On 10/8/2021 12:28 PM, Takashi Yano wrote:
- If two or more pty masters are opened in a process, closing master
causes error when closing attach_mutex. This patch fixes the issue.
Addresses:
https://cygwin.com/pipermail/cygwin-developers/2021-October/012418.html
---
winsup/cygwin/fhandler_tty.cc | 7 +++++--
winsup/cygwin/release/3.3.0 | 3 +++
2 files changed, 8 insertions(+), 2 deletions(-)
diff --git a/winsup/cygwin/fhandler_tty.cc b/winsup/cygwin/fhandler_tty.cc
index 05fe5348a..823dabf73 100644
--- a/winsup/cygwin/fhandler_tty.cc
+++ b/winsup/cygwin/fhandler_tty.cc
@@ -57,6 +57,7 @@ struct pipe_reply {
};
extern HANDLE attach_mutex; /* Defined in fhandler_console.cc */
+static LONG NO_COPY master_cnt = 0;
inline static bool pcon_pid_alive (DWORD pid);
@@ -2041,7 +2042,8 @@ fhandler_pty_master::close ()
}
release_output_mutex ();
master_fwd_thread->terminate_thread ();
- CloseHandle (attach_mutex);
+ if (InterlockedDecrement (&master_cnt) == 0)
+ CloseHandle (attach_mutex);
}
}
@@ -2876,7 +2878,8 @@ fhandler_pty_master::setup ()
if (!(pcon_mutex = CreateMutex (&sa, FALSE, buf)))
goto err;
- attach_mutex = CreateMutex (&sa, FALSE, NULL);
+ if (InterlockedIncrement (&master_cnt) == 1)
+ attach_mutex = CreateMutex (&sa, FALSE, NULL);
/* Create master control pipe which allows the master to duplicate
the pty pipe handles to processes which deserve it. */
diff --git a/winsup/cygwin/release/3.3.0 b/winsup/cygwin/release/3.3.0
index 2f7340ac5..2df81a4ae 100644
--- a/winsup/cygwin/release/3.3.0
+++ b/winsup/cygwin/release/3.3.0
@@ -71,3 +71,6 @@ Bug Fixes
in ps(1) output.
Addresses: https://cygwin.com/pipermail/cygwin/2021-July/248998.html
https://cygwin.com/pipermail/cygwin/2021-August/249124.html
+
+- Fix pty master closing error regarding attach_mutex.
+ Addresses:
https://cygwin.com/pipermail/cygwin-developers/2021-October/012418.html
Pushed. Thanks.
Ken
