Replace the approach using Foo_thread_args + Foo_thread and manually

spawned threads with a reusable class Thread.

This is the second idea implemented in the Alik's patch for
BUG#22306: STOP INSTANCE can not be applied for instances in Crashed,
Failed and Abandoned.
Commiting separately to ease review process. 


server-tools/instance-manager/commands.cc:
  Remove an unused header.
server-tools/instance-manager/guardian.cc:
  Use Thread framework instead of manually spawning the Guardian thread.
  Tidy up.
server-tools/instance-manager/guardian.h:
  Use Thread framework instead of manually spawning the Guardian thread.
server-tools/instance-manager/instance.cc:
  Use Thread framework instead of manually spawning the instance
  monitoring thread.
server-tools/instance-manager/listener.cc:
  Use Thread framework instead of manually spawning the 
  mysql connection thread.
server-tools/instance-manager/listener.h:
  Use Thread framework instead of manually spawning the 
  mysql connection thread.
  Rename Listener_thread to Listener for brevity.
server-tools/instance-manager/manager.cc:
  Change references to pointers, as per the coding style.
  Use Thread framework instead of manually spawning threads.
server-tools/instance-manager/mysql_connection.cc:
  Get rid of Mysql_connection_thread_args. Use class Thread framework
  instead. Rename Mysql_connection_thread to Mysql_connection for brevity.
server-tools/instance-manager/mysql_connection.h:
  Get rid of Mysql_connection_thread_args. Use class Thread framework
  instead. Rename Mysql_connection_thread to Mysql_connection for brevity.
server-tools/instance-manager/priv.cc:
  Move set_stacksize_and_create_thread to thread_registry.cc and make it
  static: it is not used anywhere else now.
server-tools/instance-manager/priv.h:
  No public set_stacksize_n_create_thread
server-tools/instance-manager/thread_registry.cc:
  Implement a base Thread class to be used for all Instance Manager
  threads.
server-tools/instance-manager/thread_registry.h:
  Implement a base Thread class to be used for all Instance Manager
  threads.

13 files changed, 336 insertions, 420 deletions

diff --git a/server-tools/instance-manager/commands.cc b/server-tools/instance-manager/commands.cc
index 50ab15f1ed3..1ecd4b38fcd 100644
--- a/server-tools/instance-manager/commands.cc
+++ b/server-tools/instance-manager/commands.cc
@@ -29,7 +29,6 @@
 #include "guardian.h"
 #include "instance_map.h"
 #include "log.h"
-#include "manager.h"
 #include "messages.h"
 #include "mysqld_error.h"
 #include "mysql_manager_error.h"
diff --git a/server-tools/instance-manager/guardian.cc b/server-tools/instance-manager/guardian.cc
index 71ad0760b06..1cb9aed559b 100644
--- a/server-tools/instance-manager/guardian.cc
+++ b/server-tools/instance-manager/guardian.cc
@@ -20,7 +20,6 @@
 #endif
 
 #include "guardian.h"
-
 #include <string.h>
 #include <sys/types.h>
 #include <signal.h>
@@ -30,15 +29,6 @@
 #include "log.h"
 #include "mysql_manager_error.h"
 
-
-pthread_handler_t guardian_thread_func(void *arg)
-{
-  Guardian *guardian= (Guardian *) arg;
-  guardian->run();
-  return 0;
-}
-
-
 const char *
 Guardian::get_instance_state_name(enum_instance_state state)
 {
@@ -68,18 +58,19 @@ Guardian::get_instance_state_name(enum_instance_state state)
   return NULL; /* just to ignore compiler warning. */
 }
 
+/* {{{ Constructor & destructor. */
 
-Guardian::Guardian(Thread_registry &thread_registry_arg,
-                                 Instance_map *instance_map_arg,
-                                 uint monitoring_interval_arg) :
-  Guardian_args(thread_registry_arg, instance_map_arg,
-                       monitoring_interval_arg),
-  thread_info(pthread_self(), TRUE), guarded_instances(0)
+Guardian::Guardian(Thread_registry *thread_registry_arg,
+                   Instance_map *instance_map_arg,
+                   uint monitoring_interval_arg)
+  :monitoring_interval(monitoring_interval_arg),
+  shutdown_requested(FALSE),
+  stopped(FALSE),
+  thread_registry(thread_registry_arg),
+  instance_map(instance_map_arg)
 {
   pthread_mutex_init(&LOCK_guardian, 0);
   pthread_cond_init(&COND_guardian, 0);
-  shutdown_requested= FALSE;
-  stopped= FALSE;
   init_alloc_root(&alloc, MEM_ROOT_BLOCK_SIZE, 0);
 }
 
@@ -94,6 +85,8 @@ Guardian::~Guardian()
   pthread_cond_destroy(&COND_guardian);
 }
 
+/* }}} */
+
 
 void Guardian::request_shutdown()
 {
@@ -106,9 +99,9 @@ void Guardian::request_shutdown()
 
 
 void Guardian::process_instance(Instance *instance,
-                                       GUARD_NODE *current_node,
-                                       LIST **guarded_instances,
-                                       LIST *node)
+                                GUARD_NODE *current_node,
+                                LIST **guarded_instances,
+                                LIST *node)
 {
   uint waitchild= (uint) Instance::DEFAULT_SHUTDOWN_DELAY;
   /* The amount of times, Guardian attempts to restart an instance */
@@ -117,7 +110,7 @@ void Guardian::process_instance(Instance *instance,
 
   if (current_node->state == STOPPING)
   {
-    /* this brach is executed during shutdown */
+    /* this branch is executed during shutdown */
     if (instance->options.shutdown_delay)
     {
       /*
@@ -235,7 +228,7 @@ void Guardian::process_instance(Instance *instance,
 /*
   Run guardian thread
 
-  SYNOPSYS
+  SYNOPSIS
     run()
 
   DESCRIPTION
@@ -252,9 +245,8 @@ void Guardian::run()
 
   log_info("Guardian: started.");
 
-  thread_registry.register_thread(&thread_info);
+  thread_registry->register_thread(&thread_info);
 
