[IAST] Delay dataflow creation (#7451)

## Summary of changes
Delay dataflow instance creation until activation is received from
managed side

## Reason for change

## Implementation details

## Test coverage

## Other details
<!-- Fixes #{issue} -->


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Author: daniel-romano-DD

tracer/src/Datadog.Tracer.Native/cor_profiler.cpp

@@ -352,11 +352,7 @@ HRESULT STDMETHODCALLTYPE CorProfiler::Initialize(IUnknown* cor_profiler_info_un
     }
 
     // CallSite stuff
-    if (IsCallSiteManagedActivationEnabled())
-    {
-        _dataflow = new iast::Dataflow(info_, rejit_handler, runtime_information_);
-    }
-    else
+    if (!IsCallSiteManagedActivationEnabled())
     {
         Logger::Info("Callsite managed activation is disabled.");
         bool isRaspEnabled = IsRaspEnabled();
@@ -2177,10 +2173,17 @@ int CorProfiler::RegisterIastAspects(WCHAR** aspects, int aspectsLength, UINT32
 {
     auto _ = trace::Stats::Instance()->InitializeProfilerMeasure();
 
-    if (_dataflow != nullptr)
+    auto dataflow = _dataflow;
+    if (dataflow == nullptr && IsCallSiteManagedActivationEnabled())
+    {
+        dataflow = new iast::Dataflow(info_, rejit_handler, runtime_information_);
+    }
+
+    if (dataflow != nullptr)
     {
         Logger::Info("Registering Callsite Aspects.");
-        _dataflow->LoadAspects(aspects, aspectsLength, enabledCategories, platform);
+        dataflow->LoadAspects(aspects, aspectsLength, enabledCategories, platform);
+        _dataflow = dataflow;
         return aspectsLength;
     }
     else

tracer/src/Datadog.Tracer.Native/iast/dataflow.cpp

@@ -179,32 +179,29 @@ Dataflow::Dataflow(ICorProfilerInfo* profiler, std::shared_ptr<RejitHandler> rej
         trace::Logger::Error("Dataflow::Dataflow -> Something very wrong happened, as QI on ICorProfilerInfo3 failed. Disabling Dataflow. HRESULT : ", Hex(hr));
     }
 
-    _initialized = (_profiler != nullptr);
-    _aspectsLoaded = false;
+    _initialized = false;
 }
+
 Dataflow::~Dataflow()
 {
-    Destroy();
-}
-
-void Dataflow::Destroy()
-{
-    if (_initialized)
-    {
-        _initialized = false;
-        _aspectsLoaded = false;
-        REL(_profiler);
-        DEL_MAP_VALUES(_modules);
-        DEL_MAP_VALUES(_appDomains);
-        DEL_MAP_VALUES(_moduleAspects);
-    }
+    _initialized = false;
+    REL(_profiler);
+    DEL_MAP_VALUES(_modules);
+    DEL_MAP_VALUES(_appDomains);
+    DEL_MAP_VALUES(_moduleAspects);
 }
 
 void Dataflow::LoadAspects(WCHAR** aspects, int aspectsLength, UINT32 enabledCategories, UINT32 platform)
 {
     // Init aspects
     DBG("Dataflow::LoadAspects -> Processing aspects... ", aspectsLength, " Enabled categories: ", enabledCategories, " Platform: ", platform);
 
+    if (aspectsLength > 10)
+    {
+        _aspectClasses.reserve(aspectsLength / 10);
+        _aspects.reserve(aspectsLength);
+    }
+
     DataflowAspectClass* aspectClass = nullptr;
     for (int x = 0; x < aspectsLength; x++)
     {
@@ -243,7 +240,7 @@ void Dataflow::LoadAspects(WCHAR** aspects, int aspectsLength, UINT32 enabledCat
     DEL_MAP_VALUES(moduleAspects);
 
     trace::Logger::Info("Dataflow::LoadAspects -> read ", _aspects.size(), " aspects");
-    _aspectsLoaded = true;
+    _initialized = true;
 }
 
 void Dataflow::LoadSecurityControls()
@@ -369,7 +366,7 @@ void Dataflow::LoadSecurityControls()
 
 HRESULT Dataflow::AppDomainShutdown(AppDomainID appDomainId)
 {
-    if (!_aspectsLoaded)
+    if (!_initialized)
     {
         return S_OK;
     }
@@ -388,7 +385,7 @@ HRESULT Dataflow::AppDomainShutdown(AppDomainID appDomainId)
 
