From b08f68cf52e38c3bd60308857b7b3f4abbcf69ae Mon Sep 17 00:00:00 2001
From: Justin Ethier <justin.ethier@gmail.com>
Date: Sat, 17 Oct 2015 02:25:22 -0400
Subject: [PATCH] Perform major GC if necessary

---
 gc.c                    |  3 ++-
 include/cyclone/types.h |  2 +-
 runtime.c               | 16 +++++++++++-----
 3 files changed, 14 insertions(+), 7 deletions(-)

diff --git a/gc.c b/gc.c
index 630381ca..f0021df9 100644
--- a/gc.c
+++ b/gc.c
@@ -71,7 +71,7 @@ void *gc_try_alloc(gc_heap *h, size_t size)
   return NULL; 
 }
 
-void *gc_alloc(gc_heap *h, size_t size) 
+void *gc_alloc(gc_heap *h, size_t size, int *heap_grown) 
 {
   void *result = NULL;
   size_t max_freed, sum_freed, total_size;
@@ -95,6 +95,7 @@ max_freed = 0;
           (total_size - sum_freed) > (total_size * 0.75))) // Grow ratio
         && ((!h->max_size) || (total_size < h->max_size))) {
       gc_grow_heap(h, size, 0);
+      *heap_grown = 1;
     }
     result = gc_try_alloc(h, size);
     if (!result) {
diff --git a/include/cyclone/types.h b/include/cyclone/types.h
index 10e88a35..bc9ecc91 100644
--- a/include/cyclone/types.h
+++ b/include/cyclone/types.h
@@ -69,7 +69,7 @@ struct gc_header_type_t {
 gc_heap *gc_heap_create(size_t size, size_t max_size, size_t chunk_size);
 int gc_grow_heap(gc_heap *h, size_t size, size_t chunk_size);
 void *gc_try_alloc(gc_heap *h, size_t size);
-void *gc_alloc(gc_heap *h, size_t size);
+void *gc_alloc(gc_heap *h, size_t size, int *heap_grown);
 size_t gc_allocated_bytes(object obj);
 gc_heap *gc_heap_last(gc_heap *h);
 size_t gc_heap_total_size(gc_heap *h);
diff --git a/runtime.c b/runtime.c
index 1be5d1c8..8b5bc315 100644
--- a/runtime.c
+++ b/runtime.c
@@ -2378,12 +2378,12 @@ void gc_collect(gc_heap *h, size_t *sum_freed)
 // TODO: move globals to thread-specific structures.
 // for example - gc_cont, gc_ans, gc_num_ans
 
-char *gc_move(char *obj, gc_thread_data *thd, int *alloci) {
+char *gc_move(char *obj, gc_thread_data *thd, int *alloci, int *heap_grown) {
   if (!is_object_type(obj)) return obj;
 
   switch(type_of(obj)){
     case cons_tag: {
-      list hobj = gc_alloc(Cyc_heap, sizeof(cons_type));
+      list hobj = gc_alloc(Cyc_heap, sizeof(cons_type), heap_grown);
       hobj->hdr.mark = 0;
       type_of(hobj) = cons_tag;
       car(hobj) = car(obj);
@@ -2403,7 +2403,7 @@ char *gc_move(char *obj, gc_thread_data *thd, int *alloci) {
   temp = obj; \
   if (check_overflow(low_limit, temp) && \
       check_overflow(temp, high_limit)){ \
-    (obj) = (object) gc_move(temp, Cyc_thread, &alloci); \
+    (obj) = (object) gc_move(temp, Cyc_thread, &alloci, &heap_grown); \
   } \
 }
 
@@ -2415,6 +2415,7 @@ void GC(cont, args, num_args) closure cont; object *args; int num_args;
   object high_limit = stack_begin; // TODO: move to thread-specific struct
   int i;
   int scani = 0, alloci = 0; // TODO: not quite sure how to do this yet, want to user pointers but realloc can move them... need to think about how this will work
+  int heap_grown = 0;
 
   // Prevent overrunning buffer
   if (num_args > NUM_GC_ANS) {
@@ -2472,8 +2473,13 @@ void GC(cont, args, num_args) closure cont; object *args; int num_args;
     scani++;
   }
 
-  // TODO: at some point during all of this, check the 'major GC' flag
-  //       to see if we need to do a gc_collect
+  // Check if we need to do a major GC
+  if (heap_grown) {
+    size_t freed = 0;
+    // TODO: not good enough, need to pass current cont/args
+    // what about mutation barrier, do we care at this point???
+    gc_collect(Cyc_heap, &freed);
+  }
 
   longjmp(jmp_main,1); // Return globals gc_cont, gc_ans
 }