Capture stack trace when ucrt-x86_64 asyncappendertestcase blocks

.github/workflows/test-msys2-ucrt.yml

@@ -0,0 +1,97 @@
+# 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.
+name: test-msys2-ucrt
+
+on: [workflow_dispatch, pull_request]
+
+jobs:
+  job:
+    name: ${{ matrix.env }}-${{ matrix.cxx }}-asyncappender-multithreading
+    runs-on: windows-2022
+    timeout-minutes: 15
+    strategy:
+      fail-fast: false
+      matrix:
+        name: [ ucrt64-clang, ucrt64-gnu ]
+        include:
+        - name: ucrt64-clang
+          sys: ucrt64
+          env: ucrt-x86_64
+          compiler-package: clang
+          cxx: clang++
+        - name: ucrt64-gnu
+          sys: ucrt64
+          env: ucrt-x86_64
+          compiler-package: gcc
+          cxx: g++
+
+    steps:
+    - uses: msys2/setup-msys2@v2
+      with:
+        msystem: ${{matrix.sys}}
+        update: true
+        install: >-
+          git
+          mingw-w64-${{ matrix.env }}-${{ matrix.compiler-package }}
+          mingw-w64-${{ matrix.env }}-ccmake
+          mingw-w64-${{ matrix.env }}-ninja
+          mingw-w64-${{ matrix.env }}-apr-util
+          sed
+          zip
+          mingw-w64-${{ matrix.env }}-gdb
+
+    - uses: actions/checkout@v4
+      with:
+        persist-credentials: false # do not persist auth token in the local git config
+        path: log4cxx
+
+    - name: 'configure and build'
+      shell: msys2 {0}
+      run: |
+        cmake -G Ninja -S log4cxx -B log4cxx/build -DCMAKE_CXX_COMPILER=${{ matrix.cxx }} -DCMAKE_BUILD_TYPE=Debug
+        cmake --build log4cxx/build -t asyncappendertestcase.exe
+
+    - name: 'test asyncappender multithreading'
+      shell: msys2 {0}
+      run: |
+        wmic cpu get caption, deviceid, name, numberofcores, maxclockspeed, status
+        test_exe=`pwd`/log4cxx/build/src/test/cpp/asyncappendertestcase.exe
+        export PATH=`pwd`/log4cxx/build/src/main/cpp:$PATH
+        cd log4cxx/src/test/resources
+        for i in {1..150}
+        do
+        $test_exe testMultiThread &
+        test_pid=$!
+        test_winpid=`ps -W -p $test_pid | grep '^ *[0-9]' | sed -E 's/ *[0-9]+ +[0-9]+ +[0-9]+ +([0-9]+).*/\1/'`
+        sleep 3s
+        if ps -p $test_pid > /dev/null; then
+           gdb $test_exe --pid=$test_winpid <<EOT
+        info threads
+        thread apply all backtrace
+        EOT
+          sleep 3s
+          if ps -p $test_pid > /dev/null; then
+              echo "asyncappender is still active"
+              gdb $test_exe --pid=$test_winpid <<EOT
+        info threads
+        thread apply all backtrace
+        EOT
+              #kill $test_pid
+              break
+          else
+              echo "asyncappender terminated OK"
+          fi
+        fi
+        done

src/main/cpp/asyncappender.cpp

@@ -310,10 +310,13 @@ void AsyncAppender::append(const spi::LoggingEventPtr& event, Pool& p)
 			// Write to the ring buffer
 			priv->buffer[index] = AsyncAppenderPriv::EventData{event, pendingCount};
 			// Notify the dispatch thread that an event has been added
+			auto failureCount = 0;
 			auto savedEventCount = oldEventCount;
 			while (!priv->commitCount.compare_exchange_weak(oldEventCount, oldEventCount + 1, std::memory_order_release))
 			{
-				 oldEventCount = savedEventCount;
+				oldEventCount = savedEventCount;
+				if (2 < ++failureCount) // Did the scheduler suspend a thread between claiming a slot and advancing commitCount?
+					std::this_thread::yield(); // Wait a bit
 			}
 			priv->bufferNotEmpty.notify_all();
 			break;