From a003b42435df7809ac6543edb38097adbdc5c45c Mon Sep 17 00:00:00 2001
From: Yuichi Nishiwaki <yuichi.nishiwaki@gmail.com>
Date: Mon, 26 May 2014 15:51:18 +0900
Subject: [PATCH] dynamically allocate GC arena

---
 include/picrin.h      | 3 ++-
 include/picrin/cont.h | 3 ++-
 src/cont.c            | 8 ++++++--
 src/gc.c              | 3 ++-
 src/state.c           | 5 +++++
 5 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/include/picrin.h b/include/picrin.h
index fa84f59b..334da138 100644
--- a/include/picrin.h
+++ b/include/picrin.h
@@ -105,7 +105,8 @@ typedef struct {
   struct pic_jmpbuf *try_jmps;
 
   struct pic_heap *heap;
-  struct pic_object *arena[PIC_ARENA_SIZE];
+  struct pic_object **arena;
+  size_t arena_size;
   int arena_idx;
 
   char *native_stack_start;
diff --git a/include/picrin/cont.h b/include/picrin/cont.h
index a4b8f32a..496454fd 100644
--- a/include/picrin/cont.h
+++ b/include/picrin/cont.h
@@ -26,7 +26,8 @@ struct pic_cont {
 
   pic_code *ip;
 
-  struct pic_object *arena[PIC_ARENA_SIZE];
+  struct pic_object **arena;
+  size_t arena_size;
   int arena_idx;
 
   pic_value results;
diff --git a/src/cont.c b/src/cont.c
index e22bcfef..f84e55c7 100644
--- a/src/cont.c
+++ b/src/cont.c
@@ -139,7 +139,9 @@ save_cont(pic_state *pic, struct pic_cont **c)
   cont->ip = pic->ip;
 
   cont->arena_idx = pic->arena_idx;
-  memcpy(cont->arena, pic->arena, sizeof(struct pic_object *) * PIC_ARENA_SIZE);
+  cont->arena_size = pic->arena_size;
+  cont->arena = (struct pic_object **)pic_alloc(pic, sizeof(struct pic_object *) * pic->arena_size);
+  memcpy(cont->arena, pic->arena, sizeof(struct pic_object *) * pic->arena_size);
 
   cont->results = pic_undef_value();
 }
@@ -182,7 +184,9 @@ restore_cont(pic_state *pic, struct pic_cont *cont)
 
   pic->ip = cont->ip;
 
-  memcpy(pic->arena, cont->arena, sizeof(struct pic_object *) * PIC_ARENA_SIZE);
+  pic->arena = (struct pic_object **)pic_realloc(pic, pic->arena, sizeof(struct pic_object *) * cont->arena_size);
+  memcpy(pic->arena, cont->arena, sizeof(struct pic_object *) * cont->arena_size);
+  pic->arena_size = cont->arena_size;
   pic->arena_idx = cont->arena_idx;
 
   memcpy(cont->stk_pos, cont->stk_ptr, cont->stk_len);
diff --git a/src/gc.c b/src/gc.c
index fd48833e..d5159055 100644
--- a/src/gc.c
+++ b/src/gc.c
@@ -179,7 +179,7 @@ pic_free(pic_state *pic, void *ptr)
 static void
 gc_protect(pic_state *pic, struct pic_object *obj)
 {
-  if (pic->arena_idx >= PIC_ARENA_SIZE) {
+  if (pic->arena_idx >= pic->arena_size) {
     pic_abort(pic, "arena overflow");
   }
   pic->arena[pic->arena_idx++] = obj;
@@ -618,6 +618,7 @@ gc_finalize_object(pic_state *pic, struct pic_object *obj)
     pic_free(pic, cont->stk_ptr);
     pic_free(pic, cont->st_ptr);
     pic_free(pic, cont->ci_ptr);
+    pic_free(pic, cont->arena);
     PIC_BLK_DECREF(pic, cont->blk);
     break;
   }
diff --git a/src/state.c b/src/state.c
index 37fab568..81c18004 100644
--- a/src/state.c
+++ b/src/state.c
@@ -70,6 +70,8 @@ pic_open(int argc, char *argv[], char **envp)
   pic->try_jmps = NULL;
 
   /* GC arena */
+  pic->arena = (struct pic_object **)calloc(PIC_ARENA_SIZE, sizeof(struct pic_object **));
+  pic->arena_size = PIC_ARENA_SIZE;
   pic->arena_idx = 0;
 
   /* native stack marker */
@@ -153,6 +155,9 @@ pic_close(pic_state *pic)
   xh_destroy(&pic->global_tbl);
   xh_destroy(&pic->macros);
 
+  /* free GC arena */
+  free(pic->arena);
+
   /* free symbol names */
   xh_begin(&it, &pic->sym_names);
   while (xh_next(&it)) {