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-rw-r--r--src/sync.cpp147
1 files changed, 102 insertions, 45 deletions
diff --git a/src/sync.cpp b/src/sync.cpp
index fd9bcb62b..1837e8d53 100644
--- a/src/sync.cpp
+++ b/src/sync.cpp
@@ -1,10 +1,24 @@
-// Copyright (c) 2011-2012 The Bitcoin developers
-// Distributed under the MIT/X11 software license, see the accompanying
-// file license.txt or http://www.opensource.org/licenses/mit-license.php.
+// Copyright (c) 2011-2012 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
#include "sync.h"
+#include "util.h"
+#include "utilstrencodings.h"
+#include <stdio.h>
+
+#include <boost/foreach.hpp>
+#include <boost/thread.hpp>
+
+#ifdef DEBUG_LOCKCONTENTION
+void PrintLockContention(const char* pszName, const char* pszFile, int nLine)
+{
+ LogPrintf("LOCKCONTENTION: %s\n", pszName);
+ LogPrintf("Locker: %s:%d\n", pszFile, nLine);
+}
+#endif /* DEBUG_LOCKCONTENTION */
#ifdef DEBUG_LOCKORDER
//
@@ -15,80 +29,111 @@
// --> may result in deadlock between the two threads, depending on when they run.
// Solution implemented here:
// Keep track of pairs of locks: (A before B), (A before C), etc.
-// Complain if any thread trys to lock in a different order.
+// Complain if any thread tries to lock in a different order.
//
-struct CLockLocation
-{
- CLockLocation(const char* pszName, const char* pszFile, int nLine)
+struct CLockLocation {
+ CLockLocation(const char* pszName, const char* pszFile, int nLine, bool fTryIn)
{
mutexName = pszName;
sourceFile = pszFile;
sourceLine = nLine;
+ fTry = fTryIn;
}
std::string ToString() const
{
- return mutexName+" "+sourceFile+":"+itostr(sourceLine);
+ return mutexName + " " + sourceFile + ":" + itostr(sourceLine) + (fTry ? " (TRY)" : "");
}
+ std::string MutexName() const { return mutexName; }
+
+ bool fTry;
private:
std::string mutexName;
std::string sourceFile;
int sourceLine;
};
-typedef std::vector< std::pair<void*, CLockLocation> > LockStack;
+typedef std::vector<std::pair<void*, CLockLocation> > LockStack;
-static boost::interprocess::interprocess_mutex dd_mutex;
+static boost::mutex dd_mutex;
static std::map<std::pair<void*, void*>, LockStack> lockorders;
static boost::thread_specific_ptr<LockStack> lockstack;
static void potential_deadlock_detected(const std::pair<void*, void*>& mismatch, const LockStack& s1, const LockStack& s2)
{
- printf("POTENTIAL DEADLOCK DETECTED\n");
- printf("Previous lock order was:\n");
- BOOST_FOREACH(const PAIRTYPE(void*, CLockLocation)& i, s2)
- {
- if (i.first == mismatch.first) printf(" (1)");
- if (i.first == mismatch.second) printf(" (2)");
- printf(" %s\n", i.second.ToString().c_str());
+ // We attempt to not assert on probably-not deadlocks by assuming that
+ // a try lock will immediately have otherwise bailed if it had
+ // failed to get the lock
+ // We do this by, for the locks which triggered the potential deadlock,
+ // in either lockorder, checking that the second of the two which is locked
+ // is only a TRY_LOCK, ignoring locks if they are reentrant.
