Update CDPAgent to take unique_ptr for State

Summary:
Changing CDPAgent interface to take `unique_ptr` for State. We should
be careful about using `shared_ptr` because it could introduce subtle
lifecycle issues.

The `DomainAgents::initialize()` still requires a `shared_ptr` because
`std::function` is needed to be copyable. `std::move_only_function` is
only C++23, so not available to us yet.

Reviewed By: huntie

Differential Revision: D54437914

fbshipit-source-id: 3d6b54fe0926955e48bc0a03d9d614186699fccf

API/hermes/cdp/CDPAgent.cpp

@@ -53,7 +53,7 @@ class CDPAgentImpl {
   ~CDPAgentImpl();
 
   /// Schedule initialization of handlers for each message domain.
-  void initializeDomainAgents(std::shared_ptr<State> state);
+  void initializeDomainAgents(std::unique_ptr<State> state);
 
   /// Process a CDP command encoded in \p json.
   void handleCommand(std::string json);
@@ -177,11 +177,12 @@ CDPAgentImpl::~CDPAgentImpl() {
   messageCallback_.invalidate();
 }
 
-void CDPAgentImpl::initializeDomainAgents(std::shared_ptr<State> state) {
+void CDPAgentImpl::initializeDomainAgents(std::unique_ptr<State> state) {
   // Call DomainAgents::initialize on the runtime thread.
+  std::shared_ptr<State> initialState = std::move(state);
   runtimeTaskRunner_.enqueueTask(
-      [domainAgents = domainAgents_, state](HermesRuntime &) {
-        domainAgents->initialize(state);
+      [domainAgents = domainAgents_, initialState](HermesRuntime &) {
+        domainAgents->initialize(initialState);
       });
 }
 
@@ -370,27 +371,27 @@ std::unique_ptr<CDPAgent> CDPAgent::create(
     CDPDebugAPI &cdpDebugAPI,
     EnqueueRuntimeTaskFunc enqueueRuntimeTaskCallback,
     OutboundMessageFunc messageCallback,
-    std::shared_ptr<State> state) {
+    std::unique_ptr<State> state) {
   return std::unique_ptr<CDPAgent>(new CDPAgent(
       executionContextID,
       cdpDebugAPI,
       enqueueRuntimeTaskCallback,
       messageCallback,
-      state));
+      std::move(state)));
 }
 
 CDPAgent::CDPAgent(
     int32_t executionContextID,
     CDPDebugAPI &cdpDebugAPI,
     EnqueueRuntimeTaskFunc enqueueRuntimeTaskCallback,
     OutboundMessageFunc messageCallback,
-    std::shared_ptr<State> state)
+    std::unique_ptr<State> state)
     : impl_(std::make_unique<CDPAgentImpl>(
           executionContextID,
           cdpDebugAPI,
           enqueueRuntimeTaskCallback,
           SynchronizedOutboundCallback(messageCallback))) {
-  impl_->initializeDomainAgents(state);
+  impl_->initializeDomainAgents(std::move(state));
 }
 
 CDPAgent::~CDPAgent() {}

API/hermes/cdp/CDPAgent.h

@@ -45,7 +45,7 @@ class HERMES_EXPORT CDPAgent {
       CDPDebugAPI &cdpDebugAPI,
       debugger::EnqueueRuntimeTaskFunc enqueueRuntimeTaskCallback,
       OutboundMessageFunc messageCallback,
-      std::shared_ptr<State> state);
+      std::unique_ptr<State> state);
 
  public:
   /// Create a new CDP Agent. This can be done on an arbitrary thread; the
@@ -55,7 +55,7 @@ class HERMES_EXPORT CDPAgent {
       CDPDebugAPI &cdpDebugAPI,
       debugger::EnqueueRuntimeTaskFunc enqueueRuntimeTaskCallback,
       OutboundMessageFunc messageCallback,
-      std::shared_ptr<State> state = nullptr);
+      std::unique_ptr<State> state = nullptr);
 
   /// Destroy the CDP Agent. This can be done on an arbitrary thread.
   /// It's expected that the integrator will continue to process any runtime

unittests/API/CDPAgentTest.cpp

@@ -1413,7 +1413,7 @@ TEST_F(CDPAgentTest, DebuggerRestoreState) {
   ensureSetBreakpointByUrlResponse(waitForMessage(), msgId++, {});
 
   for (int i = 0; i < 2; i++) {
-    std::shared_ptr<State> state;
+    std::unique_ptr<State> state;
     if (i == 0) {
       // Save CDPAgent state on non-runtime thread and shut everything down.
       state = cdpAgent_->getState();
@@ -1448,7 +1448,7 @@ TEST_F(CDPAgentTest, DebuggerRestoreState) {
         *cdpDebugAPI_,
         std::bind(&CDPAgentTest::handleRuntimeTask, this, _1),
         std::bind(&CDPAgentTest::handleResponse, this, _1),
-        state);
+        std::move(state));
 
     sendAndCheckResponse("Debugger.enable", msgId++);
     scheduleScript(R"(