src/mc/explo/odpor/Execution_test.cpp

   1 /* Copyright (c) 2017-2023. The SimGrid Team. All rights reserved.               */
   2
   3 /* This program is free software; you can redistribute it and/or modify it
   4  * under the terms of the license (GNU LGPL) which comes with this package. */
   5
   6 #include "src/3rd-party/catch.hpp"
   7 #include "src/mc/explo/odpor/Execution.hpp"
   8 #include "src/mc/explo/udpor/udpor_tests_private.hpp"
   9 #include "src/mc/transition/TransitionComm.hpp"
  10
  11 using namespace simgrid::mc;
  12 using namespace simgrid::mc::odpor;
  13 using namespace simgrid::mc::udpor;
  14
  15 TEST_CASE("simgrid::mc::odpor::Execution: Constructing Executions")
  16 {
  17   Execution execution;
  18   REQUIRE(execution.empty());
  19   REQUIRE(execution.size() == 0);
  20   REQUIRE_FALSE(execution.get_latest_event_handle().has_value());
  21 }
  22
  23 TEST_CASE("simgrid::mc::odpor::Execution: Testing Happens-Before")
  24 {
  25   SECTION("Example 1")
  26   {
  27     // We check each permutation for happens before
  28     // among the given actions added to the execution
  29     const auto a1 = std::make_shared<ConditionallyDependentAction>(Transition::Type::UNKNOWN, 1);
  30     const auto a2 = std::make_shared<IndependentAction>(Transition::Type::UNKNOWN, 2);
  31     const auto a3 = std::make_shared<IndependentAction>(Transition::Type::UNKNOWN, 3);
  32     const auto a4 = std::make_shared<DependentAction>(Transition::Type::UNKNOWN, 4);
  33
  34     Execution execution;
  35     execution.push_transition(a1);
  36     execution.push_transition(a2);
  37     execution.push_transition(a3);
  38     execution.push_transition(a4);
  39
  40     SECTION("Happens-before is irreflexive")
  41     {
  42       REQUIRE_FALSE(execution.happens_before(0, 0));
  43       REQUIRE_FALSE(execution.happens_before(1, 1));
  44       REQUIRE_FALSE(execution.happens_before(2, 2));
  45       REQUIRE_FALSE(execution.happens_before(3, 3));
  46     }
  47
  48     SECTION("Happens-before values for each pair of events")
  49     {
  50       REQUIRE_FALSE(execution.happens_before(0, 1));
  51       REQUIRE_FALSE(execution.happens_before(0, 2));
  52       REQUIRE(execution.happens_before(0, 3));
  53       REQUIRE_FALSE(execution.happens_before(1, 2));
  54       REQUIRE_FALSE(execution.happens_before(1, 3));
  55       REQUIRE_FALSE(execution.happens_before(2, 3));
  56     }
  57
  58     SECTION("Happens-before is a subset of 'occurs-before' ")
  59     {
  60       REQUIRE_FALSE(execution.happens_before(1, 0));
  61       REQUIRE_FALSE(execution.happens_before(2, 0));
  62       REQUIRE_FALSE(execution.happens_before(3, 0));
  63       REQUIRE_FALSE(execution.happens_before(2, 1));
  64       REQUIRE_FALSE(execution.happens_before(3, 1));
  65       REQUIRE_FALSE(execution.happens_before(3, 2));
  66     }
  67   }
  68
  69   SECTION("Example 2")
  70   {
  71     const auto a1 = std::make_shared<IndependentAction>(Transition::Type::UNKNOWN, 1);
  72     const auto a2 = std::make_shared<IndependentAction>(Transition::Type::UNKNOWN, 3);
  73     const auto a3 = std::make_shared<IndependentAction>(Transition::Type::UNKNOWN, 3);
  74     const auto a4 = std::make_shared<IndependentAction>(Transition::Type::UNKNOWN, 3);
  75
