wingo pushed a commit to branch wip-whippet
in repository guile.
commit c614c2e40b6f8531ce096b6c3a42f814ca32dc13
Author: Andy Wingo <wi...@igalia.com>
AuthorDate: Wed Oct 26 11:59:56 2022 +0200
Refactor embedder interface for conservative GC
Now users don't have to #ifdef on conservative vs precise tracing; it's
just a generic embedder concern.
---
bdw.c | 2 -
conservative-roots-api.h | 12 ------
conservative-roots-embedder.h | 54 ------------------------
conservative-roots-types.h | 8 ----
gc-embedder-api.h | 9 +---
gc-trace.h | 44 +++++++++++++++++++
mt-gcbench.c | 8 +---
precise-roots-embedder.h | 61 ---------------------------
quads.c | 7 +--
semi.c | 4 --
simple-gc-embedder.h | 58 +++++++++++++++++++------
precise-roots-api.h => simple-roots-api.h | 18 +++++---
precise-roots-types.h => simple-roots-types.h | 6 +--
whippet.c | 16 +------
14 files changed, 109 insertions(+), 198 deletions(-)
diff --git a/bdw.c b/bdw.c
index caf53b69f..c8fdc5a80 100644
--- a/bdw.c
+++ b/bdw.c
@@ -20,8 +20,6 @@
#error bdw-gc is a conservative collector
#endif
-#include "conservative-roots-embedder.h"
-
// When pthreads are used, let `libgc' know about it and redirect
// allocation calls such as `GC_MALLOC ()' to (contention-free, faster)
// thread-local allocation.
diff --git a/conservative-roots-api.h b/conservative-roots-api.h
deleted file mode 100644
index 1619cf640..000000000
--- a/conservative-roots-api.h
+++ /dev/null
@@ -1,12 +0,0 @@
-#ifndef CONSERVATIVE_ROOTS_API_H
-#define CONSERVATIVE_ROOTS_API_H
-
-#include "conservative-roots-types.h"
-
-#define HANDLE_TO(T) union { T* v; struct handle handle; }
-#define HANDLE_REF(h) h.v
-#define HANDLE_SET(h,val) do { h.v = val; } while (0)
-#define PUSH_HANDLE(cx, h) do { (void) &h; } while (0)
-#define POP_HANDLE(cx) do { } while (0)
-
-#endif // CONSERVATIVE_ROOTS_API_H
diff --git a/conservative-roots-embedder.h b/conservative-roots-embedder.h
deleted file mode 100644
index 4d2c4fa7b..000000000
--- a/conservative-roots-embedder.h
+++ /dev/null
@@ -1,54 +0,0 @@
-#ifndef CONSERVATIVE_ROOTS_EMBEDDER_H
-#define CONSERVATIVE_ROOTS_EMBEDDER_H
-
-#include "gc-config.h"
-#include "gc-embedder-api.h"
-
-static inline int gc_has_mutator_conservative_roots(void) {
- return 1;
-}
-static inline int gc_mutator_conservative_roots_may_be_interior(void) {
- return 1;
-}
-static inline int gc_has_global_conservative_roots(void) {
- return 1;
-}
-static inline int gc_has_conservative_intraheap_edges(void) {
- return GC_CONSERVATIVE_TRACE;
-}
-
-static inline int
-gc_is_valid_conservative_ref_displacement(uintptr_t displacement) {
- // Here is where you would allow tagged heap object references.
- return displacement == 0;
-}
-static inline int
-gc_conservative_ref_might_be_a_heap_object(struct gc_conservative_ref ref,
- int possibly_interior) {
- // Assume that the minimum page size is 4096, and that the first page
- // will contain no heap objects.
