diff -r ea891871f481 -r bb5522e88ab2 misc/libphysfs/lzma/CPP/7zip/Common/VirtThread.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/misc/libphysfs/lzma/CPP/7zip/Common/VirtThread.cpp	Mon Apr 10 12:06:43 2017 -0400
@@ -0,0 +1,45 @@
+// VirtThread.cpp
+
+#include "StdAfx.h"
+
+#include "VirtThread.h"
+
+static THREAD_FUNC_DECL CoderThread(void *p)
+{
+  for (;;)
+  {
+    CVirtThread *t = (CVirtThread *)p;
+    t->StartEvent.Lock();
+    if (t->ExitEvent)
+      return 0;
+    t->Execute();
+    t->FinishedEvent.Set();
+  }
+}
+
+HRes CVirtThread::Create()
+{
+  RINOK(StartEvent.CreateIfNotCreated());
+  RINOK(FinishedEvent.CreateIfNotCreated());
+  StartEvent.Reset();
+  FinishedEvent.Reset();
+  ExitEvent = false;
+  if (Thread.IsCreated())
+    return S_OK;
+  return Thread.Create(CoderThread, this);
+}
+
+void CVirtThread::Start()
+{
+  ExitEvent = false;
+  StartEvent.Set();
+}
+
+CVirtThread::~CVirtThread()
+{
+  ExitEvent = true;
+  if (StartEvent.IsCreated())
+    StartEvent.Set();
+  Thread.Wait();
+}
+