  76     // Notice that `a5` and `a6` are executed by the same actor; thus, although
  77     // the actor is executing independent actions, each still "happen-before"
  78     // the another
  79
  80     Execution execution;
  81     execution.push_transition(a1);
  82     execution.push_transition(a2);
  83     execution.push_transition(a3);
  84     execution.push_transition(a4);
  85
  86     SECTION("Happens-before is irreflexive")
  87     {
  88       REQUIRE_FALSE(execution.happens_before(0, 0));
  89       REQUIRE_FALSE(execution.happens_before(1, 1));
  90       REQUIRE_FALSE(execution.happens_before(2, 2));
  91       REQUIRE_FALSE(execution.happens_before(3, 3));
  92     }
  93
  94     SECTION("Happens-before values for each pair of events")
  95     {
  96       REQUIRE_FALSE(execution.happens_before(0, 1));
  97       REQUIRE_FALSE(execution.happens_before(0, 2));
  98       REQUIRE_FALSE(execution.happens_before(0, 3));
  99       REQUIRE(execution.happens_before(1, 2));
 100       REQUIRE(execution.happens_before(1, 3));
 101       REQUIRE(execution.happens_before(2, 3));
 102     }
 103
 104     SECTION("Happens-before is a subset of 'occurs-before'")
 105     {
 106       REQUIRE_FALSE(execution.happens_before(1, 0));
 107       REQUIRE_FALSE(execution.happens_before(2, 0));
 108       REQUIRE_FALSE(execution.happens_before(3, 0));
 109       REQUIRE_FALSE(execution.happens_before(2, 1));
 110       REQUIRE_FALSE(execution.happens_before(3, 1));
 111       REQUIRE_FALSE(execution.happens_before(3, 2));
 112     }
 113   }
 114 }
 115
 116 TEST_CASE("simgrid::mc::odpor::Execution: Testing Racing Events and Initials")
 117 {
 118   SECTION("Example 1")
 119   {
 120     const auto a1 = std::make_shared<ConditionallyDependentAction>(Transition::Type::UNKNOWN, 1);
 121     const auto a2 = std::make_shared<ConditionallyDependentAction>(Transition::Type::UNKNOWN, 2);
 122     const auto a3 = std::make_shared<DependentAction>(Transition::Type::UNKNOWN, 1);
 123     const auto a4 = std::make_shared<ConditionallyDependentAction>(Transition::Type::UNKNOWN, 1);
 124     const auto a5 = std::make_shared<DependentAction>(Transition::Type::UNKNOWN, 2);
 125
 126     Execution execution;
 127     execution.push_transition(a1);
 128     execution.push_transition(a2);
 129     execution.push_transition(a3);
 130     execution.push_transition(a4);
 131     execution.push_transition(a5);
 132
 133     // Nothing comes before event 0
 134     REQUIRE(execution.get_racing_events_of(0) == std::unordered_set<Execution::EventHandle>{});
 135
 136     // Events 0 and 1 are independent
 137     REQUIRE(execution.get_racing_events_of(1) == std::unordered_set<Execution::EventHandle>{});
 138
 139     // 2 and 1 are executed by different actors and happen right after each other
 140     REQUIRE(execution.get_racing_events_of(2) == std::unordered_set<Execution::EventHandle>{1});
 141
 142     // Although a3 and a4 are dependent, they are executed by the same actor
 143     REQUIRE(execution.get_racing_events_of(3) == std::unordered_set<Execution::EventHandle>{});
 144
 145     // Event 4 is in a race with neither event 0 nor event 2 since those events
 146     // "happen-before" event 3 with which event 4 races
 147     //
 148     // Furthermore, event 1 is run by the same actor and thus also is not in a race.
