Polishing:

1) add support for joinable threads to Thread class;
2) move checking of thread model to Manager from mysqlmanager.cc,
because it is needed only for IM-main process.

server-tools/instance-manager/instance.cc

@@ -105,7 +105,7 @@ static int wait_process(My_process_info *pi)
     couldn't use wait(), because it could return in any wait() in the program.
   */
 
-  if (linuxthreads)
+  if (Manager::is_linux_threads())
     wait(NULL);                               /* LinuxThreads were detected */
   else
     waitpid(*pi, NULL, 0);
@@ -564,7 +564,7 @@ int Instance::start()
 
     instance_monitor= new Instance_monitor(this);
 
-    if (instance_monitor == NULL || instance_monitor->start_detached())
+    if (instance_monitor == NULL || instance_monitor->start(Thread::DETACHED))
     {
       delete instance_monitor;
       log_error("Instance::start(): failed to create the monitoring thread"

server-tools/instance-manager/listener.cc

@@ -323,7 +323,7 @@ void Listener::handle_new_mysql_connection(struct st_vio *vio)
   Mysql_connection *mysql_connection=
     new Mysql_connection(thread_registry, user_map,
                          vio, ++total_connection_count);
-  if (mysql_connection == NULL || mysql_connection->start_detached())
+  if (mysql_connection == NULL || mysql_connection->start(Thread::DETACHED))
   {
     log_error("handle_one_mysql_connection() failed");
     delete mysql_connection;

server-tools/instance-manager/manager.cc

@@ -93,6 +93,65 @@ int my_sigwait(const sigset_t *set, int *sig)
 #endif
 
 
+/**********************************************************************
+  Implementation of checking the actual thread model.
+***********************************************************************/
+
+namespace { /* no-indent */
+
+class ThreadModelChecker: public Thread
+{
+public:
+  ThreadModelChecker()
+    :main_pid(getpid())
+  { }
+
+public:
+  inline bool is_linux_threads() const
+  {
+    return linux_threads;
+  }
+
+protected:
+  virtual void run()
+  {
+    linux_threads= main_pid != getpid();
+  }
+
+private:
+  pid_t main_pid;
+  bool linux_threads;
+};
+
+bool check_if_linux_threads(bool *linux_threads)
+{
+  ThreadModelChecker checker;
+
+  if (checker.start() || checker.join())
+    return TRUE;
+
+  *linux_threads= checker.is_linux_threads();
+
+  return FALSE;
+}
+
+}
+
+
+/**********************************************************************
+  Manager implementation
+***********************************************************************/
+
+Guardian *Manager::p_guardian;
+Instance_map *Manager::p_instance_map;
+Thread_registry *Manager::p_thread_registry;
+User_map *Manager::p_user_map;
+
+#ifndef __WIN__
+bool Manager::linux_threads;
+#endif // __WIN__
+
+
 void Manager::stop_all_threads()
 {
   /*
@@ -106,14 +165,6 @@ void Manager::stop_all_threads()
   p_thread_registry->deliver_shutdown();
 }
 
-/**********************************************************************
-  Manager implementation
-***********************************************************************/
-
-Guardian *Manager::p_guardian;
-Instance_map *Manager::p_instance_map;
-Thread_registry *Manager::p_thread_registry;
-User_map *Manager::p_user_map;
 
 /*
   manager - entry point to the main instance manager process: start
@@ -132,6 +183,15 @@ int Manager::main()
   bool shutdown_complete= FALSE;
   pid_t manager_pid= getpid();
 
+  if (check_if_linux_threads(&linux_threads))
+  {
+    log_error("Error: can not check if Linux Threads are used.");
+    return 1;
+  }
+
+  log_info("Detected threads model: %s.",
+           (const char *) (linux_threads ? "LINUX threads" : "POSIX threads"));
+
   Thread_registry thread_registry;
   /*
     All objects created in the manager() function live as long as
@@ -228,7 +288,7 @@ int Manager::main()
     permitted to process instances. And before flush_instances() has
     completed, there are no instances to guard.
   */
-  if (guardian.start_detached())
+  if (guardian.start(Thread::DETACHED))
   {
     log_error("Error: can not start Guardian thread.");
     goto err;
@@ -255,7 +315,7 @@ int Manager::main()
 