-  my_thread_init();
   pthread_mutex_lock(&LOCK_guardian);
 
   /* loop, until all instances were shut down at the end */
@@ -275,8 +267,8 @@ void Guardian::run()
 
     /* check the loop predicate before sleeping */
     if (!(shutdown_requested && (!(guarded_instances))))
-      thread_registry.cond_timedwait(&thread_info, &COND_guardian,
-                                     &LOCK_guardian, &timeout);
+      thread_registry->cond_timedwait(&thread_info, &COND_guardian,
+                                      &LOCK_guardian, &timeout);
   }
 
   log_info("Guardian: stopped.");
@@ -284,9 +276,8 @@ void Guardian::run()
   stopped= TRUE;
   pthread_mutex_unlock(&LOCK_guardian);
   /* now, when the Guardian is stopped we can stop the IM */
-  thread_registry.unregister_thread(&thread_info);
-  thread_registry.request_shutdown();
-  my_thread_end();
+  thread_registry->unregister_thread(&thread_info);
+  thread_registry->request_shutdown();
 
   log_info("Guardian: finished.");
 }
@@ -306,7 +297,7 @@ int Guardian::is_stopped()
   Initialize the list of guarded instances: loop through the Instance_map and
   add all of the instances, which don't have 'nonguarded' option specified.
 
-  SYNOPSYS
+  SYNOPSIS
     Guardian::init()
 
   NOTE: The operation should be invoked with the following locks acquired:
@@ -315,7 +306,7 @@ int Guardian::is_stopped()
 
   RETURN
     0 - ok
-    1 - error occured
+    1 - error occurred
 */
 
 int Guardian::init()
@@ -344,7 +335,7 @@ int Guardian::init()
 /*
   Add instance to the Guardian list
 
-  SYNOPSYS
+  SYNOPSIS
     guard()
     instance           the instance to be guarded
     nolock             whether we prefer do not lock Guardian here,
@@ -357,7 +348,7 @@ int Guardian::init()
 
   RETURN
     0 - ok
-    1 - error occured
+    1 - error occurred
 */
 
 int Guardian::guard(Instance *instance, bool nolock)
@@ -418,7 +409,7 @@ int Guardian::stop_guard(Instance *instance)
   An internal method which is called at shutdown to unregister instances and
   attempt to stop them if requested.
 
-  SYNOPSYS
+  SYNOPSIS
     stop_instances()
 
   DESCRIPTION
@@ -431,7 +422,7 @@ int Guardian::stop_guard(Instance *instance)
 
   RETURN
     0 - ok
-    1 - error occured
+    1 - error occurred
 */
 
 int Guardian::stop_instances()
diff --git a/server-tools/instance-manager/guardian.h b/server-tools/instance-manager/guardian.h
index 4c518dddf23..0eee1dc631d 100644
--- a/server-tools/instance-manager/guardian.h
+++ b/server-tools/instance-manager/guardian.h
@@ -16,11 +16,10 @@
    along with this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
 
-#include <my_global.h>
-#include <my_sys.h>
-#include <my_list.h>
 
 #include "thread_registry.h"
+#include <my_sys.h>
+#include <my_list.h>
 
 #if defined(__GNUC__) && defined(USE_PRAGMA_INTERFACE)
 #pragma interface
@@ -31,30 +30,12 @@ class Instance_map;
 class Thread_registry;
 struct GUARD_NODE;
 
-pthread_handler_t guardian_thread_func(void *arg);
-
-struct Guardian_args
-{
-  Thread_registry &thread_registry;
-  Instance_map *instance_map;
-  int monitoring_interval;
-
-  Guardian_args(Thread_registry &thread_registry_arg,
-                       Instance_map *instance_map_arg,
-                       uint monitoring_interval_arg) :
-    thread_registry(thread_registry_arg),
-    instance_map(instance_map_arg),
-    monitoring_interval(monitoring_interval_arg)
-  {}
-};
-
-
-/*
+/**
   The guardian thread is responsible for monitoring and restarting of guarded
   instances.
 */
 
-class Guardian: public Guardian_args
+class Guardian: public Thread
 {
 public:
   /* states of an instance */
@@ -82,12 +63,10 @@ public:
   /* Return client state name. */
   static const char *get_instance_state_name(enum_instance_state state);
 
-  Guardian(Thread_registry &thread_registry_arg,
-                  Instance_map *instance_map_arg,
-                  uint monitoring_interval_arg);
-  ~Guardian();
-  /* Main funtion of the thread */
-  void run();
+  Guardian(Thread_registry *thread_registry_arg,
+           Instance_map *instance_map_arg,
+           uint monitoring_interval_arg);
+  virtual ~Guardian();
   /* Initialize or refresh the list of guarded instances */
   int init();
   /* Request guardian shutdown. Stop instances if needed */
@@ -117,6 +96,9 @@ public:
     a valid list node.
   */
   inline enum_instance_state get_instance_state(LIST *instance_node);
+protected:
+  /* Main funtion of the thread */
+  virtual void run();
 
 public:
   pthread_cond_t COND_guardian;
@@ -133,6 +115,9 @@ private:
 private:
   pthread_mutex_t LOCK_guardian;
   Thread_info thread_info;
+  int monitoring_interval;
+  Thread_registry *thread_registry;
+  Instance_map *instance_map;
   LIST *guarded_instances;
   MEM_ROOT alloc;
   /* this variable is set to TRUE when we want to stop Guardian thread */
diff --git a/server-tools/instance-manager/instance.cc b/server-tools/instance-manager/instance.cc
index 3927363a3e5..f170332e132 100644
--- a/server-tools/instance-manager/instance.cc
+++ b/server-tools/instance-manager/instance.cc
@@ -44,9 +44,6 @@ static const char * const INSTANCE_NAME_PREFIX= Instance::DFLT_INSTANCE_NAME.str
 static const int INSTANCE_NAME_PREFIX_LEN= Instance::DFLT_INSTANCE_NAME.length;
 
 
-static void start_and_monitor_instance(Instance_options *old_instance_options,
-                                       Instance_map *instance_map,
-                                       Thread_registry *thread_registry);
 