 149     // Hence, only event 3 races with event 4
 150     REQUIRE(execution.get_racing_events_of(4) == std::unordered_set<Execution::EventHandle>{3});
 151   }
 152
 153   SECTION("Example 2: Events with multiple races")
 154   {
 155     const auto a1 = std::make_shared<ConditionallyDependentAction>(Transition::Type::UNKNOWN, 1);
 156     const auto a2 = std::make_shared<ConditionallyDependentAction>(Transition::Type::UNKNOWN, 2);
 157     const auto a3 = std::make_shared<ConditionallyDependentAction>(Transition::Type::UNKNOWN, 1);
 158     const auto a4 = std::make_shared<DependentAction>(Transition::Type::UNKNOWN, 3);
 159
 160     Execution execution;
 161     execution.push_transition(a1);
 162     execution.push_transition(a2);
 163     execution.push_transition(a3);
 164     execution.push_transition(a4);
 165
 166     // Nothing comes before event 0
 167     REQUIRE(execution.get_racing_events_of(0) == std::unordered_set<Execution::EventHandle>{});
 168
 169     // Events 0 and 1 are independent
 170     REQUIRE(execution.get_racing_events_of(1) == std::unordered_set<Execution::EventHandle>{});
 171
 172     // Event 2 is independent with event 1 and run by the same actor as event 0
 173     REQUIRE(execution.get_racing_events_of(2) == std::unordered_set<Execution::EventHandle>{});
 174
 175     // All events are dependent with event 3, but event 0 "happens-before" event 2
 176     REQUIRE(execution.get_racing_events_of(3) == std::unordered_set<Execution::EventHandle>{1, 2});
 177
 178     SECTION("Check initials with respect to event 1")
 179     {
 180       // First, note that v := notdep(1, execution).p == {e2}.{e3} == {e2, e3}
 181       // Since e2 -->_E e3, actor 3 is not an initial for E' := pre(1, execution)
 182       // with respect to `v`. e2, however, has nothing happening before it in dom_E(v),
 183       // so it is an initial of E' wrt. `v`
 184       const auto initial_wrt_event1 = execution.get_missing_source_set_actors_from(1, std::unordered_set<aid_t>{});
 185       REQUIRE(initial_wrt_event1 == std::unordered_set<aid_t>{1});
 186     }
 187
 188     SECTION("Check initials with respect to event 2")
 189     {
 190       // First, note that v := notdep(1, execution).p == {}.{e3} == {e3}
 191       // e3 has nothing happening before it in dom_E(v), so it is an initial
 192       // of E' wrt. `v`
 193       const auto initial_wrt_event2 = execution.get_missing_source_set_actors_from(2, std::unordered_set<aid_t>{});
 194       REQUIRE(initial_wrt_event2 == std::unordered_set<aid_t>{3});
 195     }
 196   }
 197
 198   SECTION("Example 3: Testing 'Lock' Example")
 199   {
 200     // In this example,
 201     const auto a1 = std::make_shared<DependentAction>(Transition::Type::UNKNOWN, 2);
 202     const auto a2 = std::make_shared<IndependentAction>(Transition::Type::UNKNOWN, 2);
 203     const auto a3 = std::make_shared<IndependentAction>(Transition::Type::UNKNOWN, 2);
 204     const auto a4 = std::make_shared<IndependentAction>(Transition::Type::UNKNOWN, 1);
 205     const auto a5 = std::make_shared<DependentAction>(Transition::Type::UNKNOWN, 3);
 206
 207     Execution execution;
 208     execution.push_transition(a1);
 209     execution.push_transition(a2);
 210     execution.push_transition(a3);
 211     execution.push_transition(a4);
 212     execution.push_transition(a5);
 213
 214     REQUIRE(execution.get_racing_events_of(4) == std::unordered_set<Execution::EventHandle>{0});
 215   }
 216
 217   SECTION("Example 4: Indirect Races")
 218   {
 219     const auto a0 = std::make_shared<ConditionallyDependentAction>(Transition::Type::UNKNOWN, 1);
 220     const auto a1 = std::make_shared<IndependentAction>(Transition::Type::UNKNOWN, 2);
 221     const auto a2 = std::make_shared<DependentAction>(Transition::Type::UNKNOWN, 1);
 222     const auto a3 = std::make_shared<ConditionallyDependentAction>(Transition::Type::UNKNOWN, 1);
 223     const auto a4 = std::make_shared<DependentAction>(Transition::Type::UNKNOWN, 6);
