From 3a0822f094b578157263e04114075ad7df81db41 Mon Sep 17 00:00:00 2001 From: Dimitry Andric Date: Sun, 21 Jun 2015 13:59:01 +0000 Subject: Vendor import of llvm trunk r240225: https://llvm.org/svn/llvm-project/llvm/trunk@240225 --- lib/Support/Windows/Memory.inc | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) (limited to 'lib/Support/Windows/Memory.inc') diff --git a/lib/Support/Windows/Memory.inc b/lib/Support/Windows/Memory.inc index ae8371abf5b3..4b2ff2e2d324 100644 --- a/lib/Support/Windows/Memory.inc +++ b/lib/Support/Windows/Memory.inc @@ -78,7 +78,15 @@ MemoryBlock Memory::allocateMappedMemory(size_t NumBytes, // While we'd be happy to allocate single pages, the Windows allocation // granularity may be larger than a single page (in practice, it is 64K) // so mapping less than that will create an unreachable fragment of memory. - static const size_t Granularity = getAllocationGranularity(); + // Avoid using one-time initialization of static locals here, since they + // aren't thread safe with MSVC. + static volatile size_t GranularityCached; + size_t Granularity = GranularityCached; + if (Granularity == 0) { + Granularity = getAllocationGranularity(); + GranularityCached = Granularity; + } + const size_t NumBlocks = (NumBytes+Granularity-1)/Granularity; uintptr_t Start = NearBlock ? reinterpret_cast(NearBlock->base()) + -- cgit v1.2.3