Feature #10590: GC.latest_gc_info returns GC state

• Status: Closed
• Priority: Normal
• Assignee: ko1 (Koichi Sasada)
• Target version: 2.2.0

[ko1 (Koichi Sasada)]

Getting current GC state by GC.latest_gc_info is useful to know the behavior of GC.

GC.latest_gc_info(:state) #=> :none or :marking (incremental major) or :sweeping

Patch is follow. Naruse-san, can I introduce it to 2.2? It is very small feature.

Index: NEWS
===================================================================
--- NEWS    (revision 48774)
+++ NEWS    (working copy)
@@ -57,6 +57,7 @@ with all sufficient information, see the
     * File::Stat#birthtime

 * GC
+  * GC.latest_gc_info returns :state to represent current GC status.
   * Improvements
     * Introduce incremental marking for major GC. [Feature #10137]

Index: gc.c
===================================================================
--- gc.c    (revision 48774)
+++ gc.c    (working copy)
@@ -6231,23 +6231,28 @@ gc_count(VALUE self)
 }

 static VALUE
-gc_info_decode(int flags, VALUE hash_or_key)
+gc_info_decode(rb_objspace_t *objspace, const VALUE hash_or_key, const int orig_flags)
 {
-    static VALUE sym_major_by = Qnil, sym_gc_by, sym_immediate_sweep, sym_have_finalizer;
+    static VALUE sym_major_by = Qnil, sym_gc_by, sym_immediate_sweep, sym_have_finalizer, sym_state;
     static VALUE sym_nofree, sym_oldgen, sym_shady, sym_force, sym_stress;
 #if RGENGC_ESTIMATE_OLDMALLOC
     static VALUE sym_oldmalloc;
 #endif
     static VALUE sym_newobj, sym_malloc, sym_method, sym_capi;
+    static VALUE sym_none, sym_marking, sym_sweeping;
     VALUE hash = Qnil, key = Qnil;
     VALUE major_by;
+    VALUE flags = orig_flags ? orig_flags : objspace->profile.latest_gc_info;

-    if (SYMBOL_P(hash_or_key))
+    if (SYMBOL_P(hash_or_key)) {
    key = hash_or_key;
-    else if (RB_TYPE_P(hash_or_key, T_HASH))
+    }
+    else if (RB_TYPE_P(hash_or_key, T_HASH)) {
    hash = hash_or_key;
-    else
+    }
+    else {
    rb_raise(rb_eTypeError, "non-hash or symbol given");
+    }

     if (sym_major_by == Qnil) {
 #define S(s) sym_##s = ID2SYM(rb_intern_const(#s))
@@ -6255,6 +6260,8 @@ gc_info_decode(int flags, VALUE hash_or_
    S(gc_by);
    S(immediate_sweep);
    S(have_finalizer);
+   S(state);
+
    S(stress);
    S(nofree);
    S(oldgen);
@@ -6267,6 +6274,10 @@ gc_info_decode(int flags, VALUE hash_or_
    S(malloc);
    S(method);
    S(capi);
+
+   S(none);
+   S(marking);
+   S(sweeping);
 #undef S
     }

@@ -6298,6 +6309,11 @@ gc_info_decode(int flags, VALUE hash_or_

     SET(have_finalizer, (flags & GPR_FLAG_HAVE_FINALIZE) ? Qtrue : Qfalse);
     SET(immediate_sweep, (flags & GPR_FLAG_IMMEDIATE_SWEEP) ? Qtrue : Qfalse);
+
+    if (orig_flags == 0) {
+   SET(state, objspace->flags.stat == gc_stat_none ? sym_none :
+              objspace->flags.stat == gc_stat_marking ? sym_marking : sym_sweeping);
+    }
 #undef SET

     if (!NIL_P(key)) {/* matched key should return above */
@@ -6311,7 +6327,7 @@ VALUE
 rb_gc_latest_gc_info(VALUE key)
 {
     rb_objspace_t *objspace = &rb_objspace;
-    return gc_info_decode(objspace->profile.latest_gc_info, key);
+    return gc_info_decode(objspace, key, 0);
 }

 /*
@@ -6339,7 +6355,7 @@ gc_latest_gc_info(int argc, VALUE *argv,
    arg = rb_hash_new();
     }

-    return gc_info_decode(objspace->profile.latest_gc_info, arg);
+    return gc_info_decode(objspace, arg, 0);
 }

 enum gc_stat_sym {
@@ -8261,7 +8277,7 @@ gc_profile_record_get(void)
    gc_profile_record *record = &objspace->profile.records[i];

    prof = rb_hash_new();
-   rb_hash_aset(prof, ID2SYM(rb_intern("GC_FLAGS")), gc_info_decode(record->flags, rb_hash_new()));
+   rb_hash_aset(prof, ID2SYM(rb_intern("GC_FLAGS")), gc_info_decode(0, rb_hash_new(), record->flags));
         rb_hash_aset(prof, ID2SYM(rb_intern("GC_TIME")), DBL2NUM(record->gc_time));
         rb_hash_aset(prof, ID2SYM(rb_intern("GC_INVOKE_TIME")), DBL2NUM(record->gc_invoke_time));
         rb_hash_aset(prof, ID2SYM(rb_intern("HEAP_USE_SIZE")), SIZET2NUM(record->heap_use_size));

[ko1 (Koichi Sasada)]

• Status changed from Open to Closed
• % Done changed from 0 to 100

Applied in changeset r48783.

---

• gc.c (gc_latest_gc_info): return :state field to show current GC state (none/marking/sweeping). [Feature #10590]