MDEV-19313 Threadpool : provide information schema tables for internals of generic threadpool

Added thread_pool_groups, thread_pool_queues, thread_pool_waits and
thread_pool_stats tables to information_schema.

1 files changed, 55 insertions, 140 deletions

diff --git a/sql/threadpool_generic.cc b/sql/threadpool_generic.cc
index 1998b8d281b..3cb7be26eb7 100644
--- a/sql/threadpool_generic.cc
+++ b/sql/threadpool_generic.cc
@@ -13,56 +13,27 @@
    along with this program; if not, write to the Free Software
    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA */
 
+#if (defined HAVE_POOL_OF_THREADS) && !defined(EMBEDDED_LIBRARY)
+
+#include "threadpool_generic.h"
 #include "mariadb.h"
 #include <violite.h>
 #include <sql_priv.h>
 #include <sql_class.h>
 #include <my_pthread.h>
 #include <scheduler.h>
-
-#ifdef HAVE_POOL_OF_THREADS
-
-#ifdef _WIN32
-/* AIX may define this, too ?*/
-#define HAVE_IOCP 
-#endif
-
-#ifdef HAVE_IOCP
-#define OPTIONAL_IO_POLL_READ_PARAM this
-#else 
-#define OPTIONAL_IO_POLL_READ_PARAM 0
-#endif
-
-#ifdef _WIN32
-typedef HANDLE TP_file_handle;
-#else
-typedef int TP_file_handle;
-#define  INVALID_HANDLE_VALUE -1
-#endif
-
-
 #include <sql_connect.h>
 #include <mysqld.h>
 #include <debug_sync.h>
 #include <time.h>
 #include <sql_plist.h>
 #include <threadpool.h>
-#include <time.h>
-#ifdef __linux__
-#include <sys/epoll.h>
-typedef struct epoll_event native_event;
-#elif defined(HAVE_KQUEUE)
-#include <sys/event.h>
-typedef struct kevent native_event;
-#elif defined (__sun)
-#include <port.h>
-typedef port_event_t native_event;
-#elif defined (HAVE_IOCP)
-typedef OVERLAPPED_ENTRY native_event;
-#else
-#error threadpool is not available on this platform
-#endif
 
+#ifdef HAVE_IOCP
+#define OPTIONAL_IO_POLL_READ_PARAM this
+#else 
+#define OPTIONAL_IO_POLL_READ_PARAM 0
+#endif
 
 static void io_poll_close(TP_file_handle fd)
 {
@@ -119,86 +90,7 @@ static PSI_thread_info	thread_list[] =
 #define PSI_register(X) /* no-op */
 #endif
 
