 (and ) 91 SB 391 2631 79 (use ) 85 SB 476 2631 74 (the ) 80 SB 556 2631 140 (copies ) 146 SB 702 2631 135 (stored ) 141 SB 843 2631 52 (in ) 59 SB 902 2631 74 (the ) 81 SB 983 2631 141 (output ) 148 SB 1131 2631 132 (queue ) 139 SB 1270 2631 52 (to ) 59 SB 1329 2631 140 (cancel ) 147 SB 1476 2631 74 (the ) 81 SB 1557 2631 236 (improperly ) 243 SB 1800 2631 93 (sent ) 100 SB 1900 2631 200 (messages.) 200 SB 300 2689 155 (TWOS ) 159 SB 459 2689 196 (rollbacks ) 200 SB 659 2689 110 (must ) 114 SB 773 2689 60 (be ) 64 SB 837 2689 96 (able ) 100 SB 937 2689 52 (to ) 56 SB 993 2689 113 (undo ) 117 SB 1110 2689 85 (any ) 90 SB 1200 2689 135 (action ) 140 SB 1340 2689 121 (taken ) 126 SB 1466 2689 63 (by ) 68 SB 1534 2689 140 (events ) 145 SB 1679 2689 110 (done ) 115 SB 1794 2689 249 (improperly. ) 254 SB 2048 2689 13 ( ) 18 SB 2066 2689 34 (If) 34 SB 300 2747 74 (the ) 77 SB 377 2747 177 (rollback ) 180 SB 557 2747 82 (can ) 85 SB 642 2747 113 (undo ) 116 SB 758 2747 85 (any ) 88 SB 846 2747 104 (such ) 107 SB 953 2747 148 (action, ) 151 SB 1104 2747 155 (TWOS ) 158 SB 1262 2747 82 (can ) 85 SB 1347 2747 60 (be ) 63 SB 1410 2747 232 (guaranteed ) 235 SB 1645 2747 102 (both ) 105 SB 1750 2747 52 (to ) 56 SB 1806 2747 121 (make ) 125 SB 1931 2747 169 (progress) 169 SB 300 2805 1027 (and to produce the same results as a sequential run.) 1027 SB 392 2863 144 (Figure ) 155 SB 547 2863 38 (4 ) 49 SB 596 2863 137 (shows ) 148 SB 744 2863 85 (one ) 96 SB 840 2863 182 (example ) 193 SB 1033 2863 55 (of ) 66 SB 1099 2863 35 (a ) 47 SB 1146 2863 190 (rollback. ) 202 SB 1348 2863 13 ( ) 25 SB 1373 2863 68 (As ) 80 SB 1453 2863 204 (described ) 216 SB 1669 2863 145 (above, ) 157 SB 1826 2863 135 (object ) 147 SB 1973 2863 49 (A ) 61 SB 2034 2863 66 (has) 66 SB 300 2921 190 (executed ) 193 SB 493 2921 49 (at ) 52 SB 545 2921 102 (time ) 105 SB 650 2921 126 (2209. ) 129 SB 779 2921 13 ( ) 16 SB 795 2921 108 (\(The ) 111 SB 906 2921 168 (shading ) 171 SB 1077 2921 63 (on ) 66 SB 1143 2921 116 (input ) 119 SB 1262 2921 132 (queue ) 135 SB 1397 2921 200 (messages ) 203 SB 1600 2921 52 (in ) 55 SB 1655 2921 133 (figure ) 136 SB 1791 2921 38 (4 ) 41 SB 1832 2921 190 (indicates ) 193 SB 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(positive copy sent to the receiver object.) 809 SB 1 lc 1 lj 0 0 0 pC 6 4 SP 255 255 255 fC /fm 256 def 1169 873 1447 1214 56 56 RR 1 F S n 0 lc 0 lj 0 0 0 hC /fm 1280 def <7ffff7ff7ffff7ff> p 120 170 1048 940 B 1 F S n /fm 1280 def 120 66 1048 940 B 1 F S n /fm 1280 def 124 170 798 940 B 1 F S n /fm 1280 def 124 66 798 940 B 1 F S n /fm 256 def 124 170 923 940 B 1 F S n /fm 256 def 124 66 923 940 B 1 F S n 0 0 0 hC /fm 1280 def <7ffff7ff7ffff7ff> p 120 170 677 940 B 1 F S n /fm 1280 def 120 66 677 940 B 1 F S n /fm 256 def 186 170 1115 1215 B 1 F S n /fm 256 def 124 66 1115 1215 B 1 F S n /fm 256 def 183 170 1302 1215 B 1 F S n /fm 256 def 124 66 1302 1215 B 1 F S n /fm 256 def 183 170 931 1215 B 1 F S n /fm 256 def 120 66 931 1215 B 1 F S n /fm 256 def 187 170 1485 1215 B 1 F S n /fm 256 def 125 66 1485 1215 B 1 F S n /fm 256 def 124 170 1573 940 B 1 F S n /fm 256 def 124 66 1573 940 B 1 F S n /fm 256 def 124 170 1448 940 B 1 F S