 224     const auto a5 = std::make_shared<DependentAction>(Transition::Type::UNKNOWN, 2);
 225     const auto a6 = std::make_shared<DependentAction>(Transition::Type::UNKNOWN, 3);
 226     const auto a7 = std::make_shared<ConditionallyDependentAction>(Transition::Type::UNKNOWN, 3);
 227     const auto a8 = std::make_shared<IndependentAction>(Transition::Type::UNKNOWN, 4);
 228     const auto a9 = std::make_shared<ConditionallyDependentAction>(Transition::Type::UNKNOWN, 2);
 229
 230     Execution execution;
 231     execution.push_transition(a0);
 232     execution.push_transition(a1);
 233     execution.push_transition(a2);
 234     execution.push_transition(a3);
 235     execution.push_transition(a4);
 236     execution.push_transition(a5);
 237     execution.push_transition(a6);
 238     execution.push_transition(a7);
 239     execution.push_transition(a8);
 240     execution.push_transition(a9);
 241
 242     // Nothing comes before event 0
 243     REQUIRE(execution.get_racing_events_of(0) == std::unordered_set<Execution::EventHandle>{});
 244
 245     // Events 0 and 1 are independent
 246     REQUIRE(execution.get_racing_events_of(1) == std::unordered_set<Execution::EventHandle>{});
 247
 248     // Events 1 and 2 are independent
 249     REQUIRE(execution.get_racing_events_of(2) == std::unordered_set<Execution::EventHandle>{});
 250
 251     // Events 1 and 3 are independent; the rest are executed by the same actor
 252     REQUIRE(execution.get_racing_events_of(3) == std::unordered_set<Execution::EventHandle>{});
 253
 254     // 1. Events 3 and 4 race
 255     // 2. Events 2 and 4 do NOT race since 2 --> 3 --> 4
 256     // 3. Events 1 and 4 do NOT race since 1 is independent of 4
 257     // 4. Events 0 and 4 do NOT race since 0 --> 2 --> 4
 258     REQUIRE(execution.get_racing_events_of(4) == std::unordered_set<Execution::EventHandle>{3});
 259
 260     // Events 4 and 5 race; and because everyone before 4 (including 3) either
 261     // a) happens-before, b) races, or c) does not race with 4, 4 is the race
 262     REQUIRE(execution.get_racing_events_of(5) == std::unordered_set<Execution::EventHandle>{4});
 263
 264     // The same logic that applied to event 5 applies to event 6
 265     REQUIRE(execution.get_racing_events_of(6) == std::unordered_set<Execution::EventHandle>{5});
 266
 267     // The same logic applies, except that this time since events 6 and 7 are run
 268     // by the same actor, they don'tt actually race with one another
 269     REQUIRE(execution.get_racing_events_of(7) == std::unordered_set<Execution::EventHandle>{});
 270
 271     // Event 8 is independent with everything
 272     REQUIRE(execution.get_racing_events_of(8) == std::unordered_set<Execution::EventHandle>{});
 273
 274     // Event 9 is independent with events 7 and 8; event 6, however, is in race with 9.
 275     // The same logic above eliminates events before 6
 276     REQUIRE(execution.get_racing_events_of(9) == std::unordered_set<Execution::EventHandle>{6});
 277   }
 278 }
 279
 280 TEST_CASE("simgrid::mc::odpor::Execution: Testing Races and Conditions")
 281 {
 282   const auto a1 = std::make_shared<DependentAction>(Transition::Type::UNKNOWN, 2);
 283   const auto a2 = std::make_shared<IndependentAction>(Transition::Type::UNKNOWN, 2);
 284   const auto a3 = std::make_shared<IndependentAction>(Transition::Type::UNKNOWN, 2);
 285   const auto a4 = std::make_shared<IndependentAction>(Transition::Type::UNKNOWN, 1);
 286   const auto a5 = std::make_shared<DependentAction>(Transition::Type::UNKNOWN, 3);
 287
 288   Execution execution;
 289   execution.push_transition(a1);
 290   execution.push_transition(a2);
 291   execution.push_transition(a3);
 292   execution.push_transition(a4);
 293   execution.push_transition(a5);
 294 }
 295
 296 TEST_CASE("simgrid::mc::odpor::Execution: Independence Tests")
 297 {
 298   SECTION("Complete independence")
 299   {
 300     // Every transition is independent with every other and run by different actors. Hopefully
 301     // we say that the events are independent with each other...