   /* Initialize the Listener. */
 
-  if (listener.start_detached())
+  if (listener.start(Thread::DETACHED))
   {
     log_error("Error: can not start Listener thread.");
     stop_all_threads();

server-tools/instance-manager/manager.h

@@ -39,6 +39,10 @@ class Manager
   static Thread_registry *get_thread_registry() { return p_thread_registry; }
   static User_map *get_user_map() { return p_user_map; }
 
+#ifndef __WIN__
+  static bool is_linux_threads() { return linux_threads; }
+#endif // __WIN__
+
 private:
   static void stop_all_threads();
 
@@ -47,6 +51,14 @@ class Manager
   static Instance_map *p_instance_map;
   static Thread_registry *p_thread_registry;
   static User_map *p_user_map;
+
+#ifndef __WIN__
+  /*
+    This flag is set if Instance Manager is running on the system using
+    LinuxThreads.
+  */
+  static bool linux_threads;
+#endif // __WIN__
 };
 
 #endif // INCLUDES_MYSQL_INSTANCE_MANAGER_MANAGER_H

server-tools/instance-manager/mysqlmanager.cc

@@ -71,7 +71,6 @@ static void daemonize(const char *log_file_name);
 static void angel();
 static struct passwd *check_user(const char *user);
 static int set_user(const char *user, struct passwd *user_info);
-static bool check_if_linuxthreads();
 #endif
 
 
@@ -111,9 +110,6 @@ int main(int argc, char *argv[])
       }
   }
 
-  if (check_if_linuxthreads())
-    goto main_end; /* out of resources */
-
   if (Options::Daemon::run_as_service)
   {
     /* forks, and returns only in child */
@@ -395,28 +391,4 @@ static void angel()
     exit(0);
   }
 }
-
-extern "C" {
-static void *check_if_linuxthreads_thread_func(void *arg)
-{
-  pid_t main_pid= *(pid_t*) arg;
-  linuxthreads= getpid() != main_pid;
-  return NULL; 
-}
-} /* extern "C" */
-
-
-static bool check_if_linuxthreads()
-{
-  pid_t pid= getpid();
-  pthread_t thread_id;
-  int rc;
-
-  rc= pthread_create(&thread_id, NULL, check_if_linuxthreads_thread_func,
-                     (void*) &pid);
-  if (rc == 0)
-    rc= pthread_join(thread_id, NULL);
-
-  return test(rc);
-}
 #endif

server-tools/instance-manager/priv.cc

@@ -22,14 +22,6 @@
 
 #include "log.h"
 
-#ifndef __WIN__
-/*
-  This flag is set if mysqlmanager has detected that it is running on the
-  system using LinuxThreads
-*/
-bool linuxthreads;
-#endif
-
 /*
   The following string must be less then 80 characters, as
   mysql_connection.cc relies on it

server-tools/instance-manager/priv.h

@@ -50,14 +50,6 @@ const int MAX_VERSION_LENGTH= 160;
 
 const int MAX_INSTANCE_NAME_SIZE= FN_REFLEN;
 
-#ifndef __WIN__
-/*
-  This flag is set if mysqlmanager has detected that it is running on the
-  system using LinuxThreads
-*/
-extern bool linuxthreads;
-#endif
-
 extern const LEX_STRING mysqlmanager_version;
 
 /* MySQL client-server protocol version: substituted from configure */

server-tools/instance-manager/thread_registry.cc

@@ -25,8 +25,6 @@
 
 #include <signal.h>
 
-#include "log.h"
-
 
 #ifndef __WIN__
 /* Kick-off signal handler */
@@ -87,8 +85,8 @@ Thread_registry::~Thread_registry()
 void Thread_registry::register_thread(Thread_info *info,
                                       bool send_signal_on_shutdown)
 {
-  log_info("Thread_registry: registering thread %d...",
-           (int) info->thread_id);
+  DBUG_PRINT("info", ("Thread_registry: registering thread %d...",
+                      (int) info->thread_id));
 
   info->init(send_signal_on_shutdown);
 
