Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!rutgers!network!ucsd!ucbvax!agate!bionet!apple!sun-barr!texsun!playroom!cliffs From: cliffs@suntrek.east.sun.com (Clifford C. Skolnick) Newsgroups: comp.lang.c Subject: Re: effect of free() Message-ID:Date: 14 Aug 89 14:25:16 GMT References: <319@cubmol.BIO.COLUMBIA.EDU> <3756@buengc.BU.EDU> Sender: news@playroom.UUCP Followup-To: comp.lang.c Lines: 25 In-reply-to: bph@buengc.BU.EDU's message of 14 Aug 89 04:09:01 GMT In article <3756@buengc.BU.EDU> bph@buengc.BU.EDU (Blair P. Houghton) writes: >then if free() is called using ONE of the points, say pt1, as its >argument, is the space pointed by pt1 really freed? Yes. It can now be allocated to something else. It is _not_, however, cleared or otherwise overwritten by free(), nor are any pointers into it deallocated or overwritten. In current implimentations this is true. But what if some person makes a C library that actually returns the space to the operating system? I would change this to a no. >[questions about using the pointer] >My answer to this question SEEMS yes according to some tests I made. No intervening [mc]alloc()'s, no problem. You have only your conscience to maintain. Again, what if the memory was returned to the operating system? Cliff Skolnick -- Cliff Skolnick cliffs@sunrock.east.sun.com