From: Peter Åstrand (astrand) <astrand@cendio.se>
Date: Mon, 7 May 2018 12:59:57 +0000 (+0200)
Subject: Avoid creating unused thread on single CPU machines
X-Git-Tag: v1.8.90~17
X-Git-Url: https://source.dussan.org/?a=commitdiff_plain;h=67814b638783f3dde6dd8df12346bbdf81c70efc;p=tigervnc.git

Avoid creating unused thread on single CPU machines
---

diff --git a/common/rfb/DecodeManager.cxx b/common/rfb/DecodeManager.cxx
index ccf084f7..774f7bb8 100644
--- a/common/rfb/DecodeManager.cxx
+++ b/common/rfb/DecodeManager.cxx
@@ -64,6 +64,12 @@ DecodeManager::DecodeManager(CConnection *conn) :
       vlog.info("Creating %d decoder thread(s)", (int)cpuCount);
   }
 
+  if (cpuCount == 1) {
+    // Threads are not used on single CPU machines
+    freeBuffers.push_back(new rdr::MemOutStream());
+    return;
+  }
+
   while (cpuCount--) {
     // Twice as many possible entries in the queue as there
     // are worker threads to make sure they don't stall
@@ -123,7 +129,7 @@ void DecodeManager::decodeRect(const Rect& r, int encoding,
 
   // Fast path for single CPU machines to avoid the context
   // switching overhead
-  if (threads.size() == 1) {
+  if (threads.empty()) {
     bufferStream = freeBuffers.front();
     bufferStream->clear();
     decoder->readRect(r, conn->getInStream(), conn->cp, bufferStream);