 #ifndef __WIN__
 typedef pid_t My_process_info;
@@ -61,13 +58,24 @@ typedef PROCESS_INFORMATION My_process_info;
   to do it in a portable way.
 */
 
-pthread_handler_t proxy(void *arg)
+class Instance_monitor: public Thread
 {
-  Instance *instance= (Instance *) arg;
-  start_and_monitor_instance(&instance->options,
-                             instance->get_map(),
+public:
+  Instance_monitor(Instance *instance_arg) :instance(instance_arg) {}
+protected:
+  virtual void run();
+  void start_and_monitor_instance(Instance_options *old_instance_options,
+                                  Instance_map *instance_map,
+                                  Thread_registry *thread_registry);
+private:
+  Instance *instance;
+};
+
+void Instance_monitor::run()
+{
+  start_and_monitor_instance(&instance->options, instance->get_map(),
                              &instance->thread_registry);
-  return 0;
+  delete this;
 }
 
 /*
@@ -242,14 +250,16 @@ static int start_process(Instance_options *instance_options,
     Function returns no value
 */
 
-static void start_and_monitor_instance(Instance_options *old_instance_options,
-                                       Instance_map *instance_map,
-                                       Thread_registry *thread_registry)
+void
+Instance_monitor::
+start_and_monitor_instance(Instance_options *old_instance_options,
+                           Instance_map *instance_map,
+                           Thread_registry *thread_registry)
 {
   Instance_name instance_name(&old_instance_options->instance_name);
   Instance *current_instance;
   My_process_info process_info;
-  Thread_info thread_info(pthread_self(), FALSE);
+  Thread_info thread_info;
 
   log_info("Monitoring thread (instance: '%s'): started.",
            (const char *) instance_name.get_c_str());
@@ -258,12 +268,10 @@ static void start_and_monitor_instance(Instance_options *old_instance_options,
   {
     /*
       Register thread in Thread_registry to wait for it to stop on shutdown
-      only if instance is nuarded. If instance is guarded, the thread will not
+      only if instance is guarded. If instance is guarded, the thread will not
       finish, because nonguarded instances are not stopped on shutdown.
     */
-
-    thread_registry->register_thread(&thread_info);
-    my_thread_init();
+    thread_registry->register_thread(&thread_info, FALSE);
   }
 
   /*
@@ -302,10 +310,7 @@ static void start_and_monitor_instance(Instance_options *old_instance_options,
   instance_map->unlock();
 
   if (!old_instance_options->nonguarded)
-  {
     thread_registry->unregister_thread(&thread_info);
-    my_thread_end();
-  }
 
   log_info("Monitoring thread (instance: '%s'): finished.",
            (const char *) instance_name.get_c_str());
@@ -369,22 +374,19 @@ int Instance::start()
 
   if (configured && !is_running())
   {
+    Instance_monitor *instance_monitor;
     remove_pid();
 
-    pthread_t proxy_thd_id;
-    pthread_attr_t proxy_thd_attr;
-    int rc;
+    instance_monitor= new Instance_monitor(this);
 
-    pthread_attr_init(&proxy_thd_attr);
-    pthread_attr_setdetachstate(&proxy_thd_attr, PTHREAD_CREATE_DETACHED);
-    rc= pthread_create(&proxy_thd_id, &proxy_thd_attr, proxy,
-                       this);
-    pthread_attr_destroy(&proxy_thd_attr);
-    if (rc)
+    if (instance_monitor == NULL || instance_monitor->start_detached())
     {
-      log_error("Instance::start(): pthread_create(proxy) failed");
+      delete instance_monitor;
+      log_error("Instance::start(): failed to create the monitoring thread"
+                " to start an instance");
       return ER_CANNOT_START_INSTANCE;
     }
+    /* The monitoring thread will delete itself when it's finished. */
 
     return 0;
   }
diff --git a/server-tools/instance-manager/listener.cc b/server-tools/instance-manager/listener.cc
index 62962c00957..b749f234560 100644
--- a/server-tools/instance-manager/listener.cc
+++ b/server-tools/instance-manager/listener.cc
@@ -29,7 +29,6 @@
 #include <sys/un.h>
 #endif
 
-#include "instance_map.h"
 #include "log.h"
 #include "mysql_connection.h"
 #include "options.h"
@@ -59,47 +58,18 @@ static void set_no_inherit(int socket)
 }
 
 
-/*
-  Listener_thread - incapsulates listening functionality
-*/
-
-class Listener_thread: public Listener_thread_args
-{
-public:
-  Listener_thread(const Listener_thread_args &args);
-  ~Listener_thread();
-  void run();
-private:
-  static const int LISTEN_BACK_LOG_SIZE= 5;     /* standard backlog size */
-  ulong total_connection_count;
-  Thread_info thread_info;
-
-  int     sockets[2];
-  int     num_sockets;
-  fd_set  read_fds;
-private:
-  void handle_new_mysql_connection(Vio *vio);
-  int   create_tcp_socket();
-  int   create_unix_socket(struct sockaddr_un &unix_socket_address);
-};
-
-
-Listener_thread::Listener_thread(const Listener_thread_args &args) :
-  Listener_thread_args(args.thread_registry, args.user_map, args.instance_map)
-  ,total_connection_count(0)
-  ,thread_info(pthread_self(), TRUE)
-  ,num_sockets(0)
-{
-}
-
-
-Listener_thread::~Listener_thread()
+Listener::Listener(Thread_registry *thread_registry_arg,
+                   User_map *user_map_arg)
+  :thread_registry(thread_registry_arg),
+  user_map(user_map_arg),
+  total_connection_count(0),
+  num_sockets(0)
 {
 }
 
 
 /*
-  Listener_thread::run() - listen all supported sockets and spawn a thread
+  Listener::run() - listen all supported sockets and spawn a thread
   to handle incoming connection.
   Using 'die' in case of syscall failure is OK now - we don't hold any
   resources and 'die' kills the signal thread automatically. To be rewritten
@@ -108,11 +78,11 @@ Listener_thread::~Listener_thread()
   architecture.
 */
 
-void Listener_thread::run()
+void Listener::run()
 {
   int i, n= 0;
 
