diff --git a/lldb/source/Core/ModuleList.cpp b/lldb/source/Core/ModuleList.cpp index d5ddf6e846112..fd306bf16ca0f 100644 --- a/lldb/source/Core/ModuleList.cpp +++ b/lldb/source/Core/ModuleList.cpp @@ -214,34 +214,38 @@ const ModuleList &ModuleList::operator=(const ModuleList &rhs) { ModuleList::~ModuleList() = default; void ModuleList::AppendImpl(const ModuleSP &module_sp, bool use_notifier) { - if (module_sp) { + if (!module_sp) + return; + { std::lock_guard guard(m_modules_mutex); // We are required to keep the first element of the Module List as the - // executable module. So check here and if the first module is NOT an - // but the new one is, we insert this module at the beginning, rather than + // executable module. So check here and if the first module is NOT an + // but the new one is, we insert this module at the beginning, rather than // at the end. // We don't need to do any of this if the list is empty: if (m_modules.empty()) { m_modules.push_back(module_sp); } else { - // Since producing the ObjectFile may take some work, first check the 0th - // element, and only if that's NOT an executable look at the incoming - // ObjectFile. That way in the normal case we only look at the element - // 0 ObjectFile. - const bool elem_zero_is_executable - = m_modules[0]->GetObjectFile()->GetType() - == ObjectFile::Type::eTypeExecutable; + // Since producing the ObjectFile may take some work, first check the + // 0th element, and only if that's NOT an executable look at the + // incoming ObjectFile. That way in the normal case we only look at the + // element 0 ObjectFile. + const bool elem_zero_is_executable = + m_modules[0]->GetObjectFile()->GetType() == + ObjectFile::Type::eTypeExecutable; lldb_private::ObjectFile *obj = module_sp->GetObjectFile(); - if (!elem_zero_is_executable && obj - && obj->GetType() == ObjectFile::Type::eTypeExecutable) { + if (!elem_zero_is_executable && obj && + obj->GetType() == ObjectFile::Type::eTypeExecutable) { m_modules.insert(m_modules.begin(), module_sp); } else { m_modules.push_back(module_sp); } } - if (use_notifier && m_notifier) - m_notifier->NotifyModuleAdded(*this, module_sp); } + // Release the mutex before calling the notifier to avoid deadlock + // NotifyModuleAdded should be thread-safe + if (use_notifier && m_notifier) + m_notifier->NotifyModuleAdded(*this, module_sp); } void ModuleList::Append(const ModuleSP &module_sp, bool notify) { diff --git a/lldb/test/API/functionalities/statusline/TestStatusline.py b/lldb/test/API/functionalities/statusline/TestStatusline.py index 087e62b387d77..33cd79736dc38 100644 --- a/lldb/test/API/functionalities/statusline/TestStatusline.py +++ b/lldb/test/API/functionalities/statusline/TestStatusline.py @@ -1,9 +1,14 @@ import lldb +import os import re +import socket +import time +from contextlib import closing from lldbsuite.test.decorators import * from lldbsuite.test.lldbtest import * from lldbsuite.test.lldbpexpect import PExpectTest +from lldbgdbserverutils import get_lldb_server_exe # PExpect uses many timeouts internally and doesn't play well @@ -115,3 +120,82 @@ def test_resize(self): # Check for the escape code to resize the scroll window. self.child.expect(re.escape("\x1b[1;19r")) self.child.expect("(lldb)") + + @skipIfRemote + @skipIfWindows + @skipIfDarwin + @add_test_categories(["lldb-server"]) + def test_modulelist_deadlock(self): + """Regression test for a deadlock that occurs when the status line is enabled before connecting + to a gdb-remote server. + """ + if get_lldb_server_exe() is None: + self.skipTest("lldb-server not found") + + MAX_RETRY_ATTEMPTS = 10 + DELAY = 0.25 + + def _find_free_port(host): + for attempt in range(MAX_RETRY_ATTEMPTS): + try: + family, type, proto, _, _ = socket.getaddrinfo( + host, 0, proto=socket.IPPROTO_TCP + )[0] + with closing(socket.socket(family, type, proto)) as sock: + sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1) + sock.bind((host, 0)) + return sock.getsockname() + except OSError: + time.sleep(DELAY * 2**attempt) # Exponential backoff + raise RuntimeError( + "Could not find a free port on {} after {} attempts.".format( + host, MAX_RETRY_ATTEMPTS + ) + ) + + def _wait_for_server_ready_in_log(log_file_path, ready_message): + """Check log file for server ready message with retry logic""" + for attempt in range(MAX_RETRY_ATTEMPTS): + if os.path.exists(log_file_path): + with open(log_file_path, "r") as f: + if ready_message in f.read(): + return + time.sleep(pow(2, attempt) * DELAY) + raise RuntimeError( + "Server not ready after {} attempts.".format(MAX_RETRY_ATTEMPTS) + ) + + self.build() + exe_path = self.getBuildArtifact("a.out") + server_log_file = self.getLogBasenameForCurrentTest() + "-lldbserver.log" + self.addTearDownHook( + lambda: os.path.exists(server_log_file) and os.remove(server_log_file) + ) + + # Find a free port for the server + addr = _find_free_port("localhost") + connect_address = "[{}]:{}".format(*addr) + commandline_args = [ + "gdbserver", + connect_address, + exe_path, + "--log-file={}".format(server_log_file), + "--log-channels=lldb conn", + ] + + server_proc = self.spawnSubprocess( + get_lldb_server_exe(), commandline_args, install_remote=False + ) + self.assertIsNotNone(server_proc) + + # Wait for server to be ready by checking log file. + server_ready_message = "Listen to {}".format(connect_address) + _wait_for_server_ready_in_log(server_log_file, server_ready_message) + + # Launch LLDB client and connect to lldb-server with statusline enabled + self.launch(timeout=self.TIMEOUT) + self.resize() + self.expect("settings set show-statusline true", ["no target"]) + self.expect( + f"gdb-remote {connect_address}", [b"a.out \xe2\x94\x82 signal SIGSTOP"] + )