More merge fixes:

- mdl.cc and mdl.h merged completely
- mysql_system_tables*.sql merged completely
- Fixed wrong merge of lock_tables
- Added some missing functions:
 - bool THD::notify_shared_lock()
 - Dynamic_array::pop, Dynamic_array::del
- Added MDL_context_owner to THD
- Added metadata_locks_hash_instances

1 files changed, 91 insertions, 13 deletions

diff --git a/sql/mdl.h b/sql/mdl.h
index 82d764bc66c..ddbd55ac467 100644
--- a/sql/mdl.h
+++ b/sql/mdl.h
@@ -1,6 +1,6 @@
 #ifndef MDL_H
 #define MDL_H
-/* Copyright (c) 2009, 2011, Oracle and/or its affiliates. All rights reserved.
+/* Copyright (c) 2009, 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
@@ -12,8 +12,8 @@
    GNU General Public License for more details.
 
    You should have received a copy of the GNU General Public License
-   along with this program; if not, write to the Free Software
-   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA */
+   along with this program; if not, write to the Free Software Foundation,
+   51 Franklin Street, Suite 500, Boston, MA 02110-1335 USA */
 
 #if defined(__IBMC__) || defined(__IBMCPP__)
 /* Further down, "next_in_lock" and "next_in_context" have the same type,
@@ -26,10 +26,11 @@
 
 #include "sql_plist.h"
 #include <my_sys.h>
-#include <my_pthread.h>
 #include <m_string.h>
 #include <mysql_com.h>
 
+#include <algorithm>
+
 class THD;
 
 class MDL_context;
@@ -55,6 +56,67 @@ class MDL_ticket;
 #define EXIT_COND(S) exit_cond(S, __func__, __FILE__, __LINE__)
 
 /**
+   An interface to separate the MDL module from the THD, and the rest of the
+   server code.
+ */
+
+class MDL_context_owner
+{
+public:
+  virtual ~MDL_context_owner() {}
+
+  /**
+    Enter a condition wait.
+    For @c enter_cond() / @c exit_cond() to work the mutex must be held before
+    @c enter_cond(); this mutex is then released by @c exit_cond().
+    Usage must be: lock mutex; enter_cond(); your code; exit_cond().
+    @param cond the condition to wait on
+    @param mutex the associated mutex
+    @param [in] stage the stage to enter, or NULL
+    @param [out] old_stage the previous stage, or NULL
+    @param src_function function name of the caller
+    @param src_file file name of the caller
+    @param src_line line number of the caller
+    @sa ENTER_COND(), THD::enter_cond()
+    @sa EXIT_COND(), THD::exit_cond()
+  */
+  virtual void enter_cond(mysql_cond_t *cond, mysql_mutex_t *mutex,
+                          const PSI_stage_info *stage, PSI_stage_info *old_stage,
+                          const char *src_function, const char *src_file,
+                          int src_line) = 0;
+
+  /**
+    @def EXIT_COND(S)
+    End a wait on a condition
+    @param [in] stage the new stage to enter
+    @param src_function function name of the caller
+    @param src_file file name of the caller
+    @param src_line line number of the caller
+    @sa ENTER_COND(), THD::enter_cond()
+    @sa EXIT_COND(), THD::exit_cond()
+  */
+  virtual void exit_cond(const PSI_stage_info *stage,
+                         const char *src_function, const char *src_file,
+                         int src_line) = 0;
+  /**
+     Has the owner thread been killed?
+   */
+  virtual int  is_killed() = 0;
+
+  /**
+     This one is only used for DEBUG_SYNC.
+     (Do not use it to peek/poke into other parts of THD.)
+   */
+  virtual THD* get_thd() = 0;
+
+  /**
+     @see THD::notify_shared_lock()
+   */
+  virtual bool notify_shared_lock(MDL_context_owner *in_use,
+                                  bool needs_thr_lock_abort) = 0;
+};
+
+/**
   Type of metadata lock request.
 