@@ -118,8 +116,8 @@ void Thread_registry::register_thread(Thread_info *info,
 
 void Thread_registry::unregister_thread(Thread_info *info)
 {
-  log_info("Thread_registry: unregistering thread %d...",
-           (int) info->thread_id);
+  DBUG_PRINT("info", ("Thread_registry: unregistering thread %d...",
+                      (int) info->thread_id));
 
   pthread_mutex_lock(&LOCK_thread_registry);
   info->prev->next= info->next;
@@ -127,7 +125,7 @@ void Thread_registry::unregister_thread(Thread_info *info)
 
   if (head.next == &head)
   {
-    log_info("Thread_registry: thread registry is empty!");
+    DBUG_PRINT("info", ("Thread_registry: thread registry is empty!"));
     pthread_cond_signal(&COND_thread_registry_is_empty);
   }
 
@@ -231,6 +229,7 @@ void Thread_registry::deliver_shutdown()
 
   wait_for_threads_to_unregister();
 
+#ifndef DBUG_OFF
   /*
     Print out threads, that didn't stopped. Thread_registry destructor will
     probably abort the program if there is still any alive thread.
@@ -238,15 +237,16 @@ void Thread_registry::deliver_shutdown()
 
   if (head.next != &head)
   {
-    log_info("Thread_registry: non-stopped threads:");
+    DBUG_PRINT("info", ("Thread_registry: non-stopped threads:"));
 
     for (Thread_info *info= head.next; info != &head; info= info->next)
-      log_info("  - %ld", (long int) info->thread_id);
+      DBUG_PRINT("info", ("  - %lu", (unsigned long) info->thread_id));
   }
   else
   {
-    log_info("Thread_registry: all threads stopped.");
+    DBUG_PRINT("info", ("Thread_registry: all threads stopped."));
   }
+#endif // DBUG_OFF
 
   pthread_mutex_unlock(&LOCK_thread_registry);
 }
@@ -278,13 +278,13 @@ void Thread_registry::wait_for_threads_to_unregister()
 
   set_timespec(shutdown_time, 1);
 
-  log_info("Thread_registry: joining threads...");
+  DBUG_PRINT("info", ("Thread_registry: joining threads..."));
 
   while (true)
   {
     if (head.next == &head)
     {
-      log_info("Thread_registry: emptied.");
+      DBUG_PRINT("info", ("Thread_registry: emptied."));
       return;
     }
 
@@ -294,7 +294,7 @@ void Thread_registry::wait_for_threads_to_unregister()
 
     if (error == ETIMEDOUT || error == ETIME)
     {
-      log_info("Thread_registry: threads shutdown timed out.");
+      DBUG_PRINT("info", ("Thread_registry: threads shutdown timed out."));
       return;
     }
   }
@@ -362,17 +362,33 @@ void *Thread::thread_func(void *arg)
 }
 
 
-bool Thread::start_detached()
+bool Thread::start(enum_thread_type thread_type)
 {
-  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);
+
+  if (thread_type == DETACHED)
+  {
+    detached = TRUE;
+    pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
+  }
+  else
+  {
+    detached = FALSE;
+  }
+
+  rc= set_stacksize_and_create_thread(&id, &attr, Thread::thread_func, this);
   pthread_attr_destroy(&attr);
 
   return rc != 0;
 }
+
+
+bool Thread::join()
+{
+  DBUG_ASSERT(!detached);
+
+  return pthread_join(id, NULL) != 0;
+}

server-tools/instance-manager/thread_registry.h

@@ -86,17 +86,42 @@ class Thread_info
 class Thread
 {
 public:
-  Thread() {}
-  bool start_detached();
+  enum enum_thread_type
+  {
+    DETACHED,
+    JOINABLE
+  };
+public:
+  Thread()
+  { }
+
+public:
+  inline bool is_detached() const;
+
+  bool start(enum_thread_type thread_type = JOINABLE);
+  bool join();
+
 protected:
   virtual void run()= 0;
   virtual ~Thread();
+
+private:
+  pthread_t id;
+  bool detached;
+
 private:
   static void *thread_func(void *arg);
+
+private:
   Thread(const Thread & /* rhs */);            /* not implemented */
   Thread &operator=(const Thread & /* rhs */); /* not implemented */
 };
 
+inline bool Thread::is_detached() const
+{
+  return detached;
+}
+
 
 /**
   Thread_registry - contains handles for each worker thread to deliver