// collects a list of CodeBlobs in the CodeCache.
//
// The created list is growable array of JvmtiCodeBlobDesc - each one describes
// a CodeBlob. Note that the list is static - this is because CodeBlob::blobs_do
// requires a a C or static function so we can't use an instance function. This
// isn't a problem as the iteration is serial anyway as we need the CodeCache_lock
// to iterate over the code cache.
//
// Note that the CodeBlobs in the CodeCache will include BufferBlobs that may
// contain multiple stubs. As a profiler is interested in the stubs rather than
// the enclosing container we first iterate over the stub code descriptors so
// that the stubs go into the list first. do_blob will then filter out the
// enclosing blobs if the starting address of the enclosing blobs matches the
// starting address of first stub generated in the enclosing blob.

void CodeBlobCollector::collect() {

  {- -------------------------------------------
  (1) (assert)
      ---------------------------------------- -}

      assert_locked_or_safepoint(CodeCache_lock);
      assert(_global_code_blobs == NULL, "checking");

  {- -------------------------------------------
  (1) 収集した情報を入れておくための GrowableArray を生成する.
      (情報は JvmtiCodeBlobDesc オブジェクトという形で蓄えていく)
      (なお, 生成した配列は CodeCache::blobs_do からでも見えるように static なフィールド(_global_code_blobs)に bind している)
      ---------------------------------------- -}

      // create the global list
      _global_code_blobs = new (ResourceObj::C_HEAP) GrowableArray<JvmtiCodeBlobDesc*>(50,true);

  {- -------------------------------------------
  (1) まずは全ての StubCodeDesc に対して iterate し, 情報を溜めていく.
      ---------------------------------------- -}

      // iterate over the stub code descriptors and put them in the list first.
      int index = 0;
      StubCodeDesc* desc;
      while ((desc = StubCodeDesc::desc_for_index(++index)) != NULL) {
        _global_code_blobs->append(new JvmtiCodeBlobDesc(desc->name(), desc->begin(), desc->end()));
      }

  {- -------------------------------------------
  (1) 次に, CodeCache 内の全 CodeBlob に対して CodeBlobCollector::do_blob で iterate し, 情報を蓄えていく.
      ---------------------------------------- -}

      // next iterate over all the non-nmethod code blobs and add them to
      // the list - as noted above this will filter out duplicates and
      // enclosing blobs.
      CodeCache::blobs_do(do_blob);

  {- -------------------------------------------
  (1) 最後に, 収集結果を _code_blobs に移し, static フィールドである _global_code_blobs は NULL に戻す.
      ---------------------------------------- -}

      // make the global list the instance list so that it can be used
      // for other iterations.
      _code_blobs = _global_code_blobs;
      _global_code_blobs = NULL;
    }