1 files changed, 144 insertions, 0 deletions
diff --git a/contrib/llvm/tools/lldb/source/Plugins/Process/gdb-remote/GDBRemoteClientBase.h b/contrib/llvm/tools/lldb/source/Plugins/Process/gdb-remote/GDBRemoteClientBase.h
new file mode 100644
index 0000000..2646405
--- /dev/null
+++ b/contrib/llvm/tools/lldb/source/Plugins/Process/gdb-remote/GDBRemoteClientBase.h
@@ -0,0 +1,144 @@
+//===-- GDBRemoteClientBase.h -----------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#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);
+
+  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;
+  uint32_t m_async_count;
+  bool m_is_running;
+  bool m_should_stop; // Whether we should resume after a stop.
+  // end of continue thread synchronization block
+
+  // 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_