fuzz: add steady clock mocking to FuzzedSock

Author: darosior

src/test/fuzz/util/net.cpp

@@ -113,8 +113,10 @@ template CAddress::SerParams ConsumeDeserializationParams(FuzzedDataProvider&) n
 FuzzedSock::FuzzedSock(FuzzedDataProvider& fuzzed_data_provider)
     : Sock{fuzzed_data_provider.ConsumeIntegralInRange<SOCKET>(INVALID_SOCKET - 1, INVALID_SOCKET)},
       m_fuzzed_data_provider{fuzzed_data_provider},
-      m_selectable{fuzzed_data_provider.ConsumeBool()}
+      m_selectable{fuzzed_data_provider.ConsumeBool()},
+      m_time{MockableSteadyClock::INITIAL_MOCK_TIME}
 {
+    ElapseTime(std::chrono::seconds(0)); // start mocking the steady clock.
 }
 
 FuzzedSock::~FuzzedSock()
@@ -126,6 +128,12 @@ FuzzedSock::~FuzzedSock()
     m_socket = INVALID_SOCKET;
 }
 
+void FuzzedSock::ElapseTime(std::chrono::milliseconds duration) const
+{
+    m_time += duration;
+    MockableSteadyClock::SetMockTime(m_time);
+}
+
 FuzzedSock& FuzzedSock::operator=(Sock&& other)
 {
     assert(false && "Move of Sock into FuzzedSock not allowed.");
@@ -388,6 +396,7 @@ bool FuzzedSock::Wait(std::chrono::milliseconds timeout, Event requested, Event*
         // FuzzedDataProvider runs out of data.
         *occurred = m_fuzzed_data_provider.ConsumeBool() ? 0 : requested;
     }
+    ElapseTime(timeout);
     return true;
 }
 
@@ -400,6 +409,7 @@ bool FuzzedSock::WaitMany(std::chrono::milliseconds timeout, EventsPerSock& even
         // FuzzedDataProvider runs out of data.
         events.occurred = m_fuzzed_data_provider.ConsumeBool() ? 0 : events.requested;
     }
+    ElapseTime(timeout);
     return true;
 }
 

src/test/fuzz/util/net.h

@@ -157,6 +157,16 @@ class FuzzedSock : public Sock
      */
     const bool m_selectable;
 
+    /**
+     * Used to mock the steady clock in methods waiting for a given duration.
+     */
+    mutable std::chrono::milliseconds m_time;
+
+    /**
+     * Set the value of the mocked steady clock such as that many ms have passed.
+     */
+    void ElapseTime(std::chrono::milliseconds duration) const;
+
 public:
     explicit FuzzedSock(FuzzedDataProvider& fuzzed_data_provider);