merge bitcoin#16127: more thread safety annotation coverage

src/logging.cpp

@@ -33,7 +33,7 @@ static int FileWriteStr(const std::string &str, FILE *fp)
 
 bool BCLog::Logger::StartLogging()
 {
-    std::lock_guard<std::mutex> scoped_lock(m_cs);
+    LockGuard scoped_lock(m_cs);
 
     assert(m_buffering);
     assert(m_fileout == nullptr);
@@ -246,7 +246,7 @@ std::string BCLog::Logger::LogTimestampStr(const std::string &str)
 
 std::string BCLog::Logger::LogThreadNameStr(const std::string &str)
 {
-    std::lock_guard<std::mutex> scoped_lock(m_cs);
+    LockGuard scoped_lock(m_cs);
     std::string strThreadLogged = str;
 
     if (!m_log_thread_names)

src/logging.h

@@ -8,6 +8,7 @@
 
 #include <fs.h>
 #include <tinyformat.h>
+#include <threadsafety.h>
 
 #include <atomic>
 #include <cstdint>
@@ -83,9 +84,10 @@ namespace BCLog {
     {
     private:
         mutable std::mutex m_cs;                   // Can not use Mutex from sync.h because in debug mode it would cause a deadlock when a potential deadlock was detected
-        FILE* m_fileout = nullptr;                 // GUARDED_BY(m_cs)
-        std::list<std::string> m_msgs_before_open; // GUARDED_BY(m_cs)
-        bool m_buffering{true};                    //!< Buffer messages before logging can be started. GUARDED_BY(m_cs)
+
+        FILE* m_fileout GUARDED_BY(m_cs) = nullptr;
+        std::list<std::string> m_msgs_before_open GUARDED_BY(m_cs);
+        bool m_buffering GUARDED_BY(m_cs) = true; //!< Buffer messages before logging can be started.
 
         /**
          * m_started_new_line is a state variable that will suppress printing of
@@ -117,7 +119,7 @@ namespace BCLog {
         /** Returns whether logs will be written to any output */
         bool Enabled() const
         {
-            std::lock_guard<std::mutex> scoped_lock(m_cs);
+            LockGuard scoped_lock(m_cs);
             return m_buffering || m_print_to_console || m_print_to_file;
         }
 

src/net.cpp

@@ -2040,7 +2040,7 @@ void CConnman::ThreadSocketHandler()
 void CConnman::WakeMessageHandler()
 {
     {
-        std::lock_guard<std::mutex> lock(mutexMsgProc);
+        LOCK(mutexMsgProc);
         fMsgProcWake = true;
     }
     condMsgProc.notify_one();
@@ -2864,7 +2864,7 @@ void CConnman::ThreadMessageHandler()
 
         WAIT_LOCK(mutexMsgProc, lock);
         if (!fMoreWork) {
-            condMsgProc.wait_until(lock, std::chrono::steady_clock::now() + std::chrono::milliseconds(100), [this] { return fMsgProcWake; });
+            condMsgProc.wait_until(lock, std::chrono::steady_clock::now() + std::chrono::milliseconds(100), [this]() EXCLUSIVE_LOCKS_REQUIRED(mutexMsgProc) { return fMsgProcWake; });
         }
         fMsgProcWake = false;
     }
@@ -3303,7 +3303,7 @@ void CExplicitNetCleanup::callCleanup()
 void CConnman::Interrupt()
 {
     {
-        std::lock_guard<std::mutex> lock(mutexMsgProc);
+        LOCK(mutexMsgProc);
         flagInterruptMsgProc = true;
     }
     condMsgProc.notify_all();

src/net.h

@@ -617,7 +617,7 @@ friend class CNode;
     const uint64_t nSeed0, nSeed1;
 
     /** flag for waking the message processor. */
-    bool fMsgProcWake;
+    bool fMsgProcWake GUARDED_BY(mutexMsgProc);
 
     std::condition_variable condMsgProc;
     Mutex mutexMsgProc;

src/rpc/blockchain.cpp

@@ -55,7 +55,7 @@ struct CUpdatedBlock
 
 static Mutex cs_blockchange;
 static std::condition_variable cond_blockchange;
-static CUpdatedBlock latestblock;
+static CUpdatedBlock latestblock GUARDED_BY(cs_blockchange);
 
 extern void TxToJSON(const CTransaction& tx, const uint256 hashBlock, UniValue& entry);
 