- if (gc_conservative_ref_value(ref) < 4096)
- return 0;
- if (possibly_interior)
- return 1;
- return gc_is_valid_conservative_ref_displacement
- (gc_conservative_ref_value(ref) & (sizeof(uintptr_t) - 1));
-}
-
-static inline void gc_trace_mutator_roots(struct gc_mutator_roots *roots,
- void (*trace_edge)(struct gc_edge
edge,
- struct gc_heap
*heap,
- void *trace_data),
- struct gc_heap *heap,
- void *trace_data) {
-}
-
-static inline void gc_trace_heap_roots(struct gc_heap_roots *roots,
- void (*trace_edge)(struct gc_edge edge,
- struct gc_heap *heap,
- void *trace_data),
- struct gc_heap *heap,
- void *trace_data) {
-}
-
-#endif // CONSERVATIVE_ROOTS_EMBEDDER_H
diff --git a/conservative-roots-types.h b/conservative-roots-types.h
deleted file mode 100644
index 4744d746e..000000000
--- a/conservative-roots-types.h
+++ /dev/null
@@ -1,8 +0,0 @@
-#ifndef CONSERVATIVE_ROOTS_TYPES_H
-#define CONSERVATIVE_ROOTS_TYPES_H
-
-struct handle { void *unused; };
-struct gc_heap_roots { void *unused; };
-struct gc_mutator_roots { void *unused; };
-
-#endif // CONSERVATIVE_ROOTS_TYPES_H
diff --git a/gc-embedder-api.h b/gc-embedder-api.h
index 3b3682a71..e0a6b3b5a 100644
--- a/gc-embedder-api.h
+++ b/gc-embedder-api.h
@@ -1,7 +1,7 @@
#ifndef GC_EMBEDDER_API_H
#define GC_EMBEDDER_API_H
-#include "gc-conservative-ref.h"
+#include "gc-config.h"
#include "gc-edge.h"
#include "gc-forwarding.h"
@@ -14,14 +14,7 @@ struct gc_heap_roots;
struct gc_atomic_forward;
struct gc_heap;
-GC_EMBEDDER_API inline int gc_has_mutator_conservative_roots(void);
-GC_EMBEDDER_API inline int gc_has_global_conservative_roots(void);
-GC_EMBEDDER_API inline int gc_has_conservative_intraheap_edges(void);
-GC_EMBEDDER_API inline int gc_mutator_conservative_roots_may_be_interior(void);
-
GC_EMBEDDER_API inline int gc_is_valid_conservative_ref_displacement(uintptr_t
displacement);
-GC_EMBEDDER_API inline int gc_conservative_ref_might_be_a_heap_object(struct
gc_conservative_ref,
- int
possibly_interior);
GC_EMBEDDER_API inline void gc_trace_object(struct gc_ref ref,
void (*visit)(struct gc_edge edge,
diff --git a/gc-trace.h b/gc-trace.h
new file mode 100644
index 000000000..b9e4691e8
--- /dev/null
+++ b/gc-trace.h
@@ -0,0 +1,44 @@
+#ifndef GC_TRACE_H
+#define GC_TRACE_H
+
+#ifndef GC_IMPL
+#error internal header file, not part of API
+#endif
+
+#include "gc-config.h"
+#include "gc-assert.h"
+#include "gc-conservative-ref.h"
+#include "gc-embedder-api.h"
+
+static inline int gc_has_mutator_conservative_roots(void) {
+ return GC_CONSERVATIVE_ROOTS;
+}
+static inline int gc_mutator_conservative_roots_may_be_interior(void) {
+ return 1;
+}
+static inline int gc_has_global_conservative_roots(void) {
+ return GC_CONSERVATIVE_ROOTS;
+}
+static inline int gc_has_conservative_intraheap_edges(void) {
+ return GC_CONSERVATIVE_TRACE;
+}
+
+static inline int gc_has_conservative_roots(void) {
+ return gc_has_mutator_conservative_roots() ||
+ gc_has_global_conservative_roots();
+}
+
+static inline int
+gc_conservative_ref_might_be_a_heap_object(struct gc_conservative_ref ref,
+ int possibly_interior) {
+ // Assume that the minimum page size is 4096, and that the first page
+ // will contain no heap objects.
