expose Tracing

src/core/moonpool.ml

@@ -34,6 +34,7 @@ module Private = struct
   module Ws_deque_ = Ws_deque_
   module Suspend_ = Suspend_
   module Domain_ = Domain_
+  module Tracing_ = Tracing_
 
   let num_domains = Domain_pool_.n_domains
 end

src/core/moonpool.mli

@@ -222,6 +222,8 @@ module Private : sig
   module Domain_ = Domain_
   (** Utils for domains *)
 
+  module Tracing_ = Tracing_
+
   val num_domains : unit -> int
   (** Number of domains in the backing domain pool *)
 end

src/private/tracing_.dummy.ml

@@ -3,3 +3,4 @@ let dummy_span = 0L
 let enter_span _name = dummy_span
 let exit_span = ignore
 let set_thread_name = ignore
+let with_span _ f = f dummy_span

src/private/tracing_.mli

@@ -1,5 +1,6 @@
 val dummy_span : int64
 val enter_span : string -> int64
 val exit_span : int64 -> unit
+val with_span : string -> (int64 -> 'a) -> 'a
 val enabled : unit -> bool
 val set_thread_name : string -> unit

src/private/tracing_.real.ml

@@ -12,3 +12,14 @@ let[@inline] enter_span name : int64 =
     Trace.enter_span ~__FILE__:dummy_file_ ~__LINE__:0 name
 
 let[@inline] exit_span sp = if sp <> dummy_span then Trace.exit_span sp
+
+let with_span name f =
+  let sp = enter_span name in
+  try
+    let x = f sp in
+    exit_span sp;
+    x
+  with exn ->
+    let bt = Printexc.get_raw_backtrace () in
+    exit_span sp;
+    Printexc.raise_with_backtrace exn bt