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Replace thread_local g_lockstack with a mutex-protected map

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This change prevents UB in case of early g_lockstack destroying.

Co-authored-by: Wladimir J. van der Laan <laanwj@protonmail.com>
This commit is contained in:
Hennadii Stepanov 2020-05-18 18:22:26 +03:00
parent 58e6881bc5
commit 26c093a995
No known key found for this signature in database
GPG key ID: 410108112E7EA81F
1 changed files with 37 additions and 14 deletions
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51
src/sync.cpp
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@ -16,6 +16,8 @@
#include <map>
#include <set>
#include <system_error>
#include <thread>
#include <unordered_map>
#include <utility>
#include <vector>
@ -77,12 +79,14 @@ private:
using LockStackItem = std::pair<void*, CLockLocation>;
using LockStack = std::vector<LockStackItem>;
using LockStacks = std::unordered_map<std::thread::id, LockStack>;
using LockPair = std::pair<void*, void*>;
using LockOrders = std::map<LockPair, LockStack>;
using InvLockOrders = std::set<LockPair>;
struct LockData {
LockStacks m_lock_stacks;
LockOrders lockorders;
InvLockOrders invlockorders;
std::mutex dd_mutex;
@ -95,8 +99,6 @@ LockData& GetLockData() {
return lock_data;
}
static thread_local LockStack g_lockstack;
static void potential_deadlock_detected(const LockPair& mismatch, const LockStack& s1, const LockStack& s2)
{
LogPrintf("POTENTIAL DEADLOCK DETECTED\n");
@ -132,16 +134,16 @@ static void push_lock(void* c, const CLockLocation& locklocation)
LockData& lockdata = GetLockData();
std::lock_guard<std::mutex> lock(lockdata.dd_mutex);
g_lockstack.push_back(std::make_pair(c, locklocation));
for (const LockStackItem& i : g_lockstack) {
LockStack& lock_stack = lockdata.m_lock_stacks[std::this_thread::get_id()];
lock_stack.emplace_back(c, locklocation);
for (const LockStackItem& i : lock_stack) {
if (i.first == c)
break;
const LockPair p1 = std::make_pair(i.first, c);
if (lockdata.lockorders.count(p1))
continue;
lockdata.lockorders.emplace(p1, g_lockstack);
lockdata.lockorders.emplace(p1, lock_stack);
const LockPair p2 = std::make_pair(c, i.first);
lockdata.invlockorders.insert(p2);
@ -152,7 +154,14 @@ static void push_lock(void* c, const CLockLocation& locklocation)
static void pop_lock()
{
g_lockstack.pop_back();
LockData& lockdata = GetLockData();
std::lock_guard<std::mutex> lock(lockdata.dd_mutex);
LockStack& lock_stack = lockdata.m_lock_stacks[std::this_thread::get_id()];
lock_stack.pop_back();
if (lock_stack.empty()) {
lockdata.m_lock_stacks.erase(std::this_thread::get_id());
}
}
void EnterCritical(const char* pszName, const char* pszFile, int nLine, void* cs, bool fTry)
@ -162,11 +171,17 @@ void EnterCritical(const char* pszName, const char* pszFile, int nLine, void* cs
void CheckLastCritical(void* cs, std::string& lockname, const char* guardname, const char* file, int line)
{
if (!g_lockstack.empty()) {
const auto& lastlock = g_lockstack.back();
if (lastlock.first == cs) {
lockname = lastlock.second.Name();
return;
{
LockData& lockdata = GetLockData();
std::lock_guard<std::mutex> lock(lockdata.dd_mutex);
const LockStack& lock_stack = lockdata.m_lock_stacks[std::this_thread::get_id()];
if (!lock_stack.empty()) {
const auto& lastlock = lock_stack.back();
if (lastlock.first == cs) {
lockname = lastlock.second.Name();
return;
}
}
}
throw std::system_error(EPERM, std::generic_category(), strprintf("%s:%s %s was not most recent critical section locked", file, line, guardname));
@ -179,15 +194,23 @@ void LeaveCritical()
std::string LocksHeld()
{
LockData& lockdata = GetLockData();
std::lock_guard<std::mutex> lock(lockdata.dd_mutex);
const LockStack& lock_stack = lockdata.m_lock_stacks[std::this_thread::get_id()];
std::string result;
for (const LockStackItem& i : g_lockstack)
for (const LockStackItem& i : lock_stack)
result += i.second.ToString() + std::string("\n");
return result;
}
static bool LockHeld(void* mutex)
{
for (const LockStackItem& i : g_lockstack) {
LockData& lockdata = GetLockData();
std::lock_guard<std::mutex> lock(lockdata.dd_mutex);
const LockStack& lock_stack = lockdata.m_lock_stacks[std::this_thread::get_id()];
for (const LockStackItem& i : lock_stack) {
if (i.first == mutex) return true;
}