Skip site navigation (1)Skip section navigation (2) 
Date:      Tue, 18 Jun 2013 17:48:49 +0900 (JST)
From:      Kohji Okuno <okuno.kohji@jp.panasonic.com>
To:        freebsd-current@FreeBSD.org
Cc:        okuno.kohji@jp.panasonic.com
Subject:   Are pthread_setcancelstate() and pthread_setcanceltype() cancellation points?
Message-ID:  <20130618.174849.1772987860003116966.okuno.kohji@jp.panasonic.com>
next in thread | raw e-mail | index | archive | help 
Hi,

I have a question.

Are pthread_setcancelstate() and pthread_setcanceltype() cancellation
points?

I refered to the following URL.

http://pubs.opengroup.org/onlinepubs/7908799/xsh/threads.html

This document shows that cancellation points in the pthread library
are only pthread_cond_timedwait(), pthread_cond_wait(), pthread_join()
and pthread_testcancel().

But, current implementation in FreeBSD is the following.
(Please take notice of "(*)" marks).

Would you check this?


lib/libthr/thread/thr_cancel.c:
77	int
78	_pthread_setcancelstate(int state, int *oldstate)
79	{
80	        struct pthread *curthread = _get_curthread();
81	        int oldval;
82	
83	        oldval = curthread->cancel_enable;
84	        switch (state) {
85	        case PTHREAD_CANCEL_DISABLE:
86	                curthread->cancel_enable = 0;
87	                break;
88	        case PTHREAD_CANCEL_ENABLE:
89	                curthread->cancel_enable = 1;
90 (*)	                testcancel(curthread);
91	                break;
92	        default:
93	                return (EINVAL);
94	        }
95	
96	        if (oldstate) {
97	                *oldstate = oldval ? PTHREAD_CANCEL_ENABLE :
98	                        PTHREAD_CANCEL_DISABLE;
99	        }
100	        return (0);
101	}
102	
103	int
104	_pthread_setcanceltype(int type, int *oldtype)
105	{
106	        struct pthread  *curthread = _get_curthread();
107	        int oldval;
108	
109	        oldval = curthread->cancel_async;
110	        switch (type) {
111	        case PTHREAD_CANCEL_ASYNCHRONOUS:
112	                curthread->cancel_async = 1;
113 (*)	                testcancel(curthread);
114	                break;
115	        case PTHREAD_CANCEL_DEFERRED:
116	                curthread->cancel_async = 0;
117	                break;
118	        default:
119	                return (EINVAL);
120	        }
121	
122	        if (oldtype) {
123	                *oldtype = oldval ? PTHREAD_CANCEL_ASYNCHRONOUS :
124	                        PTHREAD_CANCEL_DEFERRED;
125	        }
126	        return (0);
127	}


Regards,
 Kohji Okuno

Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20130618.174849.1772987860003116966.okuno.kohji>