Ensure instantaneous_domain_index

polytypic · polytypic · commit 2100893e7dba · 2024-08-28T10:55:49.000+03:00
diff --git a/lib/picos_select/dune b/lib/picos_select/dune
@@ -15,6 +15,7 @@
   backoff
   threads.posix
   psq
+  multicore-magic
   mtime
   mtime.clock.os))
 
diff --git a/lib/picos_select/picos_select.ml b/lib/picos_select/picos_select.ml
@@ -319,6 +319,9 @@ let configure ?(intr_sig = Sys.sigusr2) ?(handle_sigchld = true)
   reconfigure_signal_handlers ()
 
 let check_configured () =
+  (* [instantenous_domain_index] uses [Domain.at_exit] and we want to ensure it
+     is called as early as possible. *)
+  Multicore_magic.instantaneous_domain_index () |> ignore;
   if config.intr_sigs == [] then configure ()
   else reconfigure_signal_handlers ()
 
diff --git a/lib/picos_select/picos_select.mli b/lib/picos_select/picos_select.mli
@@ -124,18 +124,22 @@ val configure :
     thread on the main domain before any threads or domains besides the main are
     created or spawned. *)
 
-val handle_signal : int -> unit
-(** [handle_signal signum] should be called to notify this module of a signal
-    when {{!configure} configured} to not handle said signals. *)
-
 val check_configured : unit -> unit
 (** [check_configured ()] checks whether this module has already been
     {{!configure} configured} or not and, if not, calls {!configure} with
     default arguments.  In either case, calling [check_configured ()] will
-    (re)configure signal handling for the current thread.
+    (re)configure signal handling for the current thread and perform other
+    required initialization for the thread to use this module.
+
+    ⚠️ This should be called at the start of every thread using this module.
 
-    ℹ️ The intended use case for [check_configure ()] is at the point of
-    entry of schedulers and other facilities that use this module. *)
+    ℹ️ The intended use case for [check_configured ()] is at the point of entry
+    of schedulers and other facilities that use this module.  In other words,
+    application code should ideally not need to call this directly. *)
+
+val handle_signal : int -> unit
+(** [handle_signal signum] should be called to notify this module of a signal
+    when {{!configure} configured} to not handle said signals. *)
 
 (** {1 Examples}
 
