From bd7e6b33f8b7bfc927aca45f0f4f4c798ef5d34e Mon Sep 17 00:00:00 2001
From: Joe Groff <arcata@gmail.com>
Date: Tue, 13 Dec 2011 12:28:09 -0800
Subject: [PATCH] vm: erase code blocks from all_blocks during sweep Fixes #437

---
 vm/code_heap.cpp           | 30 ++++++++++++++++++++++++++++++
 vm/code_heap.hpp           |  2 ++
 vm/free_list_allocator.hpp | 18 +++++++++++++++++-
 vm/full_collector.cpp      |  2 +-
 4 files changed, 50 insertions(+), 2 deletions(-)

diff --git a/vm/code_heap.cpp b/vm/code_heap.cpp
index e15b9488b5..5f6967535a 100755
--- a/vm/code_heap.cpp
+++ b/vm/code_heap.cpp
@@ -72,6 +72,31 @@ void code_heap::flush_icache()
 	factor::flush_icache(seg->start,seg->size);
 }
 
+struct clear_free_blocks_from_all_blocks_iterator
+{
+	code_heap *code;
+
+	clear_free_blocks_from_all_blocks_iterator(code_heap *code) : code(code) {}
+
+	void operator()(code_block *free_block, cell size) {
+		std::set<code_block*>::iterator erase_from =
+			code->all_blocks.lower_bound(free_block);
+		std::set<code_block*>::iterator erase_to =
+			code->all_blocks.lower_bound((code_block*)((char*)free_block + size));
+
+		code->all_blocks.erase(erase_from, erase_to);
+	}
+};
+
+void code_heap::sweep()
+{
+	clear_free_blocks_from_all_blocks_iterator clearer(this);
+	allocator->sweep(clearer);
+#ifdef FACTOR_DEBUG
+	verify_all_blocks_set();
+#endif
+}
+
 struct all_blocks_set_verifier {
 	std::set<code_block*> *leftovers;
 
@@ -104,6 +129,11 @@ code_block *code_heap::code_block_for_address(cell address)
 		&& address - (cell)found_block->entry_point() < found_block->size()))
 	{
 		std::cerr << "invalid block found in all_blocks set!" << std::endl;
+		std::cerr << "address " << (void*)address
+			<< " block " << (void*)found_block
+			<< " entry point " << (void*)found_block->entry_point()
+			<< " size " << found_block->size()
+			<< " free? " << found_block->free_p();
 		verify_all_blocks_set();
 		FACTOR_ASSERT(false);
 	}
diff --git a/vm/code_heap.hpp b/vm/code_heap.hpp
index 8db96016dd..83b3ae586d 100755
--- a/vm/code_heap.hpp
+++ b/vm/code_heap.hpp
@@ -48,6 +48,8 @@ struct code_heap {
 	void verify_all_blocks_set();
 	void initialize_all_blocks_set();
 
+	void sweep();
+
 	code_block *code_block_for_address(cell address);
 
 	bool safepoint_p(cell addr)
diff --git a/vm/free_list_allocator.hpp b/vm/free_list_allocator.hpp
index ea7b5b1a5d..7106f7cf13 100644
--- a/vm/free_list_allocator.hpp
+++ b/vm/free_list_allocator.hpp
@@ -23,6 +23,7 @@ template<typename Block> struct free_list_allocator {
 	cell largest_free_block();
 	cell free_block_count();
 	void sweep();
+	template<typename Iterator> void sweep(Iterator &iter);
 	template<typename Iterator, typename Fixup> void compact(Iterator &iter, Fixup fixup, const Block **finger);
 	template<typename Iterator, typename Fixup> void iterate(Iterator &iter, Fixup fixup);
 	template<typename Iterator> void iterate(Iterator &iter);
@@ -124,7 +125,8 @@ template<typename Block> cell free_list_allocator<Block>::free_block_count()
 }
 
 template<typename Block>
-void free_list_allocator<Block>::sweep()
+template<typename Iterator>
+void free_list_allocator<Block>::sweep(Iterator &iter)
 {
 	free_blocks.clear_free_list();
 
@@ -145,12 +147,26 @@ void free_list_allocator<Block>::sweep()
 			free_heap_block *free_block = (free_heap_block *)start;
 			free_block->make_free(size);
 			free_blocks.add_to_free_list(free_block);
+			iter(start, size);
 
 			start = (Block *)((char *)start + size);
 		}
 	}
 }
 
+template<typename Block>
+struct null_sweep_iterator
+{
+	void operator()(Block *free_block, cell size) {}
+};
+
+template<typename Block>
+void free_list_allocator<Block>::sweep()
+{
+	null_sweep_iterator<Block> none;
+	sweep(none);
+}
+
 template<typename Block, typename Iterator> struct heap_compactor {
 	mark_bits<Block> *state;
 	char *address;
diff --git a/vm/full_collector.cpp b/vm/full_collector.cpp
index f53760ceca..fad855301e 100644
--- a/vm/full_collector.cpp
+++ b/vm/full_collector.cpp
@@ -101,7 +101,7 @@ void factor_vm::collect_sweep_impl()
 	update_code_roots_for_sweep();
 
 	if(event) event->started_code_sweep();
-	code->allocator->sweep();
+	code->sweep();
 	if(event) event->ended_code_sweep();
 }