[Lldb-commits] [lldb] [lldb][progress] Add progress manager class (PR #81319)

[Chelsea Cassanova via lldb-commits]

https://github.com/chelcassanova updated https://github.com/llvm/llvm-project/pull/81319

>From f5ef07849c61ee9387f92376d5e1bd13bedc43e5 Mon Sep 17 00:00:00 2001
From: Chelsea Cassanova <chelsea_cassanova at apple.com>
Date: Thu, 8 Feb 2024 15:31:33 -0800
Subject: [PATCH] [lldb][progress] Add progress manager class

Per discussions from https://github.com/llvm/llvm-project/pull/81026,
it was decided that having a class that manages a map of progress
reports would be beneficial in order to categorize them. This class is a
part of the overall `Progress` class and utilizes a map that keeps a
count of how many times a progress report category has been sent. This
would be used with the new debugger broadcast bit added in
https://github.com/llvm/llvm-project/pull/81169 so that a user listening
with that bit will receive grouped progress reports.
---
 lldb/include/lldb/Core/Progress.h | 27 +++++++++++++++++++
 lldb/source/Core/Progress.cpp     | 44 +++++++++++++++++++++++++++++++
 2 files changed, 71 insertions(+)

diff --git a/lldb/include/lldb/Core/Progress.h b/lldb/include/lldb/Core/Progress.h
index 5d882910246054..5e07789b0e5337 100644
--- a/lldb/include/lldb/Core/Progress.h
+++ b/lldb/include/lldb/Core/Progress.h
@@ -11,6 +11,7 @@
 
 #include "lldb/Utility/ConstString.h"
 #include "lldb/lldb-types.h"
+#include "llvm/ADT/StringMap.h"
 #include <atomic>
 #include <mutex>
 #include <optional>
@@ -119,6 +120,32 @@ class Progress {
   bool m_complete = false;
 };
 
+/// A class used to group progress reports by category. This is done by using a
+/// map that maintains a refcount of each category of progress reports that have
+/// come in. Keeping track of progress reports this way will be done if a
+/// debugger is listening to the eBroadcastBitProgressByCategory broadcast bit.
+class ProgressManager {
+public:
+  ProgressManager();
+  ~ProgressManager();
+
+  static void Initialize();
+  static void Terminate();
+  // Control the refcount of the progress report category as needed
+  void Increment(std::string category);
+  void Decrement(std::string category);
+
+  // Public accessor for the class instance
+  static ProgressManager &Instance();
+
+private:
+  // Manage the class instance internally using a std::optional
+  static std::optional<ProgressManager> &InstanceImpl();
+
+  llvm::StringMap<uint64_t> m_progress_category_map;
+  std::mutex m_progress_map_mutex;
+};
+
 } // namespace lldb_private
 
 #endif // LLDB_CORE_PROGRESS_H
diff --git a/lldb/source/Core/Progress.cpp b/lldb/source/Core/Progress.cpp
index 732efbc342b450..063e64a0ef499c 100644
--- a/lldb/source/Core/Progress.cpp
+++ b/lldb/source/Core/Progress.cpp
@@ -66,3 +66,47 @@ void Progress::ReportProgress() {
                              m_debugger_id);
   }
 }
+
+void ProgressManager::Initialize() {
+  lldbassert(!InstanceImpl() && "A progress report manager already exists.");
+  InstanceImpl().emplace();
+}
+
+void ProgressManager::Terminate() {
+  lldbassert(InstanceImpl() &&
+             "A progress report manager has already been terminated.");
+  InstanceImpl().reset();
+}
+
+std::optional<ProgressManager> &ProgressManager::InstanceImpl() {
+  static std::optional<ProgressManager> g_progress_manager;
+  return g_progress_manager;
+}
+
+ProgressManager::ProgressManager() : m_progress_category_map() {}
+
+ProgressManager::~ProgressManager() {}
+
+ProgressManager &ProgressManager::Instance() { return *InstanceImpl(); }
+
+void ProgressManager::Increment(std::string title) {
+  std::lock_guard<std::mutex> lock(m_progress_map_mutex);
+  auto pair = m_progress_category_map.insert(std::pair(title, 1));
+
+  // If pair.first is not empty after insertion it means that that
+  // category was entered for the first time and should not be incremented
+  if (!pair.second)
+    ++pair.first->second;
+}
+
+void ProgressManager::Decrement(std::string title) {
+  std::lock_guard<std::mutex> lock(m_progress_map_mutex);
+  auto pos = m_progress_category_map.find(title);
+
+  if (pos == m_progress_category_map.end())
+    return;
+
+  // Remove the category from the map if the refcount reaches 0
+  if (--pos->second == 0)
+    m_progress_category_map.erase(title);
+}