From 4dab8c74264424fa5fcd8861854e4d32e242d6d3 Mon Sep 17 00:00:00 2001
From: Sebastian Messmer <messmer@cryfs.org>
Date: Thu, 12 Nov 2015 13:08:43 -0800
Subject: [PATCH] Add a class that runs a callback after a (resettable)
 timeout. This will be used later for unmounting after a certain idle time

---
 src/cli/CallAfterTimeout.cpp      |  1 +
 src/cli/CallAfterTimeout.h        | 57 ++++++++++++++++++++++++++
 test/cli/CallAfterTimeoutTest.cpp | 67 +++++++++++++++++++++++++++++++
 3 files changed, 125 insertions(+)
 create mode 100644 src/cli/CallAfterTimeout.cpp
 create mode 100644 src/cli/CallAfterTimeout.h
 create mode 100644 test/cli/CallAfterTimeoutTest.cpp

diff --git a/src/cli/CallAfterTimeout.cpp b/src/cli/CallAfterTimeout.cpp
new file mode 100644
index 00000000..bd5ef1d5
--- /dev/null
+++ b/src/cli/CallAfterTimeout.cpp
@@ -0,0 +1 @@
+#include "CallAfterTimeout.h"
diff --git a/src/cli/CallAfterTimeout.h b/src/cli/CallAfterTimeout.h
new file mode 100644
index 00000000..30a70a70
--- /dev/null
+++ b/src/cli/CallAfterTimeout.h
@@ -0,0 +1,57 @@
+#pragma once
+#ifndef MESSMER_CRYFS_SRC_CLI_CALLAFTERTIMEOUT_H
+#define MESSMER_CRYFS_SRC_CLI_CALLAFTERTIMEOUT_H
+
+#include <functional>
+#include <mutex>
+#include <messmer/cpp-utils/thread/LoopThread.h>
+
+namespace cryfs {
+    class CallAfterTimeout final {
+    public:
+        CallAfterTimeout(boost::chrono::milliseconds timeout, std::function<void()> callback);
+        void resetTimer();
+    private:
+        bool _checkTimeoutThreadIteration();
+        boost::chrono::time_point<boost::chrono::steady_clock> _targetTime();
+        bool _callCallbackIfTimeout();
+
+        std::function<void()> _callback;
+        boost::chrono::milliseconds _timeout;
+        boost::chrono::time_point<boost::chrono::steady_clock> _start;
+        cpputils::LoopThread _checkTimeoutThread;
+        std::mutex _mutex;
+    };
+
+    inline CallAfterTimeout::CallAfterTimeout(boost::chrono::milliseconds timeout, std::function<void()> callback)
+        :_callback(callback), _timeout(timeout), _start(), _checkTimeoutThread(std::bind(&CallAfterTimeout::_checkTimeoutThreadIteration, this)) {
+        resetTimer();
+        _checkTimeoutThread.start();
+    }
+
+    inline void CallAfterTimeout::resetTimer() {
+        std::unique_lock<std::mutex> lock(_mutex);
+        _start = boost::chrono::steady_clock::now();
+    }
+
+    inline bool CallAfterTimeout::_checkTimeoutThreadIteration() {
+        boost::this_thread::sleep_until(_targetTime());
+        return _callCallbackIfTimeout();
+    }
+
+    inline boost::chrono::time_point<boost::chrono::steady_clock> CallAfterTimeout::_targetTime() {
+        std::unique_lock<std::mutex> lock(_mutex);
+        return _start + _timeout;
+    }
+
+    inline bool CallAfterTimeout::_callCallbackIfTimeout() {
+        std::unique_lock<std::mutex> lock(_mutex);
+        if (boost::chrono::steady_clock::now() >= _start + _timeout) {
+            _callback();
+            return false; // Stop thread
+        }
+        return true; // Continue thread
+    }
+}
+
+#endif
diff --git a/test/cli/CallAfterTimeoutTest.cpp b/test/cli/CallAfterTimeoutTest.cpp
new file mode 100644
index 00000000..f6eb8b4f
--- /dev/null
+++ b/test/cli/CallAfterTimeoutTest.cpp
@@ -0,0 +1,67 @@
+#include <google/gtest/gtest.h>
+#include <messmer/cpp-utils/pointer/unique_ref.h>
+#include "../../src/cli/CallAfterTimeout.h"
+
+using cpputils::unique_ref;
+using cpputils::make_unique_ref;
+using boost::chrono::milliseconds;
+using boost::chrono::minutes;
+using boost::chrono::duration_cast;
+using boost::this_thread::sleep_for;
+using namespace cryfs;
+
+class CallAfterTimeoutTest : public ::testing::Test {
+public:
+    unique_ref<CallAfterTimeout> callAfterTimeout(milliseconds timeout) {
+        return make_unique_ref<CallAfterTimeout>(timeout, [this] {called = true;});
+    }
+
+    bool called = false;
+};
+
+TEST_F(CallAfterTimeoutTest, NoReset_1) {
+    auto obj = callAfterTimeout(milliseconds(50));
+    sleep_for(milliseconds(40));
+    EXPECT_FALSE(called);
+    sleep_for(milliseconds(20));
+    EXPECT_TRUE(called);
+}
+
+TEST_F(CallAfterTimeoutTest, NoReset_2) {
+    auto obj = callAfterTimeout(milliseconds(100));
+    sleep_for(milliseconds(90));
+    EXPECT_FALSE(called);
+    sleep_for(milliseconds(20));
+    EXPECT_TRUE(called);
+}
+
+TEST_F(CallAfterTimeoutTest, DoesntCallTwice) {
+    auto obj = callAfterTimeout(milliseconds(50));
+    sleep_for(milliseconds(60));
+    EXPECT_TRUE(called);
+    called = false;
+    sleep_for(milliseconds(60));
+    EXPECT_FALSE(called);
+}
+
+TEST_F(CallAfterTimeoutTest, OneReset) {
+    auto obj = callAfterTimeout(milliseconds(50));
+    sleep_for(milliseconds(40));
+    obj->resetTimer();
+    sleep_for(milliseconds(40));
+    EXPECT_FALSE(called);
+    sleep_for(milliseconds(20));
+    EXPECT_TRUE(called);
+}
+
+TEST_F(CallAfterTimeoutTest, TwoResets) {
+    auto obj = callAfterTimeout(milliseconds(50));
+    sleep_for(milliseconds(20));
+    obj->resetTimer();
+    sleep_for(milliseconds(40));
+    obj->resetTimer();
+    sleep_for(milliseconds(40));
+    EXPECT_FALSE(called);
+    sleep_for(milliseconds(20));
+    EXPECT_TRUE(called);
+}