-  log_info("Listener_thread: started.");
+  log_info("Listener: started.");
 
 #ifndef __WIN__
   /* we use this var to check whether we are running on LinuxThreads */
@@ -125,9 +95,7 @@ void Listener_thread::run()
   linuxthreads= (thread_pid != manager_pid);
 #endif
 
-  thread_registry.register_thread(&thread_info);
-
-  my_thread_init();
+  thread_registry->register_thread(&thread_info);
 
   FD_ZERO(&read_fds);
 
@@ -146,7 +114,7 @@ void Listener_thread::run()
   n++;
 
   timeval tv;
-  while (!thread_registry.is_shutdown())
+  while (!thread_registry->is_shutdown())
   {
     fd_set read_fds_arg= read_fds;
     /*
@@ -166,7 +134,7 @@ void Listener_thread::run()
     if (rc == 0 || rc == -1)
     {
       if (rc == -1 && errno != EINTR)
-        log_error("Listener_thread: select() failed, %s",
+        log_error("Listener: select() failed, %s",
                   strerror(errno));
       continue;
     }
@@ -200,7 +168,7 @@ void Listener_thread::run()
 
   /* III. Release all resources and exit */
 
-  log_info("Listener_thread: shutdown requested, exiting...");
+  log_info("Listener: shutdown requested, exiting...");
 
   for (i= 0; i < num_sockets; i++)
     close(sockets[i]);
@@ -209,10 +177,9 @@ void Listener_thread::run()
   unlink(unix_socket_address.sun_path);
 #endif
 
-  thread_registry.unregister_thread(&thread_info);
-  my_thread_end();
+  thread_registry->unregister_thread(&thread_info);
 
-  log_info("Listener_thread: finished.");
+  log_info("Listener: finished.");
   return;
 
 err:
@@ -220,13 +187,12 @@ err:
   for (i= 0; i < num_sockets; i++)
     close(sockets[i]);
 
-  thread_registry.unregister_thread(&thread_info);
-  thread_registry.request_shutdown();
-  my_thread_end();
+  thread_registry->unregister_thread(&thread_info);
+  thread_registry->request_shutdown();
   return;
 }
 
-int Listener_thread::create_tcp_socket()
+int Listener::create_tcp_socket()
 {
   /* value to be set by setsockopt */
   int arg= 1;
@@ -265,7 +231,7 @@ int Listener_thread::create_tcp_socket()
   if (bind(ip_socket, (struct sockaddr *) &ip_socket_address,
            sizeof(ip_socket_address)))
   {
-    log_error("Listener_thread: bind(ip socket) failed, '%s'",
+    log_error("Listener: bind(ip socket) failed, '%s'",
               strerror(errno));
     close(ip_socket);
     return -1;
@@ -273,7 +239,7 @@ int Listener_thread::create_tcp_socket()
 
   if (listen(ip_socket, LISTEN_BACK_LOG_SIZE))
   {
-    log_error("Listener_thread: listen(ip socket) failed, %s",
+    log_error("Listener: listen(ip socket) failed, %s",
               strerror(errno));
     close(ip_socket);
     return -1;
@@ -292,7 +258,7 @@ int Listener_thread::create_tcp_socket()
 }
 
 #ifndef __WIN__
-int Listener_thread::
+int Listener::
 create_unix_socket(struct sockaddr_un &unix_socket_address)
 {
   int unix_socket= socket(AF_UNIX, SOCK_STREAM, 0);
@@ -318,7 +284,7 @@ create_unix_socket(struct sockaddr_un &unix_socket_address)
   if (bind(unix_socket, (struct sockaddr *) &unix_socket_address,
            sizeof(unix_socket_address)))
   {
-    log_error("Listener_thread: bind(unix socket) failed, "
+    log_error("Listener: bind(unix socket) failed, "
               "socket file name is '%s', error '%s'",
               unix_socket_address.sun_path, strerror(errno));
     close(unix_socket);
@@ -329,7 +295,7 @@ create_unix_socket(struct sockaddr_un &unix_socket_address)
 
   if (listen(unix_socket, LISTEN_BACK_LOG_SIZE))
   {
-    log_error("Listener_thread: listen(unix socket) failed, %s",
+    log_error("Listener: listen(unix socket) failed, %s",
               strerror(errno));
     close(unix_socket);
     return -1;
@@ -357,46 +323,16 @@ create_unix_socket(struct sockaddr_un &unix_socket_address)
     handle_new_mysql_connection()
 */
 
-void Listener_thread::handle_new_mysql_connection(Vio *vio)
+void Listener::handle_new_mysql_connection(Vio *vio)
 {
-  if (Mysql_connection_thread_args *mysql_thread_args=
-      new Mysql_connection_thread_args(vio, thread_registry, user_map,
-                                       ++total_connection_count,
-                                       instance_map)
-      )
+  Mysql_connection *mysql_connection=
+    new Mysql_connection(thread_registry, user_map,
+                         vio, ++total_connection_count);
+  if (mysql_connection == NULL || mysql_connection->start_detached())
   {
-    /*
-      Initialize thread attributes to create detached thread; it seems
-      easier to do it ad-hoc than have a global variable for attributes.
-    */
-    pthread_t mysql_thd_id;
-    pthread_attr_t mysql_thd_attr;
-    pthread_attr_init(&mysql_thd_attr);
-    pthread_attr_setdetachstate(&mysql_thd_attr, PTHREAD_CREATE_DETACHED);
-    if (set_stacksize_n_create_thread(&mysql_thd_id, &mysql_thd_attr,
-                                      mysql_connection, mysql_thread_args))
-    {
-      delete mysql_thread_args;
-      vio_delete(vio);
-      log_error("handle_one_mysql_connection():"
-                "set_stacksize_n_create_thread(mysql) failed");
-    }
-    pthread_attr_destroy(&mysql_thd_attr);
-  }
-  else
+    log_error("handle_one_mysql_connection() failed");
+    delete mysql_connection;
     vio_delete(vio);
+  }
+  /* The connection will delete itself when the thread is finished */
 }
-
-
-pthread_handler_t listener(void *arg)
-{
-  Listener_thread_args *args= (Listener_thread_args *) arg;
-  Listener_thread listener(*args);
-  listener.run();
-  /*
-    args is a stack variable because listener thread lives as long as the
-    manager process itself
-  */
-  return 0;
-}
-
diff --git a/server-tools/instance-manager/listener.h b/server-tools/instance-manager/listener.h
index c28ab0649d7..7758c2dc13d 100644
--- a/server-tools/instance-manager/listener.h
+++ b/server-tools/instance-manager/listener.h
@@ -16,33 +16,39 @@
    along with this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
 