-
-struct thread_group_t;
-
-/* Per-thread structure for workers */
-struct worker_thread_t
-{
-  ulonglong  event_count; /* number of request handled by this thread */
-  thread_group_t* thread_group;   
-  worker_thread_t *next_in_list;
-  worker_thread_t **prev_in_list;
-  
-  mysql_cond_t  cond;
-  bool          woken;
-};
-
-typedef I_P_List<worker_thread_t, I_P_List_adapter<worker_thread_t,
-                 &worker_thread_t::next_in_list,
-                 &worker_thread_t::prev_in_list> 
-                 >
-worker_list_t;
-
-struct TP_connection_generic:public TP_connection
-{
-  TP_connection_generic(CONNECT *c);
-  ~TP_connection_generic();
- 
-  virtual int init(){ return 0; };
-  virtual void set_io_timeout(int sec);
-  virtual int  start_io();
-  virtual void wait_begin(int type);
-  virtual void wait_end();
-
-  thread_group_t *thread_group;
-  TP_connection_generic *next_in_queue;
-  TP_connection_generic **prev_in_queue;
-  ulonglong abs_wait_timeout;
-  ulonglong dequeue_time;
-  TP_file_handle fd;
-  bool bound_to_poll_descriptor;
-  int waiting;
-#ifdef HAVE_IOCP
-  OVERLAPPED overlapped;
-#endif
-#ifdef _WIN32
-  enum_vio_type vio_type;
-#endif
-};
-
-
-typedef I_P_List<TP_connection_generic,
-                     I_P_List_adapter<TP_connection_generic,
-                                      &TP_connection_generic::next_in_queue,
-                                      &TP_connection_generic::prev_in_queue>,
-                     I_P_List_null_counter,
-                     I_P_List_fast_push_back<TP_connection_generic> >
-connection_queue_t;
-
-const int NQUEUES=2; /* We have high and low priority queues*/
-
-struct MY_ALIGNED(CPU_LEVEL1_DCACHE_LINESIZE) thread_group_t
-{
-  mysql_mutex_t mutex;
-  connection_queue_t queues[NQUEUES];
-  worker_list_t waiting_threads; 
-  worker_thread_t *listener;
-  pthread_attr_t *pthread_attr;
-  TP_file_handle  pollfd;
-  int  thread_count;
-  int  active_thread_count;
-  int  connection_count;
-  /* Stats for the deadlock detection timer routine.*/
-  int io_event_count;
-  int queue_event_count;
-  ulonglong last_thread_creation_time;
-  int  shutdown_pipe[2];
-  bool shutdown;
-  bool stalled; 
-};
-
-static thread_group_t *all_groups;
+thread_group_t *all_groups;
 static uint group_count;
 static int32 shutdown_group_count;
 
@@ -224,9 +116,9 @@ static pool_timer_t pool_timer;
 
 static void queue_put(thread_group_t *thread_group, TP_connection_generic *connection);
 static void queue_put(thread_group_t *thread_group, native_event *ev, int cnt);
-static int  wake_thread(thread_group_t *thread_group);
-static int  wake_or_create_thread(thread_group_t *thread_group);
-static int  create_worker(thread_group_t *thread_group);
+static int  wake_thread(thread_group_t *thread_group,bool due_to_stall);
+static int  wake_or_create_thread(thread_group_t *thread_group, bool due_to_stall=false);
+static int  create_worker(thread_group_t *thread_group, bool due_to_stall);
 static void *worker_main(void *param);
 static void check_stall(thread_group_t *thread_group);
 static void set_next_timeout_check(ulonglong abstime);
@@ -563,11 +455,11 @@ static void queue_init(thread_group_t *thread_group)
 
 static void queue_put(thread_group_t *thread_group, native_event *ev, int cnt)
 {
-  ulonglong now= pool_timer.current_microtime;
+  ulonglong now= threadpool_exact_stats?microsecond_interval_timer():pool_timer.current_microtime;
   for(int i=0; i < cnt; i++)
   {
     TP_connection_generic *c = (TP_connection_generic *)native_event_get_userdata(&ev[i]);
-    c->dequeue_time= now;
+    c->enqueue_time= now;
     thread_group->queues[c->priority].push_back(c);
   }
 }
@@ -681,7 +573,7 @@ void check_stall(thread_group_t *thread_group)
   for (;;)
   {
     c= thread_group->queues[TP_PRIORITY_LOW].front();
-    if (c && pool_timer.current_microtime - c->dequeue_time > 1000ULL * threadpool_prio_kickup_timer)
+    if (c && pool_timer.current_microtime - c->enqueue_time > 1000ULL * threadpool_prio_kickup_timer)
     {
       thread_group->queues[TP_PRIORITY_LOW].remove(c);
       thread_group->queues[TP_PRIORITY_HIGH].push_back(c);
@@ -698,7 +590,7 @@ void check_stall(thread_group_t *thread_group)
   */
   if (!thread_group->listener && !thread_group->io_event_count)
   {
-    wake_or_create_thread(thread_group);
+    wake_or_create_thread(thread_group, true);
     mysql_mutex_unlock(&thread_group->mutex);
     return;
   }
@@ -735,7 +627,8 @@ void check_stall(thread_group_t *thread_group)
   if (!is_queue_empty(thread_group) && !thread_group->queue_event_count)
   {
     thread_group->stalled= true;
-    wake_or_create_thread(thread_group);
+    TP_INCREMENT_GROUP_COUNTER(thread_group,stalls);
+    wake_or_create_thread(thread_group,true);
   }
   
