Changeset f229fc2 for src/Common/GC.cc

Timestamp:

Apr 13, 2018, 12:25:33 PM (6 years ago)

Author:

Aaron Moss <a3moss@…>

Branches:

new-env, with_gc

Children:

b5aa3d8

Parents:

09a1ae6

Message:

Modify resolver to use young-generation collection per-top-level expression

File:

• src/Common/GC.cc (modified) (7 diffs)

src/Common/GC.cc

@@ -23 +23 @@
 #include <cassert>
 
-// #include <csignal>
-
 GC& GC::get() {
         static GC gc;
@@ -47 +45 @@
         if( obj )
         {
-                bool isMarked = obj->mark == this->mark;
-                if( !isMarked ) {
+                if( obj->mark != this->mark ) {
                         obj->mark = this->mark;
                         obj->trace( *this );
@@ -57 +54 @@
 
 void GC::register_object(GC_Object* obj) {
-        // if ( obj == (GC_Object*)0x60f00000e410ul ) std::raise( SIGTRAP );
         (using_young ? young : old).push_back(obj);
-        obj->mark = ! this->mark;  // initialize as un-marked
+        obj->mark = !this->mark;  // initialize as un-marked
 }
 
@@ -67 +63 @@
 
 void GC::new_generation() {
-        using_young = true;
+        assert(!using_young && "Cannot start new generation when young generation already in use");
+        
+        using_young = true;  // mark young generation as in-use
+        mark = !mark;        // switch mark so aged young objects will still be unmarked in old
 }
 
@@ -78 +77 @@
 
 void GC::collect_young() {
-        // check young generation, just reset mark if not using
-        if ( ! using_young ) {
-                mark = !mark;
-                return;
-        }
-
         // collect young gen
         for ( GC_Object*& obj : young ) {
@@ -100 +93 @@
         young.clear();
 
-        // reset mark for next collection
+        // reset mark to return to old generation mark
         mark = !mark;
 }
 
 void GC::collect() {
+        // ensure not called when young gen is active
+        assert(!using_young && "Cannot do old collection when young generation is active");
+
         // collect old gen
         for ( GC_Object*& obj : old ) {
                 if ( obj->mark != mark ) {
-                        // if ( obj == (GC_Object*)0x60f00000e410ul ) std::raise( SIGTRAP );
                         delete obj;
                         obj = nullptr;
@@ -117 +112 @@
         old.erase( std::remove( old.begin(), old.end(), nullptr ), old.end() );
 
-        // collect young gen (also resets mark)
-        collect_young();
+        // reset mark
+        mark = !mark;
 }