os_posix.hpp revision 6010:abec000618bf 
1/*
2 * Copyright (c) 1999, 2013, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25#ifndef OS_POSIX_VM_OS_POSIX_HPP
26#define OS_POSIX_VM_OS_POSIX_HPP
27class Posix {
28  friend class os;
29
30protected:
31  static void print_distro_info(outputStream* st);
32  static void print_rlimit_info(outputStream* st);
33  static void print_uname_info(outputStream* st);
34  static void print_libversion_info(outputStream* st);
35  static void print_load_average(outputStream* st);
36
37public:
38
39  // Returns true if signal is valid.
40  static bool is_valid_signal(int sig);
41
42  // Helper function, returns a string (e.g. "SIGILL") for a signal.
43  // Returned string is a constant. For unknown signals "UNKNOWN" is returned.
44  static const char* get_signal_name(int sig, char* out, size_t outlen);
45
46  // Returns one-line short description of a signal set in a user provided buffer.
47  static const char* describe_signal_set_short(const sigset_t* set, char* buffer, size_t size);
48
49  // Prints a short one-line description of a signal set.
50  static void print_signal_set_short(outputStream* st, const sigset_t* set);
51
52  // Writes a one-line description of a combination of sigaction.sa_flags
53  // into a user provided buffer. Returns that buffer.
54  static const char* describe_sa_flags(int flags, char* buffer, size_t size);
55
56  // Prints a one-line description of a combination of sigaction.sa_flags.
57  static void print_sa_flags(outputStream* st, int flags);
58
59  // A POSIX conform, platform-independend siginfo print routine.
60  static void print_siginfo_brief(outputStream* os, const siginfo_t* si);
61
62};
63
64/*
65 * Crash protection for the watcher thread. Wrap the callback
66 * with a sigsetjmp and in case of a SIGSEGV/SIGBUS we siglongjmp
67 * back.
68 * To be able to use this - don't take locks, don't rely on destructors,
69 * don't make OS library calls, don't allocate memory, don't print,
70 * don't call code that could leave the heap / memory in an inconsistent state,
71 * or anything else where we are not in control if we suddenly jump out.
72 */
73class WatcherThreadCrashProtection : public StackObj {
74public:
75  WatcherThreadCrashProtection();
76  bool call(os::CrashProtectionCallback& cb);
77
78  static void check_crash_protection(int signal, Thread* thread);
79private:
80  void restore();
81  sigjmp_buf _jmpbuf;
82};
83
84#endif // OS_POSIX_VM_OS_POSIX_HPP
85