-#include <my_global.h>
-#include <my_pthread.h>
+#include "thread_registry.h"
 
 #if defined(__GNUC__) && defined(USE_PRAGMA_INTERFACE)
 #pragma interface
 #endif
 
-
-pthread_handler_t listener(void *arg);
-
 class Thread_registry;
 class User_map;
-class Instance_map;
 
-struct Listener_thread_args
+/**
+  Listener - a thread listening on sockets and spawning
+  connection threads.
+*/
+
+class Listener: public Thread
 {
-  Thread_registry &thread_registry;
-  const User_map &user_map;
-  Instance_map &instance_map;
-
-  Listener_thread_args(Thread_registry &thread_registry_arg,
-                       const User_map &user_map_arg,
-                       Instance_map &instance_map_arg) :
-    thread_registry(thread_registry_arg)
-    ,user_map(user_map_arg)
-    ,instance_map(instance_map_arg)
-  {}
+public:
+  Listener(Thread_registry *thread_registry_arg, User_map *user_map_arg);
+protected:
+  virtual void run();
+private:
+  Thread_info thread_info;
+  Thread_registry *thread_registry;
+  User_map *user_map;
+  static const int LISTEN_BACK_LOG_SIZE= 5;     /* standard backlog size */
+  ulong total_connection_count;
+
+  int     sockets[2];
+  int     num_sockets;
+  fd_set  read_fds;
+  void handle_new_mysql_connection(struct st_vio *vio);
+  int   create_tcp_socket();
+  int   create_unix_socket(struct sockaddr_un &unix_socket_address);
 };
 
 #endif // INCLUDES_MYSQL_INSTANCE_MANAGER_LISTENER_H
diff --git a/server-tools/instance-manager/manager.cc b/server-tools/instance-manager/manager.cc
index 55d7137c97a..8c6bffa8d97 100644
--- a/server-tools/instance-manager/manager.cc
+++ b/server-tools/instance-manager/manager.cc
@@ -139,10 +139,10 @@ int Manager::main()
   User_map user_map;
   Instance_map instance_map(Options::Main::default_mysqld_path,
                             thread_registry);
-  Guardian guardian(thread_registry, &instance_map,
+  Guardian guardian(&thread_registry, &instance_map,
                     Options::Main::monitoring_interval);
 
-  Listener_thread_args listener_args(thread_registry, user_map, instance_map);
+  Listener listener(&thread_registry, &user_map);
 
   manager_pid= getpid();
   p_instance_map= &instance_map;
@@ -212,40 +212,29 @@ int Manager::main()
   sigset_t mask;
   set_signals(&mask);
 
-  /* create guardian thread */
+  /*
+    Create the guardian thread. The newly started thread will block until
+    we actually load instances.
+
+    NOTE: Guardian should be shutdown first. Only then all other threads
+    can be stopped. This should be done in this order because the guardian
+    is responsible for shutting down all the guarded instances, and this
+    is a long operation.
+
+    NOTE: Guardian uses thr_alarm() when detects the current state of an
+    instance (is_running()), but this does not interfere with
+    flush_instances() call later in the code, because until
+    flush_instances() completes in the main thread, Guardian thread is not
+    permitted to process instances. And before flush_instances() has
+    completed, there are no instances to guard.
+  */
+  if (guardian.start_detached())
   {
-    pthread_t guardian_thd_id;
-    pthread_attr_t guardian_thd_attr;
-    int rc;
-
-    /*
-      NOTE: Guardian should be shutdown first. Only then all other threads
-      need to be stopped. This should be done, as guardian is responsible
-      for shutting down the instances, and this is a long operation.
-
-      NOTE: Guardian uses thr_alarm() when detects current state of
-      instances (is_running()), but it is not interfere with
-      flush_instances() later in the code, because until flush_instances()
-      complete in the main thread, Guardian thread is not permitted to
-      process instances. And before flush_instances() there is no instances
-      to proceed.
-    */
-
-    pthread_attr_init(&guardian_thd_attr);
-    pthread_attr_setdetachstate(&guardian_thd_attr, PTHREAD_CREATE_DETACHED);
-    rc= set_stacksize_n_create_thread(&guardian_thd_id, &guardian_thd_attr,
-                                      guardian_thread_func, &guardian);
-    pthread_attr_destroy(&guardian_thd_attr);
-    if (rc)
-    {
-      log_error("manager(): set_stacksize_n_create_thread(guardian) failed");
-      goto err;
-    }
-
+    log_error("manager(): Failed to create the guardian thread");
+    goto err;
   }
 
   /* Load instances. */
-
   {
     instance_map.guardian->lock();
     instance_map.lock();
@@ -265,23 +254,12 @@ int Manager::main()
     }
   }
 
-  /* create the listener */
+  /* start the listener */
+  if (listener.start_detached())
   {
-    pthread_t listener_thd_id;
-    pthread_attr_t listener_thd_attr;
-    int rc;
-
-    pthread_attr_init(&listener_thd_attr);
-    pthread_attr_setdetachstate(&listener_thd_attr, PTHREAD_CREATE_DETACHED);
-    rc= set_stacksize_n_create_thread(&listener_thd_id, &listener_thd_attr,
-                                      listener, &listener_args);
-    pthread_attr_destroy(&listener_thd_attr);
-    if (rc)
-    {
-      log_error("manager(): set_stacksize_n_create_thread(listener) failed");
-      stop_all(&guardian, &thread_registry);
-      goto err;
-    }
+    log_error("manager(): set_stacksize_n_create_thread(listener) failed");
+    stop_all(&guardian, &thread_registry);
+    goto err;
   }
 
