Add tests that exercise the cancellation code branches

src/Makefile.gtest.include

@@ -6,6 +6,7 @@ zcash_gtest_SOURCES = \
 	gtest/main.cpp \
 	gtest/test_tautology.cpp \
 	gtest/test_checktransaction.cpp \
+	gtest/test_equihash.cpp \
 	gtest/test_joinsplit.cpp \
 	gtest/test_noteencryption.cpp \
 	gtest/test_merkletree.cpp \

src/crypto/equihash.cpp

@@ -193,7 +193,7 @@ eh_trunc* TruncatedStepRow<WIDTH>::GetTruncatedIndices(size_t len, size_t lenInd
 }
 
 template<unsigned int N, unsigned int K>
-std::set<std::vector<eh_index>> Equihash<N,K>::BasicSolve(const eh_HashState& base_state, const std::function<bool()> cancelled)
+std::set<std::vector<eh_index>> Equihash<N,K>::BasicSolve(const eh_HashState& base_state, const std::function<bool(EhSolverCancelCheck)> cancelled)
 {
     eh_index init_size { 1 << (CollisionBitLength + 1) };
 
@@ -206,7 +206,7 @@ std::set<std::vector<eh_index>> Equihash<N,K>::BasicSolve(const eh_HashState& ba
     for (eh_index i = 0; i < init_size; i++) {
         X.emplace_back(N, base_state, i);
         // Slow down checking to prevent segfaults (??)
-        if (i % 10000 == 0 && cancelled()) throw solver_cancelled;
+        if (i % 10000 == 0 && cancelled(ListGeneration)) throw solver_cancelled;
     }
 
     // 3) Repeat step 2 until 2n/(k+1) bits remain
@@ -215,7 +215,7 @@ std::set<std::vector<eh_index>> Equihash<N,K>::BasicSolve(const eh_HashState& ba
         // 2a) Sort the list
         LogPrint("pow", "- Sorting list\n");
         std::sort(X.begin(), X.end(), CompareSR(CollisionByteLength));
-        if (cancelled()) throw solver_cancelled;
+        if (cancelled(ListSorting)) throw solver_cancelled;
 
         LogPrint("pow", "- Finding collisions\n");
         int i = 0;
@@ -245,7 +245,7 @@ std::set<std::vector<eh_index>> Equihash<N,K>::BasicSolve(const eh_HashState& ba
             }
 
             i += j;
-            if (cancelled()) throw solver_cancelled;
+            if (cancelled(ListColliding)) throw solver_cancelled;
         }
 
         // 2e) Handle edge case where final table entry has no collision
@@ -265,7 +265,7 @@ std::set<std::vector<eh_index>> Equihash<N,K>::BasicSolve(const eh_HashState& ba
 
         hashLen -= CollisionByteLength;
         lenIndices *= 2;
-        if (cancelled()) throw solver_cancelled;
+        if (cancelled(RoundEnd)) throw solver_cancelled;
     }
 
     // k+1) Find a collision on last 2n(k+1) bits
@@ -274,6 +274,7 @@ std::set<std::vector<eh_index>> Equihash<N,K>::BasicSolve(const eh_HashState& ba
     if (X.size() > 1) {
         LogPrint("pow", "- Sorting list\n");
         std::sort(X.begin(), X.end(), CompareSR(hashLen));
+        if (cancelled(FinalSorting)) throw solver_cancelled;
         LogPrint("pow", "- Finding collisions\n");
         int i = 0;
         while (i < X.size() - 1) {
@@ -293,7 +294,7 @@ std::set<std::vector<eh_index>> Equihash<N,K>::BasicSolve(const eh_HashState& ba
             }
 
             i += j;
-            if (cancelled()) throw solver_cancelled;
+            if (cancelled(FinalColliding)) throw solver_cancelled;
         }
     } else
         LogPrint("pow", "- List is empty\n");
@@ -354,7 +355,7 @@ void CollideBranches(std::vector<FullStepRow<WIDTH>>& X, const size_t hlen, cons
 }
 
