Mercurial > hg > octave-lyh > gnulib-hg
changeset 8077:9cd2d21f40cc
* lib/xalloc.h (x2nrealloc): Fix an unlikely bug in the overflow
checking code. Set N = ceil (1.5 * N) rather than to a slightly
larger value.
Give tools a better chance to allocate space for very large buffers.
* lib/xalloc.h (x2nrealloc): Use 3/2, not 2, as buffer size factor.
author | Paul Eggert <eggert@cs.ucla.edu> |
---|---|
date | Sun, 04 Feb 2007 02:20:40 +0000 |
parents | 662352a3327e |
children | 0a080a2d054b |
files | ChangeLog lib/xalloc.h |
diffstat | 2 files changed, 16 insertions(+), 3 deletions(-) [+] |
line wrap: on
line diff
--- a/ChangeLog +++ b/ChangeLog @@ -1,5 +1,14 @@ +2007-02-03 Paul Eggert <eggert@cs.ucla.edu> + + * lib/xalloc.h (x2nrealloc): Fix an unlikely bug in the overflow + checking code. Set N = ceil (1.5 * N) rather than to a slightly + larger value. + 2007-02-03 Jim Meyering <jim@meyering.net> + Give tools a better chance to allocate space for very large buffers. + * lib/xalloc.h (x2nrealloc): Use 3/2, not 2, as buffer size factor. + Make pwd and readlink work also when run with an unreadable parent dir on systems with openat support. * lib/getcwd.c (__getcwd) [HAVE_PARTLY_WORKING_GETCWD]: Use the system
--- a/lib/xalloc.h +++ b/lib/xalloc.h @@ -141,7 +141,7 @@ In the following implementation, nonzero sizes are increased by a factor of approximately 1.5 so that repeated reallocations have - O(N log N) overall cost rather than O(N**2) cost, but the + O(N) overall cost rather than O(N**2) cost, but the specification for this function does not guarantee that rate. Here is an example of use: @@ -204,9 +204,13 @@ } else { - if ((2 * (((size_t) -1 - 1) / 3)) / s < n) + /* Set N = ceil (1.5 * N) so that progress is made if N == 1. + Check for overflow, so that N * S stays in size_t range. + The check is slightly conservative, but an exact check isn't + worth the trouble. */ + if ((size_t) -1 / 3 * 2 / s <= n) xalloc_die (); - n = n + n / 2 + 1; + n += (n + 1) / 2; } *pn = n;