1 files changed, 62 insertions, 0 deletions
diff --git a/src/VBox/Runtime/generic/RTMpGetArraySize-generic.cpp b/src/VBox/Runtime/generic/RTMpGetArraySize-generic.cpp
new file mode 100644
index 00000000..1f625ae6
--- /dev/null
+++ b/src/VBox/Runtime/generic/RTMpGetArraySize-generic.cpp
@@ -0,0 +1,62 @@
+/* $Id: RTMpGetArraySize-generic.cpp $ */
+/** @file
+ * IPRT - Multiprocessor, Generic RTMpGetArraySize.
+ */
+
+/*
+ * Copyright (C) 2010-2019 Oracle Corporation
+ *
+ * This file is part of VirtualBox Open Source Edition (OSE), as
+ * available from http://www.virtualbox.org. This file is free software;
+ * you can redistribute it and/or modify it under the terms of the GNU
+ * General Public License (GPL) as published by the Free Software
+ * Foundation, in version 2 as it comes in the "COPYING" file of the
+ * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
+ * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
+ *
+ * The contents of this file may alternatively be used under the terms
+ * of the Common Development and Distribution License Version 1.0
+ * (CDDL) only, as it comes in the "COPYING.CDDL" file of the
+ * VirtualBox OSE distribution, in which case the provisions of the
+ * CDDL are applicable instead of those of the GPL.
+ *
+ * You may elect to license modified versions of this file under the
+ * terms and conditions of either the GPL or the CDDL or both.
+ */
+
+
+/*********************************************************************************************************************************
+*   Header Files                                                                                                                 *
+*********************************************************************************************************************************/
+#include <iprt/mp.h>
+#include "internal/iprt.h"
+
+#include <iprt/asm.h>
+#include <iprt/cpuset.h>
+
+
+RTDECL(uint32_t) RTMpGetArraySize(void)
+{
+    /*
+     * Cache the result here.  This whole point of this function is that it
+     * will always return the same value, so that should be safe.
+     *
+     * Note! Because RTCPUSET may be to small to represent all the CPUs, we
+     *       check with RTMpGetCount() as well.
+     */
+    static uint32_t s_cMaxCpus = 0;
+    uint32_t cCpus = s_cMaxCpus;
+    if (RT_UNLIKELY(cCpus == 0))
+    {
+        RTCPUSET    CpuSet;
+        uint32_t    cCpus1 = RTCpuLastIndex(RTMpGetSet(&CpuSet)) + 1;
+        uint32_t    cCpus2 = RTMpGetCount();
+        cCpus              = RT_MAX(cCpus1, cCpus2);
+        ASMAtomicCmpXchgU32(&s_cMaxCpus, cCpus, 0);
+        return cCpus;
+    }
+    return s_cMaxCpus;
+
+}
+RT_EXPORT_SYMBOL(RTMpGetArraySize);
+