Commit 5018b663 authored by Paul Eggert's avatar Paul Eggert

Inhibit GC after inhibit_garbage_collection

Without this patch, there are unlikely ways that garbage
collection could occur (sometimes causing undefined behavior)
even when inhibit_garbage_collection is in effect.
* src/alloc.c (garbage_collection_inhibited): New var.
(pure_alloc): Increment it if pure space is exhausted, so that
garbage_collect_1 no longer needs to inspect
pure_bytes_used_before_overflow.
(allow_garbage_collection): New function.
(inhibit_garbage_collection): Increment the new variable rather
than specbinding a user variable.
(garbage_collect_1): Do not garbage collect if the new variable
is set, rather than if pure_bytes_used_before_overflow is set.
parent 26de2d42
......@@ -292,6 +292,10 @@ static ptrdiff_t pure_bytes_used_lisp;
static ptrdiff_t pure_bytes_used_non_lisp;
/* If positive, garbage collection is inhibited. Otherwise, zero. */
static intptr_t garbage_collection_inhibited;
/* If nonzero, this is a warning delivered by malloc and not yet
displayed. */
......@@ -5120,6 +5124,10 @@ pure_alloc (size_t size, int type)
pure_bytes_used_before_overflow += pure_bytes_used - size;
pure_bytes_used = 0;
pure_bytes_used_lisp = pure_bytes_used_non_lisp = 0;
/* Can't GC if pure storage overflowed because we can't determine
if something is a pure object or not. */
garbage_collection_inhibited++;
goto again;
}
......@@ -5486,12 +5494,19 @@ staticpro (Lisp_Object const *varaddress)
/* Temporarily prevent garbage collection. */
static void
allow_garbage_collection (void)
{
garbage_collection_inhibited--;
}
ptrdiff_t
inhibit_garbage_collection (void)
{
ptrdiff_t count = SPECPDL_INDEX ();
specbind (Qgc_cons_threshold, make_fixnum (MOST_POSITIVE_FIXNUM));
record_unwind_protect_void (allow_garbage_collection);
garbage_collection_inhibited++;
return count;
}
......@@ -5779,9 +5794,7 @@ garbage_collect_1 (struct gcstat *gcst)
eassert (weak_hash_tables == NULL);
/* Can't GC if pure storage overflowed because we can't determine
if something is a pure object or not. */
if (pure_bytes_used_before_overflow)
if (garbage_collection_inhibited)
return false;
/* Record this function, so it appears on the profiler's backtraces. */
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment