From: Takashi Yano <takashi.yano@nifty.ne.jp>
To: cygwin-patches@cygwin.com
Subject: [PATCH] Cygwin: pty: Fix master closing error regarding attach_mutex.
Date: Sat, 9 Oct 2021 01:28:54 +0900 [thread overview]
Message-ID: <20211008162854.1085-1-takashi.yano@nifty.ne.jp> (raw)
- 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
--
2.33.0
next reply other threads:[~2021-10-08 16:29 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-08 16:28 Takashi Yano [this message]
2021-10-08 17:30 ` Ken Brown
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