   @sa Comments for MDL_object_lock::can_grant_lock() and
@@ -273,8 +335,16 @@ public:
                     const char *db, const char *name)
   {
     m_ptr[0]= (char) mdl_namespace;
-    m_db_name_length= (uint16) (strmov(m_ptr + 1, db) - m_ptr - 1);
-    m_length= (uint16) (strmov(m_ptr + m_db_name_length + 2, name) - m_ptr + 1);
+    /*
+      It is responsibility of caller to ensure that db and object names
+      are not longer than NAME_LEN. Still we play safe and try to avoid
+      buffer overruns.
+    */
+    DBUG_ASSERT(strlen(db) <= NAME_LEN && strlen(name) <= NAME_LEN);
+    m_db_name_length= static_cast<uint16>(strmake(m_ptr + 1, db, NAME_LEN) -
+                                          m_ptr - 1);
+    m_length= static_cast<uint16>(strmake(m_ptr + m_db_name_length + 2, name,
+                                          NAME_LEN) - m_ptr + 1);
   }
   void mdl_key_init(const MDL_key *rhs)
   {
@@ -297,7 +367,8 @@ public:
       character set is utf-8, we can safely assume that no
       character starts with a zero byte.
     */
-    return memcmp(m_ptr, rhs->m_ptr, MY_MIN(m_length, rhs->m_length));
+    using std::min;
+    return memcmp(m_ptr, rhs->m_ptr, min(m_length, rhs->m_length));
   }
 
   MDL_key(const MDL_key *rhs)
@@ -624,7 +695,7 @@ public:
   bool set_status(enum_wait_status result_arg);
   enum_wait_status get_status();
   void reset_status();
-  enum_wait_status timed_wait(THD *thd,
+  enum_wait_status timed_wait(MDL_context_owner *owner,
                               struct timespec *abs_timeout,
                               bool signal_timeout,
                               const PSI_stage_info *wait_state_name);
@@ -706,7 +777,7 @@ public:
   void release_transactional_locks();
   void rollback_to_savepoint(const MDL_savepoint &mdl_savepoint);
 
-  inline THD *get_thd() const { return m_thd; }
+  MDL_context_owner *get_owner() { return m_owner; }
 
   /** @pre Only valid if we started waiting for lock. */
   inline uint get_deadlock_weight() const
@@ -719,7 +790,7 @@ public:
                     already has received some signal or closed
                     signal slot.
   */
-  void init(THD *thd_arg) { m_thd= thd_arg; }
+  void init(MDL_context_owner *arg) { m_owner= arg; }
 
   void set_needs_thr_lock_abort(bool needs_thr_lock_abort)
   {
@@ -799,7 +870,7 @@ private:
       involved schemas and global intention exclusive lock.
   */
   Ticket_list m_tickets[MDL_DURATION_END];
-  THD *m_thd;
+  MDL_context_owner *m_owner;
   /**
     TRUE -  if for this context we will break protocol and try to
             acquire table-level locks while having only S lock on
@@ -828,6 +899,7 @@ private:
    */
   MDL_wait_for_subgraph *m_waiting_for;
 private:
+  THD *get_thd() const { return m_owner->get_thd(); }
   MDL_ticket *find_ticket(MDL_request *mdl_req,
                           enum_mdl_duration *duration);
   void release_locks_stored_before(enum_mdl_duration duration, MDL_ticket *sentinel);
@@ -872,8 +944,6 @@ private:
 void mdl_init();
 void mdl_destroy();
 
-extern bool mysql_notify_thread_having_shared_lock(THD *thd, THD *in_use,
-                                                   bool needs_thr_lock_abort);
 
 #ifndef DBUG_OFF
 extern mysql_mutex_t LOCK_open;
@@ -888,6 +958,14 @@ extern ulong mdl_locks_cache_size;
 static const ulong MDL_LOCKS_CACHE_SIZE_DEFAULT = 1024;
 
 /*
+  Start-up parameter for the number of partitions of the hash
+  containing all the MDL_lock objects and a constant for
+  its default value.
+*/
+extern ulong mdl_locks_hash_partitions;
+static const ulong MDL_LOCKS_HASH_PARTITIONS_DEFAULT = 8;
+
+/*
   Metadata locking subsystem tries not to grant more than
   max_write_lock_count high-prio, strong locks successively,
   to avoid starving out weak, low-prio locks.