git.m6w6.name Git - m6w6/libmemcached/blob - test/lib/Cluster.cpp

   1 #include "Cluster.hpp"
   2 #include "Retry.hpp"
   3
   4 #include <sys/wait.h>
   5
   6 Cluster::Cluster(Server serv, uint16_t cnt)
   7 : count{cnt}
   8 , proto{move(serv)}
   9 {
  10   if (count < 4) {
  11       count = stoi(getenv_else("MEMCACHED_CLUSTER", "4"));
  12   }
  13   if (!count) {
  14     count = 1;
  15   }
  16   for (int i = 0; i < count; ++i) {
  17     cluster.push_back(proto);
  18   }
  19 }
  20
  21 Cluster::Cluster(vector<Server> servers)
  22 : count{servers.size()}
  23 , cluster{move(servers)}
  24 {
  25
  26 }
  27
  28 Cluster::~Cluster() {
  29   stop();
  30   wait();
  31 }
  32
  33 const vector<Server> &Cluster::getServers() const {
  34   return cluster;
  35 }
  36
  37 bool Cluster::start() {
  38   bool started = true;
  39
  40   for (auto &server : cluster) {
  41     if (!startServer(server)) {
  42       started = false;
  43     }
  44   }
  45
  46   return started;
  47 }
  48
  49 void Cluster::stop() {
  50   for (auto &server : cluster) {
  51     server.drain();
  52     // no cookies for memcached; TERM is just too slow
  53     server.signal(SIGKILL);
  54   }
  55 }
  56
  57 bool Cluster::isStopped() {
  58   for (auto &server : cluster) {
  59     if (server.getPid() && !server.tryWait()) {
  60       return false;
  61     }
  62   }
  63   return true;
  64 }
  65
  66 bool Cluster::isListening() {
  67   for (auto &server : cluster) {
  68     Retry server_is_listening{[&] {
  69       if (!server.isListening()) {
  70         // zombie?
  71         auto old_pid = server.getPid();
  72         if (server.tryWait()) {
  73           cerr << "Collected zombie " << server << "(old pid=" << old_pid << ")\n";
  74           pids.erase(old_pid);
  75           // restart
  76           startServer(server);
  77         }
  78         if (!server.isListening()) {
  79           return false;
  80         }
  81       }
  82       return true;
  83     }};
  84     if (!server_is_listening()) {
  85       return false;
  86     }
  87   }
  88
  89   return true;
  90 }
  91
  92 bool Cluster::startServer(Server &server) {
  93   if (server.start().has_value()) {
  94     pids[server.getPid()] = &server;
  95     return true;
  96   }
  97   return false;
  98 }
  99
 100 void Cluster::wait() {
 101   siginfo_t inf;
 102
 103   while (!isStopped()) {
 104     if (waitid(P_ALL, 0, &inf, WEXITED | WNOWAIT)) {
 105       perror("Cluster::wait waitid()");
 106       return;
 107     }
 108
 109     auto server = pids.find(inf.si_pid);
 110     if (server != pids.end()) {
 111       server->second->wait();
 112     }
 113   }
 114 }
 115
 116 bool Cluster::restart() {
 117   stop();
 118   wait();
 119   return start();
 120 }