n /fm 256 def 124 66 1448 940 B 1 F S n /fm 256 def gs 1158 667 667 863 CB 124 170 1698 940 B 1 F S n gr /fm 256 def gs 1158 667 667 863 CB 124 66 1698 940 B 1 F S n gr 32 0 0 50 50 0 0 0 45 /Times-Roman /font32 ANSIFont font 0 0 0 fC gs 1158 667 667 863 CB 688 946 100 (1500) 100 SB gr gs 1158 667 667 863 CB 809 946 100 (1800) 100 SB gr gs 1158 667 667 863 CB 934 946 100 (2038) 100 SB gr gs 1158 667 667 863 CB 1063 946 100 (2209) 100 SB gr gs 1158 667 667 863 CB 1463 946 100 (1800) 100 SB gr gs 1158 667 667 863 CB 1592 946 100 (1800) 100 SB gr gs 1158 667 667 863 CB 1713 946 100 (2209) 100 SB gr gs 1158 667 667 863 CB 946 1222 100 (1200) 100 SB gr gs 1158 667 667 863 CB 1129 1222 100 (1500) 100 SB gr gs 1158 667 667 863 CB 1317 1222 100 (1800) 100 SB gr gs 1158 667 667 863 CB 1500 1222 100 (2209) 100 SB gr 32 0 0 58 58 0 0 0 54 /Times-Bold /font29 ANSIFont font gs 1158 667 667 863 CB 1188 1455 224 (Object A) 224 SB gr 32 0 0 50 50 0 0 0 48 /Times-Bold /font29 ANSIFont font 822 1588 193 (Figure 4.) 193 SB 32 0 0 50 50 0 0 0 45 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1333 1999 135 (useful ) 138 SB 1471 1999 129 (work. ) 132 SB 1603 1999 13 ( ) 16 SB 1619 1999 44 (It ) 47 SB 1666 1999 82 (can ) 85 SB 1751 1999 60 (be ) 63 SB 1814 1999 143 (shown ) 146 SB 1960 1999 101 (that, ) 104 SB 2064 1999 36 (at) 36 SB 300 2057 85 (any ) 90 SB 390 2057 88 (real ) 93 SB 483 2057 102 (time ) 107 SB 590 2057 159 (instant, ) 164 SB 754 2057 118 (some ) 123 SB 877 2057 181 (message ) 187 SB 1064 2057 52 (in ) 58 SB 1122 2057 74 (the ) 80 SB 1202 2057 151 (system ) 157 SB 1359 2057 46 (is ) 52 SB 1411 2057 74 (the ) 80 SB 1491 2057 157 (earliest ) 163 SB 1654 2057 259 (unprocessed ) 265 SB 1919 2057 181 (message.) 181 SB 300 2115 124 (Since ) 130 SB 430 2115 200 (messages ) 207 SB 637 2115 146 (cannot ) 153 SB 790 2115 60 (be ) 67 SB 857 2115 93 (sent ) 100 SB 957 2115 207 (backward ) 214 SB 1171 2115 52 (in ) 59 SB 1230 2115 115 (time, ) 122 SB 1352 2115 85 (and ) 92 SB 1444 2115 102 (only ) 109 SB 1553 2115 200 (messages ) 207 SB 1760 2115 123 (cause ) 130 SB 1890 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SB 953 2089 74 (the ) 84 SB 1037 2089 179 (physical ) 189 SB 1226 2089 162 (address ) 172 SB 1398 2089 55 (of ) 65 SB 1463 2089 104 (each ) 114 SB 1577 2089 192 (segment, ) 202 SB 1779 2089 88 (real ) 98 SB 1877 2089 180 (memory ) 190 SB 2067 2089 33 (is) 33 SB 300 2147 193 (allocated ) 197 SB 497 2147 72 (for ) 76 SB 573 2147 35 (a ) 39 SB 612 2147 96 (new ) 101 SB 713 2147 160 (version ) 165 SB 878 2147 55 (of ) 60 SB 938 2147 74 (the ) 79 SB 1017 2147 179 (segment ) 184 SB 1201 2147 85 (and ) 90 SB 1291 2147 74 (the ) 79 SB 1370 2147 185 (previous ) 190 SB 1560 2147 179 (contents ) 184 SB 1744 2147 55 (of ) 60 SB 1804 2147 74 (the ) 79 SB 1883 2147 179 (segment ) 184 SB 2067 2147 33 (is) 33 SB 300 2205 146 (copied ) 151 SB 451 2205 91 (into ) 96 SB 547 2205 74 (the ) 79 SB 626 2205 96 (new ) 101 SB 727 2205 75 (allo) 75 SB 802 2205 148 (cation. ) 153 SB 955 2205 13 ( ) 18 SB 973 2205 124 (Since ) 129 SB 1102 2205 74 (the ) 79 SB 1181 2205 135 (object ) 140 SB 1321 2205 82 (can ) 87 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