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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 "mongo/base/string_data.h"
#include "mongo/db/client.h"
#include "mongo/platform/mutex.h"
#include "mongo/stdx/condition_variable.h"
#include "mongo/util/fail_point.h"
#include "mongo/util/time_support.h"
namespace mongo {
/**
* DiagnosticInfo keeps track of diagnostic information such as a developer provided
* name, the time when a lock was first acquired, and a partial caller call stack.
*/
class DiagnosticInfo {
public:
// Maximum number of stack frames to appear in a DiagnosticInfo::Backtrace.
static constexpr size_t kMaxBackTraceFrames = 100ull;
struct Backtrace {
std::vector<void*> data = std::vector<void*>(kMaxBackTraceFrames, nullptr);
};
/**
* A simple RAII guard to attempt to join a blocked op once it is no longer needed
*
* This type is used in tests in conjunction with maybeMakeBlockedOpForTest
*/
class BlockedOpGuard {
public:
~BlockedOpGuard();
};
static boost::optional<DiagnosticInfo> get(Client& client);
virtual ~DiagnosticInfo() = default;
Date_t getTimestamp() const {
return _timestamp;
}
StringData getCaptureName() const {
return _captureName;
}
std::string toString() const;
/**
* Simple options struct to go with takeDiagnosticInfo
*/
struct Options {
Options() : shouldTakeBacktrace{false} {}
bool shouldTakeBacktrace;
};
/**
* Captures the diagnostic information based on the caller's context.
*/
static const DiagnosticInfo& capture(Client* client,
const StringData& captureName,
Options options = Options{}) noexcept;
/**
* This function checks the FailPoint currentOpSpawnsThreadWaitingForLatch and potentially
* launches a blocked operation to populate waitingForLatch for $currentOp.
*/
static std::unique_ptr<BlockedOpGuard> maybeMakeBlockedOpForTest(Client* client);
friend std::ostream& operator<<(std::ostream& s, const DiagnosticInfo& info) {
return s << info.toString();
}
private:
friend bool operator==(const DiagnosticInfo& info1, const DiagnosticInfo& info2);
friend bool operator!=(const DiagnosticInfo& info1, const DiagnosticInfo& info2) {
return !(info1 == info2);
}
friend std::ostream& operator<<(std::ostream& s, const DiagnosticInfo& info);
Date_t _timestamp;
StringData _captureName;
Backtrace _backtrace;
DiagnosticInfo(const Date_t& timestamp, const StringData& captureName, Backtrace backtrace)
: _timestamp(timestamp), _captureName(captureName), _backtrace(std::move(backtrace)) {}
};
} // namespace mongo
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