feat(python/adbc_driver_manager): handle KeyboardInterrupt

Fixes #1484.

.github/workflows/native-unix.yml

@@ -477,7 +477,20 @@ jobs:
       - name: Test Python Driver Flight SQL
         shell: bash -l {0}
         run: |
+          # Can't use Docker on macOS
+          pushd $(pwd)/go/adbc
+          go build -o testserver ./driver/flightsql/cmd/testserver
+          popd
+          $(pwd)/go/adbc/testserver -host 0.0.0.0 -port 41414 &
+          while ! curl --http2-prior-knowledge -H "content-type: application/grpc" -v localhost:41414 -XPOST;
+          do
+              echo "Waiting for test server..."
+              jobs
+              sleep 5
+          done
+          export ADBC_TEST_FLIGHTSQL_URI=grpc://localhost:41414
           env BUILD_ALL=0 BUILD_DRIVER_FLIGHTSQL=1 ./ci/scripts/python_test.sh "$(pwd)" "$(pwd)/build" "$HOME/local"
+          kill %1
       - name: Build Python Driver PostgreSQL
         shell: bash -l {0}
         run: |

ci/scripts/python_test.sh

@@ -58,8 +58,8 @@ test_subproject() {
     fi
 
     echo "=== Testing ${subproject} ==="
-    echo env ${options[@]} python -m pytest -vv "${source_dir}/python/${subproject}/tests"
-    env ${options[@]} python -m pytest -vv "${source_dir}/python/${subproject}/tests"
+    echo env ${options[@]} python -m pytest -vvs --full-trace "${source_dir}/python/${subproject}/tests"
+    env ${options[@]} python -m pytest -vvs --full-trace "${source_dir}/python/${subproject}/tests"
     echo
 }
 

docker-compose.yml

@@ -150,6 +150,12 @@ services:
       dockerfile: ci/docker/flightsql-test.dockerfile
       args:
         GO: ${GO}
+    healthcheck:
+      test: ["CMD", "curl", "--http2-prior-knowledge", "-XPOST", "-H", "content-type: application/grpc"]
+      interval: 5s
+      timeout: 30s
+      retries: 3
+      start_period: 5m
     ports:
       - "41414:41414"
     volumes:

python/adbc_driver_flightsql/tests/test_errors.py

@@ -16,6 +16,8 @@
 # under the License.
 
 import re
+import threading
+import time
 
 import google.protobuf.any_pb2 as any_pb2
 import google.protobuf.wrappers_pb2 as wrappers_pb2
@@ -45,6 +47,24 @@ def test_query_cancel(test_dbapi):
             cur.fetchone()
 
 
+def test_query_cancel_async(test_dbapi):
+    with test_dbapi.cursor() as cur:
+        cur.execute("forever")
+
+        def _cancel():
+            time.sleep(2)
+            cur.adbc_cancel()
+
+        t = threading.Thread(target=_cancel, daemon=True)
+        t.start()
+
+        with pytest.raises(
+            test_dbapi.OperationalError,
+            match=re.escape("CANCELLED: [FlightSQL] context canceled"),
+        ):
+            cur.fetchone()
+
+
 def test_query_error_fetch(test_dbapi):
     with test_dbapi.cursor() as cur:
         cur.execute("error_do_get")

python/adbc_driver_manager/MANIFEST.in

@@ -22,6 +22,8 @@ include NOTICE.txt
 include adbc_driver_manager/adbc.h
 include adbc_driver_manager/adbc_driver_manager.cc
 include adbc_driver_manager/adbc_driver_manager.h
+include adbc_driver_manager/_blocking_impl.cc
+include adbc_driver_manager/_blocking_impl.h
 include adbc_driver_manager/_lib.pxd
 include adbc_driver_manager/_lib.pyi
 include adbc_driver_manager/_reader.pyi

