nghttpx: Split thread into worker_process and thread

Split thread into worker_process and thread.  Use thread to O(1)
lookup for Worker.  This new machinery is not compatible to the
previous version.  The old instance of nghttpx must not be upgraded
with USR2 signal.  It should be restarted instead.

src/shrpx.cc

@@ -205,7 +205,7 @@ struct WorkerProcess {
   WorkerProcess(struct ev_loop *loop, pid_t worker_pid, int ipc_fd
 #ifdef ENABLE_HTTP3
                 ,
-                int quic_ipc_fd, std::vector<WorkerID> worker_ids
+                int quic_ipc_fd, std::vector<WorkerID> worker_ids, uint16_t seq
 #endif // ENABLE_HTTP3
                 )
       : loop(loop),
@@ -214,7 +214,8 @@ struct WorkerProcess {
 #ifdef ENABLE_HTTP3
         ,
         quic_ipc_fd(quic_ipc_fd),
-        worker_ids(std::move(worker_ids))
+        worker_ids(std::move(worker_ids)),
+        seq(seq)
 #endif // ENABLE_HTTP3
   {
     ev_child_init(&worker_process_childev, worker_process_child_cb, worker_pid,
@@ -246,6 +247,7 @@ struct WorkerProcess {
 #ifdef ENABLE_HTTP3
   int quic_ipc_fd;
   std::vector<WorkerID> worker_ids;
+  uint16_t seq;
 #endif // ENABLE_HTTP3
 };
 
@@ -255,6 +257,10 @@ void reload_config();
 
 namespace {
 std::deque<std::unique_ptr<WorkerProcess>> worker_processes;
+
+#ifdef ENABLE_HTTP3
+uint16_t worker_process_seq;
+#endif // ENABLE_HTTP3
 } // namespace
 
 namespace {
@@ -1288,11 +1294,19 @@ get_inherited_quic_lingering_worker_process_from_env() {
       p = end + 1;
     }
 
-    std::sort(std::begin(worker_ids), std::end(worker_ids));
-
     lwps.emplace_back(std::move(worker_ids), fd);
   }
 
+  if (!lwps.empty()) {
+    const auto &lwp = lwps.back();
+
+    if (!lwp.worker_ids.empty() &&
+        worker_process_seq <= lwp.worker_ids[0].worker_process) {
+      worker_process_seq = lwp.worker_ids[0].worker_process;
+      ++worker_process_seq;
+    }
+  }
+
   return lwps;
 }
 } // namespace
@@ -1422,7 +1436,7 @@ int create_quic_ipc_socket(std::array<int, 2> &quic_ipc_fd) {
 } // namespace
 
 namespace {
-int generate_worker_id(std::vector<WorkerID> &worker_ids,
+int generate_worker_id(std::vector<WorkerID> &worker_ids, uint16_t wp_seq,
                        const Config *config) {
   auto &apiconf = config->api;
   auto &quicconf = config->quic;
@@ -1443,13 +1457,13 @@ int generate_worker_id(std::vector<WorkerID> &worker_ids,
 
   worker_ids.resize(num_wid);
 
-  for (auto &wid : worker_ids) {
-    if (create_worker_id(wid, quicconf.server_id) != 0) {
-      return -1;
-    }
-  }
+  uint16_t idx = 0;
 
-  std::sort(std::begin(worker_ids), std::end(worker_ids));
+  for (auto &wid : worker_ids) {
+    wid.server = quicconf.server_id;
+    wid.worker_process = wp_seq;
+    wid.thread = idx++;
+  }
 
   return 0;
 }
@@ -1840,7 +1854,7 @@ int event_loop() {
 
   std::vector<WorkerID> worker_ids;
 
-  if (generate_worker_id(worker_ids, config) != 0) {
+  if (generate_worker_id(worker_ids, worker_process_seq, config) != 0) {
     return -1;
   }
 #endif // ENABLE_HTTP3
@@ -1872,13 +1886,13 @@ int event_loop() {
   ev_timer_init(&worker_process_grace_period_timer,
                 worker_process_grace_period_timercb, 0., 0.);
 
-  worker_process_add(std::make_unique<WorkerProcess>(loop, pid, ipc_fd
+  worker_process_add(std::make_unique<WorkerProcess>(
+      loop, pid, ipc_fd
 #ifdef ENABLE_HTTP3
-                                                     ,
-                                                     quic_ipc_fd,
-                                                     std::move(worker_ids)
+      ,
+      quic_ipc_fd, std::move(worker_ids), worker_process_seq++
 #endif // ENABLE_HTTP3
-                                                         ));
+      ));
 
   // Write PID file when we are ready to accept connection from peer.
   // This makes easier to write restart script for nghttpx.  Because
@@ -4010,7 +4024,8 @@ void reload_config() {
 
   std::vector<WorkerID> worker_ids;
 
-  if (generate_worker_id(worker_ids, new_config.get()) != 0) {
+  if (generate_worker_id(worker_ids, worker_process_seq, new_config.get()) !=
+      0) {
     close_not_inherited_fd(new_config.get(), iaddrs);
     return;
   }
@@ -4046,13 +4061,13 @@ void reload_config() {
 
   close_unused_inherited_addr(iaddrs);
 
