From 0de7c6b98bef59111f7dd8e7843606c85b5d8680 Mon Sep 17 00:00:00 2001
From: Justin Ethier <justin.ethier@gmail.com>
Date: Tue, 12 Apr 2016 23:10:21 -0400
Subject: [PATCH] Experimenting with gradual heap growth

---
 gc.c      | 30 ++++++++++++++++++++++++++----
 runtime.c |  6 +++---
 2 files changed, 29 insertions(+), 7 deletions(-)

diff --git a/gc.c b/gc.c
index 9357f1da..bc7f7f1c 100644
--- a/gc.c
+++ b/gc.c
@@ -382,10 +382,32 @@ int gc_grow_heap(gc_heap *h, size_t size, size_t chunk_size)
   size_t cur_size, new_size;
   gc_heap *h_last, *h_new;
   pthread_mutex_lock(&heap_lock);
-  h_last = gc_heap_last(h);
-  cur_size = h_last->size;
-  // JAE - For now, just add a new page
-  new_size = cur_size; //gc_heap_align(((cur_size > size) ? cur_size : size) * 2);
+  // TODO: experiment with
+  // 1) growing heap gradually using a fibonnaci sequence growth
+  // 2) cap at HEAP_SIZE
+  // 3) allocate larger pages if heap aligned size is > page size?
+  {
+    size_t prev_size = 0;
+    new_size = 0;
+    h_last = h;
+    while (h_last->next) {
+      if (new_size < HEAP_SIZE){
+        new_size = prev_size + h_last->size;
+        prev_size = h_last->size;
+      } else {
+        new_size = HEAP_SIZE;
+      }
+      h_last = h_last->next;
+    }
+    if (new_size == 0) 
+      new_size = h_last->size;
+    //fprintf(stderr, "Growing heap new page size = %zu\n", new_size);
+  }
+// OLD code:
+//  h_last = gc_heap_last(h);
+//  cur_size = h_last->size;
+//  new_size = cur_size; //gc_heap_align(((cur_size > size) ? cur_size : size) * 2);
+// END TODO
   h_new = gc_heap_create(new_size, h_last->max_size, chunk_size);
   h_last->next = h_new;
   pthread_mutex_unlock(&heap_lock);
diff --git a/runtime.c b/runtime.c
index a649f5fc..78d22a19 100644
--- a/runtime.c
+++ b/runtime.c
@@ -166,9 +166,9 @@ void gc_init_heap(long heap_size)
 {
 
   Cyc_heap = malloc(sizeof(gc_heap_root));
-  Cyc_heap->heap = gc_heap_create(heap_size, 0, 0);
-  Cyc_heap->small_obj_heap = gc_heap_create(heap_size, 0, 0);
-  Cyc_heap->medium_obj_heap = gc_heap_create(heap_size, 0, 0);
+  Cyc_heap->heap = gc_heap_create(1 * 1024 * 1024, 0, 0);
+  Cyc_heap->small_obj_heap = gc_heap_create(1 * 1024 * 1024, 0, 0);
+  Cyc_heap->medium_obj_heap = gc_heap_create(1 * 1024 * 1024, 0, 0);
 
   if (!ck_hs_init(&symbol_table, 
                   CK_HS_MODE_OBJECT | CK_HS_MODE_SPMC,