@@ -247,7 +247,7 @@ static UniValue getbestchainlock(const JSONRPCRequest& request)
 void RPCNotifyBlockChange(bool ibd, const CBlockIndex * pindex)
 {
     if(pindex) {
-        std::lock_guard<std::mutex> lock(cs_blockchange);
+        LOCK(cs_blockchange);
         latestblock.hash = pindex->GetBlockHash();
         latestblock.height = pindex->nHeight;
     }
@@ -281,9 +281,9 @@ static UniValue waitfornewblock(const JSONRPCRequest& request)
         WAIT_LOCK(cs_blockchange, lock);
         block = latestblock;
         if(timeout)
-            cond_blockchange.wait_for(lock, std::chrono::milliseconds(timeout), [&block]{return latestblock.height != block.height || latestblock.hash != block.hash || !IsRPCRunning(); });
+            cond_blockchange.wait_for(lock, std::chrono::milliseconds(timeout), [&block]() EXCLUSIVE_LOCKS_REQUIRED(cs_blockchange) {return latestblock.height != block.height || latestblock.hash != block.hash || !IsRPCRunning(); });
         else
-            cond_blockchange.wait(lock, [&block]{return latestblock.height != block.height || latestblock.hash != block.hash || !IsRPCRunning(); });
+            cond_blockchange.wait(lock, [&block]() EXCLUSIVE_LOCKS_REQUIRED(cs_blockchange) {return latestblock.height != block.height || latestblock.hash != block.hash || !IsRPCRunning(); });
         block = latestblock;
     }
     UniValue ret(UniValue::VOBJ);
@@ -322,9 +322,9 @@ static UniValue waitforblock(const JSONRPCRequest& request)
     {
         WAIT_LOCK(cs_blockchange, lock);
         if(timeout)
-            cond_blockchange.wait_for(lock, std::chrono::milliseconds(timeout), [&hash]{return latestblock.hash == hash || !IsRPCRunning();});
+            cond_blockchange.wait_for(lock, std::chrono::milliseconds(timeout), [&hash]() EXCLUSIVE_LOCKS_REQUIRED(cs_blockchange) {return latestblock.hash == hash || !IsRPCRunning();});
         else
-            cond_blockchange.wait(lock, [&hash]{return latestblock.hash == hash || !IsRPCRunning(); });
+            cond_blockchange.wait(lock, [&hash]() EXCLUSIVE_LOCKS_REQUIRED(cs_blockchange) {return latestblock.hash == hash || !IsRPCRunning(); });
         block = latestblock;
     }
 
@@ -365,9 +365,9 @@ static UniValue waitforblockheight(const JSONRPCRequest& request)
     {
         WAIT_LOCK(cs_blockchange, lock);
         if(timeout)
-            cond_blockchange.wait_for(lock, std::chrono::milliseconds(timeout), [&height]{return latestblock.height >= height || !IsRPCRunning();});
+            cond_blockchange.wait_for(lock, std::chrono::milliseconds(timeout), [&height]() EXCLUSIVE_LOCKS_REQUIRED(cs_blockchange) {return latestblock.height >= height || !IsRPCRunning();});
         else
-            cond_blockchange.wait(lock, [&height]{return latestblock.height >= height || !IsRPCRunning(); });
+            cond_blockchange.wait(lock, [&height]() EXCLUSIVE_LOCKS_REQUIRED(cs_blockchange) {return latestblock.height >= height || !IsRPCRunning(); });
         block = latestblock;
     }
     UniValue ret(UniValue::VOBJ);

src/test/checkqueue_tests.cpp

@@ -2,6 +2,7 @@
 // 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 <utiltime.h>
 #include <validation.h>
@@ -59,14 +60,14 @@ struct FailingCheck {
 };
 
 struct UniqueCheck {
-    static std::mutex m;
-    static std::unordered_multiset<size_t> results;
+    static Mutex m;
+    static std::unordered_multiset<size_t> results GUARDED_BY(m);
     size_t check_id;
     UniqueCheck(size_t check_id_in) : check_id(check_id_in){};
     UniqueCheck() : check_id(0){};
     bool operator()()
     {
-        std::lock_guard<std::mutex> l(m);
+        LOCK(m);
         results.insert(check_id);
         return true;
     }
@@ -129,7 +130,7 @@ struct FrozenCleanupCheck {
 std::mutex FrozenCleanupCheck::m{};
 std::atomic<uint64_t> FrozenCleanupCheck::nFrozen{0};
 std::condition_variable FrozenCleanupCheck::cv{};
-std::mutex UniqueCheck::m;
+Mutex UniqueCheck::m;
 std::unordered_multiset<size_t> UniqueCheck::results;
 std::atomic<size_t> FakeCheckCheckCompletion::n_calls{0};
 std::atomic<size_t> MemoryCheck::fake_allocated_memory{0};
@@ -293,11 +294,15 @@ BOOST_AUTO_TEST_CASE(test_CheckQueue_UniqueCheck)
             control.Add(vChecks);
         }
     }
-    bool r = true;
-    BOOST_REQUIRE_EQUAL(UniqueCheck::results.size(), COUNT);
-    for (size_t i = 0; i < COUNT; ++i)
-        r = r && UniqueCheck::results.count(i) == 1;
-    BOOST_REQUIRE(r);
+    {
+        LOCK(UniqueCheck::m);
+        bool r = true;
+        BOOST_REQUIRE_EQUAL(UniqueCheck::results.size(), COUNT);
+        for (size_t i = 0; i < COUNT; ++i) {
+            r = r && UniqueCheck::results.count(i) == 1;
+        }
+        BOOST_REQUIRE(r);
+    }
     tg.interrupt_all();
     tg.join_all();
 }
@@ -442,4 +447,3 @@ BOOST_AUTO_TEST_CASE(test_CheckQueueControl_Locks)
     }
 }
 BOOST_AUTO_TEST_SUITE_END()
-