   /*
diff --git a/server-tools/instance-manager/mysql_connection.cc b/server-tools/instance-manager/mysql_connection.cc
index 72081234c94..b6f62d0f6eb 100644
--- a/server-tools/instance-manager/mysql_connection.cc
+++ b/server-tools/instance-manager/mysql_connection.cc
@@ -23,7 +23,6 @@
 #include <m_string.h>
 #include <m_string.h>
 #include <my_global.h>
-#include <mysql_com.h>
 #include <mysql.h>
 #include <my_sys.h>
 #include <violite.h>
@@ -40,66 +39,15 @@
 #include "user_map.h"
 
 
-Mysql_connection_thread_args::Mysql_connection_thread_args(
-                             struct st_vio *vio_arg,
-                             Thread_registry &thread_registry_arg,
-                             const User_map &user_map_arg,
-                             ulong connection_id_arg,
-                             Instance_map &instance_map_arg) :
-    vio(vio_arg)
-    ,thread_registry(thread_registry_arg)
-    ,user_map(user_map_arg)
-    ,connection_id(connection_id_arg)
-    ,instance_map(instance_map_arg)
-  {}
-
-/*
-  MySQL connection - handle one connection with mysql command line client
-  See also comments in mysqlmanager.cc to picture general Instance Manager
-  architecture.
-  We use conventional technique to work with classes without exceptions:
-  class acquires all vital resource in init(); Thus if init() succeed,
-  a user must call cleanup(). All other methods are valid only between
-  init() and cleanup().
-*/
-
-class Mysql_connection_thread: public Mysql_connection_thread_args
-{
-public:
-  Mysql_connection_thread(const Mysql_connection_thread_args &args);
-
-  int init();
-  void cleanup();
-
-  void run();
-
-  ~Mysql_connection_thread();
-private:
-  Thread_info thread_info;
-  NET net;
-  struct rand_struct rand_st;
-  char scramble[SCRAMBLE_LENGTH + 1];
-  uint status;
-  ulong client_capabilities;
-private:
-  /* Names are conventionally the same as in mysqld */
-  int check_connection();
-  int do_command();
-  int dispatch_command(enum enum_server_command command,
-                       const char *text, uint len);
-};
-
-
-Mysql_connection_thread::Mysql_connection_thread(
-                                   const Mysql_connection_thread_args &args) :
-  Mysql_connection_thread_args(args.vio,
-                               args.thread_registry,
-                               args.user_map,
-                               args.connection_id,
-                               args.instance_map)
-  ,thread_info(pthread_self(), TRUE)
+Mysql_connection::Mysql_connection(Thread_registry *thread_registry_arg,
+                                   User_map *user_map_arg,
+                                   struct st_vio *vio_arg, ulong
+                                   connection_id_arg)
+  :vio(vio_arg),
+  connection_id(connection_id_arg),
+  thread_registry(thread_registry_arg),
+  user_map(user_map_arg)
 {
-  thread_registry.register_thread(&thread_info);
 }
 
 
@@ -129,7 +77,7 @@ C_MODE_END
   This function is complementary to cleanup().
 */
 
-int Mysql_connection_thread::init()
+int Mysql_connection::init()
 {
   /* Allocate buffers for network I/O */
   if (my_net_init(&net, vio))
@@ -145,52 +93,46 @@ int Mysql_connection_thread::init()
   create_random_string(scramble, SCRAMBLE_LENGTH, &rand_st);
   /* We don't support transactions, every query is atomic */
   status= SERVER_STATUS_AUTOCOMMIT;
+  thread_registry->register_thread(&thread_info);
   return 0;
 }
 
 
-void Mysql_connection_thread::cleanup()
+void Mysql_connection::cleanup()
 {
   net_end(&net);
+  thread_registry->unregister_thread(&thread_info);
 }
 
 
-Mysql_connection_thread::~Mysql_connection_thread()
+Mysql_connection::~Mysql_connection()
 {
   /* vio_delete closes the socket if necessary */
   vio_delete(vio);
-  thread_registry.unregister_thread(&thread_info);
 }
 
 
-void Mysql_connection_thread::run()
+void Mysql_connection::main()
 {
   log_info("accepted mysql connection %lu", (unsigned long) connection_id);
 
-  my_thread_init();
-
   if (check_connection())
-  {
-    my_thread_end();
     return;
-  }
 
   log_info("connection %lu is checked successfully",
            (unsigned long) connection_id);
 
   vio_keepalive(vio, TRUE);
 
-  while (!net.error && net.vio && !thread_registry.is_shutdown())
+  while (!net.error && net.vio && !thread_registry->is_shutdown())
   {
     if (do_command())
       break;
   }
-
-  my_thread_end();
 }
 
 
-int Mysql_connection_thread::check_connection()
+int Mysql_connection::check_connection()
 {
   ulong pkt_len=0;                              // to hold client reply length
 
@@ -279,7 +221,7 @@ int Mysql_connection_thread::check_connection()
     net_send_error(&net, ER_ACCESS_DENIED_ERROR);
     return 1;
   }
-  if (user_map.authenticate(&user_name, password, scramble))
+  if (user_map->authenticate(&user_name, password, scramble))
   {
     net_send_error(&net, ER_ACCESS_DENIED_ERROR);
     return 1;
@@ -289,7 +231,7 @@ int Mysql_connection_thread::check_connection()
 }
 
 
-int Mysql_connection_thread::do_command()
+int Mysql_connection::do_command()
 {
   char *packet;
   ulong packet_length;
@@ -302,7 +244,7 @@ int Mysql_connection_thread::do_command()
     /* Check if we can continue without closing the connection */
     if (net.error != 3) // what is 3 - find out
       return 1;
-    if (thread_registry.is_shutdown())
+    if (thread_registry->is_shutdown())
       return 1;
     net_send_error(&net, net.last_errno);
     net.error= 0;
@@ -310,7 +252,7 @@ int Mysql_connection_thread::do_command()
   }
   else
   {
-    if (thread_registry.is_shutdown())
+    if (thread_registry->is_shutdown())
       return 1;
     packet= (char*) net.read_pos;
     enum enum_server_command command= (enum enum_server_command)
@@ -321,8 +263,8 @@ int Mysql_connection_thread::do_command()
   }
 }
 
