1//===-- Progress.h ----------------------------------------------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#ifndef LLDB_CORE_PROGRESS_H
10#define LLDB_CORE_PROGRESS_H
11
12#include "lldb/Utility/ConstString.h"
13#include "lldb/lldb-types.h"
14#include <atomic>
15#include <mutex>
16#include <optional>
17
18namespace lldb_private {
19
20/// A Progress indicator helper class.
21///
22/// Any potentially long running sections of code in LLDB should report
23/// progress so that clients are aware of delays that might appear during
24/// debugging. Delays commonly include indexing debug information, parsing
25/// symbol tables for object files, downloading symbols from remote
26/// repositories, and many more things.
27///
28/// The Progress class helps make sure that progress is correctly reported
29/// and will always send an initial progress update, updates when
30/// Progress::Increment() is called, and also will make sure that a progress
31/// completed update is reported even if the user doesn't explicitly cause one
32/// to be sent.
33///
34/// The progress is reported via a callback whose type is ProgressCallback:
35///
36/// typedef void (*ProgressCallback)(uint64_t progress_id,
37/// const char *message,
38/// uint64_t completed,
39/// uint64_t total,
40/// void *baton);
41///
42/// This callback will always initially be called with "completed" set to zero
43/// and "total" set to the total amount specified in the contructor. This is
44/// considered the progress start event. As Progress::Increment() is called,
45/// the callback will be called as long as the Progress::m_completed has not
46/// yet exceeded the Progress::m_total. When the callback is called with
47/// Progress::m_completed == Progress::m_total, that is considered a progress
48/// completed event. If Progress::m_completed is non-zero and less than
49/// Progress::m_total, then this is considered a progress update event.
50///
51/// This callback will be called in the destructor if Progress::m_completed is
52/// not equal to Progress::m_total with the "completed" set to
53/// Progress::m_total. This ensures we always send a progress completed update
54/// even if the user does not.
55
56class Progress {
57public:
58 /// Construct a progress object that will report information.
59 ///
60 /// The constructor will create a unique progress reporting object and
61 /// immediately send out a progress update by calling the installed callback
62 /// with completed set to zero out of the specified total.
63 ///
64 /// @param [in] title The title of this progress activity.
65 ///
66 /// @param [in] total The total units of work to be done if specified, if
67 /// set to std::nullopt then an indeterminate progress indicator should be
68 /// displayed.
69 ///
70 /// @param [in] debugger An optional debugger pointer to specify that this
71 /// progress is to be reported only to specific debuggers.
72 Progress(std::string title, std::string details = {},
73 std::optional<uint64_t> total = std::nullopt,
74 lldb_private::Debugger *debugger = nullptr);
75
76 /// Destroy the progress object.
77 ///
78 /// If the progress has not yet sent a completion update, the destructor
79 /// will send out a notification where the completed == m_total. This ensures
80 /// that we always send out a progress complete notification.
81 ~Progress();
82
83 /// Increment the progress and send a notification to the intalled callback.
84 ///
85 /// If incrementing ends up exceeding m_total, m_completed will be updated
86 /// to match m_total and no subsequent progress notifications will be sent.
87 /// If no total was specified in the constructor, this function will not do
88 /// anything nor send any progress updates.
89 ///
90 /// @param [in] amount The amount to increment m_completed by.
91 ///
92 /// @param [in] an optional message associated with this update.
93 void Increment(uint64_t amount = 1,
94 std::optional<std::string> updated_detail = {});
95
96 /// Used to indicate a non-deterministic progress report
97 static constexpr uint64_t kNonDeterministicTotal = UINT64_MAX;
98
99private:
100 void ReportProgress();
101 static std::atomic<uint64_t> g_id;
102 /// The title of the progress activity.
103 std::string m_title;
104 std::string m_details;
105 std::mutex m_mutex;
106 /// A unique integer identifier for progress reporting.
107 const uint64_t m_id;
108 /// How much work ([0...m_total]) that has been completed.
109 uint64_t m_completed;
110 /// Total amount of work, use a std::nullopt in the constructor for non
111 /// deterministic progress.
112 uint64_t m_total;
113 /// The optional debugger ID to report progress to. If this has no value then
114 /// all debuggers will receive this event.
115 std::optional<lldb::user_id_t> m_debugger_id;
116 /// Set to true when progress has been reported where m_completed == m_total
117 /// to ensure that we don't send progress updates after progress has
118 /// completed.
119 bool m_complete = false;
120};
121
122} // namespace lldb_private
123
124#endif // LLDB_CORE_PROGRESS_H
125

source code of lldb/include/lldb/Core/Progress.h