//===-- AppleGetQueuesHandler.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_APPLEGETQUEUESHANDLER_H

#define LLDB_SOURCE_PLUGINS_SYSTEMRUNTIME_MACOSX_APPLEGETQUEUESHANDLER_H

#include <map>

#include <mutex>

#include <vector>

#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_get_dispatch_queues()

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

// with these members:

//

//     struct get_current_queues_return_values

//     {

//         introspection_dispatch_queue_info_t *queues_buffer;

//         uint64_t queues_buffer_size;

//         uint64_t count;

//     };

//

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

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

// lldb.  count is the number of queues that were stored in the buffer.

//

// The AppleGetQueuesHandler object should persist so that the UtilityFunction

// can be reused multiple times.

namespace lldb_private {

class AppleGetQueuesHandler {

public:

  AppleGetQueuesHandler(lldb_private::Process *process);

  ~AppleGetQueuesHandler();

  struct GetQueuesReturnInfo {

    lldb::addr_t queues_buffer_ptr =

        LLDB_INVALID_ADDRESS; /* the address of the queues buffer from

          libBacktraceRecording */

    lldb::addr_t queues_buffer_size = 0; /* the size of the queues buffer from

                                        libBacktraceRecording */

    uint64_t count = 0; /* the number of queues included in the queues buffer */

    GetQueuesReturnInfo() = default;

  };

  /// Get the list of queues that exist (with any active or pending items) via

  /// a call to introspection_get_dispatch_queues().  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] 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 queues_buffer_ptr value will be

  ///     LLDB_INVALID_ADDRESS.

  GetQueuesReturnInfo GetCurrentQueues(Thread &thread,

                                       lldb::addr_t page_to_free,

                                       uint64_t page_to_free_size,

                                       lldb_private::Status &error);

  void Detach();

private:

  lldb::addr_t SetupGetQueuesFunction(Thread &thread,

                                      ValueList &get_queues_arglist);

  static const char *g_get_current_queues_function_name;

  static const char *g_get_current_queues_function_code;

  lldb_private::Process *m_process;

  std::unique_ptr<UtilityFunction> m_get_queues_impl_code_up;

  std::mutex m_get_queues_function_mutex;

  lldb::addr_t m_get_queues_return_buffer_addr;

  std::mutex m_get_queues_retbuffer_mutex;

};

} // using namespace lldb_private

#endif // LLDB_SOURCE_PLUGINS_SYSTEMRUNTIME_MACOSX_APPLEGETQUEUESHANDLER_H