 template<unsigned int N, unsigned int K>
-std::set<std::vector<eh_index>> Equihash<N,K>::OptimisedSolve(const eh_HashState& base_state, const std::function<bool()> cancelled)
+std::set<std::vector<eh_index>> Equihash<N,K>::OptimisedSolve(const eh_HashState& base_state, const std::function<bool(EhSolverCancelCheck)> cancelled)
 {
     eh_index init_size { 1 << (CollisionBitLength + 1) };
 
@@ -375,7 +376,7 @@ std::set<std::vector<eh_index>> Equihash<N,K>::OptimisedSolve(const eh_HashState
         for (eh_index i = 0; i < init_size; i++) {
             Xt.emplace_back(N, base_state, i, CollisionBitLength + 1);
             // Slow down checking to prevent segfaults (??)
-            if (i % 10000 == 0 && cancelled()) throw solver_cancelled;
+            if (i % 10000 == 0 && cancelled(ListGeneration)) throw solver_cancelled;
         }
 
         // 3) Repeat step 2 until 2n/(k+1) bits remain
@@ -384,7 +385,7 @@ std::set<std::vector<eh_index>> Equihash<N,K>::OptimisedSolve(const eh_HashState
             // 2a) Sort the list
             LogPrint("pow", "- Sorting list\n");
             std::sort(Xt.begin(), Xt.end(), CompareSR(CollisionByteLength));
-            if (cancelled()) throw solver_cancelled;
+            if (cancelled(ListSorting)) throw solver_cancelled;
 
             LogPrint("pow", "- Finding collisions\n");
             int i = 0;
@@ -413,7 +414,7 @@ std::set<std::vector<eh_index>> Equihash<N,K>::OptimisedSolve(const eh_HashState
                 }
 
                 i += j;
-                if (cancelled()) throw solver_cancelled;
+                if (cancelled(ListColliding)) throw solver_cancelled;
             }
 
             // 2e) Handle edge case where final table entry has no collision
@@ -433,7 +434,7 @@ std::set<std::vector<eh_index>> Equihash<N,K>::OptimisedSolve(const eh_HashState
 
             hashLen -= CollisionByteLength;
             lenIndices *= 2;
-            if (cancelled()) throw solver_cancelled;
+            if (cancelled(RoundEnd)) throw solver_cancelled;
         }
 
         // k+1) Find a collision on last 2n(k+1) bits
@@ -441,7 +442,7 @@ std::set<std::vector<eh_index>> Equihash<N,K>::OptimisedSolve(const eh_HashState
         if (Xt.size() > 1) {
             LogPrint("pow", "- Sorting list\n");
             std::sort(Xt.begin(), Xt.end(), CompareSR(hashLen));
-            if (cancelled()) throw solver_cancelled;
+            if (cancelled(FinalSorting)) throw solver_cancelled;
             LogPrint("pow", "- Finding collisions\n");
             int i = 0;
             while (i < Xt.size() - 1) {
@@ -459,7 +460,7 @@ std::set<std::vector<eh_index>> Equihash<N,K>::OptimisedSolve(const eh_HashState
                 }
 
