Bug#51295 Build warnings in mdl.cc

Before this fix, the performance schema instrumentation
in mdl.h / mdl.cc was incomplete, causing:
- build warnings,
- no data collection for the performance schema

This fix:
- added instrumentation helpers for the new preferred
  reader read write lock, mysql_prlock_*
- implemented completely the performance schema
  instrumentation of mdl.h / mdl.cc

include/mysql/psi/mysql_thread.h

@@ -106,6 +106,22 @@ struct st_mysql_rwlock
   struct PSI_rwlock *m_psi;
 };
 
+/**
+  An instrumented prlock structure.
+  @sa mysql_prlock_t
+*/
+struct st_mysql_prlock
+{
+  /** The real prlock */
+  rw_pr_lock_t m_prlock;
+  /**
+    The instrumentation hook.
+    Note that this hook is not conditionally defined,
+    for binary compatibility of the @c mysql_rwlock_t interface.
+  */
+  struct PSI_rwlock *m_psi;
+};
+
 /**
   Type of an instrumented rwlock.
   @c mysql_rwlock_t is a drop-in replacement for @c pthread_rwlock_t.
@@ -119,6 +135,20 @@ struct st_mysql_rwlock
 */
 typedef struct st_mysql_rwlock mysql_rwlock_t;
 
+/**
+  Type of an instrumented prlock.
+  A prlock is a read write lock that 'prefers readers' (pr).
+  @c mysql_prlock_t is a drop-in replacement for @c rw_pr_lock_t.
+  @sa mysql_prlock_init
+  @sa mysql_prlock_rdlock
+  @sa mysql_prlock_tryrdlock
+  @sa mysql_prlock_wrlock
+  @sa mysql_prlock_trywrlock
+  @sa mysql_prlock_unlock
+  @sa mysql_prlock_destroy
+*/
+typedef struct st_mysql_prlock mysql_prlock_t;
+
 /**
   An instrumented cond structure.
   @sa mysql_cond_t
@@ -281,6 +311,19 @@ typedef struct st_mysql_cond mysql_cond_t;
   #define mysql_rwlock_init(K, RW) inline_mysql_rwlock_init(RW)
 #endif
 
+/**
+  @def mysql_prlock_init(K, RW)
+  Instrumented rw_pr_init.
+  @c mysql_prlock_init is a replacement for @c rw_pr_init.
+  @param K The PSI_rwlock_key for this instrumented prlock
+  @param RW The prlock to initialize
+*/
+#ifdef HAVE_PSI_INTERFACE
+  #define mysql_prlock_init(K, RW) inline_mysql_prlock_init(K, RW)
+#else
+  #define mysql_prlock_init(K, RW) inline_mysql_prlock_init(RW)
+#endif
+
 /**
   @def mysql_rwlock_destroy(RW)
   Instrumented rwlock_destroy.
@@ -289,6 +332,14 @@ typedef struct st_mysql_cond mysql_cond_t;
 */
 #define mysql_rwlock_destroy(RW) inline_mysql_rwlock_destroy(RW)
 
+/**
+  @def mysql_prlock_destroy(RW)
+  Instrumented rw_pr_destroy.
+  @c mysql_prlock_destroy is a drop-in replacement
+  for @c rw_pr_destroy.
+*/
+#define mysql_prlock_destroy(RW) inline_mysql_prlock_destroy(RW)
+
 /**
   @def mysql_rwlock_rdlock(RW)
   Instrumented rwlock_rdlock.
@@ -303,6 +354,20 @@ typedef struct st_mysql_cond mysql_cond_t;
     inline_mysql_rwlock_rdlock(RW)
 #endif
 
+/**
+  @def mysql_prlock_rdlock(RW)
+  Instrumented rw_pr_rdlock.
+  @c mysql_prlock_rdlock is a drop-in replacement
+  for @c rw_pr_rdlock.
+*/
+#ifdef HAVE_PSI_INTERFACE
+  #define mysql_prlock_rdlock(RW) \
+    inline_mysql_prlock_rdlock(RW, __FILE__, __LINE__)
+#else
+  #define mysql_prlock_rdlock(RW) \
+    inline_mysql_prlock_rdlock(RW)
+#endif
+
 /**
   @def mysql_rwlock_wrlock(RW)
   Instrumented rwlock_wrlock.
@@ -317,6 +382,20 @@ typedef struct st_mysql_cond mysql_cond_t;
     inline_mysql_rwlock_wrlock(RW)
 #endif
 
+/**
+  @def mysql_prlock_wrlock(RW)
+  Instrumented rw_pr_wrlock.
+  @c mysql_prlock_wrlock is a drop-in replacement
+  for @c rw_pr_wrlock.
+*/
+#ifdef HAVE_PSI_INTERFACE
+  #define mysql_prlock_wrlock(RW) \
+    inline_mysql_prlock_wrlock(RW, __FILE__, __LINE__)
+#else
+  #define mysql_prlock_wrlock(RW) \
+    inline_mysql_prlock_wrlock(RW)
+#endif
+
 /**
   @def mysql_rwlock_tryrdlock(RW)
   Instrumented rwlock_tryrdlock.
@@ -331,6 +410,20 @@ typedef struct st_mysql_cond mysql_cond_t;
     inline_mysql_rwlock_tryrdlock(RW)
 #endif
 
+/**
+  @def mysql_prlock_tryrdlock(RW)
+  Instrumented rw_pr_tryrdlock.
+  @c mysql_prlock_tryrdlock is a drop-in replacement
+  for @c rw_pr_tryrdlock.
+*/
+#ifdef HAVE_PSI_INTERFACE
+  #define mysql_prlock_tryrdlock(RW) \
+    inline_mysql_prlock_tryrdlock(RW, __FILE__, __LINE__)
+#else
+  #define mysql_prlock_tryrdlock(RW) \
+    inline_mysql_prlock_tryrdlock(RW)
+#endif
+
 /**
   @def mysql_rwlock_trywrlock(RW)
   Instrumented rwlock_trywrlock.
@@ -345,6 +438,20 @@ typedef struct st_mysql_cond mysql_cond_t;
     inline_mysql_rwlock_trywrlock(RW)
 #endif
 
+/**
+  @def mysql_prlock_trywrlock(RW)
+  Instrumented rw_pr_trywrlock.
+  @c mysql_prlock_trywrlock is a drop-in replacement
+  for @c rw_pr_trywrlock.
+*/
+#ifdef HAVE_PSI_INTERFACE
+  #define mysql_prlock_trywrlock(RW) \
+    inline_mysql_prlock_trywrlock(RW, __FILE__, __LINE__)
+#else
+  #define mysql_prlock_trywrlock(RW) \
+    inline_mysql_prlock_trywrlock(RW)
+#endif
+
 /**
   @def mysql_rwlock_unlock(RW)
   Instrumented rwlock_unlock.
@@ -353,9 +460,17 @@ typedef struct st_mysql_cond mysql_cond_t;
 */
 #define mysql_rwlock_unlock(RW) inline_mysql_rwlock_unlock(RW)
 
+/**
+  @def mysql_prlock_unlock(RW)
+  Instrumented rw_pr_unlock.
+  @c mysql_prlock_unlock is a drop-in replacement
+  for @c rw_pr_unlock.
+*/
+#define mysql_prlock_unlock(RW) inline_mysql_prlock_unlock(RW)
+
 /**
   @def mysql_cond_init(K, C, A)
-  Instrumented rwlock_init.
+  Instrumented cond_init.
   @c mysql_cond_init is a replacement for @c pthread_cond_init.
   @param C The cond to initialize
   @param K The PSI_cond_key for this instrumented cond
@@ -599,6 +714,21 @@ static inline int inline_mysql_rwlock_init(
   return my_rwlock_init(&that->m_rwlock, NULL);
 }
 
+static inline int inline_mysql_prlock_init(
+#ifdef HAVE_PSI_INTERFACE
+  PSI_rwlock_key key,
+#endif
+  mysql_prlock_t *that)
+{
+#ifdef HAVE_PSI_INTERFACE
+  that->m_psi= (PSI_server ? PSI_server->init_rwlock(key, &that->m_prlock)
+                           : NULL);
+#else
+  that->m_psi= NULL;
+#endif
+  return rw_pr_init(&that->m_prlock);
+}
+
 static inline int inline_mysql_rwlock_destroy(
   mysql_rwlock_t *that)
 {
@@ -612,6 +742,19 @@ static inline int inline_mysql_rwlock_destroy(
   return rwlock_destroy(&that->m_rwlock);
 }
 
