[PATCH v2 1/2] Cygwin: console: Make read() thread-safe.

[Takashi Yano via Cygwin-patches]

- Currently read() is somehow not thread-safe. This patch fixes the
  issue.
---
 winsup/cygwin/fhandler_console.cc | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/winsup/cygwin/fhandler_console.cc 
b/winsup/cygwin/fhandler_console.cc
index 02d0ac052..d0e5bb33a 100644
--- a/winsup/cygwin/fhandler_console.cc
+++ b/winsup/cygwin/fhandler_console.cc
@@ -530,12 +530,14 @@ fhandler_console::read (void *pv, size_t& buflen)
   if (wincap.has_con_24bit_colors ())
     request_xterm_mode_input (true, &handle_set);
 
+  acquire_input_mutex (INFINITE);
   while (!input_ready && !get_cons_readahead_valid ())
     {
       int bgres;
       if ((bgres = bg_check (SIGTTIN)) <= bg_eof)
        {
          buflen = bgres;
+         release_input_mutex ();
          return;
        }
 
@@ -552,6 +554,7 @@ wait_retry:
          pthread::static_cancel_self ();
          /*NOTREACHED*/
        case WAIT_TIMEOUT:
+         release_input_mutex ();
          set_sig_errno (EAGAIN);
          buflen = (size_t) -1;
          return;
@@ -572,9 +575,7 @@ wait_retry:
 
       int ret;
       acquire_attach_mutex (INFINITE);
-      acquire_input_mutex (INFINITE);
       ret = process_input_message ();
-      release_input_mutex ();
       release_attach_mutex ();
       switch (ret)
        {
@@ -595,7 +596,6 @@ wait_retry:
     }
 
   /* Check console read-ahead buffer filled from terminal requests */
-  acquire_input_mutex (INFINITE);
   while (con.cons_rapoi && *con.cons_rapoi && buflen)
     {
       buf[copied_chars++] = *con.cons_rapoi++;
@@ -615,11 +615,13 @@ wait_retry:
   return;
 
 err:
+  release_input_mutex ();
   __seterrno ();
   buflen = (size_t) -1;
   return;
 
 sig_exit:
+  release_input_mutex ();
   set_sig_errno (EINTR);
   buflen = (size_t) -1;
 }
@@ -984,9 +986,7 @@ fhandler_console::process_input_message (void)
       if (toadd)
        {
          ssize_t ret;
-         release_input_mutex ();
          line_edit_status res = line_edit (toadd, nread, *ti, &ret);
-         acquire_input_mutex (INFINITE);
          if (res == line_edit_signalled)
            {
              stat = input_signalled;
-- 
2.30.0