                 i += j;
-                if (cancelled()) break;
+                if (cancelled(FinalColliding)) break;
             }
         } else
             LogPrint("pow", "- List is empty\n");
@@ -473,7 +474,7 @@ std::set<std::vector<eh_index>> Equihash<N,K>::OptimisedSolve(const eh_HashState
     std::set<std::vector<eh_index>> solns;
     eh_index recreate_size { UntruncateIndex(1, 0, CollisionBitLength + 1) };
     int invalidCount = 0;
-    if (cancelled()) goto cancelsolver;
+    if (cancelled(StartCulling)) goto cancelsolver;
     for (eh_trunc* partialSoln : partialSolns) {
         size_t hashLen;
         size_t lenIndices;
@@ -488,7 +489,7 @@ std::set<std::vector<eh_index>> Equihash<N,K>::OptimisedSolve(const eh_HashState
             for (eh_index j = 0; j < recreate_size; j++) {
                 eh_index newIndex { UntruncateIndex(partialSoln[i], j, CollisionBitLength + 1) };
                 icv.emplace_back(N, base_state, newIndex);
-                if (cancelled()) goto cancelsolver;
+                if (cancelled(PartialGeneration)) goto cancelsolver;
             }
             boost::optional<std::vector<FullStepRow<FinalFullWidth>>> ic = icv;
 
@@ -504,7 +505,7 @@ std::set<std::vector<eh_index>> Equihash<N,K>::OptimisedSolve(const eh_HashState
                         ic->reserve(ic->size() + X[r]->size());
                         ic->insert(ic->end(), X[r]->begin(), X[r]->end());
                         std::sort(ic->begin(), ic->end(), CompareSR(hashLen));
-                        if (cancelled()) goto cancelsolver;
+                        if (cancelled(PartialSorting)) goto cancelsolver;
                         size_t lti = rti-(1<<r);
                         CollideBranches(*ic, hashLen, lenIndices,
                                         CollisionByteLength,
@@ -527,9 +528,9 @@ std::set<std::vector<eh_index>> Equihash<N,K>::OptimisedSolve(const eh_HashState
                     X.push_back(ic);
                     break;
                 }
-                if (cancelled()) goto cancelsolver;
+                if (cancelled(PartialSubtreeEnd)) goto cancelsolver;
             }
-            if (cancelled()) goto cancelsolver;
+            if (cancelled(PartialIndexEnd)) goto cancelsolver;
         }
 
         // We are at the top of the tree
@@ -537,7 +538,7 @@ std::set<std::vector<eh_index>> Equihash<N,K>::OptimisedSolve(const eh_HashState
         for (FullStepRow<FinalFullWidth> row : *X[K]) {
             solns.insert(row.GetIndices(hashLen, lenIndices));
         }
-        if (cancelled()) goto cancelsolver;
+        if (cancelled(PartialEnd)) goto cancelsolver;
         continue;
 
 invalidsolution:
@@ -604,18 +605,18 @@ bool Equihash<N,K>::IsValidSolution(const eh_HashState& base_state, std::vector<
 
 // Explicit instantiations for Equihash<96,3>
 template int Equihash<96,3>::InitialiseState(eh_HashState& base_state);
-template std::set<std::vector<eh_index>> Equihash<96,3>::BasicSolve(const eh_HashState& base_state, const std::function<bool()> cancelled);
-template std::set<std::vector<eh_index>> Equihash<96,3>::OptimisedSolve(const eh_HashState& base_state, const std::function<bool()> cancelled);
+template std::set<std::vector<eh_index>> Equihash<96,3>::BasicSolve(const eh_HashState& base_state, const std::function<bool(EhSolverCancelCheck)> cancelled);
+template std::set<std::vector<eh_index>> Equihash<96,3>::OptimisedSolve(const eh_HashState& base_state, const std::function<bool(EhSolverCancelCheck)> cancelled);
 template bool Equihash<96,3>::IsValidSolution(const eh_HashState& base_state, std::vector<eh_index> soln);
 
 // Explicit instantiations for Equihash<96,5>
 template int Equihash<96,5>::InitialiseState(eh_HashState& base_state);
-template std::set<std::vector<eh_index>> Equihash<96,5>::BasicSolve(const eh_HashState& base_state, const std::function<bool()> cancelled);
-template std::set<std::vector<eh_index>> Equihash<96,5>::OptimisedSolve(const eh_HashState& base_state, const std::function<bool()> cancelled);
+template std::set<std::vector<eh_index>> Equihash<96,5>::BasicSolve(const eh_HashState& base_state, const std::function<bool(EhSolverCancelCheck)> cancelled);
+template std::set<std::vector<eh_index>> Equihash<96,5>::OptimisedSolve(const eh_HashState& base_state, const std::function<bool(EhSolverCancelCheck)> cancelled);
 template bool Equihash<96,5>::IsValidSolution(const eh_HashState& base_state, std::vector<eh_index> soln);
 