   /* Reset queue event count */
@@ -790,13 +683,13 @@ static TP_connection_generic * listener(worker_thread_t *current_thread,
       break;
   
     cnt = io_poll_wait(thread_group->pollfd, ev, MAX_EVENTS, -1);
-    
+    TP_INCREMENT_GROUP_COUNTER(thread_group, polls_by_listener);
     if (cnt <=0)
     {
       DBUG_ASSERT(thread_group->shutdown);
       break;
     }
-
+    
     mysql_mutex_lock(&thread_group->mutex);
 
     if (thread_group->shutdown)
@@ -864,7 +757,7 @@ static TP_connection_generic * listener(worker_thread_t *current_thread,
     if(thread_group->active_thread_count==0)
     {
       /* We added some work items to queue, now wake a worker. */
-      if(wake_thread(thread_group))
+      if(wake_thread(thread_group, false))
       {
         /* 
           Wake failed, hence groups has no idle threads. Now check if there are
@@ -882,7 +775,7 @@ static TP_connection_generic * listener(worker_thread_t *current_thread,
              create thread, but waiting for timer would be an inefficient and
              pointless delay.
            */
-           create_worker(thread_group);
+           create_worker(thread_group, false);
         }
       }
     }
@@ -919,7 +812,7 @@ static void add_thread_count(thread_group_t *thread_group, int32 count)
   per group to prevent deadlocks (one listener + one worker)
 */
 
-static int create_worker(thread_group_t *thread_group)
+static int create_worker(thread_group_t *thread_group, bool due_to_stall)
 {
   pthread_t thread_id;
   bool max_threads_reached= false;
@@ -942,6 +835,11 @@ static int create_worker(thread_group_t *thread_group)
     thread_group->last_thread_creation_time=microsecond_interval_timer();
     statistic_increment(thread_created,&LOCK_status);
     add_thread_count(thread_group, 1);
+    TP_INCREMENT_GROUP_COUNTER(thread_group,thread_creations);
+    if(due_to_stall)
+    {
+      TP_INCREMENT_GROUP_COUNTER(thread_group, thread_creations_due_to_stall);
+    }
   }
   else
   {
@@ -993,15 +891,17 @@ static ulonglong microsecond_throttling_interval(thread_group_t *thread_group)
   Worker creation is throttled, so we avoid too many threads
   to be created during the short time.
 */
-static int wake_or_create_thread(thread_group_t *thread_group)
+static int wake_or_create_thread(thread_group_t *thread_group, bool due_to_stall)
 {
   DBUG_ENTER("wake_or_create_thread");
   
   if (thread_group->shutdown)
    DBUG_RETURN(0);
 
-  if (wake_thread(thread_group) == 0)
+  if (wake_thread(thread_group, due_to_stall) == 0)
+  {
     DBUG_RETURN(0);
+  }
 
   if (thread_group->thread_count > thread_group->connection_count)
     DBUG_RETURN(-1);
@@ -1015,7 +915,7 @@ static int wake_or_create_thread(thread_group_t *thread_group)
      idle  thread to wakeup. Smells like a potential deadlock or very slowly 
      executing requests, e.g sleeps or user locks.
     */
-    DBUG_RETURN(create_worker(thread_group));
+    DBUG_RETURN(create_worker(thread_group, due_to_stall));
   }
 
   ulonglong now = microsecond_interval_timer();
@@ -1026,9 +926,10 @@ static int wake_or_create_thread(thread_group_t *thread_group)
   if (time_since_last_thread_created >
        microsecond_throttling_interval(thread_group))
   {
-    DBUG_RETURN(create_worker(thread_group));
+    DBUG_RETURN(create_worker(thread_group, due_to_stall));
   }
-  
+
+  TP_INCREMENT_GROUP_COUNTER(thread_group,throttles);
   DBUG_RETURN(-1);
 }
 
