Author: Whiteknight
Date: Fri Dec 19 17:46:49 2008
New Revision: 34123
Modified:
branches/pdd09gc_part1/include/parrot/settings.h
branches/pdd09gc_part1/src/gc/incremental_ms.c
branches/pdd09gc_part1/src/headers.c
Log:
[pdd09gc_part1] some simplifications to the incremental GC, and integrate it
into the rest of Parrot a little
Modified: branches/pdd09gc_part1/include/parrot/settings.h
==============================================================================
--- branches/pdd09gc_part1/include/parrot/settings.h (original)
+++ branches/pdd09gc_part1/include/parrot/settings.h Fri Dec 19 17:46:49 2008
@@ -49,16 +49,25 @@
# define PARROT_GC_MS 1
# define PARROT_GC_IMS 0
# define PARROT_GC_GMS 0
+# define PARROT_GC_IT 0
#endif
#if PARROT_GC_SUBSYSTEM == 1
# define PARROT_GC_MS 0
# define PARROT_GC_IMS 1
# define PARROT_GC_GMS 0
+# define PARROT_GC_IT 0
#endif
#if PARROT_GC_SUBSYSTEM == 2
# define PARROT_GC_MS 0
# define PARROT_GC_IMS 0
# define PARROT_GC_GMS 1
+# define PARROT_GC_IT 0
+#endif
+#if PARROT_GC_SUBSYSTEM == 3
+# define PARROT_GC_MS 0
+# define PARROT_GC_IMS 0
+# define PARROT_GC_GMS 0
+# define PARROT_GC_IT 1
#endif
Modified: branches/pdd09gc_part1/src/gc/incremental_ms.c
==============================================================================
--- branches/pdd09gc_part1/src/gc/incremental_ms.c (original)
+++ branches/pdd09gc_part1/src/gc/incremental_ms.c Fri Dec 19 17:46:49 2008
@@ -185,7 +185,7 @@
objects after a run has completed and all black objects have been turned
back to white (which would free all objects, alive or dead).
-Flags and other issues:
+Flags and other issues, as I understand them:
GC_trace_normal = run a trace, or a partial trace, but not a sweep.
set the macro CHECK_IF_WE_BREAK_BEFORE_SWEEP, however we do that,
to break off the function after the trace phase.
@@ -228,8 +228,7 @@
const UINTVAL gc_force = gc_lazy &&
interp->arena_base->num_early_DOD_PMCs;
/* on a lazy run, we only sweep if there are PMCs needing early
destruction.
- However, we must also sweep from the very beginning, to ensure the
timely
- objects get destroyed. */
+ We don't really cover that now, so we ignore and return. */
if (gc_lazy && !gc_force)
return;
if (gc_finish) {
@@ -350,7 +349,6 @@
*/
-# if GC_IT_SERIAL_MODE
void
gc_it_trace_normal(PARROT_INTERP)
{
@@ -369,16 +367,14 @@
for (hdr = gc_priv_data->queue; hdr; hdr = gc_priv_data->queue) {
/* for each item, add all chidren to the queue, and then mark the item
- black. Once black, the item can be removed from the queue and
- discarded */
+ black. Once black, the item can be removed from the queue */
PARROT_ASSERT(hdr);
gc_it_mark_PObj_children_grey(interp, hdr);
gc_it_set_card_mark(hdr, GC_IT_CARD_BLACK);
gc_priv_data->queue = hdr->next;
- /* Items that have been marked are not left to just float like they
- were. They are instead put into a "marked" list to keep them from
- being marked twice in the same mark phase. */
+ /* Items that have been marked are put into a "marked" list to keep
+ them from being marked twice in the same mark phase. */
hdr->next = gc_priv_data->marked;
gc_priv_data->marked = hdr->next;
@@ -414,6 +410,7 @@
const Arenas * const arena_base = interp->arena_base;
Gc_it_data * const gc_priv_data = (Gc_it_data *)arena_base->gc_private;
+ /* If the queue has stuff on it, trace that first */
if (gc_priv_data->queue)
gc_it_trace(interp);
gc_it_sweep_PMC_arenas(interp, gc_priv_data, arena_base->pmc_pool);
@@ -437,9 +434,9 @@
const Arenas * const arena_base = interp->arena_base;
Gc_it_data * const gc_priv_data = (Gc_it_data *)arena_base->gc_private;
register UINTVAL i;
+
/* PMCs need to be handled differently from other types of pools. Set
up lists of our pools here, and handle different types differently. */
-
gc_it_finalize_PMC_arenas(interp, gc_priv_data, arena_base->pmc_pool);
}
@@ -473,10 +470,11 @@
=item C<static void gc_it_finalize_arena>
-Finalizes one arena, assume the objects in it are PMCs.
+Finalizes one arena, assuming the objects in it are PMCs.
Loops through the arena and adds all objects in it to a linked list in
reverse order. Then, traverse through this linked list and finalize any
-items that are still alive.
+items that are still alive. This isn't perfect, and may create order-
+of-destruction bugs when a parent is destroyed before it's children.
=cut
@@ -568,8 +566,7 @@
while (i > 0) {
/* this is a heavily stripped-down version of what it should be.
