SL-16220: Add a WorkQueue to be serviced by mainloop.

Make LLAppViewer::idle() call LL::WorkQueue::runFor() to dequeue and run some
or all of the pending responses from worker threads.

Add a MainWorkTime setting to specify the time slice the main loop may devote
each frame to servicing such responses.

1 files changed, 18 insertions, 0 deletions

diff --git a/indra/newview/llappviewer.cpp b/indra/newview/llappviewer.cpp
index 722a6caa65..7c932a3959 100644
--- a/indra/newview/llappviewer.cpp
+++ b/indra/newview/llappviewer.cpp
@@ -233,6 +233,8 @@
 #include "llavatariconctrl.h"
 #include "llgroupiconctrl.h"
 #include "llviewerassetstats.h"
+#include "workqueue.h"
+using namespace LL;
 
 // Include for security api initialization
 #include "llsecapi.h"
@@ -366,6 +368,8 @@ BOOL gLogoutInProgress = FALSE;
 
 BOOL gSimulateMemLeak = FALSE;
 
+WorkQueue gMainloopWork("mainloop");
+
 ////////////////////////////////////////////////////////////
 // Internal globals... that should be removed.
 static std::string gArgs;
@@ -5210,6 +5214,20 @@ void LLAppViewer::idle()
 	// Execute deferred tasks.
 	LLDeferredTaskList::instance().run();
 
+	// Service the WorkQueue we use for replies from worker threads.
+	// Use function statics for the timeslice setting so we only have to fetch
+	// and convert MainWorkTime once.
+	static F32 MainWorkTimeRaw = gSavedSettings.getF32("MainWorkTime");
+	static F32Milliseconds MainWorkTimeMs(MainWorkTimeRaw);
+	// MainWorkTime is specified in fractional milliseconds, but std::chrono
+	// uses integer representations. What if we want less than a microsecond?
+	// Use nanoseconds. We're very sure we will never need to specify a
+	// MainWorkTime that would be larger than we could express in
+	// std::chrono::nanoseconds.
+	static std::chrono::nanoseconds MainWorkTimeNanoSec{
+		std::chrono::nanoseconds::rep(MainWorkTimeMs.value() * 1000000)};
+	gMainloopWork.runFor(MainWorkTimeNanoSec);
+
 	// Handle shutdown process, for example,
 	// wait for floaters to close, send quit message,
 	// forcibly quit if it has taken too long