src/threadsafety.h

@@ -6,6 +6,8 @@
 #ifndef BITCOIN_THREADSAFETY_H
 #define BITCOIN_THREADSAFETY_H
 
+#include <mutex>
+
 #ifdef __clang__
 // TL;DR Add GUARDED_BY(mutex) to member variables. The others are
 // rarely necessary. Ex: int nFoo GUARDED_BY(cs_foo);
@@ -54,4 +56,13 @@
 #define ASSERT_EXCLUSIVE_LOCK(...)
 #endif // __GNUC__
 
+// LockGuard provides an annotated version of lock_guard for us
+// should only be used when sync.h Mutex/LOCK/etc aren't usable
+class SCOPED_LOCKABLE LockGuard : public std::lock_guard<std::mutex>
+{
+public:
+    explicit LockGuard(std::mutex& cs) EXCLUSIVE_LOCK_FUNCTION(cs) : std::lock_guard<std::mutex>(cs) { }
+    ~LockGuard() UNLOCK_FUNCTION() {};
+};
+
 #endif // BITCOIN_THREADSAFETY_H

src/util.cpp

@@ -153,18 +153,19 @@ class CInit
 }
 instance_of_cinit;
 
+/** Mutex to protect dir_locks. */
+static Mutex cs_dir_locks;
+
 /** A map that contains all the currently held directory locks. After
  * successful locking, these will be held here until the global destructor
  * cleans them up and thus automatically unlocks them, or ReleaseDirectoryLocks
  * is called.
  */
-static std::map<std::string, std::unique_ptr<fsbridge::FileLock>> dir_locks;
-/** Mutex to protect dir_locks. */
-static std::mutex cs_dir_locks;
+static std::map<std::string, std::unique_ptr<fsbridge::FileLock>> dir_locks GUARDED_BY(cs_dir_locks);
 
 bool LockDirectory(const fs::path& directory, const std::string lockfile_name, bool probe_only)
 {
-    std::lock_guard<std::mutex> ulock(cs_dir_locks);
+    LOCK(cs_dir_locks);
     fs::path pathLockFile = directory / lockfile_name;
 
     // If a lock for this directory already exists in the map, don't try to re-lock it
@@ -188,7 +189,7 @@ bool LockDirectory(const fs::path& directory, const std::string lockfile_name, b
 
 void ReleaseDirectoryLocks()
 {
-    std::lock_guard<std::mutex> ulock(cs_dir_locks);
+    LOCK(cs_dir_locks);
     dir_locks.clear();
 }
 

src/wallet/wallet.h

@@ -703,7 +703,6 @@ class CWallet final : public CCryptoKeyStore, public CValidationInterface
     std::atomic<bool> fScanningWallet{false}; // controlled by WalletRescanReserver
     std::atomic<int64_t> m_scanning_start{0};
     std::atomic<double> m_scanning_progress{0};
-    std::mutex mutexScanning;
     friend class WalletRescanReserver;
 
     WalletBatch *encrypted_batch = nullptr;
@@ -1332,13 +1331,11 @@ class WalletRescanReserver
     bool reserve()
     {
         assert(!m_could_reserve);
-        std::lock_guard<std::mutex> lock(m_wallet->mutexScanning);
-        if (m_wallet->fScanningWallet) {
+        if (m_wallet->fScanningWallet.exchange(true)) {
             return false;
         }
         m_wallet->m_scanning_start = GetTimeMillis();
         m_wallet->m_scanning_progress = 0;
-        m_wallet->fScanningWallet = true;
         m_could_reserve = true;
         return true;
     }
@@ -1350,7 +1347,6 @@ class WalletRescanReserver
 
     ~WalletRescanReserver()
     {
-        std::lock_guard<std::mutex> lock(m_wallet->mutexScanning);
         if (m_could_reserve) {
             m_wallet->fScanningWallet = false;
         }