+#define PAGES_PER_CHUNK 16
+
+//"type free" chunk stacking
+struct chunk_stack
+{ void* chunks[MAX_CHUNKS];
+ void* *csp; //chunk stack pointer
+ void* dsp[MAX_CHUNKS]; //dat stack pointer (per chunk)
+ int chunk_size; //size of a chunk (including its forfeited page)
+ int max_dats; //number of dats per chunk for this stack
+} ocs, vcs, ccs, rcs, lcs, pcs, mcs; //odat, vdat, cdat,map, ref, link, post stacks
+
+//type safety handled by macro expansion (do not call these directly from code, make dependent macros for access to these)
+#define CHUNKS_LEN(STACK) ((STACK).csp - (STACK).chunks)
+#define CURRENT_CHUNK(STACK) ((STACK).chunks[CHUNKS_LEN(STACK) - 1])
+#define CHUNKS_FULL(STACK) ( (STACK).csp >= \
+ (STACK).chunks + MAX_CHUNKS * (STACK).chunk_size)
+#define CURRENT_DSP(STACK,TYPE) ((TYPE*) ((STACK).dsp[CHUNKS_LEN(STACK) - 1]))
+#define DATA_FULL(STACK,TYPE) ((void*) CURRENT_DSP(STACK,TYPE) >= \
+ (CURRENT_CHUNK(STACK) + (STACK).chunk_size))
+#define CSP_PUSH(STACK) (*(++(STACK).csp) = malloc((STACK).chunk_size))
+#define CURRENT_DATP(STACK,TYPE) (((TYPE**)(STACK).dsp)[CHUNKS_LEN(STACK) - 1])
+#define PREVIOUS_DATP(STACK,TYPE) (((TYPE**)(STACK).dsp)[CHUNKS_LEN(STACK) - 2])
+#define ALLOC_DAT(STACK,TYPE) (++CURRENT_DATP(STACK,TYPE))
+#define INIT_STACK(STACK,TYPE) \
+ { int i; \
+ (STACK).chunk_size = PAGES_PER_CHUNK * pagesize; \
+ (STACK).max_dats = (STACK).chunk_size / sizeof (TYPE); \
+ CSP_PUSH(STACK); \
+ for( i = 0; i < MAX_CHUNKS; i++){ \
+ (STACK).dsp[i] += pagesize; \
+ } \
+ }
+//Stack-specific macros (called directly from code (safety enforcement)
+#define INIT_ODAT() (INIT_STACK(ocs, struct odat))
+#define CURRENT_ODAT() (CURRENT_DATP(ocs,struct odat))
+#define ODAT_FULL() (DATA_FULL(ocs,struct odat))
+#define ODAT_ALLOC() (ALLOC_DAT(ocs,struct odat))
+#define OCS_FULL() (CHUNKS_FULL(ocs))
+#define INIT_VDAT() (INIT_STACK(vcs, struct vdat))
+#define CURRENT_VDAT() (CURRENT_DATP(vcs,struct vdat))
+#define VDAT_FULL() (DATA_FULL(vcs,struct vdat))
+#define VDAT_ALLOC() (ALLOC_DAT(vcs,struct vdat))
+#define VCS_FULL() (CHUNKS_FULL(vcs))
+#define INIT_CDAT() (INIT_STACK(ccs, struct cdat))
+#define CURRENT_CDAT() (CURRENT_DATP(ccs,struct cdat))
+#define CDAT_FULL() (DATA_FULL(ccs, struct cdat))
+#define CDAT_ALLOC() (ALLOC_DAT(ccs, struct cdat))
+#define CCS_FULL() (CHUNKS_FULL(ccs))
+#define INIT_MAP() (INIT_STACK(mcs, struct map))
+#define CURRENT_MAP() (CURRENT_DATP(mcs, struct map))
+#define MAP_FULL() (DATA_FULL(mcs, struct map))
+#define MAP_ALLOC() (ALLOC_DAT(mcs, struct map))
+#define MCS_FULL() (CHUNKS_FULL(mcs))
+#define INIT_LINK() (INIT_STACK(lcs, struct link))
+#define CURRENT_LINK() (CURRENT_DATP(lcs,struct link))
+#define LDAT_FULL() (DATA_FULL(lcs, struct link))
+#define LDAT_ALLOC() (ALLOC_DAT(lcs, struct link))
+#define LCS_FULL() (CHUNKS_FULL(lcs))
+#define INIT_POST() (INIT_STACK(rcs, struct ref))
+#define CURRENT_POST() (CURRENT_DATP(pcs,struct ref))
+#define POST_FULL() (DATA_FULL(pcs,struct ref))
+#define POST_ALLOC() (ALLOC_DAT(pcs,struct ref))
+#define PCS_FULL() (CHUNKS_FULL(pcs))
+#define INIT_REF() (INIT_STACK(rcs, struct ref))
+#define CURRENT_REF() (CURRENT_DATP(rcs,struct ref))
+#define PREVIOUS_REF() (PREVIOUS_DATP(rcs, struct ref))
+#define REF_FULL() (DATA_FULL(rcs,struct ref))
+#define REF_ALLOC() (ALLOC_DAT(rcs,struct ref))
+#define RCS_FULL() (CHUNKS_FULL(rcs))
+//Metadata
+#define CURRENT_SET() (CURRENT_CDAT()->set_list[CURRENT_CDAT()->num_sets])
+//#define CURRENT_QUAD() (CURRENT_MAP()->quad_list[CURRENT_MAP()->num_quads])
+//#define CURRENT_MODEL() (CURRENT_VDAT()->model_list[CURRENT_VDAT()->num_models])
+
+
+
+long pagesize;