[lldb-dap] Move the event and progress event threads into DAP (NFC) (#139167)

JDevlieghere · web-flow · commit 60b62c65bd69 · 2025-05-09T00:29:59.000-07:00
diff --git a/lldb/tools/lldb-dap/DAP.cpp b/lldb/tools/lldb-dap/DAP.cpp
@@ -8,6 +8,7 @@
 
 #include "DAP.h"
 #include "DAPLog.h"
+#include "EventHelper.h"
 #include "Handler/RequestHandler.h"
 #include "Handler/ResponseHandler.h"
 #include "JSONUtils.h"
@@ -20,6 +21,7 @@
 #include "lldb/API/SBBreakpoint.h"
 #include "lldb/API/SBCommandInterpreter.h"
 #include "lldb/API/SBCommandReturnObject.h"
+#include "lldb/API/SBEvent.h"
 #include "lldb/API/SBLanguageRuntime.h"
 #include "lldb/API/SBListener.h"
 #include "lldb/API/SBProcess.h"
@@ -52,6 +54,7 @@
 #include <mutex>
 #include <optional>
 #include <string>
+#include <thread>
 #include <utility>
 #include <variant>
 
@@ -77,6 +80,48 @@ const char DEV_NULL[] = "/dev/null";
 
 namespace lldb_dap {
 
+static std::string GetStringFromStructuredData(lldb::SBStructuredData &data,
+                                               const char *key) {
+  lldb::SBStructuredData keyValue = data.GetValueForKey(key);
+  if (!keyValue)
+    return std::string();
+
+  const size_t length = keyValue.GetStringValue(nullptr, 0);
+
+  if (length == 0)
+    return std::string();
+
+  std::string str(length + 1, 0);
+  keyValue.GetStringValue(&str[0], length + 1);
+  return str;
+}
+
+static uint64_t GetUintFromStructuredData(lldb::SBStructuredData &data,
+                                          const char *key) {
+  lldb::SBStructuredData keyValue = data.GetValueForKey(key);
+
+  if (!keyValue.IsValid())
+    return 0;
+  return keyValue.GetUnsignedIntegerValue();
+}
+
+static llvm::StringRef GetModuleEventReason(uint32_t event_mask) {
+  if (event_mask & lldb::SBTarget::eBroadcastBitModulesLoaded)
+    return "new";
+  if (event_mask & lldb::SBTarget::eBroadcastBitModulesUnloaded)
+    return "removed";
+  assert(event_mask & lldb::SBTarget::eBroadcastBitSymbolsLoaded ||
+         event_mask & lldb::SBTarget::eBroadcastBitSymbolsChanged);
+  return "changed";
+}
+
+/// Return string with first character capitalized.
+static std::string capitalize(llvm::StringRef str) {
+  if (str.empty())
+    return "";
+  return ((llvm::Twine)llvm::toUpper(str[0]) + str.drop_front()).str();
+}
+
 llvm::StringRef DAP::debug_adapter_path = "";
 
 DAP::DAP(Log *log, const ReplMode default_repl_mode,
@@ -94,13 +139,6 @@ DAP::DAP(Log *log, const ReplMode default_repl_mode,
 
 DAP::~DAP() = default;
 
-/// Return string with first character capitalized.
-static std::string capitalize(llvm::StringRef str) {
-  if (str.empty())
-    return "";
-  return ((llvm::Twine)llvm::toUpper(str[0]) + str.drop_front()).str();
-}
-
 void DAP::PopulateExceptionBreakpoints() {
   llvm::call_once(init_exception_breakpoints_flag, [this]() {
     exception_breakpoints = std::vector<ExceptionBreakpoint>{};
@@ -1387,4 +1425,213 @@ protocol::Capabilities DAP::GetCapabilities() {
   return capabilities;
 }
 
