shaba/systemd-stable
1
1
Fork 0
mirror of https://github.com/systemd/systemd-stable.git synced 2025-01-11 05:17:44 +03:00
Code

manager: fix GC algorithm

Browse Source
This commit is contained in:
Lennart Poettering 2010-04-23 18:47:49 +02:00
parent 6542952f8b
commit eced69b301
2 changed files with 46 additions and 15 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

59
manager.c
View File

@ -395,14 +395,24 @@ static unsigned manager_dispatch_cleanup_queue(Manager *m) {
return n;
}
static void unit_gc_sweep(Unit *u, int gc_marker) {
enum {
GC_OFFSET_IN_PATH, /* This one is on the path we were travelling */
GC_OFFSET_UNSURE, /* No clue */
GC_OFFSET_GOOD, /* We still need this unit */
GC_OFFSET_BAD, /* We don't need this unit anymore */
_GC_OFFSET_MAX
};
static void unit_gc_sweep(Unit *u, unsigned gc_marker) {
Iterator i;
Unit *other;
bool is_bad;
assert(u);
if (u->meta.gc_marker == gc_marker ||
u->meta.gc_marker == -gc_marker)
if (u->meta.gc_marker == gc_marker + GC_OFFSET_GOOD ||
u->meta.gc_marker == gc_marker + GC_OFFSET_BAD ||
u->meta.gc_marker == gc_marker + GC_OFFSET_IN_PATH)
return;
if (u->meta.in_cleanup_queue)
@ -411,26 +421,44 @@ static void unit_gc_sweep(Unit *u, int gc_marker) {
if (unit_check_gc(u))
goto good;
u->meta.gc_marker = gc_marker + GC_OFFSET_IN_PATH;
is_bad = true;
SET_FOREACH(other, u->meta.dependencies[UNIT_REFERENCED_BY], i) {
unit_gc_sweep(other, gc_marker);
if (other->meta.gc_marker == gc_marker)
if (other->meta.gc_marker == gc_marker + GC_OFFSET_GOOD)
goto good;
if (other->meta.gc_marker != gc_marker + GC_OFFSET_BAD)
is_bad = false;
}
if (is_bad)
goto bad;
/* We were unable to find anything out about this entry, so
* let's investigate it later */
u->meta.gc_marker = gc_marker + GC_OFFSET_UNSURE;
unit_add_to_gc_queue(u);
return;
bad:
/* So there is no reason to keep this unit around, hence let's get rid of it */
u->meta.gc_marker = -gc_marker;
/* We definitely know that this one is not useful anymore, so
* let's mark it for deletion */
u->meta.gc_marker = gc_marker + GC_OFFSET_BAD;
unit_add_to_cleanup_queue(u);
return;
good:
u->meta.gc_marker = gc_marker;
u->meta.gc_marker = gc_marker + GC_OFFSET_GOOD;
}
static unsigned manager_dispatch_gc_queue(Manager *m) {
Meta *meta;
unsigned n = 0;
int gc_marker;
unsigned gc_marker;
assert(m);
@ -441,23 +469,26 @@ static unsigned manager_dispatch_gc_queue(Manager *m) {
log_debug("Running GC...");
gc_marker = ++m->gc_marker;
if (m->gc_marker < 0)
m->gc_marker += _GC_OFFSET_MAX;
if (m->gc_marker + _GC_OFFSET_MAX <= _GC_OFFSET_MAX)
m->gc_marker = 1;
gc_marker = m->gc_marker;
while ((meta = m->gc_queue)) {
assert(meta->in_gc_queue);
unit_gc_sweep(UNIT(meta), gc_marker);
LIST_REMOVE(Meta, gc_queue, m->gc_queue, meta);
meta->in_gc_queue = false;
n++;
unit_gc_sweep(UNIT(meta), gc_marker);
if (meta->gc_marker == -gc_marker) {
if (meta->gc_marker == gc_marker + GC_OFFSET_BAD ||
meta->gc_marker == gc_marker + GC_OFFSET_UNSURE) {
log_debug("Collecting %s", meta->id);
meta->gc_marker = gc_marker + GC_OFFSET_BAD;
unit_add_to_cleanup_queue(UNIT(meta));
}
}

2
unit.h
View File

@ -170,7 +170,7 @@ struct Meta {
LIST_FIELDS(Meta, gc_queue);
/* Used during GC sweeps */
int gc_marker;
unsigned gc_marker;
/* If we go down, pull down everything that depends on us, too */
bool recursive_stop;