Hallvard Furuseth a35f9b2a53 Remove mdb data races. Use (txnid_t)-1 as "no ID". ... Avoid race between numreaders++ and reading numreaders at cleanup. Make the un-mutexed reset of reader table entry, atomic: Reset mr_pid only. Instead check mr_pid != 0 in mdb_page_alloc()'s scan for readers. (txnid_t)-1 as "no ID"-mark avoids a check for mr_txnid != 0. The scan can stop when seeing an old reader.		2012-09-17 15:42:14 +02:00
libraries/libmdb	Remove mdb data races. Use (txnid_t)-1 as "no ID".	2012-09-17 15:42:14 +02:00