Add process heap locking to DetourTransaction (#128)

I realized based on
cyb3rpsych0s1s/audioware#81, that Detours use
`new`/`delete` operators while the threads are suspended. which cause
deadlocks when a thread has the lock on the process' heap.

This PR gets the heap lock when the transactions starts.

Author: wopss

src/dll/DetourTransaction.cpp

@@ -19,10 +19,21 @@ extern "C" NTSYSCALLAPI NTSTATUS NTAPI NtGetNextThread(_In_ HANDLE ProcessHandle
 DetourTransaction::DetourTransaction(const std::source_location aSource)
     : m_source(aSource)
     , m_state(State::Invalid)
+    , m_hasHeapLock(false)
 {
     spdlog::trace("Trying to start a detour transaction in '{}' ({}:{})", m_source.function_name(),
                   m_source.file_name(), m_source.line());
 
+    auto hasLock = HeapLock(GetProcessHeap());
+    if (!hasLock)
+    {
+        spdlog::error("Could not lock the process heap in '{}' ({}:{}). Last error: {}", m_source.function_name(),
+                      m_source.file_name(), m_source.line(), GetLastError());
+        return;
+    }
+
+    m_hasHeapLock = true;
+
     auto result = DetourTransactionBegin();
     if (result == NO_ERROR)
     {
@@ -45,6 +56,11 @@ DetourTransaction::~DetourTransaction()
     {
         Abort();
     }
+
+    if (m_hasHeapLock)
+    {
+        HeapUnlock(GetProcessHeap());
+    }
 }
 
 const bool DetourTransaction::IsValid() const

src/dll/DetourTransaction.hpp

@@ -33,4 +33,5 @@ class DetourTransaction
     const std::source_location m_source;
     State m_state;
     std::vector<wil::unique_handle> m_handles;
+    bool m_hasHeapLock;
 };