 // Explicit instantiations for Equihash<48,5>
 template int Equihash<48,5>::InitialiseState(eh_HashState& base_state);
-template std::set<std::vector<eh_index>> Equihash<48,5>::BasicSolve(const eh_HashState& base_state, const std::function<bool()> cancelled);
-template std::set<std::vector<eh_index>> Equihash<48,5>::OptimisedSolve(const eh_HashState& base_state, const std::function<bool()> cancelled);
+template std::set<std::vector<eh_index>> Equihash<48,5>::BasicSolve(const eh_HashState& base_state, const std::function<bool(EhSolverCancelCheck)> cancelled);
+template std::set<std::vector<eh_index>> Equihash<48,5>::OptimisedSolve(const eh_HashState& base_state, const std::function<bool(EhSolverCancelCheck)> cancelled);
 template bool Equihash<48,5>::IsValidSolution(const eh_HashState& base_state, std::vector<eh_index> soln);

src/crypto/equihash.h

@@ -110,12 +110,27 @@ public:
     eh_trunc* GetTruncatedIndices(size_t len, size_t lenIndices) const;
 };
 
+enum EhSolverCancelCheck
+{
+    ListGeneration,
+    ListSorting,
+    ListColliding,
+    RoundEnd,
+    FinalSorting,
+    FinalColliding,
+    StartCulling,
+    PartialGeneration,
+    PartialSorting,
+    PartialSubtreeEnd,
+    PartialIndexEnd,
+    PartialEnd
+};
+
 class EhSolverCancelledException : public std::exception
 {
-  virtual const char* what() const throw()
-  {
-    return "Equihash solver was cancelled";
-  }
+    virtual const char* what() const throw() {
+        return "Equihash solver was cancelled";
+    }
 };
 
 inline constexpr const size_t max(const size_t A, const size_t B) { return A > B ? A : B; }
@@ -140,8 +155,8 @@ public:
     Equihash() { }
 
     int InitialiseState(eh_HashState& base_state);
-    std::set<std::vector<eh_index>> BasicSolve(const eh_HashState& base_state, const std::function<bool()> cancelled);
-    std::set<std::vector<eh_index>> OptimisedSolve(const eh_HashState& base_state, const std::function<bool()> cancelled);
+    std::set<std::vector<eh_index>> BasicSolve(const eh_HashState& base_state, const std::function<bool(EhSolverCancelCheck)> cancelled);
+    std::set<std::vector<eh_index>> OptimisedSolve(const eh_HashState& base_state, const std::function<bool(EhSolverCancelCheck)> cancelled);
     bool IsValidSolution(const eh_HashState& base_state, std::vector<eh_index> soln);
 };
 
@@ -172,8 +187,8 @@ static Equihash<48,5> Eh48_5;
     } else {                                               \
         throw std::invalid_argument("Unsupported Equihash parameters"); \
     }
-#define EhBasicSolveUncancellable(n, k, base_state, solns)  \
-    EhBasicSolve(n, k, base_state, solns, [] { return false; })
+#define EhBasicSolveUncancellable(n, k, base_state, solns) \
+    EhBasicSolve(n, k, base_state, solns, [](EhSolverCancelCheck pos) { return false; })
 
