(logging-log4cxx) branch master updated: Improve asyncappender robustness (#403)

[swebb2066]

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swebb2066 pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/logging-log4cxx.git


The following commit(s) were added to refs/heads/master by this push:
     new bf873fcd Improve asyncappender robustness (#403)
bf873fcd is described below

commit bf873fcda0d9d2213dce7cd95a3c9af66765b705
Author: Stephen Webb <stephen.w...@ieee.org>
AuthorDate: Fri Jul 26 13:29:46 2024 +1000

    Improve asyncappender robustness (#403)
    
    * The lock must be acquired before notify_all
---
 src/main/cpp/asyncappender.cpp | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/src/main/cpp/asyncappender.cpp b/src/main/cpp/asyncappender.cpp
index 69533ff6..cd302f62 100644
--- a/src/main/cpp/asyncappender.cpp
+++ b/src/main/cpp/asyncappender.cpp
@@ -223,6 +223,11 @@ struct AsyncAppender::AsyncAppenderPriv : public 
AppenderSkeleton::AppenderSkele
                std::lock_guard<std::mutex> lock(this->bufferMutex);
                this->closed = true;
        }
+
+       /**
+        * Used to ensure the dispatch thread does not wait when a logging 
thread is waiting.
+       */
+       int blockedCount{0};
 };
 
 
@@ -313,11 +318,11 @@ void AsyncAppender::append(const spi::LoggingEventPtr& 
event, Pool& p)
                        priv->bufferNotEmpty.notify_all();
                        break;
                }
-               priv->bufferNotEmpty.notify_all();
                //
                //   Following code is only reachable if buffer is full or 
eventCount has overflowed
                //
                std::unique_lock<std::mutex> lock(priv->bufferMutex);
+               priv->bufferNotEmpty.notify_all();
                //
                //   if blocking and thread is not already interrupted
                //      and not the dispatcher then
@@ -328,10 +333,12 @@ void AsyncAppender::append(const spi::LoggingEventPtr& 
event, Pool& p)
                        && !priv->closed
                        && (priv->dispatcher.get_id() != 
std::this_thread::get_id()) )
                {
+                       ++priv->blockedCount;
                        priv->bufferNotFull.wait(lock, [this]()
                        {
                                return priv->eventCount - priv->dispatchedCount 
< priv->bufferSize;
                        });
+                       --priv->blockedCount;
                        discard = false;
                }
 
@@ -519,7 +526,7 @@ void AsyncAppender::dispatch()
                {
                        std::unique_lock<std::mutex> lock(priv->bufferMutex);
                        priv->bufferNotEmpty.wait(lock, [this]() -> bool
-                               { return priv->dispatchedCount != 
priv->commitCount || priv->closed; }
+                               { return 0 < priv->blockedCount || 
priv->dispatchedCount != priv->commitCount || priv->closed; }
                        );
                }
                isActive = !priv->isClosed();