First implementation for signal handling and multi-threading:

safe shutdown and signal deliverence to all threads in 
the manager process

server-tools/instance-manager/listener.cc

@@ -0,0 +1,72 @@
+#include "listener.h"
+#include "thread_repository.h"
+#include "log.h"
+
+C_MODE_START
+
+pthread_handler_decl(listener, arg)
+{
+  Thread_info info(pthread_self());
+  Thread_repository &thread_repository=
+    ((Listener_thread_args *) arg)->thread_repository;
+  thread_repository.register_thread(&info);
+
+  while (true)
+  {
+    log_info("listener is alive");
+    sleep(2);
+    if (thread_repository.is_shutdown())
+      break;
+  }
+  log_info("listener(): shutdown requested, exiting...");
+
+  thread_repository.unregister_thread(&info);
+  return 0;
+}
+
+C_MODE_END
+
+#if 0
+  while (true)
+  {
+  }
+  /*
+    Dummy manager implementation: listens on a UNIX socket and
+    starts echo server in a dedicated thread for each accepted connection.
+    Enough to test startup/shutdown/options/logging of the instance manager.
+  */
+
+  int fd= socket(AF_UNIX, SOCK_STREAM, 0);
+  
+  if (!fd)
+    die("socket(): failed");
+
+  struct sockaddr_un address;
+  bzero(&address, sizeof(address));
+  address.sun_family= AF_UNIX;
+  strcpy(address.sun_path, socket_path);
+  int opt= 1;
+
+  if (unlink(socket_path) ||
+      bind(fd, (struct sockaddr *) &address, sizeof(address)) ||
+      setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt)))
+    die("unlink | bind | setsockopt failed");
+  
+  if (listen(fd, 5))
+    die("listen() failed");
+  
+  int client_fd;
+  while ((client_fd= accept(fd, 0, 0)) != -1);
+  {
+    printf("accepted\n");
+    const char *message= "\n10hel";
+    send(client_fd, message, strlen(message), 0);
+
+    int sleep_seconds= argc > 1 && atoi(argv[1]) ? atoi(argv[1]) : 1;
+    printf("sleeping %d seconds\n", sleep_seconds);
+    sleep(sleep_seconds);
+    close(client_fd);
+  }
+  printf("accept(): failed\n");
+  close(fd);
+#endif