From c754792a07d340c30128b2fd064a58b1f15623da Mon Sep 17 00:00:00 2001
From: Tao Bao <tbao@google.com>
Date: Thu, 6 Aug 2015 18:35:05 -0700
Subject: Use unique_ptr and unique_fd to manager FDs.

Clean up leaky file descriptors in uncrypt/uncrypt.cpp. Add unique_fd
for open() and unique_file for fopen() to close FDs on destruction.

Bug: 21496020
Change-Id: I0174db0de9d5f59cd43b44757b8ef0f5912c91a2
---
 unique_fd.h | 73 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 73 insertions(+)
 create mode 100644 unique_fd.h

(limited to 'unique_fd.h')

diff --git a/unique_fd.h b/unique_fd.h
new file mode 100644
index 000000000..98a7c7b67
--- /dev/null
+++ b/unique_fd.h
@@ -0,0 +1,73 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef UNIQUE_FD_H
+#define UNIQUE_FD_H
+
+#include <stdio.h>
+
+#include <memory>
+
+class unique_fd {
+  public:
+    unique_fd(int fd) : fd_(fd) { }
+
+    unique_fd(unique_fd&& uf) {
+        fd_ = uf.fd_;
+        uf.fd_ = -1;
+    }
+
+    ~unique_fd() {
+        if (fd_ != -1) {
+            close(fd_);
+        }
+    }
+
+    int get() {
+        return fd_;
+    }
+
+    // Movable.
+    unique_fd& operator=(unique_fd&& uf) {
+        fd_ = uf.fd_;
+        uf.fd_ = -1;
+        return *this;
+    }
+
+    explicit operator bool() const {
+        return fd_ != -1;
+    }
+
+  private:
+    int fd_;
+
+    // Non-copyable.
+    unique_fd(const unique_fd&) = delete;
+    unique_fd& operator=(const unique_fd&) = delete;
+};
+
+// Custom deleter for unique_file to avoid fclose(NULL).
+struct safe_fclose {
+    void operator()(FILE *fp) const {
+        if (fp) {
+            fclose(fp);
+        };
+    }
+};
+
+using unique_file = std::unique_ptr<FILE, safe_fclose>;
+
+#endif  // UNIQUE_FD_H
-- 
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