Eventually, this is all going to get more efficient:
- 1) going to re-unroll the loop like I have in the sized header
- sweep loop.
+ 1) need to unroll the loop a little bit
2) Going to handle the cards directly, instead of making all
these function calls.
*/
@@ -642,55 +639,6 @@
}
}
}
-# endif
-
-
-/*
-
-=item C<void gc_it_trace_threaded>
-
-If the GC is running in multithreaded mode, we do whatever we need to do
-in that situation. This is not implemented. Here are some ideas of what we
-could do:
-
-1) We have a GC thread which is persistent. In that case, this function will
-do nothing, and that thread will run continuously in the background doing it's
-thing.
-2) We launch child threads every time this function is called. For each child
-thread, we enqueue a single root (probably as a thread function parameter)
-and run the thread to completion. The GC thread will trace through it's queue
-entirely, and will terminate when it's queue has become empty. When all child
-threads have terminated, and when all root queue items have been scanned, we
-move on to the sweep phase.
-3) Same as #2, but instead of blindly launching a child thread every time this
-function is called, we only launch up to a finite number of threads. If we
-have too many threads running already, we do not launch another one here.
-
-=cut
-
-*/
-
-# if GC_IT_PARALLEL_MODE
-void
-gc_it_trace_threaded(SHIM_INTERP) {}
-
-
-/*
-
-=item C<void gc_it_mark_threaded>
-
-Run one thread's worth of the trace algorithm, as discussed in the function
-documentation of C<gc_it_trace_threaded>
-
-=cut
-
-*/
-
-void
-gc_it_mark_threaded(SHIM_INTERP) {}
-
-# endif
-
/*
@@ -828,7 +776,8 @@
pobject_lives(interp, (PObj *)(pmc->real_self));
}
else if (PObj_is_string_TEST(obj)) {
- /* It's a string or a const-string, or whatever. Deal with that here.
*/
+ /* XXX: It's a string or a const-string, or whatever. Deal
+ with that here. */
}
/* if the PMC is an array of other PMCs, we cycle through those. I'm
@@ -1048,6 +997,7 @@
pool->name, pool, hdr, pool->num_free_objects);
# endif
*/
+
/* return pointer to the object from the header */
return (void *)IT_HDR_to_PObj(hdr);
}
@@ -1247,12 +1197,12 @@
gc_it_get_card_mark(ARGMOD(Gc_it_hdr *hdr))
{
# ifdef GC_IT_USE_POBJ_FLAGS
- /* Add the stuff here to check the PObj flags in the object, if it's an
- aggregate. Get the data from the hdr->data.flag, and compare values
- to make sure we have a sensical result (PARROR_ASSERT it). Return
- the value if it's good. */
-# endif
+ /* if defined, GC_IT_USE_POBJ_FLAGS says that we should use the ->flags
+ field of the PObj structure to hold the white/grey/black state of
+ the object, instead of using the ->data.flag field of the header. */
+# else
return hdr->data.flag;
+# endif
}
/*
@@ -1331,7 +1281,11 @@
=item C<void gc_it_ptr_set_aggregate>
-Sets whether the given object is a PObj or not
+Sets whether the given object is a PObj or not. "aggregates" are mostly
+PMCs which need to get marked themselves and may also contain pointers
+to other data structures which also need to be marked.
+
+This function should be called on all PMC objects when they are allocated.
=item C<UINTVAL gc_it_ptr_get_aggregate>
@@ -1371,9 +1325,9 @@
UINTVAL
gc_it_pmc_dead(ARGIN(PMC * p))
{
- return(p->pmc_ext == (PMC_EXT *)0xdeadbeef ||
- p->vtable == (void *)0xdeadbeef ||
- PMC_pmc_val(p) == (PMC *)0xdeadbeef);
+ return(p->pmc_ext == (PMC_EXT *)0xdeadbeef ||
+ p->vtable == (void *)0xdeadbeef ||
+ PMC_pmc_val(p) == (PMC *)0xdeadbeef);
}
# endif
Modified: branches/pdd09gc_part1/src/headers.c
==============================================================================
--- branches/pdd09gc_part1/src/headers.c (original)
+++ branches/pdd09gc_part1/src/headers.c Fri Dec 19 17:46:49 2008
@@ -340,6 +340,11 @@
#if ! PMC_DATA_IN_EXT
PMC_data(pmc) = NULL;
#endif
+#if PARROT_GC_IT
+ /* In the GC_IT, we need to mark all PMCs as being PMCs so the system
+ knows to do all the special mark stuff that PMCs need. */
+ gc_it_ptr_set_aggregate(pmc, 1);
+#endif
return pmc;
}
@@ -447,7 +452,12 @@
flags | PObj_is_string_FLAG | PObj_is_COWable_FLAG | PObj_live_FLAG;
string->strstart = NULL;
-
+#if PARROT_GC_IT
+ /* the GC_IT needs to know that this is just a dumb buffer, and that
+ we shouldn't try to examine it's "children", because there are none.
+ */
+ gc_it_ptr_set_aggregate(string, 0);
+#endif
return string;
}
