1// Licensed to the .NET Foundation under one or more agreements.
2// The .NET Foundation licenses this file to you under the MIT license.
3// See the LICENSE file in the project root for more information.
4
5
6#ifndef TwoWayPipe_H
7#define TwoWayPipe_H
8
9#include "processdescriptor.h"
10
11#ifdef FEATURE_PAL
12#define INVALID_PIPE -1
13#else
14#define INVALID_PIPE INVALID_HANDLE_VALUE
15#endif
16
17// This file contains definition of a simple IPC mechanism - bidirectional named pipe.
18// It is implemented on top of two one-directional names pipes (fifos on UNIX)
19
20// One Windows it is possible to ask OS to create a bidirectional pipe, but it is not the case on UNIX.
21// In order to unify implementation we use two pipes on all systems.
22
23// This all methods of this class are *NOT* thread safe: it is assumed the caller provides synchronization at a higher level.
24class TwoWayPipe
25{
26public:
27 enum State
28 {
29 NotInitialized, // Object didn't create or connect to any pipes.
30 Created, // Server side of the pipe has been created, but didn't bind it to a client.
31 ServerConnected, // Server side of the pipe is connected to a client
32 ClientConnected, // Client side of the pipe is connected to a server.
33 };
34
35 TwoWayPipe()
36 :m_state(NotInitialized),
37 m_inboundPipe(INVALID_PIPE),
38 m_outboundPipe(INVALID_PIPE)
39 {}
40
41
42 ~TwoWayPipe()
43 {
44 Disconnect();
45 }
46
47 // Creates a server side of the pipe.
48 // pd is used to create pipes names and uniquely identify the pipe on the machine.
49 // true - success, false - failure (use GetLastError() for more details)
50 bool CreateServer(const ProcessDescriptor& pd);
51
52 // Connects to a previously opened server side of the pipe.
53 // pd is used to locate the pipe on the machine.
54 // true - success, false - failure (use GetLastError() for more details)
55 bool Connect(const ProcessDescriptor& pd);
56
57 // Waits for incoming client connections, assumes GetState() == Created
58 // true - success, false - failure (use GetLastError() for more details)
59 bool WaitForConnection();
60
61 // Reads data from pipe. Returns number of bytes read or a negative number in case of an error.
62 // use GetLastError() for more details
63 int Read(void *buffer, DWORD bufferSize);
64
65 // Writes data to pipe. Returns number of bytes written or a negative number in case of an error.
66 // use GetLastError() for more details
67 int Write(const void *data, DWORD dataSize);
68
69 // Disconnects server or client side of the pipe.
70 // true - success, false - failure (use GetLastError() for more details)
71 bool Disconnect();
72
73 State GetState()
74 {
75 return m_state;
76 }
77
78 // Used by debugger side (RS) to cleanup the target (LS) named pipes
79 // and semaphores when the debugger detects the debuggee process exited.
80 void CleanupTargetProcess();
81
82private:
83
84 State m_state;
85
86#ifdef FEATURE_PAL
87
88 int m_inboundPipe, m_outboundPipe; // two one sided pipes used for communication
89 char m_inPipeName[MAX_DEBUGGER_TRANSPORT_PIPE_NAME_LENGTH]; // filename of the inbound pipe
90 char m_outPipeName[MAX_DEBUGGER_TRANSPORT_PIPE_NAME_LENGTH]; // filename of the outbound pipe
91
92#else
93 // Connects to a one sided pipe previously created by CreateOneWayPipe.
94 // In order to successfully connect id and inbound flag should be the same.
95 HANDLE OpenOneWayPipe(DWORD id, bool inbound);
96
97 // Creates a one way pipe, id and inboud flag are used for naming.
98 // Created pipe is supposed to be connected to by OpenOneWayPipe.
99 HANDLE CreateOneWayPipe(DWORD id, bool inbound);
100
101 HANDLE m_inboundPipe, m_outboundPipe; //two one sided pipes used for communication
102#endif //FEATURE_PAL
103};
104
105#endif //TwoWayPipe_H
106