Merge #7846: Clean up lockorder data of destroyed mutexes

5eeb913 Clean up lockorder data of destroyed mutexes (Pieter Wuille)

2 files changed, 65 insertions, 23 deletions

diff --git a/src/sync.cpp b/src/sync.cpp
index 8df8ae43f4..641ed2c8ca 100644
--- a/src/sync.cpp
+++ b/src/sync.cpp
@@ -56,11 +56,24 @@ private:
 };
 
 typedef std::vector<std::pair<void*, CLockLocation> > LockStack;
+typedef std::map<std::pair<void*, void*>, LockStack> LockOrders;
+typedef std::set<std::pair<void*, void*> > InvLockOrders;
 
-static boost::mutex dd_mutex;
-static std::map<std::pair<void*, void*>, LockStack> lockorders;
-static boost::thread_specific_ptr<LockStack> lockstack;
+struct LockData {
+    // Very ugly hack: as the global constructs and destructors run single
+    // threaded, we use this boolean to know whether LockData still exists,
+    // as DeleteLock can get called by global CCriticalSection destructors
+    // after LockData disappears.
+    bool available;
+    LockData() : available(true) {}
+    ~LockData() { available = false; }
 
+    LockOrders lockorders;
+    InvLockOrders invlockorders;
+    boost::mutex dd_mutex;
+} static lockdata;
+
+boost::thread_specific_ptr<LockStack> lockstack;
 
 static void potential_deadlock_detected(const std::pair<void*, void*>& mismatch, const LockStack& s1, const LockStack& s2)
 {
@@ -117,7 +130,7 @@ static void push_lock(void* c, const CLockLocation& locklocation, bool fTry)
     if (lockstack.get() == NULL)
         lockstack.reset(new LockStack);
 
-    dd_mutex.lock();
+    boost::unique_lock<boost::mutex> lock(lockdata.dd_mutex);
 
     (*lockstack).push_back(std::make_pair(c, locklocation));
 
@@ -127,23 +140,21 @@ static void push_lock(void* c, const CLockLocation& locklocation, bool fTry)
                 break;
 
             std::pair<void*, void*> p1 = std::make_pair(i.first, c);
-            if (lockorders.count(p1))
+            if (lockdata.lockorders.count(p1))
                 continue;
-            lockorders[p1] = (*lockstack);
+            lockdata.lockorders[p1] = (*lockstack);
 
             std::pair<void*, void*> p2 = std::make_pair(c, i.first);
-            if (lockorders.count(p2))
-                potential_deadlock_detected(p1, lockorders[p2], lockorders[p1]);
+            lockdata.invlockorders.insert(p2);
+            if (lockdata.lockorders.count(p2))
+                potential_deadlock_detected(p1, lockdata.lockorders[p2], lockdata.lockorders[p1]);
         }
     }
-    dd_mutex.unlock();
 }
 
 static void pop_lock()
 {
-    dd_mutex.lock();
     (*lockstack).pop_back();
-    dd_mutex.unlock();
 }
 
 void EnterCritical(const char* pszName, const char* pszFile, int nLine, void* cs, bool fTry)
@@ -173,4 +184,26 @@ void AssertLockHeldInternal(const char* pszName, const char* pszFile, int nLine,
     abort();
 }
 
+void DeleteLock(void* cs)
+{
+    if (!lockdata.available) {
+        // We're already shutting down.
+        return;
+    }
+    boost::unique_lock<boost::mutex> lock(lockdata.dd_mutex);
+    std::pair<void*, void*> item = std::make_pair(cs, (void*)0);
+    LockOrders::iterator it = lockdata.lockorders.lower_bound(item);
+    while (it != lockdata.lockorders.end() && it->first.first == cs) {
+        std::pair<void*, void*> invitem = std::make_pair(it->first.second, it->first.first);
+        lockdata.invlockorders.erase(invitem);
+        lockdata.lockorders.erase(it++);
+    }
+    InvLockOrders::iterator invit = lockdata.invlockorders.lower_bound(item);
+    while (invit != lockdata.invlockorders.end() && invit->first == cs) {
+        std::pair<void*, void*> invinvitem = std::make_pair(invit->second, invit->first);
+        lockdata.lockorders.erase(invinvitem);
+        lockdata.invlockorders.erase(invit++);
+    }
+}
+
 #endif /* DEBUG_LOCKORDER */
diff --git a/src/sync.h b/src/sync.h
index 34dd8c228e..0c58fb6b4e 100644
--- a/src/sync.h
+++ b/src/sync.h
@@ -71,30 +71,39 @@ public:
     }
 };
 
-/**
- * Wrapped boost mutex: supports recursive locking, but no waiting
- * TODO: We should move away from using the recursive lock by default.
- */
-typedef AnnotatedMixin<boost::recursive_mutex> CCriticalSection;
-
-/** Wrapped boost mutex: supports waiting but not recursive locking */
-typedef AnnotatedMixin<boost::mutex> CWaitableCriticalSection;
-
-/** Just a typedef for boost::condition_variable, can be wrapped later if desired */
-typedef boost::condition_variable CConditionVariable;
-
 #ifdef DEBUG_LOCKORDER
 void EnterCritical(const char* pszName, const char* pszFile, int nLine, void* cs, bool fTry = false);
 void LeaveCritical();
 std::string LocksHeld();
 void AssertLockHeldInternal(const char* pszName, const char* pszFile, int nLine, void* cs);
+void DeleteLock(void* cs);
 #else
 void static inline EnterCritical(const char* pszName, const char* pszFile, int nLine, void* cs, bool fTry = false) {}
 void static inline LeaveCritical() {}
 void static inline AssertLockHeldInternal(const char* pszName, const char* pszFile, int nLine, void* cs) {}
+void static inline DeleteLock(void* cs) {}
 #endif
 #define AssertLockHeld(cs) AssertLockHeldInternal(#cs, __FILE__, __LINE__, &cs)
 
+/**
+ * Wrapped boost mutex: supports recursive locking, but no waiting
+ * TODO: We should move away from using the recursive lock by default.
+ */
+class CCriticalSection : public AnnotatedMixin<boost::recursive_mutex>
+{
+public:
+    ~CCriticalSection() {
+        DeleteLock((void*)this);
+    }
+};
+
+typedef CCriticalSection CDynamicCriticalSection;
+/** Wrapped boost mutex: supports waiting but not recursive locking */
+typedef AnnotatedMixin<boost::mutex> CWaitableCriticalSection;
+
+/** Just a typedef for boost::condition_variable, can be wrapped later if desired */
+typedef boost::condition_variable CConditionVariable;
+
 #ifdef DEBUG_LOCKCONTENTION
 void PrintLockContention(const char* pszName, const char* pszFile, int nLine);
 #endif