From: Corinna Vinschen <corinna-cygwin@cygwin.com>
To: cygwin@cygwin.com
Subject: Re: malloc segfaults
Date: Thu, 04 Sep 2003 11:03:00 -0000 [thread overview]
Message-ID: <20030904110300.GA27802@cygbert.vinschen.de> (raw)
In-Reply-To: <3F549C88.9040103@osc-es.de>
On Tue, Sep 02, 2003 at 03:35:04PM +0200, Juergen Bohn wrote:
> Tested with cygwin1.dll 1.5.3-1 and 1.3.22-1 on Win2000-SP4, malloc() does
> not (always)
> return NULL if there is no more memory available. Try, for example, simple
> loops like:
>
> x = malloc(10000);
> for (i=0; x != NULL; i++)
> {
> x = malloc(10000);
> if (x == NULL) printf("x is NULL\n");
> }
>
> My application terminates with a segmentation violation, but all attempts
I've applied a patch to cygwin which solves this problem. You should
get NULL at one point instead.
> to handle this by signal() or atexit() fail. Unfortunately, also sysconf()
> does not work to get the number of available pages (_SC_AVPHYS_PAGES, I get
> always the same but wrong value).
I've changed sysconf to return a more accurate value for _SC_AVPHYS_PAGES.
However, this is not a value you can rely on. Cygwin processes might run
out of memory even though there are still a lot of physical pages available.
This is related to the fact that small allocations (less than 1 Meg) are
taken from the applications heap which might be unraisable for some reason.
Corinna
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prev parent reply other threads:[~2003-09-04 11:03 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-09-02 13:35 Juergen Bohn
2003-09-02 20:51 ` Bill C. Riemers
2003-09-03 13:20 ` Christopher Faylor
[not found] ` <20030903094303.GB19365@linux_rln.harvest>
2003-09-03 22:03 ` Juergen Bohn
2003-09-04 11:03 ` Corinna Vinschen [this message]
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