+ if (gc_conservative_ref_value(ref) < 4096)
+ return 0;
+ if (possibly_interior)
+ return 1;
+ return gc_is_valid_conservative_ref_displacement
+ (gc_conservative_ref_value(ref) & (sizeof(uintptr_t) - 1));
+}
+
+#endif // GC_TRACE_H
diff --git a/mt-gcbench.c b/mt-gcbench.c
index 744a7e66b..ac0eb1ff9 100644
--- a/mt-gcbench.c
+++ b/mt-gcbench.c
@@ -47,13 +47,7 @@
#include "assert.h"
#include "gc-api.h"
#include "mt-gcbench-types.h"
-#if GC_PRECISE_ROOTS
-#include "precise-roots-api.h"
-#endif
-#if GC_CONSERVATIVE_ROOTS
-#include "conservative-roots-api.h"
-#endif
-#include "mt-gcbench-types.h"
+#include "simple-roots-api.h"
#include "simple-allocator.h"
#define MAX_THREAD_COUNT 256
diff --git a/precise-roots-embedder.h b/precise-roots-embedder.h
deleted file mode 100644
index 94192cb51..000000000
--- a/precise-roots-embedder.h
+++ /dev/null
@@ -1,61 +0,0 @@
-#ifndef PRECISE_ROOTS_EMBEDDER_H
-#define PRECISE_ROOTS_EMBEDDER_H
-
-#include "gc-edge.h"
-#include "gc-embedder-api.h"
-#include "precise-roots-types.h"
-
-static inline int gc_has_mutator_conservative_roots(void) {
- return 0;
-}
-static inline int gc_mutator_conservative_roots_may_be_interior(void) {
- return 0;
-}
-static inline int gc_has_global_conservative_roots(void) {
- return 0;
-}
-static inline int gc_has_conservative_intraheap_edges(void) {
- return 0;
-}
-
-static inline int
-gc_is_valid_conservative_ref_displacement(uintptr_t displacement) {
- GC_CRASH();
-}
-static inline int
-gc_conservative_ref_might_be_a_heap_object(struct gc_conservative_ref ref,
- int possibly_interior) {
- GC_CRASH();
-}
-
-static inline void visit_roots(struct handle *roots,
- void (*trace_edge)(struct gc_edge edge,
- struct gc_heap *heap,
- void *trace_data),
- struct gc_heap *heap,
- void *trace_data) {
- for (struct handle *h = roots; h; h = h->next)
- trace_edge(gc_edge(&h->v), heap, trace_data);
-}
-
-static inline void gc_trace_mutator_roots(struct gc_mutator_roots *roots,
- void (*trace_edge)(struct gc_edge
edge,
- struct gc_heap
*heap,
- void *trace_data),
- struct gc_heap *heap,
- void *trace_data) {
- if (roots)
- visit_roots(roots->roots, trace_edge, heap, trace_data);
-}
-
-static inline void gc_trace_heap_roots(struct gc_heap_roots *roots,
- void (*trace_edge)(struct gc_edge edge,
- struct gc_heap *heap,
- void *trace_data),
- struct gc_heap *heap,
- void *trace_data) {
- if (roots)
- visit_roots(roots->roots, trace_edge, heap, trace_data);
-}
-
-#endif // PRECISE_ROOTS_EMBEDDER_H
diff --git a/quads.c b/quads.c
index b7d1bccc3..27923f1f7 100644
--- a/quads.c
+++ b/quads.c
@@ -5,12 +5,7 @@
#include "assert.h"
#include "gc-api.h"
-#if GC_PRECISE_ROOTS
-#include "precise-roots-api.h"
-#endif
-#if GC_CONSERVATIVE_ROOTS
-#include "conservative-roots-api.h"
-#endif
+#include "simple-roots-api.h"
#include "quads-types.h"
#include "simple-allocator.h"
diff --git a/semi.c b/semi.c
index 2a3b19f23..4c505b60e 100644
--- a/semi.c
+++ b/semi.c
@@ -11,10 +11,6 @@
#include "semi-attrs.h"
#include "large-object-space.h"
-#if GC_PRECISE_ROOTS
-#include "precise-roots-embedder.h"
-#endif
-
#if GC_CONSERVATIVE_ROOTS
#error semi is a precise collector
#endif
diff --git a/simple-gc-embedder.h b/simple-gc-embedder.h
index b97d1d7f0..758e56462 100644
--- a/simple-gc-embedder.h
+++ b/simple-gc-embedder.h
@@ -1,8 +1,21 @@
#include <stdatomic.h>
#include "simple-tagging-scheme.h"
+#include "simple-roots-types.h"
+#include "gc-config.h"
#include "gc-embedder-api.h"
+static inline int
+gc_is_valid_conservative_ref_displacement(uintptr_t displacement) {
+#if GC_CONSERVATIVE_ROOTS || GC_CONSERVATIVE_TRACE
+ // Here is where you would allow tagged heap object references.
