Author: Jonas Devlieghere Date: 2026-05-11T09:27:24-05:00 New Revision: 912176016cfe18b6a848f0999e4aa94b6e323572
URL: https://github.com/llvm/llvm-project/commit/912176016cfe18b6a848f0999e4aa94b6e323572 DIFF: https://github.com/llvm/llvm-project/commit/912176016cfe18b6a848f0999e4aa94b6e323572.diff LOG: [lldb] Release output lock across blocking el_wgetc in DisplayCompletions (#196686) DisplayCompletions held m_output_stream_sp->Lock() across the blocking el_wgetc() call used by the "More (Y/n/a)" pager. Because the lock is a recursive_mutex, this worked when Editline::Interrupt() ran on the same thread (the synchronous SIGINT handler), but deadlocks when Interrupt() runs on another thread: it blocks on the lock and can never call InterruptRead() to wake the editor thread. Mirror the pattern already used by Editline::GetCharacter: drop the lock across the blocking read and reacquire it afterward. The status check and the "^C\n" / "\n" prints stay under the lock. Added: Modified: lldb/source/Host/common/Editline.cpp Removed: ################################################################################ diff --git a/lldb/source/Host/common/Editline.cpp b/lldb/source/Host/common/Editline.cpp index 39b0a649a7f60..833516b0b2c2d 100644 --- a/lldb/source/Host/common/Editline.cpp +++ b/lldb/source/Host/common/Editline.cpp @@ -1054,9 +1054,10 @@ void Editline::DisplayCompletions( Editline &editline, llvm::ArrayRef<CompletionResult::Completion> results) { assert(!results.empty()); - LockedStreamFile locked_stream = editline.m_output_stream_sp->Lock(); + std::optional<LockedStreamFile> locked_stream = + editline.m_output_stream_sp->Lock(); - fprintf(locked_stream.GetFile().GetStream(), + fprintf(locked_stream->GetFile().GetStream(), "\n" ANSI_CLEAR_BELOW "Available completions:\n"); /// Account for the current line, the line showing "Available completions" @@ -1075,14 +1076,20 @@ void Editline::DisplayCompletions( size_t cur_pos = 0; while (cur_pos < results.size()) { cur_pos += PrintCompletion( - locked_stream.GetFile().GetStream(), results.slice(cur_pos), max_len, + locked_stream->GetFile().GetStream(), results.slice(cur_pos), max_len, editline.GetTerminalWidth(), all ? std::nullopt : std::optional<size_t>(page_size)); if (cur_pos >= results.size()) break; - fprintf(locked_stream.GetFile().GetStream(), "More (Y/n/a): "); + fprintf(locked_stream->GetFile().GetStream(), "More (Y/n/a): "); + + // Release the output lock across the blocking el_wgetc() so that + // Interrupt(), which may run on another thread, can acquire it to wake + // up the read. + locked_stream.reset(); + // The type for the output and the type for the parameter are diff erent, // to allow interoperability with older versions of libedit. The container // for the reply must be as wide as what our implementation is using, @@ -1091,14 +1098,17 @@ void Editline::DisplayCompletions( EditLineGetCharType reply = L'n'; int got_char = el_wgetc(editline.m_editline, reinterpret_cast<EditLineCharType *>(&reply)); + + locked_stream.emplace(editline.m_output_stream_sp->Lock()); + // Check for a ^C or other interruption. if (editline.m_editor_status == EditorStatus::Interrupted) { editline.m_editor_status = EditorStatus::Editing; - fprintf(locked_stream.GetFile().GetStream(), "^C\n"); + fprintf(locked_stream->GetFile().GetStream(), "^C\n"); break; } - fprintf(locked_stream.GetFile().GetStream(), "\n"); + fprintf(locked_stream->GetFile().GetStream(), "\n"); if (got_char == -1 || reply == 'n') break; if (reply == 'a') _______________________________________________ lldb-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits
