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// Copyright (C) 2019 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.
#include "utility.h"
#include <errno.h>
#include <unistd.h>
#include <thread>
using namespace std::literals;
namespace android {
namespace dm {
bool WaitForCondition(const std::function<WaitResult()>& condition,
const std::chrono::milliseconds& timeout_ms) {
auto start_time = std::chrono::steady_clock::now();
while (true) {
auto result = condition();
if (result == WaitResult::Done) return true;
if (result == WaitResult::Fail) return false;
std::this_thread::sleep_for(20ms);
auto now = std::chrono::steady_clock::now();
auto time_elapsed = std::chrono::duration_cast<std::chrono::milliseconds>(now - start_time);
if (time_elapsed > timeout_ms) return false;
}
}
bool WaitForFile(const std::string& path, const std::chrono::milliseconds& timeout_ms) {
auto condition = [&]() -> WaitResult {
// If the file exists but returns EPERM or something, we consider the
// condition met.
if (access(path.c_str(), F_OK) != 0) {
if (errno == ENOENT) return WaitResult::Wait;
}
return WaitResult::Done;
};
return WaitForCondition(condition, timeout_ms);
}
bool WaitForFileDeleted(const std::string& path, const std::chrono::milliseconds& timeout_ms) {
auto condition = [&]() -> WaitResult {
if (access(path.c_str(), F_OK) == 0 || errno != ENOENT) {
return WaitResult::Wait;
}
return WaitResult::Done;
};
return WaitForCondition(condition, timeout_ms);
}
} // namespace dm
} // namespace android
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