>However the Microsoft WaitForSingleObject and WaitForMultipleObjects did not have an efficient implementation, which is why they had to add WaitOnAddress
WaitForSingle/MultipleObjects wait for kernel objects, similiar to poll. WaitOnAddress is lightweight synchronization, equivalent to futex. Windows doesn't have something like WaitForMultipleAddresses. futex_waitv was used by Wine patches because they implement NT kernel objects in userspace, and there were some semantic differences that made it hard to represent them as eventfds.
PS: But using futexes to emulate kernel objects breaks security boundaries of a process. That's why it was never merged into upstream Wine, and NTSYNC was developed.
WaitForSingle/MultipleObjects wait for kernel objects, similiar to poll. WaitOnAddress is lightweight synchronization, equivalent to futex. Windows doesn't have something like WaitForMultipleAddresses. futex_waitv was used by Wine patches because they implement NT kernel objects in userspace, and there were some semantic differences that made it hard to represent them as eventfds.
PS: But using futexes to emulate kernel objects breaks security boundaries of a process. That's why it was never merged into upstream Wine, and NTSYNC was developed.