WL#5363: Thread Pool Service Interface

In order to allow thread schedulers to be dynamically loaded,
it is necessary to make the following changes to the server:

- Two new service interfaces

- Modifications to InnoDB to inform the thread scheduler of state changes.

- Changes to the VIO subsystem for checking if data is available on a socket.

- Elimination of remains of the old thread pool implementation.

The two new service interfaces introduces are:

my_thread_scheduler
  A service interface to register a thread
  scheduler.

thd_wait
  A service interface to inform thread scheduler
  that the thread is about to start waiting.

In addition, the patch adds code that:

- Add a call to thd_wait for table locks in mysys
  thd_lock.c by introducing a set function that
  can be used to set a callback to be used when
  waiting on a lock and resuming from waiting.

- Calling the mysys set function from the server
  to set the callbacks correctly.

1 files changed, 1 insertions, 0 deletions

diff --git a/include/violite.h b/include/violite.h
index 05ceaa272c1..f4083216894 100644
--- a/include/violite.h
+++ b/include/violite.h
@@ -217,6 +217,7 @@ struct st_vio
   void	  (*timeout)(Vio*, unsigned int which, unsigned int timeout);
   my_bool (*poll_read)(Vio *vio, uint timeout);
   my_bool (*is_connected)(Vio*);
+  my_bool (*has_data) (Vio*);
 #ifdef HAVE_OPENSSL
   void	  *ssl_arg;
 #endif