1 /*
   2  * Copyright (c) 1999, 2014, 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 #include "runtime/os.hpp"
  26 
  27 #ifndef OS_POSIX_VM_OS_POSIX_HPP
  28 #define OS_POSIX_VM_OS_POSIX_HPP
  29 
  30 // File conventions
  31 static const char* file_separator() { return "/"; }
  32 static const char* line_separator() { return "\n"; }
  33 static const char* path_separator() { return ":"; }
  34 
  35 class Posix {
  36   friend class os;
  37 
  38 protected:
  39   static void print_distro_info(outputStream* st);
  40   static void print_rlimit_info(outputStream* st);
  41   static void print_uname_info(outputStream* st);
  42   static void print_libversion_info(outputStream* st);
  43   static void print_load_average(outputStream* st);
  44 
  45 public:
  46 
  47   // Returns true if signal is valid.
  48   static bool is_valid_signal(int sig);
  49 
  50   // Helper function, returns a string (e.g. "SIGILL") for a signal.
  51   // Returned string is a constant. For unknown signals "UNKNOWN" is returned.
  52   static const char* get_signal_name(int sig, char* out, size_t outlen);
  53 
  54   // Returns one-line short description of a signal set in a user provided buffer.
  55   static const char* describe_signal_set_short(const sigset_t* set, char* buffer, size_t size);
  56 
  57   // Prints a short one-line description of a signal set.
  58   static void print_signal_set_short(outputStream* st, const sigset_t* set);
  59 
  60   // Writes a one-line description of a combination of sigaction.sa_flags
  61   // into a user provided buffer. Returns that buffer.
  62   static const char* describe_sa_flags(int flags, char* buffer, size_t size);
  63 
  64   // Prints a one-line description of a combination of sigaction.sa_flags.
  65   static void print_sa_flags(outputStream* st, int flags);
  66 
  67   // A POSIX conform, platform-independend siginfo print routine.
  68   static void print_siginfo_brief(outputStream* os, const siginfo_t* si);
  69 
  70 };
  71 
  72 /*
  73  * Crash protection for the watcher thread. Wrap the callback
  74  * with a sigsetjmp and in case of a SIGSEGV/SIGBUS we siglongjmp
  75  * back.
  76  * To be able to use this - don't take locks, don't rely on destructors,
  77  * don't make OS library calls, don't allocate memory, don't print,
  78  * don't call code that could leave the heap / memory in an inconsistent state,
  79  * or anything else where we are not in control if we suddenly jump out.
  80  */
  81 class WatcherThreadCrashProtection : public StackObj {
  82 public:
  83   WatcherThreadCrashProtection();
  84   bool call(os::CrashProtectionCallback& cb);
  85 
  86   static void check_crash_protection(int signal, Thread* thread);
  87 private:
  88   void restore();
  89   sigjmp_buf _jmpbuf;
  90 };
  91 
  92 class PosixSemaphore : public Semaphore {
  93  public:
  94   PosixSemaphore(uint value = 0) : Semaphore(value) {}
  95 
  96   bool trywait();
  97   bool timedwait(struct timespec ts);
  98 };
  99 
 100 #endif // OS_POSIX_VM_OS_POSIX_HPP