backport: bitcoin#27405 — util: Use steady clock instead of system clock to measure durations (#11)

* Merge bitcoin#27405: util: Use steady clock instead of system clock to measure durations

fa83fb3 wallet: Use steady clock to calculate number of derive iterations (MarcoFalke)
fa2c099 wallet: Use steady clock to measure scanning duration (MarcoFalke)
fa97621 qt: Use steady clock to throttle GUI notifications (MarcoFalke)
fa1d804 test: Use steady clock in index tests (MarcoFalke)
fa454dc net: Use steady clock in InterruptibleRecv (MarcoFalke)

Pull request description:

  `GetTimeMillis` has multiple issues:

  * It doesn't denote the underlying clock type
  * It isn't type-safe
  * It is used incorrectly in places that should use a steady clock

  Fix all issues here.

ACKs for top commit:
  willcl-ark:
    ACK fa83fb3
  martinus:
    Code review ACK bitcoin@fa83fb3, also ran all tests. All usages of the steady_clock are just for duration measurements, so the change to a different epoch is ok.

Tree-SHA512: 5ec4fede8c7f97e2e08863c011856e8304f16ba30a68fdeb42f96a50a04961092cbe46ccf9ea6ac99ff5203c09f9e0924eb483eb38d7df0759addc85116c8a9f

* fix: add MillisecondsDouble type alias for backport compatibility

* fix: add missing util/time.h include to wallet.cpp

The backport of bitcoin#27405 introduced usage of MillisecondsDouble
and SteadyClock in wallet/wallet.cpp but didn't add the corresponding
include for util/time.h, causing build failures across all CI
platforms.

---------

Co-authored-by: fanquake <fanquake@gmail.com>
Co-authored-by: PastaClaw <thepastaclaw@users.noreply.github.com>

Author: thepastaclaw

src/netbase.cpp

@@ -35,8 +35,8 @@ static Proxy nameProxy GUARDED_BY(g_proxyinfo_mutex);
 int nConnectTimeout = DEFAULT_CONNECT_TIMEOUT;
 bool fNameLookup = DEFAULT_NAME_LOOKUP;
 
-// Need ample time for negotiation for very slow proxies such as Tor (milliseconds)
-int g_socks5_recv_timeout = 20 * 1000;
+// Need ample time for negotiation for very slow proxies such as Tor
+std::chrono::milliseconds g_socks5_recv_timeout = 20s;
 static std::atomic<bool> interruptSocks5Recv(false);
 
 ReachableNets g_reachable_nets;
@@ -300,7 +300,7 @@ enum class IntrRecvError {
  *
  * @param data The buffer where the read bytes should be stored.
  * @param len The number of bytes to read into the specified buffer.
- * @param timeout The total timeout in milliseconds for this read.
+ * @param timeout The total timeout for this read.
  * @param sock The socket (has to be in non-blocking mode) from which to read bytes.
  *
  * @returns An IntrRecvError indicating the resulting status of this read.
@@ -310,10 +310,10 @@ enum class IntrRecvError {
  * @see This function can be interrupted by calling InterruptSocks5(bool).
  *      Sockets can be made non-blocking with Sock::SetNonBlocking().
  */
-static IntrRecvError InterruptibleRecv(uint8_t* data, size_t len, int timeout, const Sock& sock)
+static IntrRecvError InterruptibleRecv(uint8_t* data, size_t len, std::chrono::milliseconds timeout, const Sock& sock)
 {
-    int64_t curTime = TicksSinceEpoch<std::chrono::milliseconds>(SystemClock::now());
-    int64_t endTime = curTime + timeout;
+    auto curTime{Now<SteadyMilliseconds>()};
+    const auto endTime{curTime + timeout};
     while (len > 0 && curTime < endTime) {
         ssize_t ret = sock.Recv(data, len, 0); // Optimistically try the recv first
         if (ret > 0) {
@@ -337,7 +337,7 @@ static IntrRecvError InterruptibleRecv(uint8_t* data, size_t len, int timeout, c
         }
         if (interruptSocks5Recv)
             return IntrRecvError::Interrupted;
-        curTime = TicksSinceEpoch<std::chrono::milliseconds>(SystemClock::now());
+        curTime = Now<SteadyMilliseconds>();
     }
     return len == 0 ? IntrRecvError::OK : IntrRecvError::Timeout;
 }

src/qt/clientmodel.cpp

@@ -34,8 +34,8 @@
 #include <QThread>
 #include <QTimer>
 
-static int64_t nLastHeaderTipUpdateNotification = 0;
-static int64_t nLastBlockTipUpdateNotification = 0;
+static SteadyClock::time_point g_last_header_tip_update_notification{};
+static SteadyClock::time_point g_last_block_tip_update_notification{};
 
 ClientModel::ClientModel(interfaces::Node& node, OptionsModel *_optionsModel, QObject *parent) :
     QObject(parent),
@@ -275,9 +275,9 @@ void ClientModel::TipChanged(SynchronizationState sync_state, interfaces::BlockT
 
