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/**
* Copyright (C) 2018-present MongoDB, Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the Server Side Public License, version 1,
* as published by MongoDB, Inc.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* Server Side Public License for more details.
*
* You should have received a copy of the Server Side Public License
* along with this program. If not, see
* <http://www.mongodb.com/licensing/server-side-public-license>.
*
* As a special exception, the copyright holders give permission to link the
* code of portions of this program with the OpenSSL library under certain
* conditions as described in each individual source file and distribute
* linked combinations including the program with the OpenSSL library. You
* must comply with the Server Side Public License in all respects for
* all of the code used other than as permitted herein. If you modify file(s)
* with this exception, you may extend this exception to your version of the
* file(s), but you are not obligated to do so. If you do not wish to do so,
* delete this exception statement from your version. If you delete this
* exception statement from all source files in the program, then also delete
* it in the license file.
*/
#pragma once
#include <string>
#include <vector>
#include "mongo/base/initializer_context.h"
#include "mongo/base/initializer_dependency_graph.h"
#include "mongo/base/status.h"
namespace mongo {
/**
* Class representing an initialization process.
*
* Such a process is described by a directed acyclic graph of initialization operations, the
* InitializerDependencyGraph. One constructs an initialization process by adding nodes and
* edges to the graph. Then, one executes the process, causing each initialization operation to
* execute in an order that respects the programmer-established prerequistes.
*/
class Initializer {
Initializer(const Initializer&) = delete;
Initializer& operator=(const Initializer&) = delete;
public:
Initializer();
~Initializer();
/**
* Get the initializer dependency graph, presumably for the purpose of adding more nodes.
*/
InitializerDependencyGraph& getInitializerDependencyGraph() {
return _graph;
}
/**
* Execute the initializer process, using the given argv and environment data as input.
*
* Returns Status::OK on success. All other returns constitute initialization failures,
* and the thing being initialized should be considered dead in the water.
*/
Status executeInitializers(const InitializerContext::ArgumentVector& args,
const InitializerContext::EnvironmentMap& env);
Status executeDeinitializers();
private:
enum class State {
kUninitialized,
kInitializing,
kInitialized,
kDeinitializing,
};
InitializerDependencyGraph _graph;
std::vector<std::string> _sortedNodes;
State _lifecycleState{State::kUninitialized};
};
/**
* Run the global initializers.
*
* It's a programming error for this to fail, but if it does it will return a status other
* than Status::OK.
*
* This means that the few initializers that might want to terminate the program by failing
* should probably arrange to terminate the process themselves.
*/
Status runGlobalInitializers(const InitializerContext::ArgumentVector& args,
const InitializerContext::EnvironmentMap& env);
Status runGlobalInitializers(int argc, const char* const* argv, const char* const* envp);
/**
* Same as runGlobalInitializers(), except prints a brief message to std::cerr
* and terminates the process on failure.
*/
void runGlobalInitializersOrDie(int argc, const char* const* argv, const char* const* envp);
/**
* Run the global deinitializers. They will execute in reverse order from initialization.
*
* It's a programming error for this to fail, but if it does it will return a status other
* than Status::OK.
*
* This means that the few initializers that might want to terminate the program by failing
* should probably arrange to terminate the process themselves.
*/
Status runGlobalDeinitializers();
} // namespace mongo
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