diff options
Diffstat (limited to 'storage/maria/ma_pagecache.c')
| -rw-r--r-- | storage/maria/ma_pagecache.c | 15 |
1 files changed, 11 insertions, 4 deletions
diff --git a/storage/maria/ma_pagecache.c b/storage/maria/ma_pagecache.c index cab3fc35ded..6efc8173915 100644 --- a/storage/maria/ma_pagecache.c +++ b/storage/maria/ma_pagecache.c @@ -2824,8 +2824,14 @@ static void read_big_block(PAGECACHE *pagecache, have read our block for us */ struct st_my_thread_var *thread; - DBUG_ASSERT(page_st == PAGE_WAIT_TO_BE_READ); - DBUG_ASSERT(page_st != PAGE_TO_BE_READ); + /* + Either the page was not yet read and there is another thread + doing the read (page_st == PAGE_WAIT_TO_BE_READ) or the page + was just read and there are other threads waiting for the page + but they have not yet unmarked the PCLBOCK_BIG_READ flag + (page_st == PAGE_READ) + */ + DBUG_ASSERT(page_st == PAGE_READ || page_st == PAGE_WAIT_TO_BE_READ); block->status|= PCBLOCK_BIG_READ; // will be read by other thread /* Block read failed because somebody else is reading the first block @@ -2844,12 +2850,12 @@ static void read_big_block(PAGECACHE *pagecache, &pagecache->cache_lock); } while (thread->next); - // page should be read by other thread + // page should be read by other thread DBUG_ASSERT(block->status & PCBLOCK_READ || block->status & PCBLOCK_ERROR); /* It is possible that other thread already removed the flag (in - case of two threads waiting) but it will not make harm to try to + case of two threads waiting) but it will not harm to try to remove it even in that case. */ block->status&= ~PCBLOCK_BIG_READ; @@ -2883,6 +2889,7 @@ static void read_big_block(PAGECACHE *pagecache, args.pageno= page_to_read; args.data= block->hash_link->file.callback_data; + pagecache->global_cache_read++; if (pagecache->big_block_read(pagecache, &args, &block->hash_link->file, &data)) { |