Commit ecbd634c9fd8d9dc3a18eef404a4d541ebc151ac
2023-09-19T17:21:30
threads: Fix double-checked locking in xmlInitParser Hopefully work around the classic problem with double-checked locking: Another thread could read xmlParserInitialized == 1 but doesn't see other initialization results yet due to compiler or hardware reordering. While unlikely, this seems theoretically possible. The solution is to add a memory barrier after initializing the data but before setting xmlParserInitialized. It might be enough to use a second initialization flag which is only used inside the locked section and update xmlParserInitialized after unlocking. But I haven't seen this approach in many articles discussing this issue, so it's possibly flawed as well.