Intermediate commit - just to make new files visible to bk in the new

tree


server-tools/instance-manager/Makefile.am:
  Fixed IM linking to avoid using both mysys and libmysql as the define the
  same symbols and therefore conflict
server-tools/instance-manager/listener.cc:
  Added ability to listen network ports
server-tools/instance-manager/listener.h:
  Various additions to the Listener_thread_args
server-tools/instance-manager/log.cc:
  merge
server-tools/instance-manager/log.h:
  merge
server-tools/instance-manager/manager.cc:
  Fixes and additions to enable guardian functionality
server-tools/instance-manager/manager.h:
  Changed manager() signature
server-tools/instance-manager/mysqlmanager.cc:
  Various fixes
server-tools/instance-manager/options.cc:
  Added handling of default values for new options in the Options struct. (such
  as default_user, default_password, monitoring_interval e.t.c)
server-tools/instance-manager/options.h:
  Added new options to the Options struct
sql/net_serv.cc:
  Added MYSQL_INSTANCE_MANAGER defines to enable alarm handling in the IM
server-tools/instance-manager/buffer.cc:
  Simple implementation of variable-length buffer
server-tools/instance-manager/command.cc:
  Abstract command. All commands are derived from Command class
server-tools/instance-manager/commands.h:
  Interfaces for all commands we have
server-tools/instance-manager/factory.cc:
  Commands factory. This class hides command instantiation. The idea is to
  handle various protocols this way. (different commands for different
  protocols
server-tools/instance-manager/guardian.cc:
  Guardian thread implementation (monitor and restart instances in case of a
  failure
server-tools/instance-manager/guardian.h:
  Guardian_thread and Guardian_thread_args class interface. The
  Guardian_thread is responsible for monitoring and restarting instances
server-tools/instance-manager/instance.cc:
  Instance class contains methods and data to manage a single instance
server-tools/instance-manager/instance.h:
  This file contains class an instance class interface. The class is
  responsible for starting/stopping an instance
server-tools/instance-manager/instance_map.cc:
  The instance repository. This class is also responsible for initialization
  of Instance class objects.
server-tools/instance-manager/instance_options.cc:
  The Instance_options class contains all methods to get and  handle options
  of an instance
server-tools/instance-manager/mysql_connection.cc:
  The class responsible for handling MySQL client/server protocol connections
server-tools/instance-manager/mysql_manager_error.h:
  The list of Instance Manger-specific errors
server-tools/instance-manager/parse.cc:
  Simple query parser
server-tools/instance-manager/parse.h:
  Parser interface
server-tools/instance-manager/protocol.cc:
  Here implemented functions used to handle mysql client/server protocol
server-tools/instance-manager/protocol.h:
  Interface for MySQL client/server protocol
server-tools/instance-manager/thread_registry.cc:
  Thread registry stores information about every thread. It's main function is
  to provide graceful shutdown for all threads.
server-tools/instance-manager/user_map.h:
  User map contains hash with user names and passwords

