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 bool SendvContPacket(llvm::StringRef payload, 52 StringExtractorGDBRemote &response); 53 54 class Lock { 55 public: 56 Lock(GDBRemoteClientBase &comm, bool interrupt); 57 ~Lock(); 58 59 explicit operator bool() { return m_acquired; } 60 61 // Whether we had to interrupt the continue thread to acquire the 62 // connection. 63 bool DidInterrupt() const { return m_did_interrupt; } 64 65 private: 66 std::unique_lock<std::recursive_mutex> m_async_lock; 67 GDBRemoteClientBase &m_comm; 68 bool m_acquired; 69 bool m_did_interrupt; 70 71 void SyncWithContinueThread(bool interrupt); 72 }; 73 74 protected: 75 PacketResult 76 SendPacketAndWaitForResponseNoLock(llvm::StringRef payload, 77 StringExtractorGDBRemote &response); 78 79 virtual void OnRunPacketSent(bool first); 80 81 private: 82 // Variables handling synchronization between the Continue thread and any 83 // other threads 84 // wishing to send packets over the connection. Either the continue thread has 85 // control over 86 // the connection (m_is_running == true) or the connection is free for an 87 // arbitrary number of 88 // other senders to take which indicate their interest by incrementing 89 // m_async_count. 90 // Semantics of individual states: 91 // - m_continue_packet == false, m_async_count == 0: connection is free 92 // - m_continue_packet == true, m_async_count == 0: only continue thread is 93 // present 94 // - m_continue_packet == true, m_async_count > 0: continue thread has 95 // control, async threads 96 // should interrupt it and wait for it to set m_continue_packet to false 97 // - m_continue_packet == false, m_async_count > 0: async threads have 98 // control, continue 99 // thread needs to wait for them to finish (m_async_count goes down to 0). 100 std::mutex m_mutex; 101 std::condition_variable m_cv; 102 // Packet with which to resume after an async interrupt. Can be changed by an 103 // async thread 104 // e.g. to inject a signal. 105 std::string m_continue_packet; 106 // When was the interrupt packet sent. Used to make sure we time out if the 107 // stub does not 108 // respond to interrupt requests. 109 std::chrono::time_point<std::chrono::steady_clock> m_interrupt_time; 110 uint32_t m_async_count; 111 bool m_is_running; 112 bool m_should_stop; // Whether we should resume after a stop. 113 // end of continue thread synchronization block 114 115 // This handles the synchronization between individual async threads. For now 116 // they just use a 117 // simple mutex. 118 std::recursive_mutex m_async_mutex; 119 120 bool ShouldStop(const UnixSignals &signals, 121 StringExtractorGDBRemote &response); 122 123 class ContinueLock { 124 public: 125 enum class LockResult { Success, Cancelled, Failed }; 126 127 explicit ContinueLock(GDBRemoteClientBase &comm); 128 ~ContinueLock(); 129 explicit operator bool() { return m_acquired; } 130 131 LockResult lock(); 132 133 void unlock(); 134 135 private: 136 GDBRemoteClientBase &m_comm; 137 bool m_acquired; 138 }; 139 }; 140 141 } // namespace process_gdb_remote 142 } // namespace lldb_private 143 144 #endif // liblldb_GDBRemoteCommunicationClient_h_ 145