 #define EhOptimisedSolve(n, k, base_state, solns, cancelled)   \
     if (n == 96 && k == 3) {                                   \
@@ -186,7 +201,7 @@ static Equihash<48,5> Eh48_5;
         throw std::invalid_argument("Unsupported Equihash parameters"); \
     }
 #define EhOptimisedSolveUncancellable(n, k, base_state, solns) \
-    EhOptimisedSolve(n, k, base_state, solns, [] { return false; })
+    EhOptimisedSolve(n, k, base_state, solns, [](EhSolverCancelCheck pos) { return false; })
 
 #define EhIsValidSolution(n, k, base_state, soln, ret)   \
     if (n == 96 && k == 3) {                             \

src/gtest/test_equihash.cpp

@@ -0,0 +1,184 @@
+#include <gtest/gtest.h>
+#include <gmock/gmock.h>
+
+#include "crypto/equihash.h"
+
+TEST(equihash_tests, check_basic_solver_cancelled) {
+    Equihash<48,5> Eh48_5;
+    crypto_generichash_blake2b_state state;
+    Eh48_5.InitialiseState(state);
+    std::set<std::vector<unsigned int>> solns;
+
+    {
+        ASSERT_NO_THROW(Eh48_5.BasicSolve(state, [](EhSolverCancelCheck pos) {
+            return false;
+        }));
+    }
+
+    {
+        ASSERT_THROW(Eh48_5.BasicSolve(state, [](EhSolverCancelCheck pos) {
+            return pos == ListGeneration;
+        }), EhSolverCancelledException);
+    }
+
+    {
+        ASSERT_THROW(Eh48_5.BasicSolve(state, [](EhSolverCancelCheck pos) {
+            return pos == ListSorting;
+        }), EhSolverCancelledException);
+    }
+
+    {
+        ASSERT_THROW(Eh48_5.BasicSolve(state, [](EhSolverCancelCheck pos) {
+            return pos == ListColliding;
+        }), EhSolverCancelledException);
+    }
+
+    {
+        ASSERT_THROW(Eh48_5.BasicSolve(state, [](EhSolverCancelCheck pos) {
+            return pos == RoundEnd;
+        }), EhSolverCancelledException);
+    }
+
+    {
+        ASSERT_THROW(Eh48_5.BasicSolve(state, [](EhSolverCancelCheck pos) {
+            return pos == FinalSorting;
+        }), EhSolverCancelledException);
+    }
+
+    {
+        ASSERT_THROW(Eh48_5.BasicSolve(state, [](EhSolverCancelCheck pos) {
+            return pos == FinalColliding;
+        }), EhSolverCancelledException);
+    }
+
+    {
+        ASSERT_NO_THROW(Eh48_5.BasicSolve(state, [](EhSolverCancelCheck pos) {
+            return pos == StartCulling;
+        }));
+    }
+
+    {
+        ASSERT_NO_THROW(Eh48_5.BasicSolve(state, [](EhSolverCancelCheck pos) {
+            return pos == PartialGeneration;
+        }));
+    }
+
+    {
+        ASSERT_NO_THROW(Eh48_5.BasicSolve(state, [](EhSolverCancelCheck pos) {
+            return pos == PartialSorting;
+        }));
+    }
+
+    {
+        ASSERT_NO_THROW(Eh48_5.BasicSolve(state, [](EhSolverCancelCheck pos) {
+            return pos == PartialSubtreeEnd;
+        }));
+    }
+
+    {
+        ASSERT_NO_THROW(Eh48_5.BasicSolve(state, [](EhSolverCancelCheck pos) {
+            return pos == PartialIndexEnd;
+        }));
+    }
+
+    {
+        ASSERT_NO_THROW(Eh48_5.BasicSolve(state, [](EhSolverCancelCheck pos) {
+            return pos == PartialEnd;
+        }));
+    }
+}
+
+TEST(equihash_tests, check_optimised_solver_cancelled) {
+    Equihash<48,5> Eh48_5;
+    crypto_generichash_blake2b_state state;
+    Eh48_5.InitialiseState(state);
+    std::set<std::vector<unsigned int>> solns;
+
+    {
+        ASSERT_NO_THROW(Eh48_5.OptimisedSolve(state, [](EhSolverCancelCheck pos) {