     // Throttle GUI notifications about (a) blocks during initial sync, and (b) both blocks and headers during reindex.
     const bool throttle = (sync_state != SynchronizationState::POST_INIT && !header) || sync_state == SynchronizationState::INIT_REINDEX;
-    const int64_t now = throttle ? TicksSinceEpoch<std::chrono::milliseconds>(SystemClock::now()) : 0;
-    int64_t& nLastUpdateNotification = header ? nLastHeaderTipUpdateNotification : nLastBlockTipUpdateNotification;
-    if (throttle && now < nLastUpdateNotification + count_milliseconds(MODEL_UPDATE_DELAY)) {
+    const auto now{throttle ? SteadyClock::now() : SteadyClock::time_point{}};
+    auto& nLastUpdateNotification = header ? g_last_header_tip_update_notification : g_last_block_tip_update_notification;
+    if (throttle && now < nLastUpdateNotification + MODEL_UPDATE_DELAY) {
         return;
     }
 

src/test/fuzz/socks5.cpp

@@ -13,12 +13,12 @@
 #include <string>
 #include <vector>
 
+extern std::chrono::milliseconds g_socks5_recv_timeout;
+
 namespace {
-int default_socks5_recv_timeout;
+decltype(g_socks5_recv_timeout) default_socks5_recv_timeout;
 };
 
-extern int g_socks5_recv_timeout;
-
 void initialize_socks5()
 {
     static const auto testing_setup = MakeNoLogFileContext<>();
@@ -34,7 +34,7 @@ FUZZ_TARGET(socks5, .init = initialize_socks5)
     InterruptSocks5(fuzzed_data_provider.ConsumeBool());
     // Set FUZZED_SOCKET_FAKE_LATENCY=1 to exercise recv timeout code paths. This
     // will slow down fuzzing.
-    g_socks5_recv_timeout = (fuzzed_data_provider.ConsumeBool() && std::getenv("FUZZED_SOCKET_FAKE_LATENCY") != nullptr) ? 1 : default_socks5_recv_timeout;
+    g_socks5_recv_timeout = (fuzzed_data_provider.ConsumeBool() && std::getenv("FUZZED_SOCKET_FAKE_LATENCY") != nullptr) ? 1ms : default_socks5_recv_timeout;
     FuzzedSock fuzzed_sock = ConsumeSock(fuzzed_data_provider);
     // This Socks5(...) fuzzing harness would have caught CVE-2017-18350 within
     // a few seconds of fuzzing.

src/util/time.h

@@ -93,6 +93,7 @@ constexpr int64_t count_microseconds(std::chrono::microseconds t) { return t.cou
 
 using HoursDouble = std::chrono::duration<double, std::chrono::hours::period>;
 using SecondsDouble = std::chrono::duration<double, std::chrono::seconds::period>;
+using MillisecondsDouble = std::chrono::duration<double, std::chrono::milliseconds::period>;
 
 /**
  * DEPRECATED

src/wallet/rpc/wallet.cpp

@@ -263,7 +263,7 @@ static RPCHelpMan getwalletinfo()
     obj.pushKV("avoid_reuse", pwallet->IsWalletFlagSet(WALLET_FLAG_AVOID_REUSE));
     if (pwallet->IsScanning()) {
         UniValue scanning(UniValue::VOBJ);
-        scanning.pushKV("duration", pwallet->ScanningDuration() / 1000);
+        scanning.pushKV("duration", Ticks<std::chrono::seconds>(pwallet->ScanningDuration()));
         scanning.pushKV("progress", pwallet->ScanningProgress());
         obj.pushKV("scanning", scanning);
     } else {

src/wallet/wallet.cpp

@@ -33,6 +33,7 @@
 #include <util/error.h>
 #include <util/moneystr.h>
 #include <util/string.h>
+#include <util/time.h>
 #include <util/translation.h>
 #ifdef USE_BDB
 #include <wallet/bdb.h>
@@ -570,13 +571,14 @@ bool CWallet::ChangeWalletPassphrase(const SecureString& strOldWalletPassphrase,
                 return false;
             if (Unlock(_vMasterKey))
             {
-                int64_t nStartTime = TicksSinceEpoch<std::chrono::milliseconds>(SystemClock::now());
+                constexpr MillisecondsDouble target{100};
+                auto start{SteadyClock::now()};
                 crypter.SetKeyFromPassphrase(strNewWalletPassphrase, pMasterKey.second.vchSalt, pMasterKey.second.nDeriveIterations, pMasterKey.second.nDerivationMethod);
-                pMasterKey.second.nDeriveIterations = static_cast<unsigned int>(pMasterKey.second.nDeriveIterations * (100 / ((double)(TicksSinceEpoch<std::chrono::milliseconds>(SystemClock::now()) - nStartTime))));
+                pMasterKey.second.nDeriveIterations = static_cast<unsigned int>(pMasterKey.second.nDeriveIterations * target / (SteadyClock::now() - start));
 