+ bool firstLocked = false;
+ bool secondLocked = false;
+ bool onlyMaybeDeadlock = false;
+
+ LogPrintf("POTENTIAL DEADLOCK DETECTED\n");
+ LogPrintf("Previous lock order was:\n");
+ BOOST_FOREACH (const PAIRTYPE(void*, CLockLocation) & i, s2) {
+ if (i.first == mismatch.first) {
+ LogPrintf(" (1)");
+ if (!firstLocked && secondLocked && i.second.fTry)
+ onlyMaybeDeadlock = true;
+ firstLocked = true;
+ }
+ if (i.first == mismatch.second) {
+ LogPrintf(" (2)");
+ if (!secondLocked && firstLocked && i.second.fTry)
+ onlyMaybeDeadlock = true;
+ secondLocked = true;
+ }
+ LogPrintf(" %s\n", i.second.ToString());
}
- printf("Current lock order is:\n");
- BOOST_FOREACH(const PAIRTYPE(void*, CLockLocation)& i, s1)
- {
- if (i.first == mismatch.first) printf(" (1)");
- if (i.first == mismatch.second) printf(" (2)");
- printf(" %s\n", i.second.ToString().c_str());
+ firstLocked = false;
+ secondLocked = false;
+ LogPrintf("Current lock order is:\n");
+ BOOST_FOREACH (const PAIRTYPE(void*, CLockLocation) & i, s1) {
+ if (i.first == mismatch.first) {
+ LogPrintf(" (1)");
+ if (!firstLocked && secondLocked && i.second.fTry)
+ onlyMaybeDeadlock = true;
+ firstLocked = true;
+ }
+ if (i.first == mismatch.second) {
+ LogPrintf(" (2)");
+ if (!secondLocked && firstLocked && i.second.fTry)
+ onlyMaybeDeadlock = true;
+ secondLocked = true;
+ }
+ LogPrintf(" %s\n", i.second.ToString());
}
+ assert(onlyMaybeDeadlock);
}
static void push_lock(void* c, const CLockLocation& locklocation, bool fTry)
{
- bool fOrderOK = true;
if (lockstack.get() == NULL)
lockstack.reset(new LockStack);
- if (fDebug) printf("Locking: %s\n", locklocation.ToString().c_str());
dd_mutex.lock();
(*lockstack).push_back(std::make_pair(c, locklocation));
- if (!fTry) BOOST_FOREACH(const PAIRTYPE(void*, CLockLocation)& i, (*lockstack))
- {
- if (i.first == c) break;
-
- std::pair<void*, void*> p1 = std::make_pair(i.first, c);
- if (lockorders.count(p1))
- continue;
- 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]);
- break;
+ if (!fTry) {
+ BOOST_FOREACH (const PAIRTYPE(void*, CLockLocation) & i, (*lockstack)) {
+ if (i.first == c)
+ break;
+
+ std::pair<void*, void*> p1 = std::make_pair(i.first, c);
+ if (lockorders.count(p1))
+ continue;
+ 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]);
}
}
dd_mutex.unlock();
@@ -96,11 +141,6 @@ static void push_lock(void* c, const CLockLocation& locklocation, bool fTry)
static void pop_lock()
{
- if (fDebug)
- {
- const CLockLocation& locklocation = (*lockstack).rbegin()->second;
- printf("Unlocked: %s\n", locklocation.ToString().c_str());
- }
dd_mutex.lock();
(*lockstack).pop_back();
dd_mutex.unlock();
@@ -108,7 +148,7 @@ static void pop_lock()
void EnterCritical(const char* pszName, const char* pszFile, int nLine, void* cs, bool fTry)
{
- push_lock(cs, CLockLocation(pszName, pszFile, nLine), fTry);
+ push_lock(cs, CLockLocation(pszName, pszFile, nLine, fTry), fTry);
}
void LeaveCritical()
@@ -116,4 +156,21 @@ void LeaveCritical()
pop_lock();
}
+std::string LocksHeld()
+{
+ std::string result;
+ BOOST_FOREACH (const PAIRTYPE(void*, CLockLocation) & i, *lockstack)
+ result += i.second.ToString() + std::string("\n");
+ return result;
+}
+
+void AssertLockHeldInternal(const char* pszName, const char* pszFile, int nLine, void* cs)
+{
+ BOOST_FOREACH (const PAIRTYPE(void*, CLockLocation) & i, *lockstack)
+ if (i.first == cs)
+ return;
+ fprintf(stderr, "Assertion failed: lock %s not held in %s:%i; locks held:\n%s", pszName, pszFile, nLine, LocksHeld().c_str());
+ abort();
+}
+
#endif /* DEBUG_LOCKORDER */
generated by cgit v1.2.3 (git 2.25.1) at 2026-04-25 08:52:42 +0000