+ return displacement == 0;
+#else
+ // Shouldn't get here.
+ GC_CRASH();
+#endif
+}
+
static inline void gc_trace_object(struct gc_ref ref,
void (*trace_edge)(struct gc_edge edge,
struct gc_heap *heap,
@@ -10,6 +23,10 @@ static inline void gc_trace_object(struct gc_ref ref,
struct gc_heap *heap,
void *trace_data,
size_t *size) {
+#if GC_CONSERVATIVE_TRACE
+ // Shouldn't get here.
+ GC_CRASH();
+#else
switch (tag_live_alloc_kind(*tag_word(ref))) {
#define SCAN_OBJECT(name, Name, NAME) \
case ALLOC_KIND_##NAME: \
@@ -24,15 +41,38 @@ static inline void gc_trace_object(struct gc_ref ref,
default:
GC_CRASH();
}
+#endif
}
-#if GC_PRECISE_ROOTS
-#include "precise-roots-embedder.h"
-#endif
+static inline void visit_roots(struct handle *roots,
+ void (*trace_edge)(struct gc_edge edge,
+ struct gc_heap *heap,
+ void *trace_data),
+ struct gc_heap *heap,
+ void *trace_data) {
+ for (struct handle *h = roots; h; h = h->next)
+ trace_edge(gc_edge(&h->v), heap, trace_data);
+}
-#if GC_CONSERVATIVE_ROOTS
-#include "conservative-roots-embedder.h"
-#endif
+static inline void gc_trace_mutator_roots(struct gc_mutator_roots *roots,
+ void (*trace_edge)(struct gc_edge
edge,
+ struct gc_heap
*heap,
+ void *trace_data),
+ struct gc_heap *heap,
+ void *trace_data) {
+ if (roots)
+ visit_roots(roots->roots, trace_edge, heap, trace_data);
+}
+
+static inline void gc_trace_heap_roots(struct gc_heap_roots *roots,
+ void (*trace_edge)(struct gc_edge edge,
+ struct gc_heap *heap,
+ void *trace_data),
+ struct gc_heap *heap,
+ void *trace_data) {
+ if (roots)
+ visit_roots(roots->roots, trace_edge, heap, trace_data);
+}
static inline uintptr_t gc_object_forwarded_nonatomic(struct gc_ref ref) {
uintptr_t tag = *tag_word(ref);
@@ -108,9 +148,3 @@ gc_atomic_forward_address(struct gc_atomic_forward *fwd) {
GC_ASSERT(fwd->state == GC_FORWARDING_STATE_FORWARDED);
return fwd->data;
}
-
-static inline uintptr_t
-gc_conservative_ref_heap_address(struct gc_conservative_ref ref) {
- // The specific spaces are responsible for checking alignment.
