1 // Copyright (c) 2011-2012 The Bitcoin developers
2 // Distributed under the MIT/X11 software license, see the accompanying
3 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
8 #include <boost/foreach.hpp>
10 #ifdef DEBUG_LOCKCONTENTION
11 void PrintLockContention(const char* pszName, const char* pszFile, int nLine)
13 printf("LOCKCONTENTION: %s\n", pszName);
14 printf("Locker: %s:%d\n", pszFile, nLine);
16 #endif /* DEBUG_LOCKCONTENTION */
18 #ifdef DEBUG_LOCKORDER
20 // Early deadlock detection.
21 // Problem being solved:
22 // Thread 1 locks A, then B, then C
23 // Thread 2 locks D, then C, then A
24 // --> may result in deadlock between the two threads, depending on when they run.
25 // Solution implemented here:
26 // Keep track of pairs of locks: (A before B), (A before C), etc.
27 // Complain if any thread tries to lock in a different order.
32 CLockLocation(const char* pszName, const char* pszFile, int nLine)
39 std::string ToString() const
41 return mutexName+" "+sourceFile+":"+itostr(sourceLine);
45 std::string mutexName;
46 std::string sourceFile;
50 typedef std::vector< std::pair<void*, CLockLocation> > LockStack;
52 static boost::mutex dd_mutex;
53 static std::map<std::pair<void*, void*>, LockStack> lockorders;
54 static boost::thread_specific_ptr<LockStack> lockstack;
57 static void potential_deadlock_detected(const std::pair<void*, void*>& mismatch, const LockStack& s1, const LockStack& s2)
59 printf("POTENTIAL DEADLOCK DETECTED\n");
60 printf("Previous lock order was:\n");
61 BOOST_FOREACH(const PAIRTYPE(void*, CLockLocation)& i, s2)
63 if (i.first == mismatch.first) printf(" (1)");
64 if (i.first == mismatch.second) printf(" (2)");
65 printf(" %s\n", i.second.ToString().c_str());
67 printf("Current lock order is:\n");
68 BOOST_FOREACH(const PAIRTYPE(void*, CLockLocation)& i, s1)
70 if (i.first == mismatch.first) printf(" (1)");
71 if (i.first == mismatch.second) printf(" (2)");
72 printf(" %s\n", i.second.ToString().c_str());
76 static void push_lock(void* c, const CLockLocation& locklocation, bool fTry)
78 if (lockstack.get() == NULL)
79 lockstack.reset(new LockStack);
81 if (fDebug) printf("Locking: %s\n", locklocation.ToString().c_str());
84 (*lockstack).push_back(std::make_pair(c, locklocation));
87 BOOST_FOREACH(const PAIRTYPE(void*, CLockLocation)& i, (*lockstack)) {
88 if (i.first == c) break;
90 std::pair<void*, void*> p1 = std::make_pair(i.first, c);
91 if (lockorders.count(p1))
93 lockorders[p1] = (*lockstack);
95 std::pair<void*, void*> p2 = std::make_pair(c, i.first);
96 if (lockorders.count(p2))
98 potential_deadlock_detected(p1, lockorders[p2], lockorders[p1]);
106 static void pop_lock()
110 const CLockLocation& locklocation = (*lockstack).rbegin()->second;
111 printf("Unlocked: %s\n", locklocation.ToString().c_str());
114 (*lockstack).pop_back();
118 void EnterCritical(const char* pszName, const char* pszFile, int nLine, void* cs, bool fTry)
120 push_lock(cs, CLockLocation(pszName, pszFile, nLine), fTry);
128 #endif /* DEBUG_LOCKORDER */