1 | // |
2 | // SignalHandler.h |
3 | // |
4 | // Library: Foundation |
5 | // Package: Threading |
6 | // Module: SignalHandler |
7 | // |
8 | // Definition of the SignalHandler class. |
9 | // |
10 | // Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH. |
11 | // and Contributors. |
12 | // |
13 | // SPDX-License-Identifier: BSL-1.0 |
14 | // |
15 | |
16 | |
17 | #ifndef Foundation_SignalHandler_INCLUDED |
18 | #define Foundation_SignalHandler_INCLUDED |
19 | |
20 | |
21 | #include "Poco/Foundation.h" |
22 | |
23 | |
24 | #if defined(POCO_OS_FAMILY_UNIX) && !defined(POCO_VXWORKS) |
25 | |
26 | |
27 | #include <vector> |
28 | #include <setjmp.h> |
29 | |
30 | |
31 | namespace Poco { |
32 | |
33 | |
34 | class Foundation_API SignalHandler |
35 | /// This helper class simplifies the handling of POSIX signals. |
36 | /// |
37 | /// The class provides a signal handler (installed with |
38 | /// installHandlers()) that translates certain POSIX |
39 | /// signals (SIGILL, SIGBUS, SIGSEGV, SIGSYS) into |
40 | /// C++ exceptions. |
41 | /// |
42 | /// Internally, a stack of sigjmp_buf structs is maintained for |
43 | /// each thread. The constructor pushes a new sigjmp_buf onto |
44 | /// the current thread's stack. The destructor pops the sigjmp_buf |
45 | /// from the stack. |
46 | /// |
47 | /// The poco_throw_on_signal macro creates an instance of SignalHandler |
48 | /// on the stack, which results in a new sigjmp_buf being created. |
49 | /// The sigjmp_buf is then set-up with sigsetjmp(). |
50 | /// |
51 | /// The handleSignal() method, which is invoked when a signal arrives, |
52 | /// checks if a sigjmp_buf is available for the current thread. |
53 | /// If so, siglongjmp() is used to jump out of the signal handler. |
54 | /// |
55 | /// Typical usage is as follows: |
56 | /// |
57 | /// try |
58 | /// { |
59 | /// poco_throw_on_signal; |
60 | /// ... |
61 | /// } |
62 | /// catch (Poco::SignalException&) |
63 | /// { |
64 | /// ... |
65 | /// } |
66 | /// |
67 | /// The best way to deal with a SignalException is to log as much context |
68 | /// information as possible, to aid in debugging, and then to exit. |
69 | /// |
70 | /// The SignalHandler can be disabled globally by compiling POCO and client |
71 | /// code with the POCO_NO_SIGNAL_HANDLER macro defined. |
72 | { |
73 | public: |
74 | SignalHandler(); |
75 | /// Creates the SignalHandler. |
76 | |
77 | ~SignalHandler(); |
78 | /// Destroys the SignalHandler. |
79 | |
80 | sigjmp_buf& jumpBuffer(); |
81 | /// Returns the top-most sigjmp_buf for the current thread. |
82 | |
83 | static void throwSignalException(int sig); |
84 | /// Throws a SignalException with a textual description |
85 | /// of the given signal as argument. |
86 | |
87 | static void install(); |
88 | /// Installs signal handlers for SIGILL, SIGBUS, SIGSEGV |
89 | /// and SIGSYS. |
90 | |
91 | protected: |
92 | static void handleSignal(int sig); |
93 | /// The actual signal handler. |
94 | |
95 | struct JumpBuffer |
96 | /// sigjmp_buf cannot be used to instantiate a std::vector, |
97 | /// so we provide a wrapper struct. |
98 | { |
99 | sigjmp_buf buf; |
100 | }; |
101 | typedef std::vector<JumpBuffer> JumpBufferVec; |
102 | |
103 | static JumpBufferVec& jumpBufferVec(); |
104 | /// Returns the JumpBufferVec for the current thread. |
105 | |
106 | private: |
107 | static JumpBufferVec _jumpBufferVec; |
108 | |
109 | friend class ThreadImpl; |
110 | }; |
111 | |
112 | |
113 | #ifndef POCO_NO_SIGNAL_HANDLER |
114 | #define poco_throw_on_signal \ |
115 | Poco::SignalHandler _poco_signalHandler; \ |
116 | int _poco_signal = sigsetjmp(_poco_signalHandler.jumpBuffer(), 1); \ |
117 | if (_poco_signal) _poco_signalHandler.throwSignalException(_poco_signal); |
118 | #else |
119 | #define poco_throw_on_signal |
120 | #endif |
121 | |
122 | |
123 | } // namespace Poco |
124 | |
125 | |
126 | #endif // POCO_OS_FAMILY_UNIX |
127 | |
128 | |
129 | #endif // Foundation_SignalHandler_INCLUDED |
130 | |