dir.c: retry glob with GC

* dir.c (do_opendir): retry after GC when the limit for open file
  descriptors reached.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@56467 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,8 @@
+Fri Oct 21 16:44:44 2016  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* dir.c (do_opendir): retry after GC when the limit for open file
+	  descriptors reached.
+
 Fri Oct 21 16:06:25 2016  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* ruby.c (open_load_file): retry after GC when the limit for open

dir.c

@@ -1286,8 +1286,19 @@ do_opendir(const char *path, int flags, rb_encoding *enc)
     }
 #endif
     dirp = opendir(path);
-    if (dirp == NULL && !to_be_ignored(errno))
+    if (!dirp) {
-	sys_warning(path, enc);
+	int e = errno;
+	switch (rb_gc_for_fd(e)) {
+	  default:
+	    dirp = opendir(path);
+	    if (dirp) break;
+	    e = errno;
+	    /* fallback */
+	  case 0:
+	    if (to_be_ignored(e)) break;
+	    sys_warning(path, enc);
+	}
+    }
 #ifdef _WIN32
     if (tmp) rb_str_resize(tmp, 0); /* GC guard */
 #endif

test/ruby/test_dir.rb

@@ -354,4 +354,18 @@ class TestDir < Test::Unit::TestCase
     assert_raise(Errno::ENOENT) {Dir.empty?(@nodir)}
     assert_not_send([Dir, :empty?, File.join(@root, "b")])
   end
+
+  def test_glob_gc_for_fd
+    assert_separately(["-C", @root], "#{<<-"begin;"}\n#{<<-"end;"}", timeout: 3)
+    begin;
+      Process.setrlimit(Process::RLIMIT_NOFILE, 50)
+      begin
+        tap {tap {tap {(0..100).map {open(IO::NULL)}}}}
+      rescue Errno::EMFILE
+      end
+      list = Dir.glob("*").sort
+      assert_not_empty(list)
+      assert_equal([*"a".."z"], list)
+    end;
+  end
 end