/* A region of the call stack, used for call frames that have not escaped to

 * the heap. */

struct MVMCallStackRegion {

    /* Next call stack region, which we start allocating in if this one is

     * full. NULL if none has been allocated yet. */

    MVMCallStackRegion *next;

    /* Previous call stack region, if any. */

    MVMCallStackRegion *prev;

    /* The place we'll allocate the next frame. */

    char *alloc;

    /* The end of the allocatable region. */

    char *alloc_limit;

};

/* The default size of a call stack region. */

#define MVM_CALLSTACK_REGION_SIZE 131072

/* Checks if a frame is allocated on a call stack or on the heap. If it is on

 * the call stack, then it will have zeroed flags (since heap-allocated frames

 * always have the "I'm a heap frame" bit set). */

MVM_STATIC_INLINE MVMuint32 MVM_FRAME_IS_ON_CALLSTACK(MVMThreadContext *tc, MVMFrame *frame) {

    return frame->header.flags == 0;

}

/* Functions for working with call stack regions. */

void MVM_callstack_region_init(MVMThreadContext *tc);

MVMCallStackRegion * MVM_callstack_region_next(MVMThreadContext *tc);

MVMCallStackRegion * MVM_callstack_region_prev(MVMThreadContext *tc);

void MVM_callstack_reset(MVMThreadContext *tc);

void MVM_callstack_region_destroy_all(MVMThreadContext *tc);