1 files changed, 152 insertions, 0 deletions
diff --git a/gnu/llvm/lldb/source/Plugins/Process/gdb-remote/GDBRemoteClientBase.h b/gnu/llvm/lldb/source/Plugins/Process/gdb-remote/GDBRemoteClientBase.h
new file mode 100644
index 00000000000..ea294ffcef2
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+++ b/gnu/llvm/lldb/source/Plugins/Process/gdb-remote/GDBRemoteClientBase.h
@@ -0,0 +1,152 @@
+//===-- GDBRemoteClientBase.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 liblldb_GDBRemoteClientBase_h_
+#define liblldb_GDBRemoteClientBase_h_
+
+#include "GDBRemoteCommunication.h"
+
+#include <condition_variable>
+
+namespace lldb_private {
+namespace process_gdb_remote {
+
+class GDBRemoteClientBase : public GDBRemoteCommunication {
+public:
+  struct ContinueDelegate {
+    virtual ~ContinueDelegate();
+    virtual void HandleAsyncStdout(llvm::StringRef out) = 0;
+    virtual void HandleAsyncMisc(llvm::StringRef data) = 0;
+    virtual void HandleStopReply() = 0;
+
+    /// Process asynchronously-received structured data.
+    ///
+    /// \param[in] data
+    ///   The complete data packet, expected to start with JSON-async.
+    virtual void HandleAsyncStructuredDataPacket(llvm::StringRef data) = 0;
+  };
+
+  GDBRemoteClientBase(const char *comm_name, const char *listener_name);
+
+  bool SendAsyncSignal(int signo);
+
+  bool Interrupt();
+
+  lldb::StateType SendContinuePacketAndWaitForResponse(
+      ContinueDelegate &delegate, const UnixSignals &signals,
+      llvm::StringRef payload, StringExtractorGDBRemote &response);
+
+  PacketResult SendPacketAndWaitForResponse(llvm::StringRef payload,
+                                            StringExtractorGDBRemote &response,
+                                            bool send_async);
+
+  PacketResult SendPacketAndReceiveResponseWithOutputSupport(
+      llvm::StringRef payload, StringExtractorGDBRemote &response,
+      bool send_async,
+      llvm::function_ref<void(llvm::StringRef)> output_callback);
+
+  bool SendvContPacket(llvm::StringRef payload,
+                       StringExtractorGDBRemote &response);
+
+  class Lock {
+  public:
+    Lock(GDBRemoteClientBase &comm, bool interrupt);
+    ~Lock();
+
+    explicit operator bool() { return m_acquired; }
+
+    // Whether we had to interrupt the continue thread to acquire the
+    // connection.
+    bool DidInterrupt() const { return m_did_interrupt; }
+
+  private:
+    std::unique_lock<std::recursive_mutex> m_async_lock;
+    GDBRemoteClientBase &m_comm;
+    bool m_acquired;
+    bool m_did_interrupt;
+
+    void SyncWithContinueThread(bool interrupt);
+  };
+
+protected:
+  PacketResult
+  SendPacketAndWaitForResponseNoLock(llvm::StringRef payload,
+                                     StringExtractorGDBRemote &response);
+
+  virtual void OnRunPacketSent(bool first);
+
+private:
+  /// Variables handling synchronization between the Continue thread and any
+  /// other threads wishing to send packets over the connection. Either the
+  /// continue thread has control over the connection (m_is_running == true) or
+  /// the connection is free for an arbitrary number of other senders to take
+  /// which indicate their interest by incrementing m_async_count.
+  ///
+  /// Semantics of individual states:
+  ///
+  /// - m_continue_packet == false, m_async_count == 0:
+  ///   connection is free
+  /// - m_continue_packet == true, m_async_count == 0:
+  ///   only continue thread is present
+  /// - m_continue_packet == true, m_async_count > 0:
+  ///   continue thread has control, async threads should interrupt it and wait
+  ///   for it to set m_continue_packet to false
+  /// - m_continue_packet == false, m_async_count > 0:
+  ///   async threads have control, continue thread needs to wait for them to
+  ///   finish (m_async_count goes down to 0).
+  /// @{
+  std::mutex m_mutex;
+  std::condition_variable m_cv;
+
+  /// Packet with which to resume after an async interrupt. Can be changed by
+  /// an async thread e.g. to inject a signal.
+  std::string m_continue_packet;
+
+  /// When was the interrupt packet sent. Used to make sure we time out if the
+  /// stub does not respond to interrupt requests.
+  std::chrono::time_point<std::chrono::steady_clock> m_interrupt_time;
+
+  /// Number of threads interested in sending.
+  uint32_t m_async_count;
+
+  /// Whether the continue thread has control.
+  bool m_is_running;
+
+  /// Whether we should resume after a stop.
+  bool m_should_stop;
+  /// @}
+
+  /// This handles the synchronization between individual async threads. For
+  /// now they just use a simple mutex.
+  std::recursive_mutex m_async_mutex;
+
+  bool ShouldStop(const UnixSignals &signals,
+                  StringExtractorGDBRemote &response);
+
+  class ContinueLock {
+  public:
+    enum class LockResult { Success, Cancelled, Failed };
+
+    explicit ContinueLock(GDBRemoteClientBase &comm);
+    ~ContinueLock();
+    explicit operator bool() { return m_acquired; }
+
+    LockResult lock();
+
+    void unlock();
+
+  private:
+    GDBRemoteClientBase &m_comm;
+    bool m_acquired;
+  };
+};
+
+} // namespace process_gdb_remote
+} // namespace lldb_private
+
+#endif // liblldb_GDBRemoteCommunicationClient_h_