src/ipc/Kid.cc

   1 /*
   2  * Copyright (C) 1996-2015 The Squid Software Foundation and contributors
   3  *
   4  * Squid software is distributed under GPLv2+ license and includes
   5  * contributions from numerous individuals and organizations.
   6  * Please see the COPYING and CONTRIBUTORS files for details.
   7  */
   8
   9 /* DEBUG: section 54    Interprocess Communication */
  10
  11 #include "squid.h"
  12 #include "globals.h"
  13 #include "ipc/Kid.h"
  14
  15 #include <ctime>
  16 #if HAVE_SYS_WAIT_H
  17 #include <sys/wait.h>
  18 #endif
  19
  20 int TheProcessKind = pkOther;
  21
  22 Kid::Kid():
  23     badFailures(0),
  24     pid(-1),
  25     startTime(0),
  26     isRunning(false),
  27     status(0)
  28 {
  29 }
  30
  31 Kid::Kid(const String& kid_name):
  32     theName(kid_name),
  33     badFailures(0),
  34     pid(-1),
  35     startTime(0),
  36     isRunning(false),
  37     status(0)
  38 {
  39 }
  40
  41 /// called when this kid got started, records PID
  42 void Kid::start(pid_t cpid)
  43 {
  44     assert(!running());
  45     assert(cpid > 0);
  46
  47     isRunning = true;
  48     pid = cpid;
  49     time(&startTime);
  50 }
  51
  52 /// called when kid terminates, sets exiting status
  53 void Kid::stop(status_type theExitStatus)
  54 {
  55     assert(running());
  56     assert(startTime != 0);
  57
  58     isRunning = false;
  59
  60     time_t stop_time;
  61     time(&stop_time);
  62     if ((stop_time - startTime) < fastFailureTimeLimit)
  63         ++badFailures;
  64     else
  65         badFailures = 0; // the failures are not "frequent" [any more]
  66
  67     status = theExitStatus;
  68 }
  69
  70 /// returns true if tracking of kid is stopped
  71 bool Kid::running() const
  72 {
  73     return isRunning;
  74 }
  75
  76 /// returns true if master process should restart this kid
  77 bool Kid::shouldRestart() const
  78 {
  79     return !(running() ||
  80              exitedHappy() ||
  81              hopeless() ||
  82              shutting_down ||
  83              signaled(SIGKILL) || // squid -k kill
  84              signaled(SIGINT) || // unexpected forced shutdown
  85              signaled(SIGTERM)); // unexpected forced shutdown
  86 }
  87
  88 /// returns current pid for a running kid and last pid for a stopped kid
  89 pid_t Kid::getPid() const
  90 {
  91     assert(pid > 0);
  92     return pid;
  93 }
  94
  95 /// whether the failures are "repeated and frequent"
  96 bool Kid::hopeless() const
  97 {
  98     return badFailures > badFailureLimit;
  99 }
 100
 101 /// returns true if the process terminated normally
 102 bool Kid::calledExit() const
 103 {
 104     return (pid > 0) && !running() && WIFEXITED(status);
 105 }
 106
 107 /// returns the exit status of the process
 108 int Kid::exitStatus() const
 109 {
 110     return WEXITSTATUS(status);
 111 }
 112
 113 /// whether the process exited with a given exit status code
 114 bool Kid::calledExit(int code) const
 115 {
 116     return calledExit() && (exitStatus() == code);
 117 }
 118
 119 /// whether the process exited with code 0
 120 bool Kid::exitedHappy() const
 121 {
 122     return calledExit(0);
 123 }
 124
 125 /// returns true if the kid was terminated by a signal
 126 bool Kid::signaled() const
 127 {
 128     return (pid > 0) && !running() && WIFSIGNALED(status);
 129 }
 130
 131 /// returns the number of the signal that caused the kid to terminate
 132 int Kid::termSignal() const
 133 {
 134     return WTERMSIG(status);
 135 }
 136
 137 /// whether the process was terminated by a given signal
 138 bool Kid::signaled(int sgnl) const
 139 {
 140     return signaled() && (termSignal() == sgnl);
 141 }
 142
 143 /// returns kid name
 144 const String& Kid::name() const
 145 {
 146     return theName;
 147 }
 148