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, 4 insertions, 1 deletions

diff --git a/vio/viossl.c b/vio/viossl.c
index 0651fd8b7a3..1c6863c9943 100644
--- a/vio/viossl.c
+++ b/vio/viossl.c
@@ -274,6 +274,9 @@ int vio_ssl_blocking(Vio *vio __attribute__((unused)),
   return (set_blocking_mode ? 0 : 1);
 }
 
-
+my_bool vio_ssl_has_data(Vio *vio)
+{
+  return SSL_pending(vio->ssl_arg) > 0 ? TRUE : FALSE;
+}
 
 #endif /* HAVE_OPENSSL */