Merge PR #13378: Add support for high resolution timeout functions

Ack-by: SkySkimmer
Ack-by: ejgallego
Reviewed-by: ppedrot

2 files changed, 8 insertions, 7 deletions

diff --git a/lib/control.ml b/lib/control.ml
index 7da95ff3dd..ea94bda064 100644
--- a/lib/control.ml
+++ b/lib/control.ml
@@ -30,11 +30,12 @@ let check_for_interrupt () =
 
 (** This function does not work on windows, sigh... *)
 let unix_timeout n f x =
+  let open Unix in
   let timeout_handler _ = raise Timeout in
   let psh = Sys.signal Sys.sigalrm (Sys.Signal_handle timeout_handler) in
-  let _ = Unix.alarm n in
+  let _ = setitimer ITIMER_REAL {it_interval = 0.; it_value = n} in
   let restore_timeout () =
-    let _ = Unix.alarm 0 in
+    let _ = setitimer ITIMER_REAL { it_interval = 0.; it_value = 0. } in
     Sys.set_signal Sys.sigalrm psh
   in
   try
@@ -52,7 +53,7 @@ let windows_timeout n f x =
   let thread init =
     while not !killed do
       let cur = Unix.gettimeofday () in
-      if float_of_int n <= cur -. init then begin
+      if n <= cur -. init then begin
         interrupt := true;
         exited := true;
         Thread.exit ()
@@ -68,7 +69,7 @@ let windows_timeout n f x =
     let cur = Unix.gettimeofday () in
     (* The thread did not interrupt, but the computation took longer than
        expected. *)
-    let () = if float_of_int n <= cur -. init then begin
+    let () = if n <= cur -. init then begin
       exited := true;
       raise Sys.Break
     end in
@@ -83,7 +84,7 @@ let windows_timeout n f x =
     let () = killed := true in
     Exninfo.iraise e
 
-type timeout = { timeout : 'a 'b. int -> ('a -> 'b) -> 'a -> 'b option }
+type timeout = { timeout : 'a 'b. float -> ('a -> 'b) -> 'a -> 'b option }
 
 let timeout_fun = match Sys.os_type with
 | "Unix" | "Cygwin" -> { timeout = unix_timeout }
diff --git a/lib/control.mli b/lib/control.mli
index 9465d8f0d5..f992d8e8d0 100644
--- a/lib/control.mli
+++ b/lib/control.mli
@@ -24,13 +24,13 @@ val check_for_interrupt : unit -> unit
 (** Use this function as a potential yield function. If {!interrupt} has been
     set, il will raise [Sys.Break]. *)
 
-val timeout : int -> ('a -> 'b) -> 'a -> 'b option
+val timeout : float -> ('a -> 'b) -> 'a -> 'b option
 (** [timeout n f x] tries to compute [Some (f x)], and if it fails to do so
     before [n] seconds, returns [None] instead. *)
 
 (** Set a particular timeout function; warning, this is an internal
    API and it is scheduled to go away. *)
-type timeout = { timeout : 'a 'b. int -> ('a -> 'b) -> 'a -> 'b option }
+type timeout = { timeout : 'a 'b. float -> ('a -> 'b) -> 'a -> 'b option }
 val set_timeout : timeout -> unit
 
 (** [protect_sigalrm f x] computes [f x], but if SIGALRM is received during that