ceph/src/common/signal.cc

   1 // -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
   2 // vim: ts=8 sw=2 smarttab
   3 /*
   4  * Ceph - scalable distributed file system
   5  *
   6  * Copyright (C) 2011 New Dream Network
   7  *
   8  * This is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License version 2.1, as published by the Free Software
  11  * Foundation.  See file COPYING.
  12  *
  13  */
  14
  15 #include <cstdlib>
  16 #include <sstream>
  17
  18 #include <sys/stat.h>
  19 #include <sys/types.h>
  20
  21 #include <signal.h>
  22
  23 #include "common/BackTrace.h"
  24 #include "common/config.h"
  25 #include "common/debug.h"
  26 #include "common/signal.h"
  27 #include "common/perf_counters.h"
  28
  29 #include "global/pidfile.h"
  30
  31 using namespace std::literals;
  32
  33 #ifndef _WIN32
  34 std::string signal_mask_to_str()
  35 {
  36   sigset_t old_sigset;
  37   if (pthread_sigmask(SIG_SETMASK, NULL, &old_sigset)) {
  38     return "(pthread_signmask failed)";
  39   }
  40
  41   std::ostringstream oss;
  42   oss << "show_signal_mask: { ";
  43   auto sep = ""s;
  44   for (int signum = 0; signum < NSIG; ++signum) {
  45     if (sigismember(&old_sigset, signum) == 1) {
  46       oss << sep << signum;
  47       sep = ", ";
  48     }
  49   }
  50   oss << " }";
  51   return oss.str();
  52 }
  53
  54 /* Block the signals in 'siglist'. If siglist == NULL, block all signals. */
  55 void block_signals(const int *siglist, sigset_t *old_sigset)
  56 {
  57   sigset_t sigset;
  58   if (!siglist) {
  59     sigfillset(&sigset);
  60   }
  61   else {
  62     int i = 0;
  63     sigemptyset(&sigset);
  64     while (siglist[i]) {
  65       sigaddset(&sigset, siglist[i]);
  66       ++i;
  67     }
  68   }
  69   int ret = pthread_sigmask(SIG_BLOCK, &sigset, old_sigset);
  70   ceph_assert(ret == 0);
  71 }
  72
  73 void restore_sigset(const sigset_t *old_sigset)
  74 {
  75   int ret = pthread_sigmask(SIG_SETMASK, old_sigset, NULL);
  76   ceph_assert(ret == 0);
  77 }
  78
  79 void unblock_all_signals(sigset_t *old_sigset)
  80 {
  81   sigset_t sigset;
  82   sigfillset(&sigset);
  83   sigdelset(&sigset, SIGKILL);
  84   int ret = pthread_sigmask(SIG_UNBLOCK, &sigset, old_sigset);
  85   ceph_assert(ret == 0);
  86 }
  87 #else
  88 std::string signal_mask_to_str()
  89 {
  90   return "(unsupported signal)";
  91 }
  92
  93 // Windows provides limited signal functionality.
  94 void block_signals(const int *siglist, sigset_t *old_sigset) {}
  95 void restore_sigset(const sigset_t *old_sigset) {}
  96 void unblock_all_signals(sigset_t *old_sigset) {}
  97 #endif /* _WIN32 */