MDEV-32537 Name threads to improve debugging experience and diagnostics.

Use SetThreadDescription/pthread_setname_np to give threads a name.

Author: vaintroub

include/my_pthread.h

@@ -619,6 +619,7 @@ typedef uint64 my_thread_id;
 
 extern void my_threadattr_global_init(void);
 extern my_bool my_thread_global_init(void);
+extern void my_thread_set_name(const char *);
 extern void my_thread_global_reinit(void);
 extern void my_thread_global_end(void);
 extern my_bool my_thread_init(void);

mysys/my_thr_init.c

@@ -172,6 +172,35 @@ my_bool my_thread_global_init(void)
  return 0;
 }
 
+#ifdef _WIN32
+#define MAX_THREAD_NAME 256
+#elif defined(__linux__)
+#define MAX_THREAD_NAME 16
+#elif defined(__FreeBSD__) || defined(__OpenBSD__)
+#include <pthread_np.h>
+#endif
+
+void my_thread_set_name(const char *name)
+{
+#ifdef _WIN32
+ wchar_t wname[MAX_THREAD_NAME];
+ wname[0]= 0;
+ MultiByteToWideChar(CP_UTF8, 0, name, -1, wname, MAX_THREAD_NAME);
+ SetThreadDescription(GetCurrentThread(), wname);
+#elif defined __linux__
+ char shortname[MAX_THREAD_NAME];
+ snprintf(shortname, MAX_THREAD_NAME, "%s", name);
+ pthread_setname_np(pthread_self(), shortname);
+#elif defined __NetBSD__
+ pthread_setname_np(pthread_self(), "%s", (void *) name);
+#elif defined __FreeBSD__ || defined __OpenBSD__
+ pthread_set_name_np(pthread_self(), name);
+#elif defined __APPLE__
+ pthread_setname_np(name);
+#else
+ (void) name;
+#endif
+}
 
 /**
  End the mysys thread system. Called when ending the last thread

mysys/thr_timer.c

@@ -304,6 +304,7 @@ static sig_handler process_timers(struct timespec *now)
 static void *timer_handler(void *arg __attribute__((unused)))
 {
  my_thread_init();
+ my_thread_set_name("statement_timer");
 
  mysql_mutex_lock(&LOCK_timer);
  while (likely(thr_timer_inited))

sql/event_scheduler.cc

@@ -227,6 +227,7 @@ event_scheduler_thread(void *arg)
  thd->thread_stack= (char *)&thd; // remember where our stack is
 
  mysql_thread_set_psi_id(thd->thread_id);
+ my_thread_set_name("event_scheduler");
 
  res= post_init_event_thread(thd);
 
@@ -263,6 +264,7 @@ event_worker_thread(void *arg)
  thd= event->thd;
 
  mysql_thread_set_psi_id(thd->thread_id);
+ my_thread_set_name("event_worker");
 
  Event_worker_thread worker_thread;
  worker_thread.run(thd, event);

sql/log.cc

@@ -11140,6 +11140,7 @@ binlog_background_thread(void *arg __attribute__((unused)))
  Binlog_background_job **freelist_endptr= &freelist;
  THD *thd;
  my_thread_init();
+ my_thread_set_name("binlog_background");
  DBUG_ENTER("binlog_background_thread");
 
  thd= new THD(next_thread_id());

sql/mysqld.cc

@@ -3219,6 +3219,7 @@ pthread_handler_t signal_hand(void *)
  sigset_t set;
  int sig;
  my_thread_init();// Init new thread
+ my_thread_set_name("signal_hand");
  signal_thread_in_use= 1;
 
  if (test_flags & TEST_SIGINT)

sql/rpl_parallel.cc

@@ -1226,6 +1226,7 @@ handle_rpl_parallel_thread(void *arg)
  struct rpl_parallel_thread *rpt= (struct rpl_parallel_thread *)arg;
 
  my_thread_init();
+ my_thread_set_name("rpl_parallel");
  thd = new THD(next_thread_id());
  thd->thread_stack = (char*)&thd;
  server_threads.insert(thd);

sql/semisync_master_ack_receiver.cc

@@ -33,6 +33,7 @@ pthread_handler_t ack_receive_handler(void *arg)
  Ack_receiver *recv= reinterpret_cast<Ack_receiver *>(arg);
 
  my_thread_init();
+ my_thread_set_name("ack_receive");
  recv->run();
  my_thread_end();
 

sql/slave.cc

@@ -4786,6 +4786,7 @@ pthread_handler_t handle_slave_io(void *arg)
 #endif
  // needs to call my_thread_init(), otherwise we get a coredump in DBUG_ stuff
  my_thread_init();
+ my_thread_set_name("slave_io");
  DBUG_ENTER("handle_slave_io");
 
  DBUG_ASSERT(mi->inited);
@@ -5441,6 +5442,7 @@ pthread_handler_t handle_slave_sql(void *arg)
 
  // needs to call my_thread_init(), otherwise we get a coredump in DBUG_ stuff
  my_thread_init();
+ my_thread_set_name("slave_sql");
  DBUG_ENTER("handle_slave_sql");
 
 #ifdef WITH_WSREP

sql/sql_connect.cc

@@ -1342,6 +1342,7 @@ pthread_handler_t handle_one_connection(void *arg)
  CONNECT *connect= (CONNECT*) arg;
 
  mysql_thread_set_psi_id(connect->thread_id);
+ my_thread_set_name("one_connection");
 
  if (init_new_connection_handler_thread())
  connect->close_with_error(0, 0, ER_OUT_OF_RESOURCES);