@@ -1074,7 +975,7 @@ void thread_group_destroy(thread_group_t *thread_group)
   Wake sleeping thread from waiting list
 */
 
-static int wake_thread(thread_group_t *thread_group)
+static int wake_thread(thread_group_t *thread_group,bool due_to_stall)
 {
   DBUG_ENTER("wake_thread");
   worker_thread_t *thread = thread_group->waiting_threads.front();
@@ -1083,6 +984,11 @@ static int wake_thread(thread_group_t *thread_group)
     thread->woken= true;
     thread_group->waiting_threads.remove(thread);
     mysql_cond_signal(&thread->cond);
+    TP_INCREMENT_GROUP_COUNTER(thread_group, wakes);
+    if (due_to_stall)
+    {
+      TP_INCREMENT_GROUP_COUNTER(thread_group, wakes_due_to_stall);
+    }
     DBUG_RETURN(0);
   }
   DBUG_RETURN(1); /* no thread in waiter list => missed wakeup */
@@ -1140,7 +1046,7 @@ static void thread_group_close(thread_group_t *thread_group)
   wake_listener(thread_group);
 
   /* Wake all workers. */
-  while(wake_thread(thread_group) == 0) 
+  while(wake_thread(thread_group, false) == 0) 
   { 
   }
   
@@ -1224,7 +1130,10 @@ TP_connection_generic *get_event(worker_thread_t *current_thread,
     {
       connection = queue_get(thread_group);
       if(connection)
+      {
+        TP_INCREMENT_GROUP_COUNTER(thread_group,dequeues_by_worker);
         break;
+      }
     }
 
     /* If there is  currently no listener in the group, become one. */
@@ -1235,7 +1144,10 @@ TP_connection_generic *get_event(worker_thread_t *current_thread,
       mysql_mutex_unlock(&thread_group->mutex);
 
       connection = listener(current_thread, thread_group);
-
+      if (connection)
+      {
+        TP_INCREMENT_GROUP_COUNTER(thread_group, dequeues_by_listener);
+      }
       mysql_mutex_lock(&thread_group->mutex);
       thread_group->active_thread_count++;
       /* There is no listener anymore, it just returned. */
@@ -1251,9 +1163,9 @@ TP_connection_generic *get_event(worker_thread_t *current_thread,
     */
     if (!oversubscribed)
     {
-
       native_event ev[MAX_EVENTS];
       int cnt = io_poll_wait(thread_group->pollfd, ev, MAX_EVENTS, 0);
+      TP_INCREMENT_GROUP_COUNTER(thread_group, polls_by_worker);
       if (cnt > 0)
       {
         queue_put(thread_group, ev, cnt);
@@ -1300,6 +1212,7 @@ TP_connection_generic *get_event(worker_thread_t *current_thread,
   }
 
   thread_group->stalled= false;
+
   mysql_mutex_unlock(&thread_group->mutex);
  
   DBUG_RETURN(connection);
@@ -1515,7 +1428,7 @@ static int change_group(TP_connection_generic *c,
   new_group->connection_count++;
   /* Ensure that there is a listener in the new group. */
   if (!new_group->thread_count)
-    ret= create_worker(new_group);
+    ret= create_worker(new_group, false);
   mysql_mutex_unlock(&new_group->mutex);
   return ret;
 }
@@ -1775,4 +1688,6 @@ static void print_pool_blocked_message(bool max_threads_reached)
   }
 }
 
+
+
 #endif /* HAVE_POOL_OF_THREADS */