+static inline int inline_mysql_prlock_destroy(
+  mysql_prlock_t *that)
+{
+#ifdef HAVE_PSI_INTERFACE
+  if (likely(PSI_server && that->m_psi))
+  {
+    PSI_server->destroy_rwlock(that->m_psi);
+    that->m_psi= NULL;
+  }
+#endif
+  return rw_pr_destroy(&that->m_prlock);
+}
+
 static inline int inline_mysql_rwlock_rdlock(
   mysql_rwlock_t *that
 #ifdef HAVE_PSI_INTERFACE
@@ -638,6 +781,32 @@ static inline int inline_mysql_rwlock_rdlock(
   return result;
 }
 
+static inline int inline_mysql_prlock_rdlock(
+  mysql_prlock_t *that
+#ifdef HAVE_PSI_INTERFACE
+  , const char *src_file, uint src_line
+#endif
+  )
+{
+  int result;
+#ifdef HAVE_PSI_INTERFACE
+  struct PSI_rwlock_locker *locker= NULL;
+  if (likely(PSI_server && that->m_psi))
+  {
+    locker= PSI_server->get_thread_rwlock_locker(that->m_psi,
+                                                 PSI_RWLOCK_READLOCK);
+    if (likely(locker != NULL))
+      PSI_server->start_rwlock_rdwait(locker, src_file, src_line);
+  }
+#endif
+  result= rw_pr_rdlock(&that->m_prlock);
+#ifdef HAVE_PSI_INTERFACE
+  if (likely(locker != NULL))
+    PSI_server->end_rwlock_rdwait(locker, result);
+#endif
+  return result;
+}
+
 static inline int inline_mysql_rwlock_wrlock(
   mysql_rwlock_t *that
 #ifdef HAVE_PSI_INTERFACE
@@ -664,6 +833,32 @@ static inline int inline_mysql_rwlock_wrlock(
   return result;
 }
 
+static inline int inline_mysql_prlock_wrlock(
+  mysql_prlock_t *that
+#ifdef HAVE_PSI_INTERFACE
+  , const char *src_file, uint src_line
+#endif
+  )
+{
+  int result;
+#ifdef HAVE_PSI_INTERFACE
+  struct PSI_rwlock_locker *locker= NULL;
+  if (likely(PSI_server && that->m_psi))
+  {
+    locker= PSI_server->get_thread_rwlock_locker(that->m_psi,
+                                                 PSI_RWLOCK_WRITELOCK);
+    if (likely(locker != NULL))
+      PSI_server->start_rwlock_wrwait(locker, src_file, src_line);
+  }
+#endif
+  result= rw_pr_wrlock(&that->m_prlock);
+#ifdef HAVE_PSI_INTERFACE
+  if (likely(locker != NULL))
+    PSI_server->end_rwlock_wrwait(locker, result);
+#endif
+  return result;
+}
+
 static inline int inline_mysql_rwlock_tryrdlock(
   mysql_rwlock_t *that
 #ifdef HAVE_PSI_INTERFACE
@@ -690,6 +885,32 @@ static inline int inline_mysql_rwlock_tryrdlock(
   return result;
 }
 
+static inline int inline_mysql_prlock_tryrdlock(
+  mysql_prlock_t *that
+#ifdef HAVE_PSI_INTERFACE
+  , const char *src_file, uint src_line
+#endif
+  )
+{
+  int result;
+#ifdef HAVE_PSI_INTERFACE
+  struct PSI_rwlock_locker *locker= NULL;
+  if (likely(PSI_server && that->m_psi))
+  {
+    locker= PSI_server->get_thread_rwlock_locker(that->m_psi,
+                                                 PSI_RWLOCK_TRYREADLOCK);
+    if (likely(locker != NULL))
+      PSI_server->start_rwlock_rdwait(locker, src_file, src_line);
+  }
+#endif
+  result= rw_pr_tryrdlock(&that->m_prlock);
+#ifdef HAVE_PSI_INTERFACE
+  if (likely(locker != NULL))
+    PSI_server->end_rwlock_rdwait(locker, result);
+#endif
+  return result;
+}
+
 static inline int inline_mysql_rwlock_trywrlock(
   mysql_rwlock_t *that
 #ifdef HAVE_PSI_INTERFACE
@@ -716,6 +937,32 @@ static inline int inline_mysql_rwlock_trywrlock(
   return result;
 }
 
+static inline int inline_mysql_prlock_trywrlock(
+  mysql_prlock_t *that
+#ifdef HAVE_PSI_INTERFACE
+  , const char *src_file, uint src_line
+#endif
+  )
+{
+  int result;
+#ifdef HAVE_PSI_INTERFACE
+  struct PSI_rwlock_locker *locker= NULL;
+  if (likely(PSI_server && that->m_psi))
+  {
+    locker= PSI_server->get_thread_rwlock_locker(that->m_psi,
+                                                 PSI_RWLOCK_TRYWRITELOCK);
+    if (likely(locker != NULL))
+      PSI_server->start_rwlock_wrwait(locker, src_file, src_line);
+  }
+#endif
+  result= rw_pr_trywrlock(&that->m_prlock);
+#ifdef HAVE_PSI_INTERFACE
+  if (likely(locker != NULL))
+    PSI_server->end_rwlock_wrwait(locker, result);
+#endif
+  return result;
+}
+
 static inline int inline_mysql_rwlock_unlock(
   mysql_rwlock_t *that)
 {
@@ -733,6 +980,23 @@ static inline int inline_mysql_rwlock_unlock(
   return result;
 }
 
+static inline int inline_mysql_prlock_unlock(
+  mysql_prlock_t *that)
+{
+  int result;
+#ifdef HAVE_PSI_INTERFACE
+  struct PSI_thread *thread;
+  if (likely(PSI_server && that->m_psi))
+  {
+    thread= PSI_server->get_thread();
+    if (likely(thread != NULL))
+      PSI_server->unlock_rwlock(thread, that->m_psi);
+  }
+#endif
+  result= rw_pr_unlock(&that->m_prlock);
+  return result;
+}
+
 static inline int inline_mysql_cond_init(
 #ifdef HAVE_PSI_INTERFACE
   PSI_cond_key key,

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

@@ -25,9 +25,10 @@ wait/synch/rwlock/sql/LOCK_system_variables_hash	YES	YES
 wait/synch/rwlock/sql/LOCK_sys_init_connect	YES	YES
 wait/synch/rwlock/sql/LOCK_sys_init_slave	YES	YES
 wait/synch/rwlock/sql/LOGGER::LOCK_logger	YES	YES
+wait/synch/rwlock/sql/MDL_context::waiting_for_lock	YES	YES
+wait/synch/rwlock/sql/MDL_lock::rwlock	YES	YES
 wait/synch/rwlock/sql/Query_cache_query::lock	YES	YES
 wait/synch/rwlock/sql/THR_LOCK_servers	YES	YES
-wait/synch/rwlock/sql/THR_LOCK_udf	YES	YES
 select * from performance_schema.SETUP_INSTRUMENTS
 where name like 'Wait/Synch/Cond/sql/%'
   and name not in (

sql/mdl.h

@@ -628,7 +628,7 @@ class MDL_context
           important as deadlock detector won't work correctly
           otherwise. @sa Comment for MDL_lock::m_rwlock.
   */
-  rw_pr_lock_t m_waiting_for_lock;
+  mysql_prlock_t m_waiting_for_lock;
   MDL_ticket *m_waiting_for;
   uint m_deadlock_weight;
   /**
@@ -652,9 +652,9 @@ class MDL_context
 
   void will_wait_for(MDL_ticket *pending_ticket)
   {
-    rw_pr_wrlock(&m_waiting_for_lock);
+    mysql_prlock_wrlock(&m_waiting_for_lock);
     m_waiting_for= pending_ticket;
-    rw_pr_unlock(&m_waiting_for_lock);
+    mysql_prlock_unlock(&m_waiting_for_lock);
   }
 
   void set_deadlock_weight(uint weight)
@@ -670,9 +670,9 @@ class MDL_context
 
   void stop_waiting()
   {
-    rw_pr_wrlock(&m_waiting_for_lock);
+    mysql_prlock_wrlock(&m_waiting_for_lock);
     m_waiting_for= NULL;
-    rw_pr_unlock(&m_waiting_for_lock);
+    mysql_prlock_unlock(&m_waiting_for_lock);
   }
 
   void wait_reset()