Bug#14298586 - NANOSECOND TIMER NOT WORKING ON WINDOWS

Before this fix, the table performance_schema.setup_timers used always the
nanosecond timer for stages and statements, be default.

The problem with that is that this timer may not be available for the
platform used, and in this case, stages and statements timing is not
functioning properly out of the box.
For example, the NANOSECOND timer is not available on windows platforms.

With this fix, the idle, stage and statement timers are set to:
- use the preferred timers when available,
- use alternate timers when the preferred timers are not supported.

This is a major change for ease of use,
as it avoids the need to explicitly update table setup_timers.

Author: marcalff

mysql-test/suite/perfschema/r/start_server_nothing.result

@@ -160,12 +160,12 @@ events_waits_history_long	YES
 global_instrumentation	YES
 thread_instrumentation	YES
 statements_digest	YES
-select * from performance_schema.setup_timers;
-NAME	TIMER_NAME
-idle	MICROSECOND
-wait	CYCLE
-stage	NANOSECOND
-statement	NANOSECOND
+select NAME from performance_schema.setup_timers;
+NAME
+idle
+wait
+stage
+statement
 select * from performance_schema.accounts;
 USER	HOST	CURRENT_CONNECTIONS	TOTAL_CONNECTIONS
 select * from performance_schema.cond_instances;

mysql-test/suite/perfschema/t/start_server_nothing.test

@@ -11,7 +11,7 @@ show variables like "performance_schema%";
 select * from performance_schema.setup_instruments;
 select TIMER_NAME from performance_schema.performance_timers;
 select * from performance_schema.setup_consumers;
-select * from performance_schema.setup_timers;
+select NAME from performance_schema.setup_timers;
 
 # All empty
 select * from performance_schema.accounts;

storage/perfschema/pfs_timer.cc

@@ -1,4 +1,4 @@
-/* Copyright (c) 2008, 2011, Oracle and/or its affiliates. All rights reserved.
+/* Copyright (c) 2008, 2012, Oracle and/or its affiliates. All rights reserved.
 
   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
@@ -117,6 +117,75 @@ void init_timers(void)
 
   to_pico_data[TIMER_NAME_TICK].m_v0= tick_v0;
   to_pico_data[TIMER_NAME_TICK].m_factor= tick_to_pico;
+
+  /*
+    Depending on the platform and build options,
+    some timers may not be available.
+    Pick best replacements.
+  */
+
+  /*
+    For STAGE and STATEMENT, a timer with a fixed frequency is better.
+    The prefered timer is nanosecond, or lower resolutions.
+  */
+
+  if (nanosec_to_pico != 0)
+  {
+    /* Normal case. */
+    stage_timer= TIMER_NAME_NANOSEC;
+    statement_timer= TIMER_NAME_NANOSEC;
+  }
+  else if (microsec_to_pico != 0)
+  {
+    /* Windows. */
+    stage_timer= TIMER_NAME_MICROSEC;
+    statement_timer= TIMER_NAME_MICROSEC;
+  }
+  else if (millisec_to_pico != 0)
+  {
+    /* Robustness, no known cases. */
+    stage_timer= TIMER_NAME_MILLISEC;
+    statement_timer= TIMER_NAME_MILLISEC;
+  }
+  else if (tick_to_pico != 0)
+  {
+    /* Robustness, no known cases. */
+    stage_timer= TIMER_NAME_TICK;
+    statement_timer= TIMER_NAME_TICK;
+  }
+  else
+  {
+    /* Robustness, no known cases. */
+    stage_timer= TIMER_NAME_CYCLE;
+    statement_timer= TIMER_NAME_CYCLE;
+  }
+
+  /*
+    For IDLE, a timer with a fixed frequency is critical,
+    as the CPU clock may slow down a lot if the server is completely idle.
+    The prefered timer is microsecond, or lower resolutions.
+  */
+
+  if (microsec_to_pico != 0)
+  {
+    /* Normal case. */
+    idle_timer= TIMER_NAME_MICROSEC;
+  }
+  else if (millisec_to_pico != 0)
+  {
+    /* Robustness, no known cases. */
+    idle_timer= TIMER_NAME_MILLISEC;
+  }
+  else if (tick_to_pico != 0)
+  {
+    /* Robustness, no known cases. */
+    idle_timer= TIMER_NAME_TICK;
+  }
+  else
+  {
+    /* Robustness, no known cases. */
+    idle_timer= TIMER_NAME_CYCLE;
+  }
 }
 
 ulonglong get_timer_raw_value(enum_timer_name timer_name)