range-based for loop seems a better fit for iterating over crange

39fa2be7 · Nickolai Zeldovich · e31c700a · 39fa2be7 · 39fa2be7
--- a/crange.hh
+++ b/crange.hh
@@ -83,7 +83,7 @@ class markptr_mark : public markptr<T> {
 };

 struct range : public rcu_freed {
-public:
+ public:
  u64 key;
  u64 size;
  void *value;
@@ -103,10 +103,22 @@ public:
  int lockif(markptr<range> e);
 } __mpalign__;

+class range_iterator {
+ private:
+  range *_e;
+
+ public:
+  range_iterator(range *e) : _e(e) {}
+  range_iterator& operator++() { _e = _e->next[0].ptr(); return *this; }
+  range*& operator*() { return _e; }
+  bool operator==(const range_iterator &other) { return _e == other._e; }
+  bool operator!=(const range_iterator &other) { return _e != other._e; }
+};
+
 struct crange {
-private:
+ private:
  range *crange_head;    // a crange skip list starts with a sentinel range (key 0, sz 0)
-public:
+ public:
  int nlevel;                  // number of levels in the crange skip list
  crange(int nlevel);
  ~crange(void);
@@ -120,12 +132,18 @@ public:
  int lock_range(u64 k, u64 sz, int l, range **er, range **pr, range **fr, range **lr, range **sr);
  int find_and_lock(u64 k, u64 sz, range **p0, range **f0, range **l0, range **s0);

-  template<class CB>
-  bool foreach(CB cb) {
-    for (range *e = crange_head->next[0].ptr(); e; e = e->next[0].ptr())
-      if (!cb(e))
-        return false;
-    return true;
-  }
+  range_iterator begin() { return range_iterator(crange_head->next[0].ptr()); };
+  range_iterator end() { return range_iterator(0); };
 };

+static inline range_iterator
+begin(crange *cr)
+{
+  return cr->begin();
+}
+
+static inline range_iterator
+end(crange *cr)
+{
+  return cr->end();
+}
--- a/vm.cc
+++ b/vm.cc
@@ -311,11 +311,12 @@ static void
 vmap_free(void *p)
 {
  struct vmap *m = (struct vmap *) p;
-  m->cr->foreach([](range *r) {
+
+  for (range *r: m->cr) {
    delete (vma*) r->value;
    r->cr->del(r->key, r->size);
-      return true;
-    });
+  }
+
  delete m->cr;
  ksfree(slab_kshared, m->kshared);
  freevm(m->pml4);
@@ -384,11 +385,11 @@ vmap_copy(struct vmap *m, int share)
    return 0;

  acquire(&m->lock);
-  if (!m->cr->foreach([share, m, nm](range *r) -> bool {
+  for (range *r: m->cr) {
    struct vma *e = (struct vma *) r->value;
    struct vma *ne = new vma();
    if (ne == 0)
-        return false;
+      goto err;

    ne->va_start = e->va_start;
    ne->va_end = e->va_end;
@@ -405,16 +406,10 @@ vmap_copy(struct vmap *m, int share)
    }

    if(ne->n == 0)
-        return false;
+      goto err;

    ne->n->ref++;
    nm->cr->add(ne->va_start, ne->va_end - ne->va_start, (void *) ne);
-      return true;
-    }))
-  {
-    vmap_free(nm);
-    release(&m->lock);
-    return 0;
  }

  if (share)
@@ -422,6 +417,11 @@ vmap_copy(struct vmap *m, int share)

  release(&m->lock);
  return nm;
+
+ err:
+  vmap_free(nm);
+  release(&m->lock);
+  return 0;
 }

 int