1 files changed, 74 insertions, 21 deletions

diff --git a/3rdparty/pybind11/tests/test_iostream.cpp b/3rdparty/pybind11/tests/test_iostream.cpp
index e9161505..421eaa2d 100644
--- a/3rdparty/pybind11/tests/test_iostream.cpp
+++ b/3rdparty/pybind11/tests/test_iostream.cpp
@@ -7,67 +7,120 @@
     BSD-style license that can be found in the LICENSE file.
 */
 
-
 #include <pybind11/iostream.h>
+
 #include "pybind11_tests.h"
-#include <iostream>
 
+#include <atomic>
+#include <iostream>
+#include <mutex>
+#include <string>
+#include <thread>
 
-void noisy_function(std::string msg, bool flush) {
+void noisy_function(const std::string &msg, bool flush) {
 
     std::cout << msg;
-    if (flush)
+    if (flush) {
         std::cout << std::flush;
+    }
 }
 
-void noisy_funct_dual(std::string msg, std::string emsg) {
+void noisy_funct_dual(const std::string &msg, const std::string &emsg) {
     std::cout << msg;
     std::cerr << emsg;
 }
 
+// object to manage C++ thread
+// simply repeatedly write to std::cerr until stopped
+// redirect is called at some point to test the safety of scoped_estream_redirect
+struct TestThread {
+    TestThread() : stop_{false} {
+        auto thread_f = [this] {
+            static std::mutex cout_mutex;
+            while (!stop_) {
+                {
+                    // #HelpAppreciated: Work on iostream.h thread safety.
+                    // Without this lock, the clang ThreadSanitizer (tsan) reliably reports a
+                    // data race, and this test is predictably flakey on Windows.
+                    // For more background see the discussion under
+                    // https://github.com/pybind/pybind11/pull/2982 and
+                    // https://github.com/pybind/pybind11/pull/2995.
+                    const std::lock_guard<std::mutex> lock(cout_mutex);
+                    std::cout << "x" << std::flush;
+                }
+                std::this_thread::sleep_for(std::chrono::microseconds(50));
+            }
+        };
+        t_ = new std::thread(std::move(thread_f));
+    }
+
+    ~TestThread() { delete t_; }
+
+    void stop() { stop_ = true; }
+
+    void join() const {
+        py::gil_scoped_release gil_lock;
+        t_->join();
+    }
+
+    void sleep() {
+        py::gil_scoped_release gil_lock;
+        std::this_thread::sleep_for(std::chrono::milliseconds(50));
+    }
+
+    std::thread *t_{nullptr};
+    std::atomic<bool> stop_;
+};
+
 TEST_SUBMODULE(iostream, m) {
 
     add_ostream_redirect(m);
 
     // test_evals
 
-    m.def("captured_output_default", [](std::string msg) {
+    m.def("captured_output_default", [](const std::string &msg) {
         py::scoped_ostream_redirect redir;
         std::cout << msg << std::flush;
     });
 
-    m.def("captured_output", [](std::string msg) {
+    m.def("captured_output", [](const std::string &msg) {
         py::scoped_ostream_redirect redir(std::cout, py::module_::import("sys").attr("stdout"));
         std::cout << msg << std::flush;
     });
 
-    m.def("guard_output", &noisy_function,
-            py::call_guard<py::scoped_ostream_redirect>(),
-            py::arg("msg"), py::arg("flush")=true);
+    m.def("guard_output",
+          &noisy_function,
+          py::call_guard<py::scoped_ostream_redirect>(),
+          py::arg("msg"),
+          py::arg("flush") = true);
 
-    m.def("captured_err", [](std::string msg) {
+    m.def("captured_err", [](const std::string &msg) {
         py::scoped_ostream_redirect redir(std::cerr, py::module_::import("sys").attr("stderr"));
         std::cerr << msg << std::flush;
     });
 
     m.def("noisy_function", &noisy_function, py::arg("msg"), py::arg("flush") = true);
 
-    m.def("dual_guard", &noisy_funct_dual,
-            py::call_guard<py::scoped_ostream_redirect, py::scoped_estream_redirect>(),
-            py::arg("msg"), py::arg("emsg"));
+    m.def("dual_guard",
+          &noisy_funct_dual,
+          py::call_guard<py::scoped_ostream_redirect, py::scoped_estream_redirect>(),
+          py::arg("msg"),
+          py::arg("emsg"));
 
-    m.def("raw_output", [](std::string msg) {
-        std::cout << msg << std::flush;
-    });
+    m.def("raw_output", [](const std::string &msg) { std::cout << msg << std::flush; });
 
-    m.def("raw_err", [](std::string msg) {
-        std::cerr << msg << std::flush;
-    });
+    m.def("raw_err", [](const std::string &msg) { std::cerr << msg << std::flush; });
 
-    m.def("captured_dual", [](std::string msg, std::string emsg) {
+    m.def("captured_dual", [](const std::string &msg, const std::string &emsg) {
         py::scoped_ostream_redirect redirout(std::cout, py::module_::import("sys").attr("stdout"));
         py::scoped_ostream_redirect redirerr(std::cerr, py::module_::import("sys").attr("stderr"));
         std::cout << msg << std::flush;
         std::cerr << emsg << std::flush;
     });
+
+    py::class_<TestThread>(m, "TestThread")
+        .def(py::init<>())
+        .def("stop", &TestThread::stop)
+        .def("join", &TestThread::join)
+        .def("sleep", &TestThread::sleep);
 }