QPID-4514: Remove IO readCredit throttling only used by removed cluster code

git-svn-id: https://svn.apache.org/repos/asf/qpid/trunk/qpid@1440616 13f79535-47bb-0310-9956-ffa450edef68

7 files changed, 1 insertions, 51 deletions

diff --git a/cpp/src/qpid/sys/AggregateOutput.cpp b/cpp/src/qpid/sys/AggregateOutput.cpp
index ff9c740926..ebc5689ce5 100644
--- a/cpp/src/qpid/sys/AggregateOutput.cpp
+++ b/cpp/src/qpid/sys/AggregateOutput.cpp
@@ -32,8 +32,6 @@ void AggregateOutput::abort() { control.abort(); }
 
 void AggregateOutput::activateOutput() { control.activateOutput(); }
 
-void AggregateOutput::giveReadCredit(int32_t credit) { control.giveReadCredit(credit); }
-
 namespace {
 // Clear the busy flag and notify waiting threads in destructor.
 struct ScopedBusy {
diff --git a/cpp/src/qpid/sys/AggregateOutput.h b/cpp/src/qpid/sys/AggregateOutput.h
index 802722ad26..e9dbd5a4cc 100644
--- a/cpp/src/qpid/sys/AggregateOutput.h
+++ b/cpp/src/qpid/sys/AggregateOutput.h
@@ -59,7 +59,6 @@ class QPID_COMMON_CLASS_EXTERN AggregateOutput : public OutputTask, public Outpu
     // These may be called concurrently with any function.
     QPID_COMMON_EXTERN void abort();
     QPID_COMMON_EXTERN void activateOutput();
-    QPID_COMMON_EXTERN void giveReadCredit(int32_t);
     QPID_COMMON_EXTERN void addOutputTask(OutputTask* t);
 
     // These functions must not be called concurrently with each other.
diff --git a/cpp/src/qpid/sys/AsynchIOHandler.cpp b/cpp/src/qpid/sys/AsynchIOHandler.cpp
index 0225b11d27..13c71e301b 100644
--- a/cpp/src/qpid/sys/AsynchIOHandler.cpp
+++ b/cpp/src/qpid/sys/AsynchIOHandler.cpp
@@ -59,8 +59,7 @@ AsynchIOHandler::AsynchIOHandler(const std::string& id, ConnectionCodec::Factory
     reads(0),
     readError(false),
     isClient(isClient0),
-    nodict(nodict0),
-    readCredit(InfiniteCredit)
+    nodict(nodict0)
 {}
 
 AsynchIOHandler::~AsynchIOHandler() {
@@ -104,21 +103,6 @@ void AsynchIOHandler::activateOutput() {
     aio->notifyPendingWrite();
 }
 
-// Input side
-void AsynchIOHandler::giveReadCredit(int32_t credit) {
-    // Check whether we started in the don't about credit state
-    if (readCredit.boolCompareAndSwap(InfiniteCredit, credit))
-        return;
-    // TODO In theory should be able to use an atomic operation before taking the lock
-    // but in practice there seems to be an unexplained race in that case
-    ScopedLock<Mutex> l(creditLock);
-    if (readCredit.fetchAndAdd(credit) != 0)
-        return;
-    assert(readCredit.get() >= 0);
-    if (readCredit.get() != 0)
-        aio->startReading();
-}
-
 namespace {
     SecuritySettings getSecuritySettings(AsynchIO* aio, bool nodict)
     {
@@ -133,26 +117,6 @@ void AsynchIOHandler::readbuff(AsynchIO& , AsynchIO::BufferBase* buff) {
         return;
     }
 
