From a15fcb1e76444f7d464b263ad37bf3b5fbfdf33e Mon Sep 17 00:00:00 2001
From: Christopher Dykes <cdykes@fb.com>
Date: Thu, 26 Oct 2017 12:15:55 -0700
Subject: [PATCH] Just use a volatile static in Malloc.h
Summary: As suggested late in the initial diff (D5840883), just mark it volatile, as it works under all supported platforms.
Reviewed By: davidtgoldblatt, yfeldblum
Differential Revision: D6155241
fbshipit-source-id: 00c07a11dc7fc2e33c2d1f9a45fd28006eeff6f9
---
folly/memory/Malloc.h | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)
diff --git a/folly/memory/Malloc.h b/folly/memory/Malloc.h
index 2726c9d8..5bad7484 100644
--- a/folly/memory/Malloc.h
+++ b/folly/memory/Malloc.h
@@ -183,15 +183,12 @@ FOLLY_MALLOC_NOINLINE inline bool usingJEMalloc() noexcept {
uint64_t origAllocated = *counter;
- const void* ptr = malloc(1);
+ static const void* volatile ptr = malloc(1);
if (!ptr) {
// wtf, failing to allocate 1 byte
return false;
}
- /* Avoid optimizing away the malloc. */
- asm volatile("" ::"m"(ptr) : "memory");
-
return (origAllocated != *counter);
}();
--
2.34.1