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authorLennart Poettering <lennart@poettering.net>2010-04-23 18:47:49 +0200
committerLennart Poettering <lennart@poettering.net>2010-04-23 18:47:49 +0200
commiteced69b3016f32bda93030f31c0e334cc1e043f2 (patch)
tree63282a01bd0b7ec2b320f4208bce5501ac636558 /manager.c
parent6542952f8bece780ddf560499e1be9b35c690d26 (diff)
manager: fix GC algorithm
Diffstat (limited to 'manager.c')
-rw-r--r--manager.c59
1 files changed, 45 insertions, 14 deletions
diff --git a/manager.c b/manager.c
index 3ac01779d3..200bbfa006 100644
--- a/manager.c
+++ b/manager.c
@@ -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));
}
}