+void DAP::StartEventThread() {
+  event_thread = std::thread(&DAP::EventThread, this);
+}
+
+void DAP::StartProgressEventThread() {
+  progress_event_thread = std::thread(&DAP::ProgressEventThread, this);
+}
+
+void DAP::ProgressEventThread() {
+  lldb::SBListener listener("lldb-dap.progress.listener");
+  debugger.GetBroadcaster().AddListener(
+      listener, lldb::SBDebugger::eBroadcastBitProgress |
+                    lldb::SBDebugger::eBroadcastBitExternalProgress);
+  broadcaster.AddListener(listener, eBroadcastBitStopProgressThread);
+  lldb::SBEvent event;
+  bool done = false;
+  while (!done) {
+    if (listener.WaitForEvent(1, event)) {
+      const auto event_mask = event.GetType();
+      if (event.BroadcasterMatchesRef(broadcaster)) {
+        if (event_mask & eBroadcastBitStopProgressThread) {
+          done = true;
+        }
+      } else {
+        lldb::SBStructuredData data =
+            lldb::SBDebugger::GetProgressDataFromEvent(event);
+
+        const uint64_t progress_id =
+            GetUintFromStructuredData(data, "progress_id");
+        const uint64_t completed = GetUintFromStructuredData(data, "completed");
+        const uint64_t total = GetUintFromStructuredData(data, "total");
+        const std::string details =
+            GetStringFromStructuredData(data, "details");
+
+        if (completed == 0) {
+          if (total == UINT64_MAX) {
+            // This progress is non deterministic and won't get updated until it
+            // is completed. Send the "message" which will be the combined title
+            // and detail. The only other progress event for thus
+            // non-deterministic progress will be the completed event So there
+            // will be no need to update the detail.
+            const std::string message =
+                GetStringFromStructuredData(data, "message");
+            SendProgressEvent(progress_id, message.c_str(), completed, total);
+          } else {
+            // This progress is deterministic and will receive updates,
+            // on the progress creation event VSCode will save the message in
+            // the create packet and use that as the title, so we send just the
+            // title in the progressCreate packet followed immediately by a
+            // detail packet, if there is any detail.
+            const std::string title =
+                GetStringFromStructuredData(data, "title");
+            SendProgressEvent(progress_id, title.c_str(), completed, total);
+            if (!details.empty())
+              SendProgressEvent(progress_id, details.c_str(), completed, total);
+          }
+        } else {
+          // This progress event is either the end of the progress dialog, or an
+          // update with possible detail. The "detail" string we send to VS Code
+          // will be appended to the progress dialog's initial text from when it
+          // was created.
+          SendProgressEvent(progress_id, details.c_str(), completed, total);
+        }
+      }
+    }
+  }
+}
+
+// All events from the debugger, target, process, thread and frames are
+// received in this function that runs in its own thread. We are using a
+// "FILE *" to output packets back to VS Code and they have mutexes in them
+// them prevent multiple threads from writing simultaneously so no locking
+// is required.
+void DAP::EventThread() {
+  llvm::set_thread_name(transport.GetClientName() + ".event_handler");
+  lldb::SBEvent event;
+  lldb::SBListener listener = debugger.GetListener();
+  broadcaster.AddListener(listener, eBroadcastBitStopEventThread);
+  debugger.GetBroadcaster().AddListener(
+      listener, lldb::eBroadcastBitError | lldb::eBroadcastBitWarning);
+  bool done = false;
+  while (!done) {
+    if (listener.WaitForEvent(1, event)) {
+      const auto event_mask = event.GetType();
+      if (lldb::SBProcess::EventIsProcessEvent(event)) {
+        lldb::SBProcess process = lldb::SBProcess::GetProcessFromEvent(event);
+        if (event_mask & lldb::SBProcess::eBroadcastBitStateChanged) {
+          auto state = lldb::SBProcess::GetStateFromEvent(event);
+          switch (state) {
+          case lldb::eStateConnected:
+          case lldb::eStateDetached:
+          case lldb::eStateInvalid:
+          case lldb::eStateUnloaded:
+            break;
+          case lldb::eStateAttaching:
+          case lldb::eStateCrashed:
+          case lldb::eStateLaunching:
+          case lldb::eStateStopped:
+          case lldb::eStateSuspended:
+            // Only report a stopped event if the process was not
+            // automatically restarted.
+            if (!lldb::SBProcess::GetRestartedFromEvent(event)) {
+              SendStdOutStdErr(*this, process);
+              SendThreadStoppedEvent(*this);
+            }
+            break;
+          case lldb::eStateRunning:
+          case lldb::eStateStepping:
+            WillContinue();
+            SendContinuedEvent(*this);
+            break;
+          case lldb::eStateExited:
+            lldb::SBStream stream;
+            process.GetStatus(stream);
+            SendOutput(OutputType::Console, stream.GetData());
+
+            // When restarting, we can get an "exited" event for the process we
+            // just killed with the old PID, or even with no PID. In that case
+            // we don't have to terminate the session.