 302     const auto a0 = std::make_shared<IndependentAction>(Transition::Type::UNKNOWN, 1);
 303     const auto a1 = std::make_shared<IndependentAction>(Transition::Type::UNKNOWN, 2);
 304     const auto a2 = std::make_shared<IndependentAction>(Transition::Type::UNKNOWN, 3);
 305     const auto a3 = std::make_shared<IndependentAction>(Transition::Type::UNKNOWN, 4);
 306     const auto a4 = std::make_shared<IndependentAction>(Transition::Type::UNKNOWN, 5);
 307     const auto a5 = std::make_shared<IndependentAction>(Transition::Type::UNKNOWN, 6);
 308     const auto a6 = std::make_shared<IndependentAction>(Transition::Type::UNKNOWN, 7);
 309     const auto a7 = std::make_shared<IndependentAction>(Transition::Type::UNKNOWN, 7);
 310     Execution execution;
 311     execution.push_transition(a0);
 312     execution.push_transition(a1);
 313     execution.push_transition(a2);
 314     execution.push_transition(a3);
 315
 316     REQUIRE(execution.is_independent_with_execution_of(PartialExecution{a4, a5}, a6));
 317     REQUIRE(execution.is_independent_with_execution_of(PartialExecution{a6, a5}, a1));
 318     REQUIRE(execution.is_independent_with_execution_of(PartialExecution{a6, a1}, a0));
 319     REQUIRE(Execution().is_independent_with_execution_of(PartialExecution{a7, a7, a1}, a3));
 320     REQUIRE(Execution().is_independent_with_execution_of(PartialExecution{a4, a0, a1}, a3));
 321     REQUIRE(Execution().is_independent_with_execution_of(PartialExecution{a0, a7, a1}, a2));
 322
 323     // In this case, we notice that `a6` and `a7` are executed by the same actor.
 324     // Hence, a6 cannot be independent with extending the execution with a4.a5.a7.
 325     // Notice that we are treating *a6* as the next step of actor 7 (that is what we
 326     // supplied as an argument)
 327     REQUIRE_FALSE(execution.is_independent_with_execution_of(PartialExecution{a4, a5, a7}, a6));
 328   }
 329
 330   SECTION("Independence is trivial with an empty extension")
 331   {
 332     REQUIRE(Execution().is_independent_with_execution_of(
 333         PartialExecution{}, std::make_shared<DependentAction>(Transition::Type::UNKNOWN, 1)));
 334   }
 335
 336   SECTION("Dependencies stopping independence from being possible")
 337   {
 338     const auto a0    = std::make_shared<ConditionallyDependentAction>(Transition::Type::UNKNOWN, 1);
 339     const auto a1    = std::make_shared<DependentAction>(Transition::Type::UNKNOWN, 1);
 340     const auto a2    = std::make_shared<ConditionallyDependentAction>(Transition::Type::UNKNOWN, 3);
 341     const auto a3    = std::make_shared<ConditionallyDependentAction>(Transition::Type::UNKNOWN, 4);
 342     const auto a4    = std::make_shared<ConditionallyDependentAction>(Transition::Type::UNKNOWN, 4);
 343     const auto a5    = std::make_shared<ConditionallyDependentAction>(Transition::Type::UNKNOWN, 2);
 344     const auto a6    = std::make_shared<DependentAction>(Transition::Type::UNKNOWN, 3);
 345     const auto a7    = std::make_shared<ConditionallyDependentAction>(Transition::Type::UNKNOWN, 1);
 346     const auto a8    = std::make_shared<ConditionallyDependentAction>(Transition::Type::UNKNOWN, 4);
 347     const auto indep = std::make_shared<IndependentAction>(Transition::Type::UNKNOWN, 2);
 348     Execution execution;
 349     execution.push_transition(a0);
 350     execution.push_transition(a1);
 351     execution.push_transition(a2);
 352     execution.push_transition(a3);
 353
 354     // We see that although `a4` comes after `a1` with which it is dependent, it
 355     // would come before "a6" in the partial execution `w`, so it would not be independent
 356     REQUIRE_FALSE(execution.is_independent_with_execution_of(PartialExecution{a5, a6, a7}, a4));
 357
 358     // Removing `a6` from the picture, though, gives us the independence we're looking for.
 359     REQUIRE(execution.is_independent_with_execution_of(PartialExecution{a5, a7}, a4));
 360
 361     // BUT, we we ask about a transition which is run by the same actor, even if they would be
 362     // independent otherwise, we again lose independence
 363     REQUIRE_FALSE(execution.is_independent_with_execution_of(PartialExecution{a5, a7, a8}, a4));
 364
 365     // This is a more interesting case:
 366     // `indep` clearly is independent with the rest of the series, even though
 367     // there are dependencies among the other events in the partial execution
 368     REQUIRE(Execution().is_independent_with_execution_of(PartialExecution{a1, a6, a7}, indep));
 369
 370     // This ensures that independence is trivial with an empty partial execution
 371     REQUIRE(execution.is_independent_with_execution_of(PartialExecution{}, a1));
 372   }
 373 }
 374
 375 TEST_CASE("simgrid::mc::odpor::Execution: Initials Test")
 376 {
 377   const auto a0    = std::make_shared<ConditionallyDependentAction>(Transition::Type::UNKNOWN, 1);
 378   const auto a1    = std::make_shared<DependentAction>(Transition::Type::UNKNOWN, 1);
 379   const auto a2    = std::make_shared<ConditionallyDependentAction>(Transition::Type::UNKNOWN, 3);
 380   const auto a3    = std::make_shared<ConditionallyDependentAction>(Transition::Type::UNKNOWN, 4);
 381   const auto a4    = std::make_shared<ConditionallyDependentAction>(Transition::Type::UNKNOWN, 4);
 382   const auto a5    = std::make_shared<ConditionallyDependentAction>(Transition::Type::UNKNOWN, 2);
 383   const auto a6    = std::make_shared<DependentAction>(Transition::Type::UNKNOWN, 3);
 384   const auto a7    = std::make_shared<ConditionallyDependentAction>(Transition::Type::UNKNOWN, 1);
 385   const auto a8    = std::make_shared<ConditionallyDependentAction>(Transition::Type::UNKNOWN, 4);
 386   const auto indep = std::make_shared<IndependentAction>(Transition::Type::UNKNOWN, 2);
 387   Execution execution;
 388   execution.push_transition(a0);
 389   execution.push_transition(a1);
 390   execution.push_transition(a2);
 391   execution.push_transition(a3);
 392
 393   SECTION("Initials trivial with empty executions")
 394   {
 395     // There are no initials for an empty extension since
 396     // a requirement is that the actor be contained in the
 397     // extension itself
 398     REQUIRE_FALSE(execution.is_initial_after_execution_of(PartialExecution{}, 0));
 399     REQUIRE_FALSE(execution.is_initial_after_execution_of(PartialExecution{}, 1));
 400     REQUIRE_FALSE(execution.is_initial_after_execution_of(PartialExecution{}, 2));
 401     REQUIRE_FALSE(Execution().is_initial_after_execution_of(PartialExecution{}, 0));
 402     REQUIRE_FALSE(Execution().is_initial_after_execution_of(PartialExecution{}, 1));
 403     REQUIRE_FALSE(Execution().is_initial_after_execution_of(PartialExecution{}, 2));
 404   }
 405
 406   SECTION("The first actor is always an initial")
 407   {
 408     // Even in the case that the action is dependent with every
 409     // other, if it is the first action to occur as part of the
 410     // extension of the execution sequence, by definition it is
 411     // an initial (recall that initials intuitively tell you which
 412     // actions can be run starting from an execution `E`; if we claim
 413     // to witness `E.w`, then clearly at least the first step of `w` is an initial)
 414     REQUIRE(execution.is_initial_after_execution_of(PartialExecution{a3}, a3->aid_));
 415     REQUIRE(execution.is_initial_after_execution_of(PartialExecution{a2, a3, a6}, a2->aid_));
 416     REQUIRE(execution.is_initial_after_execution_of(PartialExecution{a6, a1, a0}, a6->aid_));
 417     REQUIRE(Execution().is_initial_after_execution_of(PartialExecution{a0, a1, a2, a3}, a0->aid_));
 418     REQUIRE(Execution().is_initial_after_execution_of(PartialExecution{a5, a2, a8, a7, a6, a0}, a5->aid_));
 419     REQUIRE(Execution().is_initial_after_execution_of(PartialExecution{a8, a7, a1}, a8->aid_));
 420   }
 421
 422   SECTION("Example: Disqualified and re-qualified after switching ordering")
 423   {
 424     // Even though actor `2` executes an independent
 425     // transition later on, it is blocked since its first transition
 426     // is dependent with actor 1's transition
