The RTLEvent family is absent from the threading RTL

PRTLEvent, RTLEventCreate, RTLeventSetEvent, RTLeventWaitFor, RTLEventResetEvent and RTLEventDestroy do not exist in lib/rtl — measured 2026-09-06 at compiler 0d77c1e48ea4, unknown type: PRTLEvent with cthreads on the uses line.

It is a HOLE IN AN OTHERWISE PRESENT SURFACE, which is why it is worth a row

The rest of FPC's threading surface is there and tested: BeginThread, WaitForThreadTerminate, EndThread, TThreadID, TThreadFunc and a native TThread (lib/rtl/palthreadobj.pas, lib/rtl/cthreads.pas, test/lib_fpc_thread_surface.pas, whose own header records that the missing piece was "the NAMES and SHAPES" rather than the machinery — compat-pascal-thread-api-surface-differs-from-fpc). RTLEvent is the one FPC-portable primitive a threaded program reaches for that has no pxx spelling at all, so a source using it needs an {$IFDEF} in exactly the place that compat ticket exists to remove.

It is the ordinary FPC idiom for "wait until the worker has done its thing" without a busy loop, and both corpus rows that use threads use it: tclass16.pp and terecs20.pp (see feature-p-threadvar-is-not-supported-at-any-scope, which those rows are also gated on — this ticket alone does not burn either).

Shape

A thin wrapper over what the PAL already has (a mutex + condvar, or an eventfd/futex on Linux), in palthreadobj.pas beside BeginThread. PRTLEvent is an opaque pointer in FPC and should stay opaque here.