Work around for bug in threads + blocking io streamlined

1 files changed, 48 insertions, 0 deletions

diff --git a/lib/cThread.ml b/lib/cThread.ml
new file mode 100644
index 0000000000..a38c88d802
--- /dev/null
+++ b/lib/cThread.ml
@@ -0,0 +1,48 @@
+(************************************************************************)
+(*  v      *   The Coq Proof Assistant  /  The Coq Development Team     *)
+(* <O___,, *   INRIA - CNRS - LIX - LRI - PPS - Copyright 1999-2012     *)
+(*   \VV/  **************************************************************)
+(*    //   *      This file is distributed under the terms of the       *)
+(*         *       GNU Lesser General Public License Version 2.1        *)
+(************************************************************************)
+
+let prepare_in_channel_for_thread_friendly_io ic =
+  Unix.set_nonblock (Unix.descr_of_in_channel ic)
+
+let thread_friendly_read_fd fd s ~off ~len =
+  let rec loop () =
+    try Unix.read fd s off len
+    with Unix.Unix_error((Unix.EWOULDBLOCK|Unix.EAGAIN),_,_) ->
+      while not (Thread.wait_timed_read fd 1.0) do Thread.yield () done;
+      loop ()
+  in 
+    loop ()
+
+let thread_friendly_read ic s ~off ~len =
+  try
+    let fd = Unix.descr_of_in_channel ic in
+    thread_friendly_read_fd fd s ~off ~len
+  with Unix.Unix_error _ -> 0
+
+let really_read_fd fd s off len =
+  let i = ref 0 in
+  while !i < len do
+    let off = off + !i in
+    let len = len - !i in
+    let r = thread_friendly_read_fd fd s ~off ~len in
+    if r = 0 then raise End_of_file;
+    i := !i + r
+  done
+
+let thread_friendly_input_value ic =
+  try
+    let fd = Unix.descr_of_in_channel ic in
+    let header = String.create Marshal.header_size in
+    really_read_fd fd header 0 Marshal.header_size;
+    let body_size = Marshal.data_size header 0 in
+    let msg = String.create (body_size + Marshal.header_size) in
+    String.blit header 0 msg 0 Marshal.header_size;
+    really_read_fd fd msg Marshal.header_size body_size;
+    Marshal.from_string msg 0
+  with Unix.Unix_error _ -> raise End_of_file
+