 427     REQUIRE_FALSE(Execution().is_initial_after_execution_of(PartialExecution{a1, a5, indep}, 2));
 428
 429     // However, if actor 2 executes its independent action first, it DOES become an initial
 430     REQUIRE(Execution().is_initial_after_execution_of(PartialExecution{a1, indep, a5}, 2));
 431   }
 432
 433   SECTION("Example: Large partial executions")
 434   {
 435     // The record trace is `1 3 4 4 3 1 4 2`
 436
 437     // Actor 1 starts the execution
 438     REQUIRE(Execution().is_initial_after_execution_of(PartialExecution{a1, a2, a3, a4, a6, a7, a8, indep}, 1));
 439
 440     // Actor 2 all the way at the end is independent with everybody: despite
 441     // the tangle that comes before it, we can more it to the front with no issue
 442     REQUIRE(Execution().is_initial_after_execution_of(PartialExecution{a1, a2, a3, a4, a6, a7, a8, indep}, 2));
 443
 444     // Actor 3 is eliminated since `a1` is dependent with `a2`
 445     REQUIRE_FALSE(Execution().is_initial_after_execution_of(PartialExecution{a1, a2, a3, a4, a6, a7, a8, indep}, 3));
 446
 447     // Likewise with actor 4
 448     REQUIRE_FALSE(Execution().is_initial_after_execution_of(PartialExecution{a1, a2, a3, a4, a6, a7, a8, indep}, 4));
 449   }
 450 }
 451
 452 TEST_CASE("simgrid::mc::odpor::Execution: ODPOR Smallest Sequence Tests")
 453 {
 454   const auto a0 = std::make_shared<DependentAction>(Transition::Type::UNKNOWN, 2);
 455   const auto a1 = std::make_shared<IndependentAction>(Transition::Type::UNKNOWN, 4);
 456   const auto a2 = std::make_shared<ConditionallyDependentAction>(Transition::Type::UNKNOWN, 3);
 457   const auto a3 = std::make_shared<DependentAction>(Transition::Type::UNKNOWN, 1);
 458   const auto a4 = std::make_shared<IndependentAction>(Transition::Type::UNKNOWN, 2);
 459   const auto a5 = std::make_shared<ConditionallyDependentAction>(Transition::Type::UNKNOWN, 4);
 460
 461   Execution execution;
 462   execution.push_transition(a0);
 463   execution.push_transition(a1);
 464   execution.push_transition(a2);
 465   execution.push_transition(a3);
 466   execution.push_transition(a4);
 467   execution.push_transition(a5);
 468
 469   SECTION("Equivalent insertions")
 470   {
 471     SECTION("Example: Eliminated through independence")
 472     {
 473       // TODO: Is this even a sensible question to ask if the two sequences
 474       // don't agree upon what each actor executed after `E`?
 475       const auto insertion =
 476           Execution().get_shortest_odpor_sq_subset_insertion(PartialExecution{a1, a2}, PartialExecution{a2, a5});
 477       REQUIRE(insertion.has_value());
 478       REQUIRE(insertion.value() == PartialExecution{});
 479     }
 480
 481     SECTION("Exact match yields empty set")
 482     {
 483       const auto insertion =
 484           Execution().get_shortest_odpor_sq_subset_insertion(PartialExecution{a1, a2}, PartialExecution{a1, a2});
 485       REQUIRE(insertion.has_value());
 486       REQUIRE(insertion.value() == PartialExecution{});
 487     }
 488   }
 489
 490   SECTION("Match against empty executions")
 491   {
 492     SECTION("Empty `v` trivially yields `w`")
 493     {
 494       auto insertion =
 495           Execution().get_shortest_odpor_sq_subset_insertion(PartialExecution{}, PartialExecution{a1, a5, a2});
 496       REQUIRE(insertion.has_value());
 497       REQUIRE(insertion.value() == PartialExecution{a1, a5, a2});
 498
 499       insertion = execution.get_shortest_odpor_sq_subset_insertion(PartialExecution{}, PartialExecution{a1, a5, a2});
 500       REQUIRE(insertion.has_value());
 501       REQUIRE(insertion.value() == PartialExecution{a1, a5, a2});
 502     }
 503
 504     SECTION("Empty `w` yields empty execution")
 505     {
 506       auto insertion =
 507           Execution().get_shortest_odpor_sq_subset_insertion(PartialExecution{a1, a4, a5}, PartialExecution{});
 508       REQUIRE(insertion.has_value());
 509       REQUIRE(insertion.value() == PartialExecution{});
 510
 511       insertion = execution.get_shortest_odpor_sq_subset_insertion(PartialExecution{a1, a5, a2}, PartialExecution{});
 512       REQUIRE(insertion.has_value());
 513       REQUIRE(insertion.value() == PartialExecution{});
 514     }
 515   }
 516
 517   SECTION("") {}
 518 }