-int Mysql_connection_thread::dispatch_command(enum enum_server_command command,
-                                              const char *packet, uint len)
+int Mysql_connection::dispatch_command(enum enum_server_command command,
+                                       const char *packet, uint len)
 {
   switch (command) {
   case COM_QUIT:                                // client exit
@@ -374,19 +316,16 @@ int Mysql_connection_thread::dispatch_command(enum enum_server_command command,
 }
 
 
-pthread_handler_t mysql_connection(void *arg)
+void Mysql_connection::run()
 {
-  Mysql_connection_thread_args *args= (Mysql_connection_thread_args *) arg;
-  Mysql_connection_thread mysql_connection_thread(*args);
-  delete args;
-  if (mysql_connection_thread.init())
-    log_info("mysql_connection(): error initializing thread");
+  if (init())
+    log_info("Mysql_connection::run(): error initializing thread");
   else
   {
-    mysql_connection_thread.run();
-    mysql_connection_thread.cleanup();
+    main();
+    cleanup();
   }
-  return 0;
+  delete this;
 }
 
 /*
diff --git a/server-tools/instance-manager/mysql_connection.h b/server-tools/instance-manager/mysql_connection.h
index 3496cc05815..aceb2d62736 100644
--- a/server-tools/instance-manager/mysql_connection.h
+++ b/server-tools/instance-manager/mysql_connection.h
@@ -16,33 +16,60 @@
    along with this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
 
-#include <my_global.h>
-#include <my_pthread.h>
+#include "thread_registry.h"
+#include <mysql_com.h>
 
 #if defined(__GNUC__) && defined(USE_PRAGMA_INTERFACE)
 #pragma interface
 #endif
 
-pthread_handler_t mysql_connection(void *arg);
-
-class Thread_registry;
-class User_map;
-class Instance_map;
 struct st_vio;
+class User_map;
 
-struct Mysql_connection_thread_args
+/*
+  MySQL connection - handle one connection with mysql command line client
+  See also comments in mysqlmanager.cc to picture general Instance Manager
+  architecture.
+  We use conventional technique to work with classes without exceptions:
+  class acquires all vital resource in init(); Thus if init() succeed,
+  a user must call cleanup(). All other methods are valid only between
+  init() and cleanup().
+*/
+
+class Mysql_connection: public Thread
 {
+public:
+  Mysql_connection(Thread_registry *thread_registry_arg,
+                   User_map *user_map_arg,
+                   struct st_vio *vio_arg,
+                   ulong connection_id_arg);
+  virtual ~Mysql_connection();
+
+protected:
+  virtual void run();
+
+private:
   struct st_vio *vio;
-  Thread_registry &thread_registry;
-  const User_map &user_map;
   ulong connection_id;
-  Instance_map &instance_map;
+  Thread_info thread_info;
+  Thread_registry *thread_registry;
+  User_map *user_map;
+  NET net;
+  struct rand_struct rand_st;
+  char scramble[SCRAMBLE_LENGTH + 1];
+  uint status;
+  ulong client_capabilities;
+private:
+  /* The main loop implementation triad */
+  int init();
+  void main();
+  void cleanup();
 
-  Mysql_connection_thread_args(struct st_vio *vio_arg,
-                               Thread_registry &thread_registry_arg,
-                               const User_map &user_map_arg,
-                               ulong connection_id_arg,
-                               Instance_map &instance_map_arg);
+  /* Names are conventionally the same as in mysqld */
+  int check_connection();
+  int do_command();
+  int dispatch_command(enum enum_server_command command,
+                       const char *text, uint len);
 };
 
 #endif // INCLUDES_MYSQL_INSTANCE_MANAGER_MYSQL_CONNECTION_H
diff --git a/server-tools/instance-manager/priv.cc b/server-tools/instance-manager/priv.cc
index 7e3553444ac..934684a1a06 100644
--- a/server-tools/instance-manager/priv.cc
+++ b/server-tools/instance-manager/priv.cc
@@ -22,17 +22,6 @@
 
 #include "log.h"
 
-#if defined(__ia64__) || defined(__ia64)
-/*
-  We can live with 32K, but reserve 64K. Just to be safe.
-  On ia64 we need to reserve double of the size.
-*/
-#define IM_THREAD_STACK_SIZE    (128*1024L)
-#else
-#define IM_THREAD_STACK_SIZE    (64*1024)
-#endif
-
-
 /* the pid of the manager process (of the signal thread on the LinuxThreads) */
 pid_t manager_pid;
 
@@ -66,33 +55,6 @@ unsigned long bytes_sent = 0L, bytes_received = 0L;
 unsigned long mysqld_net_retry_count = 10L;
 unsigned long open_files_limit;
 
-/*
-  Change the stack size and start a thread. Return an error if either
-  pthread_attr_setstacksize or pthread_create fails.
-  Arguments are the same as for pthread_create().
-*/
-
-int set_stacksize_n_create_thread(pthread_t  *thread, pthread_attr_t *attr,
-                                  void *(*start_routine)(void *), void *arg)
-{
-  int rc= 0;
-
-#ifndef __WIN__
-#ifndef PTHREAD_STACK_MIN
-#define PTHREAD_STACK_MIN      32768
-#endif
-  /*
-    Set stack size to be safe on the platforms with too small
-    default thread stack.
-  */
-  rc= pthread_attr_setstacksize(attr,
-                                (size_t) (PTHREAD_STACK_MIN +
-                                          IM_THREAD_STACK_SIZE));
-#endif
-  if (!rc)
-    rc= pthread_create(thread, attr, start_routine, arg);
-  return rc;
-}
 
 
 int create_pid_file(const char *pid_file_name, int pid)
diff --git a/server-tools/instance-manager/priv.h b/server-tools/instance-manager/priv.h
index 33be81bc3eb..7ac8ac73c6f 100644
--- a/server-tools/instance-manager/priv.h
+++ b/server-tools/instance-manager/priv.h
@@ -105,10 +105,6 @@ extern unsigned long bytes_sent, bytes_received;
 extern unsigned long mysqld_net_retry_count;
 extern unsigned long open_files_limit;
 
