[msan] Introduce MsanThread. Move thread-local allocator cache out of TLS.

This reduces .tbss from 109K down to almost nothing.

llvm-svn: 205618

1 files changed, 33 insertions, 0 deletions

diff --git a/compiler-rt/lib/msan/msan_allocator.h b/compiler-rt/lib/msan/msan_allocator.h
new file mode 100644
index 00000000000..407942e54c1
--- /dev/null
+++ b/compiler-rt/lib/msan/msan_allocator.h
@@ -0,0 +1,33 @@
+//===-- msan_allocator.h ----------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is a part of MemorySanitizer.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef MSAN_ALLOCATOR_H
+#define MSAN_ALLOCATOR_H
+
+#include "sanitizer_common/sanitizer_common.h"
+
+namespace __msan {
+
+struct MsanThreadLocalMallocStorage {
+  uptr quarantine_cache[16];
+  // Allocator cache contains atomic_uint64_t which must be 8-byte aligned.
+  ALIGNED(8) uptr allocator_cache[96 * (512 * 8 + 16)];  // Opaque.
+  void CommitBack();
+
+ private:
+  // These objects are allocated via mmap() and are zero-initialized.
+  MsanThreadLocalMallocStorage() {}
+};
+
+} // namespace __msan
+#endif // MSAN_ALLOCATOR_H