xref: /llvm-project/lldb/source/Plugins/SystemRuntime/MacOSX/AppleGetThreadItemInfoHandler.h (revision fd2433e139f78658e059cf911af8ae735fcda57c)
1 //===-- AppleGetThreadItemInfoHandler.h ----------------------------*- C++
2 //-*-===//
3 //
4 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5 // See https://llvm.org/LICENSE.txt for license information.
6 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #ifndef LLDB_SOURCE_PLUGINS_SYSTEMRUNTIME_MACOSX_APPLEGETTHREADITEMINFOHANDLER_H
11 #define LLDB_SOURCE_PLUGINS_SYSTEMRUNTIME_MACOSX_APPLEGETTHREADITEMINFOHANDLER_H
12 
13 #include <map>
14 #include <mutex>
15 #include <vector>
16 
17 #include "lldb/Symbol/CompilerType.h"
18 #include "lldb/Utility/Status.h"
19 #include "lldb/lldb-public.h"
20 
21 // This class will insert a UtilityFunction into the inferior process for
22 // calling libBacktraceRecording's
23 // __introspection_dispatch_thread_get_item_info()
24 // function.  The function in the inferior will return a struct by value
25 // with these members:
26 //
27 //     struct get_thread_item_info_return_values
28 //     {
29 //         introspection_dispatch_item_info_ref *item_buffer;
30 //         uint64_t item_buffer_size;
31 //     };
32 //
33 // The item_buffer pointer is an address in the inferior program's address
34 // space (item_buffer_size in size) which must be mach_vm_deallocate'd by
35 // lldb.
36 //
37 // The AppleGetThreadItemInfoHandler object should persist so that the
38 // UtilityFunction
39 // can be reused multiple times.
40 
41 namespace lldb_private {
42 
43 class AppleGetThreadItemInfoHandler {
44 public:
45   AppleGetThreadItemInfoHandler(lldb_private::Process *process);
46 
47   ~AppleGetThreadItemInfoHandler();
48 
49   struct GetThreadItemInfoReturnInfo {
50     lldb::addr_t item_buffer_ptr = LLDB_INVALID_ADDRESS; /* the address of the
51                                      item buffer from libBacktraceRecording */
52     lldb::addr_t item_buffer_size = 0; /* the size of the item buffer from
53                                       libBacktraceRecording */
54 
55     GetThreadItemInfoReturnInfo() = default;
56   };
57 
58   /// Get the information about a work item by calling
59   /// __introspection_dispatch_thread_get_item_info.  If there's a page of
60   /// memory that needs to be freed, pass in the address and size and it will
61   /// be freed before getting the list of queues.
62   ///
63   /// \param [in] thread_id
64   ///     The thread to get the extended backtrace for.
65   ///
66   /// \param [in] page_to_free
67   ///     An address of an inferior process vm page that needs to be
68   ///     deallocated,
69   ///     LLDB_INVALID_ADDRESS if this is not needed.
70   ///
71   /// \param [in] page_to_free_size
72   ///     The size of the vm page that needs to be deallocated if an address was
73   ///     passed in to page_to_free.
74   ///
75   /// \param [out] error
76   ///     This object will be updated with the error status / error string from
77   ///     any failures encountered.
78   ///
79   /// \returns
80   ///     The result of the inferior function call execution.  If there was a
81   ///     failure of any kind while getting
82   ///     the information, the item_buffer_ptr value will be
83   ///     LLDB_INVALID_ADDRESS.
84   GetThreadItemInfoReturnInfo GetThreadItemInfo(Thread &thread,
85                                                 lldb::tid_t thread_id,
86                                                 lldb::addr_t page_to_free,
87                                                 uint64_t page_to_free_size,
88                                                 lldb_private::Status &error);
89 
90   void Detach();
91 
92 private:
93   lldb::addr_t
94   SetupGetThreadItemInfoFunction(Thread &thread,
95                                  ValueList &get_thread_item_info_arglist);
96 
97   static const char *g_get_thread_item_info_function_name;
98   static const char *g_get_thread_item_info_function_code;
99 
100   lldb_private::Process *m_process;
101   std::unique_ptr<UtilityFunction> m_get_thread_item_info_impl_code;
102   std::mutex m_get_thread_item_info_function_mutex;
103 
104   lldb::addr_t m_get_thread_item_info_return_buffer_addr;
105   std::mutex m_get_thread_item_info_retbuffer_mutex;
106 };
107 
108 } // using namespace lldb_private
109 
110 #endif // LLDB_SOURCE_PLUGINS_SYSTEMRUNTIME_MACOSX_APPLEGETTHREADITEMINFOHANDLER_H
111