[Lldb-commits] [lldb] [llvm] [lldb-dap] Add multi-session support with shared debugger instances (PR #163653)

[Walter Erquinigo via lldb-commits]

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@@ -0,0 +1,119 @@
+//===-- DAPSessionManager.h ------------------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLDB_TOOLS_LLDB_DAP_DAPSESSIONMANAGER_H
+#define LLDB_TOOLS_LLDB_DAP_DAPSESSIONMANAGER_H
+
+#include "lldb/API/SBBroadcaster.h"
+#include "lldb/API/SBDebugger.h"
+#include "lldb/API/SBTarget.h"
+#include "lldb/Host/MainLoop.h"
+#include "lldb/lldb-types.h"
+#include "llvm/Support/Error.h"
+#include <condition_variable>
+#include <map>
+#include <memory>
+#include <mutex>
+#include <optional>
+#include <thread>
+#include <vector>
+
+namespace lldb_dap {
+
+// Forward declarations
+struct DAP;
+
+class ManagedEventThread {
+public:
+  // Constructor declaration
+  ManagedEventThread(lldb::SBBroadcaster broadcaster, std::thread t);
+
+  ~ManagedEventThread();
+
+  ManagedEventThread(const ManagedEventThread &) = delete;
+  ManagedEventThread &operator=(const ManagedEventThread &) = delete;
+
+private:
+  lldb::SBBroadcaster m_broadcaster;
+  std::thread m_event_thread;
+};
+
+/// Global DAP session manager.
+class DAPSessionManager {
+public:
+  /// Get the singleton instance of the DAP session manager.
+  static DAPSessionManager &GetInstance();
+
+  /// Register a DAP session.
+  void RegisterSession(lldb_private::MainLoop *loop, DAP *dap);
+
+  /// Unregister a DAP session.
+  void UnregisterSession(lldb_private::MainLoop *loop);
+
+  /// Get all active DAP sessions.
+  std::vector<DAP *> GetActiveSessions();
+
+  /// Disconnect all active sessions.
+  void DisconnectAllSessions();
+
+  /// Wait for all sessions to finish disconnecting.
+  /// Returns an error if any client disconnection failed, otherwise success.
+  llvm::Error WaitForAllSessionsToDisconnect();
+
+  /// Set the shared debugger instance for a unique target ID.
+  void SetSharedDebugger(uint32_t target_id, lldb::SBDebugger debugger);
+
+  /// Get the shared debugger instance for a unique target ID.
+  std::optional<lldb::SBDebugger> GetSharedDebugger(uint32_t target_id);
+
+  /// Get or create event thread for a specific debugger.
+  std::shared_ptr<ManagedEventThread>
+  GetEventThreadForDebugger(lldb::SBDebugger debugger, DAP *requesting_dap);
+
+  /// Find the DAP instance that owns the given target.
+  DAP *FindDAPForTarget(lldb::SBTarget target);
+
+  /// Static convenience method for FindDAPForTarget.
+  static DAP *FindDAP(lldb::SBTarget target) {
+    return GetInstance().FindDAPForTarget(target);
+  }
+
+  /// Clean up shared resources when the last session exits.
+  void CleanupSharedResources();
+
+  /// Clean up expired event threads from the collection.
+  void ReleaseExpiredEventThreads();
+
+private:
+  DAPSessionManager() = default;
+  ~DAPSessionManager() = default;
+
+  // Non-copyable and non-movable.
+  DAPSessionManager(const DAPSessionManager &) = delete;
+  DAPSessionManager &operator=(const DAPSessionManager &) = delete;
+  DAPSessionManager(DAPSessionManager &&) = delete;
+  DAPSessionManager &operator=(DAPSessionManager &&) = delete;
+
+  bool m_client_failed = false;
+  std::mutex m_sessions_mutex;
+  std::condition_variable m_sessions_condition;
+  std::map<lldb_private::MainLoop *, DAP *> m_active_sessions;
+
+  /// Optional map from target ID to shared debugger set when the native
+  /// process creates a new target.
+  std::map<uint32_t, lldb::SBDebugger> m_target_to_debugger_map;
+
+  /// Map from debugger ID to its event thread used for when
+  /// multiple DAP sessions are using the same debugger instance.
+  std::map<lldb::user_id_t, std::weak_ptr<ManagedEventThread>>
----------------
walter-erquinigo wrote:

nope, in this case user_id_t is fine

https://github.com/llvm/llvm-project/pull/163653