diff options
| -rw-r--r-- | ChangeLog | 14 | ||||
| -rw-r--r-- | gc.c | 17 | ||||
| -rw-r--r-- | gc.h | 2 | ||||
| -rw-r--r-- | match.c | 2 |
4 files changed, 35 insertions, 0 deletions
@@ -1,5 +1,19 @@ 2010-01-21 Kaz Kylheku <kkylheku@gmail.com> + Fix for unbounded memory growth problem reproduced with GCC 4.4.1 + on 32 bit x86 Fedora. This happens because the lazy list variable + ``data'' in the match_files function is optimized to a register, + but a stale value of that variable persists in the backing storage. + + * gc.h (gc_hint): New macro. + (gc_hint_func): Declared. + + * gc.c (gc_hint_func): New function. + + * match.c (match_files): Use gc_hint on the data lazy list. + +2010-01-21 Kaz Kylheku <kkylheku@gmail.com> + * match.c (match_files): Reduce scope, and bogus use of, dataline variable. @@ -486,3 +486,20 @@ void unmark(void) } } } + +/* + * This function does nothing. + * gc_hint(x) just takes the address of local variable x + * and passes it to this function. This prevents the compiler + * from caching the value across function calls. + * This is needed for situations where + * - a compiler caches a variable in a register, but not entirely (the variable + * has a backing memory location); and + * - that location contains a stale old value of the variable, which cannot be + * garbage-collected as a result; and + * - this causes a problem, like unbounded memory growth. + */ +void gc_hint_func(val *val) +{ + (void) val; +} @@ -34,3 +34,5 @@ int gc_state(int); void gc_mark(val); int gc_is_reachable(val); void unmark(void); +void gc_hint_func(val *); +#define gc_hint(var) gc_hint_func(&var) @@ -874,6 +874,8 @@ static val match_files(val spec, val files, val data = nil; cnum data_lineno = 0; + gc_hint(data); + if (listp(first_file_parsed)) { data = first_file_parsed; data_lineno = c_num(data_linenum); |