-
-int set_stacksize_n_create_thread(pthread_t  *thread, pthread_attr_t *attr,
-                                  void *(*start_routine)(void *), void *arg);
-
 int create_pid_file(const char *pid_file_name, int pid);
 
 #endif // INCLUDES_MYSQL_INSTANCE_MANAGER_PRIV_H
diff --git a/server-tools/instance-manager/thread_registry.cc b/server-tools/instance-manager/thread_registry.cc
index 10370e0981e..037f104f7bd 100644
--- a/server-tools/instance-manager/thread_registry.cc
+++ b/server-tools/instance-manager/thread_registry.cc
@@ -38,15 +38,13 @@ static void handle_signal(int __attribute__((unused)) sig_no)
 }
 #endif
 
-/*
-  Thread_info initializer methods
-*/
+/* Thread_info initializer methods */
 
-Thread_info::Thread_info() {}
-Thread_info::Thread_info(pthread_t thread_id_arg,
-                         bool send_signal_on_shutdown_arg) :
-  thread_id(thread_id_arg),
-  send_signal_on_shutdown(send_signal_on_shutdown_arg) {}
+void Thread_info::init(bool send_signal_on_shutdown_arg)
+{
+  thread_id= pthread_self();
+  send_signal_on_shutdown= send_signal_on_shutdown_arg;
+}
 
 /*
   TODO: think about moving signal information (now it's shutdown_in_progress)
@@ -86,11 +84,14 @@ Thread_registry::~Thread_registry()
   points to the last node.
 */
 
-void Thread_registry::register_thread(Thread_info *info)
+void Thread_registry::register_thread(Thread_info *info,
+                                      bool send_signal_on_shutdown)
 {
   log_info("Thread_registry: registering thread %d...",
            (int) info->thread_id);
 
+  info->init(send_signal_on_shutdown);
+
 #ifndef __WIN__
   struct sigaction sa;
   sa.sa_handler= handle_signal;
@@ -298,3 +299,80 @@ void Thread_registry::wait_for_threads_to_unregister()
     }
   }
 }
+
+
+/*********************************************************************
+  class Thread
+*********************************************************************/
+
+#if defined(__ia64__) || defined(__ia64)
+/*
+  We can live with 32K, but reserve 64K. Just to be safe.
+  On ia64 we need to reserve double of the size.
+*/
+#define IM_THREAD_STACK_SIZE    (128*1024L)
+#else
+#define IM_THREAD_STACK_SIZE    (64*1024)
+#endif
+
+/*
+  Change the stack size and start a thread. Return an error if either
+  pthread_attr_setstacksize or pthread_create fails.
+  Arguments are the same as for pthread_create().
+*/
+
+static
+int set_stacksize_and_create_thread(pthread_t  *thread, pthread_attr_t *attr,
+                                    void *(*start_routine)(void *), void *arg)
+{
+  int rc= 0;
+
+#ifndef __WIN__
+#ifndef PTHREAD_STACK_MIN
+#define PTHREAD_STACK_MIN      32768
+#endif
+  /*
+    Set stack size to be safe on the platforms with too small
+    default thread stack.
+  */
+  rc= pthread_attr_setstacksize(attr,
+                                (size_t) (PTHREAD_STACK_MIN +
+                                          IM_THREAD_STACK_SIZE));
+#endif
+  if (!rc)
+    rc= pthread_create(thread, attr, start_routine, arg);
+  return rc;
+}
+
+
+Thread::~Thread()
+{
+}
+
+
+void *Thread::thread_func(void *arg)
+{
+  Thread *thread= (Thread *) arg;
+  my_thread_init();
+
+  thread->run();
+
+  my_thread_end();
+  return NULL;
+}
+
+
+bool Thread::start_detached()
+{
+  pthread_t thd_id;
+  pthread_attr_t attr;
+  int rc;
+
+  pthread_attr_init(&attr);
+  pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
+  rc= set_stacksize_and_create_thread(&thd_id, &attr,
+                                    Thread::thread_func, this);
+  pthread_attr_destroy(&attr);
+
+  return rc != 0;
+}
diff --git a/server-tools/instance-manager/thread_registry.h b/server-tools/instance-manager/thread_registry.h
index 3af7c8e0240..034ac1b0ca8 100644
--- a/server-tools/instance-manager/thread_registry.h
+++ b/server-tools/instance-manager/thread_registry.h
@@ -57,7 +57,7 @@
 #pragma interface
 #endif
 
-/*
+/**
   Thread_info - repository entry for each worker thread
   All entries comprise double-linked list like:
      0 -- entry -- entry -- entry - 0
@@ -67,12 +67,10 @@
 class Thread_info
 {
 public:
-  Thread_info(pthread_t thread_id_arg, bool send_signal_on_shutdown_arg);
+  Thread_info() {}
   friend class Thread_registry;
-
 private:
-  Thread_info();
-
+  void init(bool send_signal_on_shutdown);
 private:
   pthread_cond_t *current_cond;
   Thread_info *prev, *next;
@@ -81,7 +79,26 @@ private:
 };
 
 
-/*
+/**
+  A base class for a detached thread.
+*/
+
+class Thread
+{
+public:
+  Thread() {}
+  bool start_detached();
+protected:
+  virtual void run()= 0;
+  virtual ~Thread();
+private:
+  static void *thread_func(void *arg);
+  Thread(const Thread & /* rhs */);            /* not implemented */
+  Thread &operator=(const Thread & /* rhs */); /* not implemented */
+};
+
+
+/**
   Thread_registry - contains handles for each worker thread to deliver
   signal information to workers.
 */
@@ -92,7 +109,7 @@ public:
   Thread_registry();
   ~Thread_registry();
 
-  void register_thread(Thread_info *info);
+  void register_thread(Thread_info *info, bool send_signal_on_shutdown= TRUE);
   void unregister_thread(Thread_info *info);
   void deliver_shutdown();
   void request_shutdown();