WL#3071 - Maria checkpoint

Adding rec_lsn to Maria's page cache. Misc fixes to Checkpoint.


mysys/mf_pagecache.c:
  adding rec_lsn, the LSN when a page first became dirty.
  It is set when unlocking a page (TODO: should also be set when
  the unlocking is an implicit part of pagecache_write()).
  It is reset in link_to_file_list() and free_block()
  (one of which is used every time we flush a block).
  It is a ulonglong and not LSN, because its destination is comparisons
  for which ulonglong is better than a struct.
storage/maria/ma_checkpoint.c:
  misc fixes to Checkpoint (updates now that the transaction manager
  and the page cache are more known)
storage/maria/ma_close.c:
  an important note for the future.
storage/maria/ma_least_recently_dirtied.c:
  comment

mysys/mf_pagecache.c

@@ -295,6 +295,7 @@ struct st_pagecache_block_link
   enum pagecache_page_type type; /* type of the block                        */
   uint hits_left;         /* number of hits left until promotion             */
   ulonglong last_hit_time; /* timestamp of the last hit                      */
+  ulonglong rec_lsn;       /* LSN when first became dirty                    */
   KEYCACHE_CONDVAR *condvar; /* condition variable for 'no readers' event    */
 };
 
@@ -1202,6 +1203,7 @@ static void link_to_file_list(PAGECACHE *pagecache,
   if (block->status & BLOCK_CHANGED)
   {
     block->status&= ~BLOCK_CHANGED;
+    block->rec_lsn= 0;
     pagecache->blocks_changed--;
     pagecache->global_blocks_changed--;
   }
@@ -2509,6 +2511,8 @@ void pagecache_unlock_page(PAGECACHE *pagecache,
     DBUG_ASSERT(lock == PAGECACHE_LOCK_WRITE_UNLOCK &&
                 pin == PAGECACHE_UNPIN);
     /* TODO: insert LSN writing code */
+    DBUG_ASSERT(first_REDO_LSN_for_page > 0);
+    set_if_bigger(block->rec_lsn, first_REDO_LSN_for_page);
   }
 
 #ifndef DBUG_OFF
@@ -2671,6 +2675,8 @@ void pagecache_unlock(PAGECACHE *pagecache,
     DBUG_ASSERT(lock == PAGECACHE_LOCK_WRITE_UNLOCK &&
                 pin == PAGECACHE_UNPIN);
     /* TODO: insert LSN writing code */
+    DBUG_ASSERT(first_REDO_LSN_for_page > 0);
+    set_if_bigger(block->rec_lsn, first_REDO_LSN_for_page);
   }
 
 #ifndef DBUG_OFF
@@ -3012,10 +3018,9 @@ restart:
       pagecache->blocks_changed--;
       pagecache->global_blocks_changed--;
       /*
-        free_block() will change the status of the block so no need to change
-        it here.
+        free_block() will change the status and rec_lsn of the block so no
+        need to change them here.
       */
-
     }
     /* Cache is locked, so we can relese page before freeing it */
     pagecache_make_lock_and_pin(pagecache, block,
@@ -3328,6 +3333,7 @@ static void free_block(PAGECACHE *pagecache, PAGECACHE_BLOCK_LINK *block)
 #ifndef DBUG_OFF
   block->type= PAGECACHE_EMPTY_PAGE;
 #endif
+  block->rec_lsn= 0;
   KEYCACHE_THREAD_TRACE("free block");
   KEYCACHE_DBUG_PRINT("free_block",
                       ("block is freed"));

storage/maria/ma_close.c

@@ -57,6 +57,12 @@ int maria_close(register MARIA_HA *info)
     info->opt_flag&= ~(READ_CACHE_USED | WRITE_CACHE_USED);
   }
   flag= !--share->reopen;
+  /*
+    RECOVERYTODO:
+    Below we are going to make the table unknown to future checkpoints, so it
+    needs to have fsync'ed itself entirely (bitmap, pages, etc) at this
+    point.
+  */
   maria_open_list=list_delete(maria_open_list,&info->open_list);
   pthread_mutex_unlock(&share->intern_lock);
 

storage/maria/ma_least_recently_dirtied.c

@@ -94,7 +94,10 @@ pthread_handler_decl background_flush_and_checkpoint_thread()
   while (this_thread_not_killed)
   {
     if ((flush_calls++) & ((2<<CHECKPOINT_PROBING_PERIOD_LOG2)-1) == 0)
-      execute_asynchronous_checkpoint_if_any();
+    {
+      /* note that we don't care of the checkpoint's success */
+      (void)execute_asynchronous_checkpoint_if_any();
+    }
     lock(global_LRD_mutex);
     flush_one_group_from_LRD();
     safemutex_assert_not_owner(global_LRD_mutex);