llvm/lldb/source/Plugins/Process/Linux/Perf.h

//===-- Perf.h --------------------------------------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
/// \file
/// This file contains a thin wrapper of the perf_event_open API
/// and classes to handle the destruction of file descriptors
/// and mmap pointers.
///
//===----------------------------------------------------------------------===//

#ifndef LLDB_SOURCE_PLUGINS_PROCESS_LINUX_PERF_H
#define LLDB_SOURCE_PLUGINS_PROCESS_LINUX_PERF_H

#include "lldb/Utility/TraceIntelPTGDBRemotePackets.h"
#include "lldb/lldb-types.h"
#include "llvm/Support/Error.h"
#include <chrono>
#include <cstdint>
#include <linux/perf_event.h>

namespace lldb_private {
namespace process_linux {
namespace resource_handle {

/// Custom deleter for the pointer returned by \a mmap.
///
/// This functor type is provided to \a unique_ptr to properly
/// unmap the region at destruction time.
class MmapDeleter { … };

/// Custom deleter for a file descriptor.
///
/// This functor type is provided to \a unique_ptr to properly release
/// the resources associated with the file descriptor at destruction time.
class FileDescriptorDeleter { … };

FileDescriptorUP;
MmapUP;

} // namespace resource_handle

/// Thin wrapper of the perf_event_open API.
///
/// Exposes the metadata page and data and aux buffers of a perf event.
/// Handles the management of the event's file descriptor and mmap'ed
/// regions.
class PerfEvent { … };

/// Create a perf event that tracks context switches on a cpu.
///
/// \param[in] cpu_id
///   The core to trace.
///
/// \param[in] parent_perf_event
///   An optional perf event that will be grouped with the
///   new perf event.
llvm::Expected<PerfEvent>
CreateContextSwitchTracePerfEvent(lldb::cpu_id_t cpu_id,
                                  const PerfEvent *parent_perf_event = nullptr);

/// Load \a PerfTscConversionParameters from \a perf_event_mmap_page, if
/// available.
llvm::Expected<LinuxPerfZeroTscConversion> LoadPerfTscConversionParameters();

} // namespace process_linux
} // namespace lldb_private

#endif // LLDB_SOURCE_PLUGINS_PROCESS_LINUX_PERF_H