Back out "Convert Marshal_tools to use poll instead of select"

Summary:
Original commit changeset: 525f90b319cc

Original Phabricator Diff: D64907234

Reviewed By: vassilmladenov

Differential Revision: D65433270

fbshipit-source-id: 4c7bc3f5edf37abe07af5ed95699fb83a0468597

hphp/hack/src/utils/marshal_tools/dune

@@ -3,7 +3,7 @@
  (wrapped false)
  (modules marshal_tools)
  (libraries
-  poll
+  sys_utils
   utils_core)
  (preprocess
   (pps lwt_ppx ppx_deriving.std)))

hphp/hack/src/utils/marshal_tools/marshal_tools.ml

@@ -107,11 +107,10 @@ module RegularWriterReader : REGULAR_WRITER_READER = struct
   let ( >>= ) a f = f a
 
   let rec write fd ~buffer ~offset ~size =
-    match Poll.wait_fd_write_non_intr ~timeout_ms:None fd with
-    | Error flags -> raise (Poll.Poll_exception flags)
-    | Ok `Timeout -> 0
-    | Ok `Ok ->
-      (* Poll.wait_fd_write_non_intr handles EINTR, but the Unix.write call can also be interrupted. If the write
+    match Sys_utils.select_non_intr [] [fd] [] (-1.) with
+    | (_, [], _) -> 0
+    | _ ->
+      (* Sys_utils.select_non_intr handles EINTR, but the Unix.write call can also be interrupted. If the write
        * is interrupted before any bytes are written, the call fails with EINTR. Otherwise, the call
        * succeeds and returns the number of bytes written.
        *)
@@ -128,11 +127,10 @@ module RegularWriterReader : REGULAR_WRITER_READER = struct
    * preamble and one or more for the data). Any read after the first might block.
    *)
   let rec read fd ~buffer ~offset ~size =
-    match Poll.wait_fd_read_non_intr ~timeout_ms:None fd with
-    | Error flags -> raise (Poll.Poll_exception flags)
-    | Ok `Timeout -> 0
-    | Ok `Ok ->
-      (* Poll.wait_fd_write_non_intr handles EINTR, but the Unix.read call can also be interrupted. If the read
+    match Sys_utils.select_non_intr [fd] [] [] (-1.) with
+    | ([], _, _) -> 0
+    | _ ->
+      (* Sys_utils.select_non_intr handles EINTR, but the Unix.read call can also be interrupted. If the read
        * is interrupted before any bytes are read, the call fails with EINTR. Otherwise, the call
        * succeeds and returns the number of bytes read.
        *)

hphp/hack/src/utils/sys/poll/poll.ml

@@ -42,7 +42,7 @@ let wait_fd
     (flags : Poll.Flags.t) (fd : Unix.file_descr) ~(timeout_ms : int option) :
     ([ `Ok | `Timeout ], Flags.error list) result =
   let timeout = make_poll_timeout_ms timeout_ms in
-  let poll = Poll.create ~maxfds:1 () in
+  let poll = Poll.create () in
   Poll.set_index poll 0 fd flags;
   let _nready = Poll.poll poll 1 timeout in
   let rflags = Poll.get_revents poll 0 in