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authorDimitry Andric <dim@FreeBSD.org>2015-06-21 13:59:01 +0000
committerDimitry Andric <dim@FreeBSD.org>2015-06-21 13:59:01 +0000
commit3a0822f094b578157263e04114075ad7df81db41 (patch)
treebc48361fe2cd1ca5f93ac01b38b183774468fc79 /lib/Support/Windows/Memory.inc
parent85d8b2bbe386bcfe669575d05b61482d7be07e5d (diff)
Diffstat (limited to 'lib/Support/Windows/Memory.inc')
-rw-r--r--lib/Support/Windows/Memory.inc10
1 files changed, 9 insertions, 1 deletions
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<uintptr_t>(NearBlock->base()) +