Add DebugConflictSet, which asserts using skip list as a reference

CC #23

ConflictSet.cpp

@@ -2510,6 +2510,10 @@ struct __attribute__((visibility("hidden"))) ConflictSet::Impl {
   }
 
   explicit Impl(int64_t oldestVersion) : oldestVersion(oldestVersion) {
+#if DEBUG_VERBOSE
+    fprintf(stderr, "radix_tree: create\n");
+#endif
+
     // Insert ""
     root = allocators.node0.allocate(0);
     root->numChildren = 0;
@@ -2524,7 +2528,12 @@ struct __attribute__((visibility("hidden"))) ConflictSet::Impl {
     root->entry.pointVersion = oldestVersion;
     root->entry.rangeVersion = oldestVersion;
   }
-  ~Impl() { destroyTree(root); }
+  ~Impl() {
+#if DEBUG_VERBOSE
+    fprintf(stderr, "radix_tree: destroy\n");
+#endif
+    destroyTree(root);
+  }
 
   NodeAllocators allocators;
 
@@ -3005,6 +3014,7 @@ void removeKey(Node *n) {
 
 struct __attribute__((visibility("default"))) PeakPrinter {
   ~PeakPrinter() {
+    printf("--- radix_tree ---\n");
     printf("malloc bytes: %g\n", double(mallocBytes));
     printf("Peak malloc bytes: %g\n", double(peakMallocBytes));
     printf("Node bytes: %g\n", double(nodeBytes));

SkipList.cpp

@@ -270,13 +270,21 @@ public:
   }
 
   explicit SkipList(Version version = 0) {
+#if DEBUG_VERBOSE
+    fprintf(stderr, "skip_list: create\n");
+#endif
     header = Node::create(StringRef(), MaxLevels - 1);
     for (int l = 0; l < MaxLevels; l++) {
       header->setNext(l, nullptr);
       header->setMaxVersion(l, version);
     }
   }
-  ~SkipList() { destroy(); }
+  ~SkipList() {
+#if DEBUG_VERBOSE
+    fprintf(stderr, "skip_list: destroy\n");
+#endif
+    destroy();
+  }
   SkipList(SkipList &&other) noexcept : header(other.header) {
     other.header = nullptr;
   }
@@ -749,6 +757,7 @@ ConflictSet_getBytes(void *cs) {
 #if SHOW_MEMORY
 struct __attribute__((visibility("default"))) PeakPrinter {
   ~PeakPrinter() {
+    printf("--- skip_list ---\n");
     printf("malloc bytes: %g\n", double(mallocBytes));
     printf("Peak malloc bytes: %g\n", double(peakMallocBytes));
   }

conflict_set.py

@@ -134,6 +134,4 @@ class ConflictSet:
             self.p = None
 
     def __exit__(self, exception_type, exception_value, exception_traceback):
-        if self.p is not None:
+        self.close()
-            self._lib.ConflictSet_destroy(self.p)
-            self.p = None

test_conflict_set.py

@@ -1,8 +1,45 @@
 from conflict_set import *
 
 
+class DebugConflictSet:
+    """
+    Bisimulates the skip list and radix tree conflict sets for testing purposes
+    """
+
+    def __init__(self, version: int = 0) -> None:
+        self.skip_list = ConflictSet(version, implementation="skip_list")
+        self.radix_tree = ConflictSet(version, implementation="radix_tree")
+
+    def addWrites(self, version: int, *writes: WriteRange):
+        self.skip_list.addWrites(version, *writes)
+        self.radix_tree.addWrites(version, *writes)
+
+    def check(self, *reads: ReadRange) -> list[Result]:
+        expected = self.skip_list.check(*reads)
+        actual = self.radix_tree.check(*reads)
+        assert expected == actual
+        return actual
+
+    def setOldestVersion(self, version: int) -> None:
+        self.skip_list.setOldestVersion(version)
+        self.radix_tree.setOldestVersion(version)
+
+    def getBytes(self) -> int:
+        return self.radix_tree.getBytes()
+
+    def __enter__(self):
+        return self
+
+    def close(self) -> None:
+        self.skip_list.close()
+        self.radix_tree.close()
+
+    def __exit__(self, exception_type, exception_value, exception_traceback):
+        self.close()
+
+
 def test_conflict_set():
-    with ConflictSet() as cs:
+    with DebugConflictSet() as cs:
         before = cs.getBytes()
         key = b"a key"
         cs.addWrites(1, write(key))