[newlib-cygwin] Cygwin: POSIX mq: avoid double calls to ipc_mutex_unlock

[Corinna Vinschen]

https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=548a4c3ca43543e66ec91df799379bc67a92804a

commit 548a4c3ca43543e66ec91df799379bc67a92804a
Author: Corinna Vinschen <corinna@vinschen.de>
Date:   Fri Apr 30 10:30:21 2021 +0200

    Cygwin: POSIX mq: avoid double calls to ipc_mutex_unlock
    
    _mq_send as well as _mq_receive call ipc_mutex_unlock twice in case
    of success, after having introduced __try/__except blocks.
    
    Fixes: 3f3bd10104550 ("* Throughout, use __try/__except/__endtry blocks, rather than myfault handler.")
    Signed-off-by: Corinna Vinschen <corinna@vinschen.de>

Diff:
---
 winsup/cygwin/posix_ipc.cc | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/winsup/cygwin/posix_ipc.cc b/winsup/cygwin/posix_ipc.cc
index c6a003c37..89ec7dbef 100644
--- a/winsup/cygwin/posix_ipc.cc
+++ b/winsup/cygwin/posix_ipc.cc
@@ -886,7 +886,6 @@ _mq_send (mqd_t mqd, const char *ptr, size_t len, unsigned int prio,
 	ipc_cond_signal (mqinfo->mqi_waitrecv);
       attr->mq_curmsgs++;
 
-      ipc_mutex_unlock (mqinfo->mqi_lock);
       ret = 0;
     }
   __except (EBADF) {}
@@ -986,8 +985,6 @@ _mq_receive (mqd_t mqd, char *ptr, size_t maxlen, unsigned int *priop,
       if (attr->mq_curmsgs == attr->mq_maxmsg)
 	ipc_cond_signal (mqinfo->mqi_waitsend);
       attr->mq_curmsgs--;
-
-      ipc_mutex_unlock (mqinfo->mqi_lock);
     }
   __except (EBADF) {}
   __endtry