-    // Check here for read credit
-    if (readCredit.get() != InfiniteCredit) {
-        if (readCredit.get() == 0) {
-            // FIXME aconway 2009-10-01:  Workaround to avoid "false wakeups".
-            // readbuff is sometimes called with no credit.
-            // This should be fixed somewhere else to avoid such calls.
-            aio->unread(buff);
-            return;
-        }
-        // TODO In theory should be able to use an atomic operation before taking the lock
-        // but in practice there seems to be an unexplained race in that case
-        ScopedLock<Mutex> l(creditLock);
-        if (--readCredit == 0) {
-            assert(readCredit.get() >= 0);
-            if (readCredit.get() == 0) {
-                aio->stopReading();
-            }
-        }
-    }
-
     ++reads;
     size_t decoded = 0;
     if (codec) {                // Already initiated
diff --git a/cpp/src/qpid/sys/AsynchIOHandler.h b/cpp/src/qpid/sys/AsynchIOHandler.h
index 91ddb022af..d93e24fd4c 100644
--- a/cpp/src/qpid/sys/AsynchIOHandler.h
+++ b/cpp/src/qpid/sys/AsynchIOHandler.h
@@ -52,9 +52,6 @@ class AsynchIOHandler : public OutputControl {
     bool readError;
     bool isClient;
     bool nodict;
-    AtomicValue<int32_t> readCredit;
-    static const int32_t InfiniteCredit = -1;
-    Mutex creditLock;
     boost::intrusive_ptr<sys::TimerTask> timeoutTimerTask;
 
     void write(const framing::ProtocolInitiation&);
@@ -67,7 +64,6 @@ class AsynchIOHandler : public OutputControl {
     // Output side
     QPID_COMMON_EXTERN void abort();
     QPID_COMMON_EXTERN void activateOutput();
-    QPID_COMMON_EXTERN void giveReadCredit(int32_t credit);
 
     // Input side
     QPID_COMMON_EXTERN void readbuff(AsynchIO& aio, AsynchIOBufferBase* buff);
diff --git a/cpp/src/qpid/sys/ConnectionOutputHandlerPtr.h b/cpp/src/qpid/sys/ConnectionOutputHandlerPtr.h
index 95a08d15ae..53d56ad716 100644
--- a/cpp/src/qpid/sys/ConnectionOutputHandlerPtr.h
+++ b/cpp/src/qpid/sys/ConnectionOutputHandlerPtr.h
@@ -45,7 +45,6 @@ class ConnectionOutputHandlerPtr : public ConnectionOutputHandler
     size_t getBuffered() const { return next->getBuffered(); }
     void abort() { next->abort(); }
     void activateOutput() { next->activateOutput(); }
-    void giveReadCredit(int32_t credit) { next->giveReadCredit(credit); }
     void send(framing::AMQFrame& f) { next->send(f); }
 
   private:
diff --git a/cpp/src/qpid/sys/OutputControl.h b/cpp/src/qpid/sys/OutputControl.h
index ad5caa3168..0d801e9d16 100644
--- a/cpp/src/qpid/sys/OutputControl.h
+++ b/cpp/src/qpid/sys/OutputControl.h
@@ -33,7 +33,6 @@ namespace sys {
         virtual ~OutputControl() {}
         virtual void abort() = 0;
         virtual void activateOutput() = 0;
-        virtual void giveReadCredit(int32_t credit) = 0;
     };
 
 }
diff --git a/cpp/src/qpid/sys/RdmaIOPlugin.cpp b/cpp/src/qpid/sys/RdmaIOPlugin.cpp
index e1f4362d64..51cc0ed109 100644
--- a/cpp/src/qpid/sys/RdmaIOPlugin.cpp
+++ b/cpp/src/qpid/sys/RdmaIOPlugin.cpp
@@ -68,7 +68,6 @@ class RdmaIOHandler : public OutputControl {
     void close();
     void abort();
     void activateOutput();
-    void giveReadCredit(int32_t credit);
     void initProtocolOut();
 
     // Input side
@@ -200,10 +199,6 @@ void RdmaIOHandler::full(Rdma::AsynchIO&) {
     QPID_LOG(debug, "Rdma: buffer full [" << identifier << "]");
 }
 
-// TODO: Dummy implementation of read throttling
-void RdmaIOHandler::giveReadCredit(int32_t) {
-}
-
 // The logic here is subtly different from TCP as RDMA is message oriented
 // so we define that an RDMA message is a frame - in this case there is no putting back
 // of any message remainder - there shouldn't be any. And what we read here can't be