 HRESULT Dataflow::ModuleLoaded(ModuleID moduleId, ModuleInfo** pModuleInfo)
 {
-    if (!_aspectsLoaded)
+    if (!_initialized)
     {
         return S_OK;
     }
@@ -399,7 +396,7 @@ HRESULT Dataflow::ModuleLoaded(ModuleID moduleId, ModuleInfo** pModuleInfo)
 
 HRESULT Dataflow::ModuleUnloaded(ModuleID moduleId)
 {
-    if (!_aspectsLoaded)
+    if (!_initialized)
     {
         return S_OK;
     }
@@ -618,7 +615,7 @@ MethodInfo* Dataflow::GetMethodInfo(ModuleID moduleId, mdMethodDef methodId)
 
 bool Dataflow::IsInlineEnabled(ModuleID calleeModuleId, mdToken calleeMethodId)
 {
-    if (!_aspectsLoaded)
+    if (!_initialized)
     {
         return true;
     }
@@ -632,7 +629,7 @@ bool Dataflow::IsInlineEnabled(ModuleID calleeModuleId, mdToken calleeMethodId)
 }
 bool Dataflow::JITCompilationStarted(ModuleID moduleId, mdToken methodId)
 {
-    if (!_aspectsLoaded)
+    if (!_initialized)
     {
         return false;
     }
@@ -642,7 +639,7 @@ bool Dataflow::JITCompilationStarted(ModuleID moduleId, mdToken methodId)
 }
 MethodInfo* Dataflow::JITProcessMethod(ModuleID moduleId, mdToken methodId, trace::FunctionControlWrapper* pFunctionControl)
 {
-    if (!_aspectsLoaded)
+    if (!_initialized)
     {
         return nullptr;
     }
@@ -765,7 +762,6 @@ bool Dataflow::InstrumentInstruction(DataflowContext& context, std::vector<Dataf
 
 void Dataflow::Shutdown()
 {
-    Destroy();
 }
 RejitHandlerModule* Dataflow::GetOrAddModule(ModuleID moduleId)
 {
@@ -784,7 +780,7 @@ void Dataflow::AddNGenInlinerModule(ModuleID moduleId)
 
 HRESULT Dataflow::RejitMethod(trace::FunctionControlWrapper& functionControl)
 {
-    if (!_aspectsLoaded)
+    if (!_initialized)
     {
         return S_FALSE;
     }

tracer/src/Datadog.Tracer.Native/iast/dataflow.h

@@ -65,8 +65,7 @@ namespace iast
 
         void LoadSecurityControls();
     protected:
-        bool _initialized = true;
-        bool _aspectsLoaded = false;
+        bool _initialized = false;
         bool _setILOnJit = false;
 
         std::vector<DataflowAspectClass*> _aspectClasses;
@@ -80,7 +79,6 @@ namespace iast
         static bool InstrumentInstruction(DataflowContext& context, std::vector<DataflowAspectReference*>& aspects);
 
     public:
-        void Destroy();
         HRESULT AppDomainShutdown(AppDomainID appDomainId);
         HRESULT ModuleLoaded(ModuleID moduleId, ModuleInfo** pModuleInfo = nullptr);
         HRESULT ModuleUnloaded(ModuleID moduleId);

tracer/src/Datadog.Tracer.Native/rejit_handler.cpp

@@ -325,11 +325,13 @@ void RejitHandler::EnqueueRequestRejit(std::vector<MethodIdentifier>& rejitReque
 RejitHandler::RejitHandler(ICorProfilerInfo7* pInfo, std::shared_ptr<RejitWorkOffloader> work_offloader) :
     m_profilerInfo(pInfo), m_profilerInfo10(nullptr), m_work_offloader(work_offloader)
 {
+    m_rejitters.reserve(5);
 }
 
 RejitHandler::RejitHandler(ICorProfilerInfo10* pInfo, std::shared_ptr<RejitWorkOffloader> work_offloader) :
     m_profilerInfo(pInfo), m_profilerInfo10(pInfo), m_work_offloader(work_offloader)
 {
+    m_rejitters.reserve(5);
 }
 
 void RejitHandler::EnqueueForRejit(std::vector<ModuleID>& modulesVector, std::vector<mdMethodDef>& modulesMethodDef,