Optimised shortcut for decoding on single CPU systems
diff --git a/common/rfb/DecodeManager.cxx b/common/rfb/DecodeManager.cxx
index d7cffcf..a655c53 100644
--- a/common/rfb/DecodeManager.cxx
+++ b/common/rfb/DecodeManager.cxx
@@ -56,7 +56,12 @@
// wasting CPU fighting for locks
if (cpuCount > 4)
cpuCount = 4;
- vlog.info("Creating %d decoder thread(s)", (int)cpuCount);
+ // The overhead of threading is small, but not small enough to
+ // ignore on single CPU systems
+ if (cpuCount == 1)
+ vlog.info("Decoding data on main thread");
+ else
+ vlog.info("Creating %d decoder thread(s)", (int)cpuCount);
}
while (cpuCount--) {
@@ -116,6 +121,17 @@
decoder = decoders[encoding];
+ // Fast path for single CPU machines to avoid the context
+ // switching overhead
+ if (threads.size() == 1) {
+ bufferStream = freeBuffers.front();
+ bufferStream->clear();
+ decoder->readRect(r, conn->getInStream(), conn->cp, bufferStream);
+ decoder->decodeRect(r, bufferStream->data(), bufferStream->length(),
+ conn->cp, pb);
+ return;
+ }
+
// Wait for an available memory buffer
queueMutex->lock();