src/hotspot/os/posix/signals_posix.hpp

/*
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
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 *
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 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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#ifndef OS_POSIX_SIGNALS_POSIX_HPP
#define OS_POSIX_SIGNALS_POSIX_HPP

#include "memory/allStatic.hpp"
#include "utilities/globalDefinitions.hpp"

class outputStream;
class Thread;
class OSThread;

extern "C" {
  typedef void (*sa_handler_t)(int);
  typedef void (*sa_sigaction_t)(int, siginfo_t*, void*);
}

class PosixSignals : public AllStatic {

public:

  // Signal number used to suspend/resume a thread
  static int SR_signum;

  static int init();
  // The platform dependent parts of the central hotspot signal handler.
  // Returns true if the signal had been recognized and handled, false if not. If true, caller should
  // return from signal handling.
  static bool pd_hotspot_signal_handler(int sig, siginfo_t* info, ucontext_t* uc, JavaThread* thread);

  static bool is_sig_ignored(int sig);

  static void hotspot_sigmask(Thread* thread);

  static void print_signal_handler(outputStream* st, int sig, char* buf, size_t buflen);

  // Suspend-resume
  static bool do_suspend(OSThread* osthread);
  static void do_resume(OSThread* osthread);

  // For signal-chaining
  static bool chained_handler(int sig, siginfo_t* siginfo, void* context);

  // Unblock all signals whose delivery cannot be deferred and which, if they happen
  //  while delivery is blocked, would cause crashes or hangs (see JDK-8252533).
  static void unblock_error_signals();

  // Signal handler installation
  static int install_sigaction_signal_handler(struct sigaction* sigAct, // Main VM handler routine
                                              struct sigaction* oldAct,
                                              int sig,
                                              sa_sigaction_t handler);
  static void* install_generic_signal_handler(int sig, void* handler); // Used by JVM_RegisterSignal
  static void* user_handler(); // Needed for signal handler comparisons
};

#endif // OS_POSIX_SIGNALS_POSIX_HPP