1 //===-- GDBRemoteClientBase.h -----------------------------------*- C++ -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 10 #ifndef liblldb_GDBRemoteClientBase_h_ 11 #define liblldb_GDBRemoteClientBase_h_ 12 13 #include "GDBRemoteCommunication.h" 14 15 #include <condition_variable> 16 17 namespace lldb_private { 18 namespace process_gdb_remote { 19 20 class GDBRemoteClientBase : public GDBRemoteCommunication { 21 public: 22 struct ContinueDelegate { 23 virtual ~ContinueDelegate(); 24 virtual void HandleAsyncStdout(llvm::StringRef out) = 0; 25 virtual void HandleAsyncMisc(llvm::StringRef data) = 0; 26 virtual void HandleStopReply() = 0; 27 28 // ========================================================================= 29 /// Process asynchronously-received structured data. 30 /// 31 /// @param[in] data 32 /// The complete data packet, expected to start with JSON-async. 33 // ========================================================================= 34 virtual void HandleAsyncStructuredDataPacket(llvm::StringRef data) = 0; 35 }; 36 37 GDBRemoteClientBase(const char *comm_name, const char *listener_name); 38 39 bool SendAsyncSignal(int signo); 40 41 bool Interrupt(); 42 43 lldb::StateType SendContinuePacketAndWaitForResponse( 44 ContinueDelegate &delegate, const UnixSignals &signals, 45 llvm::StringRef payload, StringExtractorGDBRemote &response); 46 47 PacketResult SendPacketAndWaitForResponse(llvm::StringRef payload, 48 StringExtractorGDBRemote &response, 49 bool send_async); 50 51 PacketResult SendPacketAndReceiveResponseWithOutputSupport( 52 llvm::StringRef payload, StringExtractorGDBRemote &response, 53 bool send_async, 54 llvm::function_ref<void(llvm::StringRef)> output_callback); 55 56 bool SendvContPacket(llvm::StringRef payload, 57 StringExtractorGDBRemote &response); 58 59 class Lock { 60 public: 61 Lock(GDBRemoteClientBase &comm, bool interrupt); 62 ~Lock(); 63 64 explicit operator bool() { return m_acquired; } 65 66 // Whether we had to interrupt the continue thread to acquire the 67 // connection. 68 bool DidInterrupt() const { return m_did_interrupt; } 69 70 private: 71 std::unique_lock<std::recursive_mutex> m_async_lock; 72 GDBRemoteClientBase &m_comm; 73 bool m_acquired; 74 bool m_did_interrupt; 75 76 void SyncWithContinueThread(bool interrupt); 77 }; 78 79 protected: 80 PacketResult 81 SendPacketAndWaitForResponseNoLock(llvm::StringRef payload, 82 StringExtractorGDBRemote &response); 83 84 virtual void OnRunPacketSent(bool first); 85 86 private: 87 // Variables handling synchronization between the Continue thread and any 88 // other threads 89 // wishing to send packets over the connection. Either the continue thread has 90 // control over 91 // the connection (m_is_running == true) or the connection is free for an 92 // arbitrary number of 93 // other senders to take which indicate their interest by incrementing 94 // m_async_count. 95 // Semantics of individual states: 96 // - m_continue_packet == false, m_async_count == 0: connection is free 97 // - m_continue_packet == true, m_async_count == 0: only continue thread is 98 // present 99 // - m_continue_packet == true, m_async_count > 0: continue thread has 100 // control, async threads 101 // should interrupt it and wait for it to set m_continue_packet to false 102 // - m_continue_packet == false, m_async_count > 0: async threads have 103 // control, continue 104 // thread needs to wait for them to finish (m_async_count goes down to 0). 105 std::mutex m_mutex; 106 std::condition_variable m_cv; 107 // Packet with which to resume after an async interrupt. Can be changed by an 108 // async thread 109 // e.g. to inject a signal. 110 std::string m_continue_packet; 111 // When was the interrupt packet sent. Used to make sure we time out if the 112 // stub does not 113 // respond to interrupt requests. 114 std::chrono::time_point<std::chrono::steady_clock> m_interrupt_time; 115 uint32_t m_async_count; 116 bool m_is_running; 117 bool m_should_stop; // Whether we should resume after a stop. 118 // end of continue thread synchronization block 119 120 // This handles the synchronization between individual async threads. For now 121 // they just use a 122 // simple mutex. 123 std::recursive_mutex m_async_mutex; 124 125 bool ShouldStop(const UnixSignals &signals, 126 StringExtractorGDBRemote &response); 127 128 class ContinueLock { 129 public: 130 enum class LockResult { Success, Cancelled, Failed }; 131 132 explicit ContinueLock(GDBRemoteClientBase &comm); 133 ~ContinueLock(); 134 explicit operator bool() { return m_acquired; } 135 136 LockResult lock(); 137 138 void unlock(); 139 140 private: 141 GDBRemoteClientBase &m_comm; 142 bool m_acquired; 143 }; 144 }; 145 146 } // namespace process_gdb_remote 147 } // namespace lldb_private 148 149 #endif // liblldb_GDBRemoteCommunicationClient_h_ 150