[newlib-cygwin] Don't test pthread objects for being already initialized at init time

Corinna Vinschen corinna@sourceware.org
Wed Apr 20 10:31:00 GMT 2016


commit 9409c5335bfac54ccd89fbe931e670b797462e05
Author: Corinna Vinschen <corinna@vinschen.de>
Date:   Wed Apr 20 12:31:45 2016 +0200

    Don't test pthread objects for being already initialized at init time
    For all pthread init functions, POSIX says
      Results are undefined if pthread_FOO_init() is called specifying an
      already initialized pthread_FOO object.
    So far our pthread init functions tested the incoming object if it's
    already an initialized object and, if so, returned EBUSY.  That's ok
    *iff* the object was already initialized.  However, as the example in
    https://cygwin.com/ml/cygwin/2016-04/msg00473.html shows, an uninitialized
    pthread object could also accidentally look like an initialized object
    and then returning EBUSY is not ok.
    Consequentially, all those tests are dangerous.  Per POSIX, an application
    has to know what its doing when calling any of the pthread init functions
    anyway, and re-initializing the object is just as well as undefined
    behaviour as is returning EBUSY on already initialized objects.
    	* thread.cc (pthread_attr_init): Drop check for already initialized
    	(pthread_condattr_init): Ditto.
    	(pthread_rwlockattr_init): Ditto.
    	(pthread_mutexattr_init): Ditto.
    Signed-off-by: Corinna Vinschen <corinna@vinschen.de>

 winsup/cygwin/thread.cc | 12 ------------
 1 file changed, 12 deletions(-)

diff --git a/winsup/cygwin/thread.cc b/winsup/cygwin/thread.cc
index 05757ac..ec59f1f 100644
--- a/winsup/cygwin/thread.cc
+++ b/winsup/cygwin/thread.cc
@@ -2175,9 +2175,6 @@ pthread::atfork (void (*prepare)(void), void (*parent)(void), void (*child)(void
 extern "C" int
 pthread_attr_init (pthread_attr_t *attr)
-  if (pthread_attr::is_good_object (attr))
-    return EBUSY;
   *attr = new pthread_attr;
   if (!pthread_attr::is_good_object (attr))
@@ -2854,9 +2851,6 @@ pthread_cond_wait (pthread_cond_t *cond, pthread_mutex_t *mutex)
 extern "C" int
 pthread_condattr_init (pthread_condattr_t *condattr)
-  if (pthread_condattr::is_good_object (condattr))
-    return EBUSY;
   *condattr = new pthread_condattr;
   if (!pthread_condattr::is_good_object (condattr))
@@ -3040,9 +3034,6 @@ pthread_rwlock_unlock (pthread_rwlock_t *rwlock)
 extern "C" int
 pthread_rwlockattr_init (pthread_rwlockattr_t *rwlockattr)
-  if (pthread_rwlockattr::is_good_object (rwlockattr))
-    return EBUSY;
   *rwlockattr = new pthread_rwlockattr;
   if (!pthread_rwlockattr::is_good_object (rwlockattr))
@@ -3370,9 +3361,6 @@ pthread_mutexattr_gettype (const pthread_mutexattr_t *attr, int *type)
 extern "C" int
 pthread_mutexattr_init (pthread_mutexattr_t *attr)
-  if (pthread_mutexattr::is_good_object (attr))
-    return EBUSY;
   *attr = new pthread_mutexattr ();
   if (!pthread_mutexattr::is_good_object (attr))

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