[Lldb-commits] [lldb] [lldb-dap] Ensure the IO forwarding threads are managed by the DAP object lifecycle. (PR #120457)

[John Harrison via lldb-commits]

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@@ -173,6 +178,63 @@ ExceptionBreakpoint *DAP::GetExceptionBreakpoint(const lldb::break_id_t bp_id) {
   return nullptr;
 }
 
+llvm::Error DAP::ConfigureIO(std::optional<std::FILE *> overrideOut,
+                             std::optional<std::FILE *> overrideErr) {
+  auto *inull = lldb_private::FileSystem::Instance().Fopen(
+      lldb_private::FileSystem::DEV_NULL, "w");
+  in = lldb::SBFile(inull, true);
+
+  lldb_private::Status status;
+  status = pout.CreateNew(/*child_process_inherit=*/false);
+  if (status.Fail())
+    return status.takeError();
+  status = perr.CreateNew(/*child_process_inherit=*/false);
+  if (status.Fail())
+    return status.takeError();
+
+  if (overrideOut) {
+    if (dup2(pout.GetWriteFileDescriptor(), fileno(*overrideOut)) == -1) {
+      return llvm::make_error<llvm::StringError>(
+          llvm::errnoAsErrorCode(),
+          llvm::formatv("override fd=%d failed", fileno(*overrideOut))
+              .str()
+              .c_str());
+    }
+  }
+
+  if (overrideErr) {
+    if (dup2(perr.GetWriteFileDescriptor(), fileno(*overrideErr)) == -1) {
+      return llvm::make_error<llvm::StringError>(
+          llvm::errnoAsErrorCode(),
+          llvm::formatv("override fd=%d failed", fileno(*overrideErr))
+              .str()
+              .c_str());
+    }
+  }
+
+  auto forwarder = [&](lldb_private::Pipe &pipe, OutputType outputType) {
+    char buffer[4098];
+    size_t bytes_read;
+    while (pipe.CanRead()) {
+      lldb_private::Status error = pipe.ReadWithTimeout(
+          &buffer, sizeof(buffer), std::chrono::seconds(1), bytes_read);
----------------
ashgti wrote:

Updated per this suggestion and I moved this logic into a `OutputRedirection` helper in the `OutputRedirection.{h,cpp}` file. I also included a comment to help explain why we need to have a write to ensure the thread stops.

https://github.com/llvm/llvm-project/pull/120457