-  worker_process_add(std::make_unique<WorkerProcess>(loop, pid, ipc_fd
+  worker_process_add(std::make_unique<WorkerProcess>(
+      loop, pid, ipc_fd
 #ifdef ENABLE_HTTP3
-                                                     ,
-                                                     quic_ipc_fd,
-                                                     std::move(worker_ids)
+      ,
+      quic_ipc_fd, std::move(worker_ids), worker_process_seq++
 #endif // ENABLE_HTTP3
-                                                         ));
+      ));
 
   worker_process_adjust_limit();
 

src/shrpx_config.cc

@@ -2975,13 +2975,28 @@ int parse_config(Config *config, int optid, const StringRef &opt,
 
     return 0;
   }
-  case SHRPX_OPTID_WORKERS:
+  case SHRPX_OPTID_WORKERS: {
 #ifdef NOTHREADS
     LOG(WARN) << "Threading disabled at build time, no threads created.";
     return 0;
 #else  // !NOTHREADS
-    return parse_uint(&config->num_worker, opt, optarg);
+    size_t n;
+
+    if (parse_uint(&n, opt, optarg) != 0) {
+      return -1;
+    }
+
+    if (n > 65530) {
+      LOG(ERROR) << opt << ": the number of workers must not exceed 65530";
+
+      return -1;
+    }
+
+    config->num_worker = n;
+
+    return 0;
 #endif // !NOTHREADS
+  }
   case SHRPX_OPTID_HTTP2_MAX_CONCURRENT_STREAMS: {
     LOG(WARN) << opt << ": deprecated. Use "
               << SHRPX_OPT_FRONTEND_HTTP2_MAX_CONCURRENT_STREAMS << " and "

src/shrpx_connection_handler.cc

@@ -1039,22 +1039,35 @@ void ConnectionHandler::set_worker_ids(std::vector<WorkerID> worker_ids) {
   worker_ids_ = std::move(worker_ids);
 }
 
+namespace {
+ssize_t find_worker_index(const std::vector<WorkerID> &worker_ids,
+                          const WorkerID &wid) {
+  assert(!worker_ids.empty());
+
+  if (wid.server != worker_ids[0].server ||
+      wid.worker_process != worker_ids[0].worker_process ||
+      wid.thread >= worker_ids.size()) {
+    return -1;
+  }
+
+  return wid.thread;
+}
+} // namespace
+
 Worker *ConnectionHandler::find_worker(const WorkerID &wid) const {
-  auto it =
-      std::lower_bound(std::begin(worker_ids_), std::end(worker_ids_), wid);
-  if (it == std::end(worker_ids_) || *it != wid) {
+  auto idx = find_worker_index(worker_ids_, wid);
+  if (idx == -1) {
     return nullptr;
   }
 
-  return workers_[std::distance(std::begin(worker_ids_), it)].get();
+  return workers_[idx].get();
 }
 
 QUICLingeringWorkerProcess *
 ConnectionHandler::match_quic_lingering_worker_process_worker_id(
     const WorkerID &wid) {
   for (auto &lwps : quic_lingering_worker_processes_) {
-    if (std::binary_search(std::begin(lwps.worker_ids),
-                           std::end(lwps.worker_ids), wid)) {
+    if (find_worker_index(lwps.worker_ids, wid) != -1) {
       return &lwps;
     }
   }

src/shrpx_connection_handler.h

@@ -121,7 +121,6 @@ enum class QUICIPCType {
 
 // WorkerProcesses which are in graceful shutdown period.
 struct QUICLingeringWorkerProcess {
-  // |worker_ids| must be sorted in the lexicographical order.
   QUICLingeringWorkerProcess(std::vector<WorkerID> worker_ids, int quic_ipc_fd)
       : worker_ids{std::move(worker_ids)}, quic_ipc_fd{quic_ipc_fd} {}
 
@@ -202,7 +201,6 @@ public:
   void set_quic_keying_materials(std::shared_ptr<QUICKeyingMaterials> qkms);
   const std::shared_ptr<QUICKeyingMaterials> &get_quic_keying_materials() const;
 
-  // |worker_ids| must be sorted in the lexicographical order.
   void set_worker_ids(std::vector<WorkerID> worker_ids);
   Worker *find_worker(const WorkerID &wid) const;
 

src/shrpx_quic.h

@@ -87,7 +87,8 @@ struct WorkerID {
   union {
     struct {
       uint32_t server;
-      uint32_t thread;
+      uint16_t worker_process;
+      uint16_t thread;
     };
     uint64_t worker;
   };
@@ -104,10 +105,6 @@ inline bool operator!=(const WorkerID &lhd, const WorkerID &rhd) {
   return lhd.worker != rhd.worker;
 }
 
-inline bool operator<(const WorkerID &lhd, const WorkerID &rhd) {
-  return lhd.worker < rhd.worker;
-}
-
 struct ConnectionID {
   WorkerID worker;
   uint64_t client;

src/shrpx_worker.cc

@@ -1441,17 +1441,4 @@ void downstream_failure(DownstreamAddr *addr, const Address *raddr) {
   }
 }
 
-#ifdef ENABLE_HTTP3
-int create_worker_id(WorkerID &dest, uint32_t server_id) {
-  dest.server = server_id;
-
-  if (RAND_bytes(reinterpret_cast<unsigned char *>(&dest.thread),
-                 sizeof(dest.thread)) != 1) {
-    return -1;
-  }
-
-  return 0;
-}
-#endif // ENABLE_HTTP3
-
 } // namespace shrpx

src/shrpx_worker.h

@@ -468,12 +468,6 @@ size_t match_downstream_addr_group(
 // nullptr.  This function may schedule live check.
 void downstream_failure(DownstreamAddr *addr, const Address *raddr);
 
-#ifdef ENABLE_HTTP3
-// Creates WorkerID used as a prefix of QUIC Connection ID.  This
-// function returns -1 on failure.
-int create_worker_id(WorkerID &dest, uint32_t server_id);
-#endif // ENABLE_HTTP3
-
 } // namespace shrpx
 
 #endif // SHRPX_WORKER_H