- return gc_conservative_ref_value(ref);
-}
diff --git a/precise-roots-api.h b/simple-roots-api.h
similarity index 60%
rename from precise-roots-api.h
rename to simple-roots-api.h
index ced560d15..1cdfc15e0 100644
--- a/precise-roots-api.h
+++ b/simple-roots-api.h
@@ -1,7 +1,8 @@
-#ifndef PRECISE_ROOTS_API_H
-#define PRECISE_ROOTS_API_H
+#ifndef SIMPLE_ROOTS_API_H
+#define SIMPLE_ROOTS_API_H
-#include "precise-roots-types.h"
+#include "gc-config.h"
+#include "simple-roots-types.h"
#define HANDLE_TO(T) union { T* v; struct handle handle; }
#define HANDLE_REF(h) h.v
@@ -10,12 +11,15 @@
#define POP_HANDLE(cx) pop_handle(&(cx)->roots.roots)
static inline void push_handle(struct handle **roots, struct handle *handle) {
- handle->next = *roots;
- *roots = handle;
+ if (GC_PRECISE_ROOTS) {
+ handle->next = *roots;
+ *roots = handle;
+ }
}
static inline void pop_handle(struct handle **roots) {
- *roots = (*roots)->next;
+ if (GC_PRECISE_ROOTS)
+ *roots = (*roots)->next;
}
-#endif // PRECISE_ROOTS_API_H
+#endif // SIMPLE_ROOTS_API_H
diff --git a/precise-roots-types.h b/simple-roots-types.h
similarity index 63%
rename from precise-roots-types.h
rename to simple-roots-types.h
index d2dc96491..6d47fa788 100644
--- a/precise-roots-types.h
+++ b/simple-roots-types.h
@@ -1,5 +1,5 @@
-#ifndef PRECISE_ROOTS_TYPES_H
-#define PRECISE_ROOTS_TYPES_H
+#ifndef SIMPLE_ROOTS_TYPES_H
+#define SIMPLE_ROOTS_TYPES_H
struct handle {
void *v;
@@ -14,4 +14,4 @@ struct gc_mutator_roots {
struct handle *roots;
};
-#endif // PRECISE_ROOTS_TYPES_H
+#endif // SIMPLE_ROOTS_TYPES_H
diff --git a/whippet.c b/whippet.c
index 7ae78671b..90f2b470c 100644
--- a/whippet.c
+++ b/whippet.c
@@ -17,6 +17,7 @@
#include "gc-inline.h"
#include "gc-platform.h"
#include "gc-stack.h"
+#include "gc-trace.h"
#include "large-object-space.h"
#if GC_PARALLEL
#include "parallel-tracer.h"
@@ -26,14 +27,6 @@
#include "spin.h"
#include "whippet-attrs.h"
-#if GC_PRECISE_ROOTS
-#include "precise-roots-embedder.h"
-#endif
-
-#if GC_CONSERVATIVE_ROOTS
-#include "conservative-roots-embedder.h"
-#endif
-
#define GRANULE_SIZE 16
#define GRANULE_SIZE_LOG_2 4
#define MEDIUM_OBJECT_THRESHOLD 256
@@ -1455,11 +1448,6 @@ static double clamp_major_gc_yield_threshold(struct
gc_heap *heap,
return threshold;
}
-static inline int has_conservative_roots(void) {
- return gc_has_mutator_conservative_roots() ||
- gc_has_global_conservative_roots();
-}
-
static enum gc_kind determine_collection_kind(struct gc_heap *heap) {
struct mark_space *mark_space = heap_mark_space(heap);
enum gc_kind previous_gc_kind = atomic_load(&heap->gc_kind);
@@ -1489,7 +1477,7 @@ static enum gc_kind determine_collection_kind(struct
gc_heap *heap) {
// blocks, try to avoid any pinning caused by the ragged-stop
// marking. Of course if the mutator has conservative roots we will
// have pinning anyway and might as well allow ragged stops.
- mark_while_stopping = has_conservative_roots();
+ mark_while_stopping = gc_has_conservative_roots();
} else if (previous_gc_kind == GC_KIND_MAJOR_EVACUATING
&& fragmentation >= heap->fragmentation_low_threshold) {
DEBUG("continuing evacuation due to fragmentation %.2f%% > %.2f%%\n",