+            return false;
+        }));
+    }
+
+    {
+        ASSERT_THROW(Eh48_5.OptimisedSolve(state, [](EhSolverCancelCheck pos) {
+            return pos == ListGeneration;
+        }), EhSolverCancelledException);
+    }
+
+    {
+        ASSERT_THROW(Eh48_5.OptimisedSolve(state, [](EhSolverCancelCheck pos) {
+            return pos == ListSorting;
+        }), EhSolverCancelledException);
+    }
+
+    {
+        ASSERT_THROW(Eh48_5.OptimisedSolve(state, [](EhSolverCancelCheck pos) {
+            return pos == ListColliding;
+        }), EhSolverCancelledException);
+    }
+
+    {
+        ASSERT_THROW(Eh48_5.OptimisedSolve(state, [](EhSolverCancelCheck pos) {
+            return pos == RoundEnd;
+        }), EhSolverCancelledException);
+    }
+
+    {
+        ASSERT_THROW(Eh48_5.OptimisedSolve(state, [](EhSolverCancelCheck pos) {
+            return pos == FinalSorting;
+        }), EhSolverCancelledException);
+    }
+
+    {
+        // More state required here, because in OptimisedSolve() the
+        // FinalColliding cancellation check can't throw because it will leak
+        // memory, and it can't goto because that steps over initialisations.
+        bool triggered = false;
+        ASSERT_THROW(Eh48_5.OptimisedSolve(state, [=](EhSolverCancelCheck pos) mutable {
+            if (triggered)
+                return pos == StartCulling;
+            if (pos == FinalColliding) {
+                triggered = true;
+                return true;
+            }
+            return false;
+        }), EhSolverCancelledException);
+    }
+
+    {
+        ASSERT_THROW(Eh48_5.OptimisedSolve(state, [](EhSolverCancelCheck pos) {
+            return pos == StartCulling;
+        }), EhSolverCancelledException);
+    }
+
+    {
+        ASSERT_THROW(Eh48_5.OptimisedSolve(state, [](EhSolverCancelCheck pos) {
+            return pos == PartialGeneration;
+        }), EhSolverCancelledException);
+    }
+
+    {
+        ASSERT_THROW(Eh48_5.OptimisedSolve(state, [](EhSolverCancelCheck pos) {
+            return pos == PartialSorting;
+        }), EhSolverCancelledException);
+    }
+
+    {
+        ASSERT_THROW(Eh48_5.OptimisedSolve(state, [](EhSolverCancelCheck pos) {
+            return pos == PartialSubtreeEnd;
+        }), EhSolverCancelledException);
+    }
+
+    {
+        ASSERT_THROW(Eh48_5.OptimisedSolve(state, [](EhSolverCancelCheck pos) {
+            return pos == PartialIndexEnd;
+        }), EhSolverCancelledException);
+    }
+
+    {
+        ASSERT_THROW(Eh48_5.OptimisedSolve(state, [](EhSolverCancelCheck pos) {
+            return pos == PartialEnd;
+        }), EhSolverCancelledException);
+    }
+}

src/miner.cpp

@@ -521,7 +521,9 @@ void static BitcoinMiner(CWallet *pwallet)
                          pblock->nNonce.ToString());
                 std::set<std::vector<unsigned int>> solns;
                 try {
-                    std::function<bool()> cancelled = [pindexPrev] { return pindexPrev != chainActive.Tip(); };
+                    std::function<bool(EhSolverCancelCheck)> cancelled = [pindexPrev](EhSolverCancelCheck pos) {
+                        return pindexPrev != chainActive.Tip();
+                    };
                     EhOptimisedSolve(n, k, curr_state, solns, cancelled);
                 } catch (EhSolverCancelledException&) {
                     LogPrint("pow", "Equihash solver cancelled\n");