-                nStartTime = TicksSinceEpoch<std::chrono::milliseconds>(SystemClock::now());
+                start = SteadyClock::now();
                 crypter.SetKeyFromPassphrase(strNewWalletPassphrase, pMasterKey.second.vchSalt, pMasterKey.second.nDeriveIterations, pMasterKey.second.nDerivationMethod);
-                pMasterKey.second.nDeriveIterations = (pMasterKey.second.nDeriveIterations + static_cast<unsigned int>(pMasterKey.second.nDeriveIterations * 100 / ((double)(TicksSinceEpoch<std::chrono::milliseconds>(SystemClock::now()) - nStartTime)))) / 2;
+                pMasterKey.second.nDeriveIterations = (pMasterKey.second.nDeriveIterations + static_cast<unsigned int>(pMasterKey.second.nDeriveIterations * target / (SteadyClock::now() - start))) / 2;
 
                 if (pMasterKey.second.nDeriveIterations < 25000)
                     pMasterKey.second.nDeriveIterations = 25000;
@@ -775,13 +777,14 @@ bool CWallet::EncryptWallet(const SecureString& strWalletPassphrase)
     GetStrongRandBytes(kMasterKey.vchSalt);
 
     CCrypter crypter;
-    int64_t nStartTime = TicksSinceEpoch<std::chrono::milliseconds>(SystemClock::now());
+    constexpr MillisecondsDouble target{100};
+    auto start{SteadyClock::now()};
     crypter.SetKeyFromPassphrase(strWalletPassphrase, kMasterKey.vchSalt, 25000, kMasterKey.nDerivationMethod);
-    kMasterKey.nDeriveIterations = static_cast<unsigned int>(2500000 / ((double)(TicksSinceEpoch<std::chrono::milliseconds>(SystemClock::now()) - nStartTime)));
+    kMasterKey.nDeriveIterations = static_cast<unsigned int>(25000 * target / (SteadyClock::now() - start));
 
-    nStartTime = TicksSinceEpoch<std::chrono::milliseconds>(SystemClock::now());
+    start = SteadyClock::now();
     crypter.SetKeyFromPassphrase(strWalletPassphrase, kMasterKey.vchSalt, kMasterKey.nDeriveIterations, kMasterKey.nDerivationMethod);
-    kMasterKey.nDeriveIterations = (kMasterKey.nDeriveIterations + static_cast<unsigned int>(kMasterKey.nDeriveIterations * 100 / ((double)(TicksSinceEpoch<std::chrono::milliseconds>(SystemClock::now()) - nStartTime)))) / 2;
+    kMasterKey.nDeriveIterations = (kMasterKey.nDeriveIterations + static_cast<unsigned int>(kMasterKey.nDeriveIterations * target / (SteadyClock::now() - start))) / 2;
 
     if (kMasterKey.nDeriveIterations < 25000)
         kMasterKey.nDeriveIterations = 25000;

src/wallet/wallet.h

@@ -290,7 +290,7 @@ class CWallet final : public WalletStorage, public interfaces::Chain::Notificati
     std::atomic<bool> fAbortRescan{false}; // reset by WalletRescanReserver::reserve()
     std::atomic<bool> fScanningWallet{false}; // controlled by WalletRescanReserver
     std::atomic<bool> m_attaching_chain{false};
-    std::atomic<int64_t> m_scanning_start{0};
+    std::atomic<SteadyClock::time_point> m_scanning_start{SteadyClock::time_point{}};
     std::atomic<double> m_scanning_progress{0};
     friend class WalletRescanReserver;
 
@@ -608,7 +608,7 @@ class CWallet final : public WalletStorage, public interfaces::Chain::Notificati
     void AbortRescan() { fAbortRescan = true; }
     bool IsAbortingRescan() const { return fAbortRescan; }
     bool IsScanning() const { return fScanningWallet; }
-    int64_t ScanningDuration() const { return fScanningWallet ? TicksSinceEpoch<std::chrono::milliseconds>(SystemClock::now()) - m_scanning_start : 0; }
+    SteadyClock::duration ScanningDuration() const { return fScanningWallet ? SteadyClock::now() - m_scanning_start.load() : SteadyClock::duration{}; }
     double ScanningProgress() const { return fScanningWallet ? (double) m_scanning_progress : 0; }
 
     //! Upgrade stored CKeyMetadata objects to store key origin info as KeyOriginInfo
@@ -1123,7 +1123,7 @@ class WalletRescanReserver
         if (m_wallet.fScanningWallet.exchange(true)) {
             return false;
         }
-        m_wallet.m_scanning_start = TicksSinceEpoch<std::chrono::milliseconds>(SystemClock::now());
+        m_wallet.m_scanning_start = SteadyClock::now();
         m_wallet.m_scanning_progress = 0;
         m_wallet.fAbortRescan = false;
         m_could_reserve = true;