Changeset f229fc2

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

Location:

src

Files:

• Common/GC.cc (modified) (7 diffs)
• Common/GC.h (modified) (1 diff)
• ResolvExpr/Alternative.cc (modified) (2 diffs)
• ResolvExpr/Alternative.h (modified) (2 diffs)
• ResolvExpr/Resolver.cc (modified) (4 diffs)
• ResolvExpr/TypeEnvironment.cc (modified) (2 diffs)
• ResolvExpr/TypeEnvironment.h (modified) (2 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;
 }
 

src/Common/GC.h

@@ -48 +48 @@
         void collect_young();
 
-        /// Collects all memory; use old generation afterward.
+        /// Collects old generation; use old generation afterward.
+        /// Error if currently using young generation
         void collect();
 

src/ResolvExpr/Alternative.cc

@@ -20 +20 @@
 #include <utility>                       // for move
 
+#include "Common/GC.h"
+#include "Common/PassVisitor.h"
 #include "Common/utility.h"              // for maybeClone
 #include "ResolvExpr/Cost.h"             // for Cost, Cost::zero, operator<<
 #include "ResolvExpr/TypeEnvironment.h"  // for TypeEnvironment
 #include "SynTree/Expression.h"          // for Expression
+#include "SynTree/GcTracer.h"
 #include "SynTree/Type.h"                // for Type
 
@@ -64 +67 @@
         }
 
+        const GC& operator<< ( const GC& gc, const Alternative& alt ) {
+                PassVisitor<GcTracer> tracer{ gc };
+                maybeAccept( alt.expr, tracer );
+                tracer << alt.env;
+                return gc;
+        }
+
 } // namespace ResolvExpr
 

src/ResolvExpr/Alternative.h

@@ -23 +23 @@
 
 class Expression;
+
+class GC;
 
 namespace ResolvExpr {
@@ -52 +54 @@
                 return os;
         }
+
+        const GC& operator<< ( const GC&, const Alternative& );
 } // namespace ResolvExpr
 

src/ResolvExpr/Resolver.cc

@@ -22 +22 @@
 #include "Alternative.h"                 // for Alternative, AltList
 #include "AlternativeFinder.h"           // for AlternativeFinder, resolveIn...
+#include "Common/GC.h"                   // for new_generation, collect_young
 #include "Common/PassVisitor.h"          // for PassVisitor
 #include "Common/SemanticError.h"        // for SemanticError
@@ -146 +147 @@
                 void findUnfinishedKindExpression(Expression * untyped, Alternative & alt, const SymTab::Indexer & indexer, const std::string & kindStr, std::function<bool(const Alternative &)> pred, bool adjust = false, bool prune = true, bool failFast = true) {
                         assertf( untyped, "expected a non-null expression." );
+
+                        new_generation();  // set up GC young generation for this top-level expression
+
                         TypeEnvironment env;
                         AlternativeFinder finder( indexer, env );
@@ -173 +177 @@
                         findMinCost( candidates.begin(), candidates.end(), back_inserter( winners ) );
                         if ( winners.size() == 0 ) {
-                                SemanticError( untyped, toString( "No reasonable alternatives for ", kindStr, (kindStr != "" ? " " : ""), "expression: ") );
+                                collect_young();
+                                SemanticError( untyped, toString( 
+                                        "No reasonable alternatives for ", kindStr, (kindStr != "" ? " " : ""), 
+                                        "expression: ") );
                         } else if ( winners.size() != 1 ) {
                                 std::ostringstream stream;
-                                stream << "Cannot choose between " << winners.size() << " alternatives for " << kindStr << (kindStr != "" ? " " : "") << "expression\n";
+                                stream << "Cannot choose between " << winners.size() << " alternatives for " 
+                                        << kindStr << (kindStr != "" ? " " : "") << "expression\n";
                                 untyped->print( stream );
                                 stream << " Alternatives are:\n";
                                 printAlts( winners, stream, 1 );
+                                
+                                collect_young();
                                 SemanticError( untyped->location, stream.str() );
                         }
@@ -186 +196 @@
                         Alternative & choice = winners.front();
                         if ( findDeletedExpr( choice.expr ) ) {
-                                SemanticError( choice.expr, "Unique best alternative includes deleted identifier in " );
+                                collect_young( choice.expr );
+                                SemanticError( choice.expr, 
+                                        "Unique best alternative includes deleted identifier in " );
                         }
                         alt = std::move( choice );
+                        collect_young( alt );
                 }
 

src/ResolvExpr/TypeEnvironment.cc

@@ -19 +19 @@
 #include <utility>                     // for pair
 
+#include "Common/PassVisitor.h"        // for PassVisitor<GcTracer>
 #include "Common/utility.h"            // for maybeClone
+#include "SynTree/GcTracer.h"          // for PassVisitor<GcTracer>
 #include "SynTree/Type.h"              // for Type, FunctionType, Type::Fora...
 #include "SynTree/TypeSubstitution.h"  // for TypeSubstitution
@@ -222 +224 @@
                 return out;
         }
+
+        PassVisitor<GcTracer> & operator<<( PassVisitor<GcTracer> & gc, const TypeEnvironment & env ) {
+                for ( const EqvClass & c : env ) {
+                        maybeAccept( c.type, gc );
+                }
+                return gc;
+        }
 } // namespace ResolvExpr
 

src/ResolvExpr/TypeEnvironment.h

@@ -26 +26 @@
 #include "SynTree/Type.h"              // for Type, Type::ForallList
 #include "SynTree/TypeSubstitution.h"  // for TypeSubstitution
+
+template< typename Pass >
+class PassVisitor;
+class GcTracer;
 
 namespace ResolvExpr {
@@ -116 +120 @@
 
         std::ostream & operator<<( std::ostream & out, const TypeEnvironment & env );
+
+        PassVisitor<GcTracer> & operator<<( PassVisitor<GcTracer> & gc, const TypeEnvironment & env );
 } // namespace ResolvExpr