//===-- AppleGetItemInfoHandler.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

//

//===----------------------------------------------------------------------===//

#ifndef LLDB_SOURCE_PLUGINS_SYSTEMRUNTIME_MACOSX_APPLEGETITEMINFOHANDLER_H

#define LLDB_SOURCE_PLUGINS_SYSTEMRUNTIME_MACOSX_APPLEGETITEMINFOHANDLER_H

#include <map>

#include <mutex>

#include <vector>

#include "lldb/Expression/UtilityFunction.h"

#include "lldb/Symbol/CompilerType.h"

#include "lldb/Utility/Status.h"

#include "lldb/lldb-public.h"

// This class will insert a UtilityFunction into the inferior process for

// calling libBacktraceRecording's

// __introspection_dispatch_queue_item_get_info()

// function.  The function in the inferior will return a struct by value

// with these members:

//

//     struct get_item_info_return_values

//     {

//         introspection_dispatch_item_info_ref *item_buffer;

//         uint64_t item_buffer_size;

//     };

//

// The item_buffer pointer is an address in the inferior program's address

// space (item_buffer_size in size) which must be mach_vm_deallocate'd by

// lldb.

//

// The AppleGetItemInfoHandler object should persist so that the UtilityFunction

// can be reused multiple times.

namespace lldb_private {

class AppleGetItemInfoHandler {

public:

  AppleGetItemInfoHandler(lldb_private::Process *process);

  ~AppleGetItemInfoHandler();

  struct GetItemInfoReturnInfo {

    lldb::addr_t item_buffer_ptr = LLDB_INVALID_ADDRESS; /* the address of the

                                     item buffer from libBacktraceRecording */

    lldb::addr_t item_buffer_size = 0; /* the size of the item buffer from

                                      libBacktraceRecording */

    GetItemInfoReturnInfo() = default;

  };

  /// Get the information about a work item by calling

  /// __introspection_dispatch_queue_item_get_info.  If there's a page of

  /// memory that needs to be freed, pass in the address and size and it will

  /// be freed before getting the list of queues.

  ///

  /// \param [in] thread

  ///     The thread to run this plan on.

  ///

  /// \param [in] item

  ///     The introspection_dispatch_item_info_ref value for the item of

  ///     interest.

  ///

  /// \param [in] page_to_free

  ///     An address of an inferior process vm page that needs to be

  ///     deallocated,

  ///     LLDB_INVALID_ADDRESS if this is not needed.

  ///

  /// \param [in] page_to_free_size

  ///     The size of the vm page that needs to be deallocated if an address was

  ///     passed in to page_to_free.

  ///

  /// \param [out] error

  ///     This object will be updated with the error status / error string from

  ///     any failures encountered.

  ///

  /// \returns

  ///     The result of the inferior function call execution.  If there was a

  ///     failure of any kind while getting

  ///     the information, the item_buffer_ptr value will be

  ///     LLDB_INVALID_ADDRESS.

  GetItemInfoReturnInfo GetItemInfo(Thread &thread, lldb::addr_t item,

                                    lldb::addr_t page_to_free,

                                    uint64_t page_to_free_size,

                                    lldb_private::Status &error);

  void Detach();

private:

  lldb::addr_t SetupGetItemInfoFunction(Thread &thread,

                                        ValueList &get_item_info_arglist);

  static const char *g_get_item_info_function_name;

  static const char *g_get_item_info_function_code;

  lldb_private::Process *m_process;

  std::unique_ptr<UtilityFunction> m_get_item_info_impl_code;

  std::mutex m_get_item_info_function_mutex;

  lldb::addr_t m_get_item_info_return_buffer_addr;

  std::mutex m_get_item_info_retbuffer_mutex;

};

} // using namespace lldb_private

#endif // LLDB_SOURCE_PLUGINS_SYSTEMRUNTIME_MACOSX_APPLEGETITEMINFOHANDLER_H