1 files changed, 206 insertions, 0 deletions

diff --git a/server-tools/instance-manager/thread_registry.cc b/server-tools/instance-manager/thread_registry.cc
new file mode 100644
index 00000000000..4037da71880
--- /dev/null
+++ b/server-tools/instance-manager/thread_registry.cc
@@ -0,0 +1,206 @@
+/* Copyright (C) 2003 MySQL AB & MySQL Finland AB & TCX DataKonsult AB
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
+
+#ifdef __GNUC__
+#pragma implementation
+#endif
+
+#include "thread_registry.h"
+
+#include <assert.h>
+#include <signal.h>
+#include <thr_alarm.h>
+#include "log.h"
+
+
+/* Kick-off signal handler */
+
+enum { THREAD_KICK_OFF_SIGNAL= SIGUSR2 };
+
+static void handle_signal(int __attribute__((unused)) sig_no)
+{
+}
+
+
+/*
+  TODO: think about moving signal information (now it's shutdown_in_progress)
+  to Thread_info. It will reduce contention and allow signal deliverence to
+  a particular thread, not to the whole worker crew
+*/
+
+Thread_registry::Thread_registry() :
+   shutdown_in_progress(false)
+  ,sigwait_thread_pid(pthread_self())
+{
+  pthread_mutex_init(&LOCK_thread_registry, 0);
+  pthread_cond_init(&COND_thread_registry_is_empty, 0);
+
+  /* head is used by-value to simplify nodes inserting */
+  head.next= head.prev= &head;
+}
+
+
+Thread_registry::~Thread_registry()
+{
+  /* Check that no one uses the repository. */
+  pthread_mutex_lock(&LOCK_thread_registry);
+
+  /* All threads must unregister */
+  DBUG_ASSERT(head.next == &head);
+
+  pthread_mutex_unlock(&LOCK_thread_registry);
+  pthread_cond_destroy(&COND_thread_registry_is_empty);
+  pthread_mutex_destroy(&LOCK_thread_registry);
+}
+
+
+/*
+  Set signal handler for kick-off thread, and insert a thread info to the
+  repository. New node is appended to the end of the list; head.prev always
+  points to the last node.
+*/
+
+void Thread_registry::register_thread(Thread_info *info)
+{
+  struct sigaction sa;
+  sa.sa_handler= handle_signal;
+  sa.sa_flags= 0;
+  sigemptyset(&sa.sa_mask);
+  sigaction(THREAD_KICK_OFF_SIGNAL, &sa, 0);
+
+  info->current_cond= 0;
+
+  pthread_mutex_lock(&LOCK_thread_registry);
+  info->next= &head;
+  info->prev= head.prev;
+  head.prev->next= info;
+  head.prev= info;
+  pthread_mutex_unlock(&LOCK_thread_registry);
+}
+
+
+/*
+  Unregister a thread from the repository and free Thread_info structure.
+  Every registered thread must unregister. Unregistering should be the last
+  thing a thread is doing, otherwise it could have no time to finalize.
+*/
+
+void Thread_registry::unregister_thread(Thread_info *info)
+{
+  pthread_mutex_lock(&LOCK_thread_registry);
+  info->prev->next= info->next;
+  info->next->prev= info->prev;
+  if (head.next == &head)
+    pthread_cond_signal(&COND_thread_registry_is_empty);
+  pthread_mutex_unlock(&LOCK_thread_registry);
+}
+
+
+/*
+  Check whether shutdown is in progress, and if yes, return immediately.
+  Else set info->current_cond and call pthread_cond_wait. When
+  pthread_cond_wait returns, unregister current cond and check the shutdown
+  status again.
+  RETURN VALUE
+    return value from pthread_cond_wait
+*/
+
+int Thread_registry::cond_wait(Thread_info *info, pthread_cond_t *cond,
+                                  pthread_mutex_t *mutex, bool *is_shutdown)
+{
+  pthread_mutex_lock(&LOCK_thread_registry);
+  *is_shutdown= shutdown_in_progress;
+  if (*is_shutdown)
+  {
+    pthread_mutex_unlock(&LOCK_thread_registry);
+    return 0;
+  }
+  info->current_cond= cond;
+  pthread_mutex_unlock(&LOCK_thread_registry);
+  /* sic: race condition here, cond can be signaled in deliver_shutdown */
+  int rc= pthread_cond_wait(cond, mutex);
+  pthread_mutex_lock(&LOCK_thread_registry);
+  info->current_cond= 0;
+  *is_shutdown= shutdown_in_progress;
+  pthread_mutex_unlock(&LOCK_thread_registry);
+  return rc;
+}
+
+
+/*
+  Deliver shutdown message to the workers crew.
+  As it's impossible to avoid all race conditions, signal latecomers
+  again.
+*/
+
+void Thread_registry::deliver_shutdown()
+{
+  struct timespec shutdown_time;
+  set_timespec(shutdown_time, 1);
+
+  pthread_mutex_lock(&LOCK_thread_registry);
+  shutdown_in_progress= true;
+
+  /* to stop reading from the network we need to flush alarm queue */
+  end_thr_alarm(0);
+  /*
+    We have to deliver final alarms this way, as the main thread has already
+    stopped alarm processing.
+  */
+  process_alarm(THR_SERVER_ALARM);
+  for (Thread_info *info= head.next; info != &head; info= info->next)
+  {
+    pthread_kill(info->thread_id, THREAD_KICK_OFF_SIGNAL);
+    /*
+      sic: race condition here, the thread may not yet fall into
+      pthread_cond_wait.
+    */
+    if (info->current_cond)
+      pthread_cond_signal(info->current_cond);
+  }
+  /*
+    The common practice is to test predicate before pthread_cond_wait.
+    I don't do that here because the predicate is practically always false
+    before wait - is_shutdown's been just set, and the lock's still not
+    released - the only case when the predicate is false is when no other
+    threads exist.
+  */
+  while (pthread_cond_timedwait(&COND_thread_registry_is_empty,
+                                &LOCK_thread_registry,
+                                &shutdown_time) != ETIMEDOUT &&
+         head.next != &head)
+    ;
+  /*
+    If previous signals did not reach some threads, they must be sleeping
+    in pthread_cond_wait or in a blocking syscall. Wake them up:
+    every thread shall check signal variables after each syscall/cond_wait,
+    so this time everybody should be informed (presumably each worker can
+    get CPU during shutdown_time.)
+  */
+  for (Thread_info *info= head.next; info != &head; info= info->next)
+  {
+    pthread_kill(info->thread_id, THREAD_KICK_OFF_SIGNAL);
+    if (info->current_cond)
+      pthread_cond_signal(info->current_cond);
+  }
+  pthread_mutex_unlock(&LOCK_thread_registry);
+}
+
+
+void Thread_registry::request_shutdown()
+{
+  pthread_kill(sigwait_thread_pid, SIGTERM);
+}