python/adbc_driver_manager/adbc_driver_manager/_blocking_impl.cc

@@ -0,0 +1,269 @@
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+#include "_blocking_impl.h"
+
+#if defined(_WIN32)
+#define NOMINMAX
+#define WIN32_LEAN_AND_MEAN
+#include <errno.h>
+#include <fcntl.h>
+#include <io.h>
+#include <windows.h>
+#else
+#include <fcntl.h>
+#include <pthread.h>
+#include <unistd.h>
+#endif
+
+#include <csignal>
+#include <cstring>
+#include <iostream>
+#include <mutex>
+#include <thread>
+
+namespace pyadbc_driver_manager {
+
+// This is somewhat derived from io_util.cc in arrow, but that implementation
+// isn't easily used outside of Arrow's monolith.
+namespace {
+static std::once_flag kInitOnce;
+// We may encounter errors below that we can't do anything about. Use this to
+// print out an error, once.
+static std::once_flag kWarnOnce;
+// This thread reads from a pipe forever.  Whenever it reads something, it
+// calls the callback below.
+static std::thread kCancelThread;
+
+static std::mutex cancel_mutex;
+// This callback is registered by the Python side; basically it will call
+// cancel() on an ADBC object.
+static void (*cancel_callback)(void*) = nullptr;
+// Callback state (a pointer to the ADBC PyObject).
+static void* cancel_callback_data = nullptr;
+// A nonblocking self-pipe.
+static int pipe[2];
+#if defined(_WIN32)
+void (*old_sigint)(int);
+#else
+// The old signal handler (most likely Python's).
+struct sigaction old_sigint;
+// Our signal handler (below).
+struct sigaction our_sigint;
+#endif
+
+std::string MakePipe() {
+  int rc = 0;
+#if defined(__linux__) && defined(__GLIBC__)
+  rc = pipe2(pipe, O_CLOEXEC);
+#elif defined(_WIN32)
+  rc = _pipe(pipe, 4096, _O_BINARY);
+#else
+  rc = ::pipe(pipe);
+#endif
+
+  if (rc != 0) {
+    return std::strerror(errno);
+  }
+
+#if (!defined(__linux__) || !defined(__GLIBC__)) && !defined(_WIN32)
+  {
+    int flags = fcntl(pipe[0], F_GETFD, 0);
+    if (flags < 0) {
+      return std::strerror(errno);
+    }
+    rc = fcntl(pipe[0], F_SETFD, flags | FD_CLOEXEC);
+    if (rc < 0) {
+      return std::strerror(errno);
+    }
+
+    flags = fcntl(pipe[1], F_GETFD, 0);
+    if (flags < 0) {
+      return std::strerror(errno);
+    }
+    rc = fcntl(pipe[1], F_SETFD, flags | FD_CLOEXEC);
+    if (rc < 0) {
+      return std::strerror(errno);
+    }
+  }
+#endif
+
+  // Make the write side nonblocking (the read side should stay blocking!)
+#if defined(_WIN32)
+  const auto handle = reinterpret_cast<HANDLE>(_get_osfhandle(pipe[1]));
+  DWORD mode = PIPE_NOWAIT;
+  if (!SetNamedPipeHandleState(handle, &mode, nullptr, nullptr)) {
+    DWORD last_error = GetLastError();
+    LPVOID message;
+
+    FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM |
+                      FORMAT_MESSAGE_IGNORE_INSERTS,
+                  /*lpSource=*/nullptr, last_error,
+                  MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
+                  reinterpret_cast<LPSTR>(&message), /*nSize=*/0, /*Arguments=*/nullptr);
+
+    std::string buffer = "(";
+    buffer += std::to_string(last_error);
+    buffer += ") ";
+    buffer += reinterpret_cast<char*>(message);
+    LocalFree(message);
+    return buffer;
+  }
+#else
+  {
+    int flags = fcntl(pipe[1], F_GETFL, 0);
+    if (flags < 0) {
+      return std::strerror(errno);
+    }
+    rc = fcntl(pipe[1], F_SETFL, flags | O_NONBLOCK);
+    if (rc < 0) {
+      return std::strerror(errno);
+    }
+  }
+#endif
+
+  return "";
+}
+
+void InterruptThread() {
+#if defined(__APPLE__)
+  pthread_setname_np("AdbcInterrupt");
+#endif
+
+  while (true) {
+    char buf = 0;
+    // Anytime something is written to the pipe, attempt to call the callback
+    auto bytes_read = read(pipe[0], &buf, 1);
+    if (bytes_read < 0) {
+      if (errno == EINTR) continue;
+
+      // XXX: we failed reading from the pipe
+      std::string message = std::strerror(errno);
+      std::call_once(kWarnOnce, [&]() {
+        std::cerr << "adbc_driver_manager (native code): error handling interrupt: "
+                  << message << std::endl;
+      });
+    } else if (bytes_read > 0) {
+      // Save the callback locally instead of calling it under the lock, since
+      // otherwise we may deadlock with the Python side trying to call us
+      void (*local_callback)(void*) = nullptr;
+      void* local_callback_data = nullptr;
+
+      {
+        std::lock_guard<std::mutex> lock(cancel_mutex);
+        if (cancel_callback != nullptr) {
+          local_callback = cancel_callback;
+          local_callback_data = cancel_callback_data;
+        }
+        cancel_callback = nullptr;
+        cancel_callback_data = nullptr;
+      }
+
+      if (local_callback != nullptr) {
+        local_callback(local_callback_data);
+      }
+    }
+  }
+}
+
+// We can't do much about failures here, so ignore the result.  If the pipe is
+// full, that's fine; it just means the thread has fallen behind in processing
+// earlier interrupts.
+void SigintHandler(int) {
+#if defined(_WIN32)
+  (void)_write(pipe[1], "X", 1);
+#else
+  (void)write(pipe[1], "X", 1);
+#endif
+}
+
+}  // namespace
+
+std::string InitBlockingCallback() {
+  std::string error;
+  std::call_once(kInitOnce, [&]() {
+    error = MakePipe();
+    if (!error.empty()) {
+      return;
+    }
+
+#if !defined(_WIN32)
+    our_sigint.sa_handler = &SigintHandler;
+    our_sigint.sa_flags = 0;
+    sigemptyset(&our_sigint.sa_mask);
+#endif
+
+    kCancelThread = std::thread(InterruptThread);
+#if defined(__linux__)
+    pthread_setname_np(kCancelThread.native_handle(), "AdbcInterrupt");
+#endif
+    kCancelThread.detach();
+  });
+  return error;
+}
+
+std::string SetBlockingCallback(void (*callback)(void*), void* data) {
+  std::lock_guard<std::mutex> lock(cancel_mutex);
+  cancel_callback = callback;
+  cancel_callback_data = data;
+
+#if defined(_WIN32)
+  if (old_sigint == nullptr) {
+    old_sigint = signal(SIGINT, &SigintHandler);
+    if (old_sigint == SIG_ERR) {
+      old_sigint = nullptr;
+      return std::strerror(errno);
+    }
+  }
+#else
+  // Don't set the handler again if we're somehow called twice
+  if (old_sigint.sa_handler == nullptr && old_sigint.sa_sigaction == nullptr) {
+    int rc = sigaction(SIGINT, &our_sigint, &old_sigint);
+    if (rc != 0) {
+      return std::strerror(errno);
+    }
+  }
+#endif
+  return "";
+}
+
+std::string ClearBlockingCallback() {
+  std::lock_guard<std::mutex> lock(cancel_mutex);
+  cancel_callback = nullptr;
+  cancel_callback_data = nullptr;
+
+#if defined(_WIN32)
+  if (old_sigint != nullptr) {
+    auto rc = signal(SIGINT, old_sigint);
+    old_sigint = nullptr;
+    if (rc == SIG_ERR) {
+      return std::strerror(errno);
+    }
+  }
+#else
+  if (old_sigint.sa_handler != nullptr || old_sigint.sa_sigaction != nullptr) {
+    int rc = sigaction(SIGINT, &old_sigint, nullptr);
+    std::memset(&old_sigint, 0, sizeof(old_sigint));
+    if (rc != 0) {
+      return std::strerror(errno);
+    }
+  }
+#endif
+  return "";
+}
+
+}  // namespace pyadbc_driver_manager

python/adbc_driver_manager/adbc_driver_manager/_blocking_impl.h

@@ -0,0 +1,38 @@
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+/// Allow KeyboardInterrupt to function with ADBC in Python.
+///
+/// Call SetBlockingCallback to register a callback.  This will temporarily
+/// suppress the Python SIGINT handler.  When SIGINT is received, this module
+/// will handle it by calling the callback.
+
+#include <string>
+
+namespace pyadbc_driver_manager {
+
+/// \brief Set up internal state to handle.
+/// \return An error message (or empty string).
+std::string InitBlockingCallback();
+/// \brief Set the callback for when SIGINT is received.
+/// \return An error message (or empty string).
+std::string SetBlockingCallback(void (*callback)(void*), void* data);
+/// \brief Clear the callback for when SIGINT is received.
+/// \return An error message (or empty string).
+std::string ClearBlockingCallback();
+
+}  // namespace pyadbc_driver_manager