+            if (process.GetProcessID() == LLDB_INVALID_PROCESS_ID ||
+                process.GetProcessID() == restarting_process_id) {
+              restarting_process_id = LLDB_INVALID_PROCESS_ID;
+            } else {
+              // Run any exit LLDB commands the user specified in the
+              // launch.json
+              RunExitCommands();
+              SendProcessExitedEvent(*this, process);
+              SendTerminatedEvent();
+              done = true;
+            }
+            break;
+          }
+        } else if ((event_mask & lldb::SBProcess::eBroadcastBitSTDOUT) ||
+                   (event_mask & lldb::SBProcess::eBroadcastBitSTDERR)) {
+          SendStdOutStdErr(*this, process);
+        }
+      } else if (lldb::SBTarget::EventIsTargetEvent(event)) {
+        if (event_mask & lldb::SBTarget::eBroadcastBitModulesLoaded ||
+            event_mask & lldb::SBTarget::eBroadcastBitModulesUnloaded ||
+            event_mask & lldb::SBTarget::eBroadcastBitSymbolsLoaded ||
+            event_mask & lldb::SBTarget::eBroadcastBitSymbolsChanged) {
+          llvm::StringRef reason = GetModuleEventReason(event_mask);
+          const uint32_t num_modules =
+              lldb::SBTarget::GetNumModulesFromEvent(event);
+          for (uint32_t i = 0; i < num_modules; ++i) {
+            lldb::SBModule module =
+                lldb::SBTarget::GetModuleAtIndexFromEvent(i, event);
+            if (!module.IsValid())
+              continue;
+
+            llvm::json::Object body;
+            body.try_emplace("reason", reason);
+            body.try_emplace("module", CreateModule(target, module));
+            llvm::json::Object module_event = CreateEventObject("module");
+            module_event.try_emplace("body", std::move(body));
+            SendJSON(llvm::json::Value(std::move(module_event)));
+          }
+        }
+      } else if (lldb::SBBreakpoint::EventIsBreakpointEvent(event)) {
+        if (event_mask & lldb::SBTarget::eBroadcastBitBreakpointChanged) {
+          auto event_type =
+              lldb::SBBreakpoint::GetBreakpointEventTypeFromEvent(event);
+          auto bp = Breakpoint(
+              *this, lldb::SBBreakpoint::GetBreakpointFromEvent(event));
+          // If the breakpoint was set through DAP, it will have the
+          // BreakpointBase::kDAPBreakpointLabel. Regardless of whether
+          // locations were added, removed, or resolved, the breakpoint isn't
+          // going away and the reason is always "changed".
+          if ((event_type & lldb::eBreakpointEventTypeLocationsAdded ||
+               event_type & lldb::eBreakpointEventTypeLocationsRemoved ||
+               event_type & lldb::eBreakpointEventTypeLocationsResolved) &&
+              bp.MatchesName(BreakpointBase::kDAPBreakpointLabel)) {
+            // As the DAP client already knows the path of this breakpoint, we
+            // don't need to send it back as part of the "changed" event. This
+            // avoids sending paths that should be source mapped. Note that
+            // CreateBreakpoint doesn't apply source mapping and certain
+            // implementation ignore the source part of this event anyway.
+            llvm::json::Value source_bp = CreateBreakpoint(&bp);
+            source_bp.getAsObject()->erase("source");
+
+            llvm::json::Object body;
+            body.try_emplace("breakpoint", source_bp);
+            body.try_emplace("reason", "changed");
+
+            llvm::json::Object bp_event = CreateEventObject("breakpoint");
+            bp_event.try_emplace("body", std::move(body));
+
+            SendJSON(llvm::json::Value(std::move(bp_event)));
+          }
+        }
+      } else if (event_mask & lldb::eBroadcastBitError ||
+                 event_mask & lldb::eBroadcastBitWarning) {
+        lldb::SBStructuredData data =
+            lldb::SBDebugger::GetDiagnosticFromEvent(event);
+        if (!data.IsValid())
+          continue;
+        std::string type = GetStringValue(data.GetValueForKey("type"));
+        std::string message = GetStringValue(data.GetValueForKey("message"));
+        SendOutput(OutputType::Important,
+                   llvm::formatv("{0}: {1}", type, message).str());
+      } else if (event.BroadcasterMatchesRef(broadcaster)) {
+        if (event_mask & eBroadcastBitStopEventThread) {
+          done = true;
+        }
+      }
+    }
+  }
+}
+
 } // namespace lldb_dap
diff --git a/lldb/tools/lldb-dap/DAP.h b/lldb/tools/lldb-dap/DAP.h
@@ -167,8 +167,6 @@ struct DAP {
   lldb::SBTarget target;
   Variables variables;
   lldb::SBBroadcaster broadcaster;
-  std::thread event_thread;
-  std::thread progress_event_thread;
   llvm::StringMap<SourceBreakpointMap> source_breakpoints;
   FunctionBreakpointMap function_breakpoints;
   InstructionBreakpointMap instruction_breakpoints;
@@ -418,7 +416,19 @@ struct DAP {
 
   lldb::SBMutex GetAPIMutex() const { return target.GetAPIMutex(); }
 
+  void StartEventThread();
+  void StartProgressEventThread();
+
 private:
+  /// Event threads.
+  /// @{
+  void EventThread();
+  void ProgressEventThread();
+
+  std::thread event_thread;
+  std::thread progress_event_thread;
+  /// @}
+
   /// Queue for all incoming messages.
   std::deque<protocol::Message> m_queue;
   std::deque<protocol::Message> m_pending_queue;
diff --git a/lldb/tools/lldb-dap/Handler/InitializeRequestHandler.cpp b/lldb/tools/lldb-dap/Handler/InitializeRequestHandler.cpp
