/*
- * Copyright 2013 Facebook, Inc.
+ * Copyright 2015 Facebook, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
#ifndef FOLLY_MALLOC_H_
#define FOLLY_MALLOC_H_
+/**
+ * Define various MALLOCX_* macros normally provided by jemalloc. We define
+ * them so that we don't have to include jemalloc.h, in case the program is
+ * built without jemalloc support.
+ */
+#ifndef MALLOCX_LG_ALIGN
+#define MALLOCX_LG_ALIGN(la) (la)
+#endif
+#ifndef MALLOCX_ZERO
+#define MALLOCX_ZERO (static_cast<int>(0x40))
+#endif
+
// If using fbstring from libstdc++, then just define stub code
// here to typedef the fbstring type into the folly namespace.
// This provides backwards compatibility for code that explicitly
// includes and uses fbstring.
#if defined(_GLIBCXX_USE_FB) && !defined(_LIBSTDCXX_FBSTRING)
+#include <folly/detail/Malloc.h>
+
#include <string>
+
namespace folly {
using std::goodMallocSize;
using std::jemallocMinInPlaceExpandable;
#ifdef _LIBSTDCXX_FBSTRING
#pragma GCC system_header
+
+/**
+ * Declare *allocx() and mallctl() as weak symbols. These will be provided by
+ * jemalloc if we are using jemalloc, or will be NULL if we are using another
+ * malloc implementation.
+ */
+extern "C" void* mallocx(size_t, int)
+__attribute__((__weak__));
+extern "C" void* rallocx(void*, size_t, int)
+__attribute__((__weak__));
+extern "C" size_t xallocx(void*, size_t, size_t, int)
+__attribute__((__weak__));
+extern "C" size_t sallocx(const void*, int)
+__attribute__((__weak__));
+extern "C" void dallocx(void*, int)
+__attribute__((__weak__));
+extern "C" size_t nallocx(size_t, int)
+__attribute__((__weak__));
+extern "C" int mallctl(const char*, void*, size_t*, void*, size_t)
+__attribute__((__weak__));
+
+#include <bits/functexcept.h>
#define FOLLY_HAVE_MALLOC_H 1
#else
-#include "folly/Portability.h"
+#include <folly/detail/Malloc.h> /* nolint */
+#include <folly/Portability.h>
#endif
// for malloc_usable_size
// NOTE: FreeBSD 9 doesn't have malloc.h. It's defitions
// are found in stdlib.h.
-#ifdef FOLLY_HAVE_MALLOC_H
+#if FOLLY_HAVE_MALLOC_H
#include <malloc.h>
#else
#include <stdlib.h>
#include <new>
-#include <bits/functexcept.h>
-
-/**
- * Declare rallocm() and malloc_usable_size() as weak symbols. It
- * will be provided by jemalloc if we are using jemalloc, or it will
- * be NULL if we are using another malloc implementation.
- */
-extern "C" int rallocm(void**, size_t*, size_t, size_t, int)
-__attribute__((weak));
-
-/**
- * Define various ALLOCM_* macros normally provided by jemalloc. We define
- * them so that we don't have to include jemalloc.h, in case the program is
- * built without jemalloc support.
- */
-#ifndef ALLOCM_SUCCESS
-
-#define ALLOCM_SUCCESS 0
-#define ALLOCM_ERR_OOM 1
-#define ALLOCM_ERR_NOT_MOVED 2
-
-#define ALLOCM_ZERO 64
-#define ALLOCM_NO_MOVE 128
-
-#define ALLOCM_LG_ALIGN(la) (la)
-
-#endif /* !ALLOCM_SUCCESS */
-
#ifdef _LIBSTDCXX_FBSTRING
namespace std _GLIBCXX_VISIBILITY(default) {
_GLIBCXX_BEGIN_NAMESPACE_VERSION
namespace folly {
#endif
+bool usingJEMallocSlow();
/**
* Determine if we are using jemalloc or not.
*/
inline bool usingJEMalloc() {
- return rallocm != NULL;
+ // Checking for rallocx != NULL is not sufficient; we may be in a dlopen()ed
+ // module that depends on libjemalloc, so rallocx is resolved, but the main
+ // program might be using a different memory allocator. Look at the
+ // implementation of usingJEMallocSlow() for the (hacky) details.
+ static const bool result = usingJEMallocSlow();
+ return result;
}
/**
* For jemalloc's size classes, see
* http://www.canonware.com/download/jemalloc/jemalloc-latest/doc/jemalloc.html
*/
-inline size_t goodMallocSize(size_t minSize) {
+inline size_t goodMallocSize(size_t minSize) noexcept {
if (!usingJEMalloc()) {
// Not using jemalloc - no smarts
return minSize;
}
+ size_t goodSize;
if (minSize <= 64) {
// Choose smallest allocation to be 64 bytes - no tripping over
// cache line boundaries, and small string optimization takes care
// of short strings anyway.
- return 64;
- }
- if (minSize <= 512) {
+ goodSize = 64;
+ } else if (minSize <= 512) {
// Round up to the next multiple of 64; we don't want to trip over
// cache line boundaries.
- return (minSize + 63) & ~size_t(63);
- }
- if (minSize <= 3840) {
- // Round up to the next multiple of 256
- return (minSize + 255) & ~size_t(255);
- }
- if (minSize <= 4072 * 1024) {
- // Round up to the next multiple of 4KB
- return (minSize + 4095) & ~size_t(4095);
+ goodSize = (minSize + 63) & ~size_t(63);
+ } else {
+ // Boundaries between size classes depend on numerious factors, some of
+ // which can even be modified at run-time. Determine the good allocation
+ // size by calling nallocx() directly.
+ goodSize = nallocx(minSize, 0);
}
- // Holy Moly
- // Round up to the next multiple of 4MB
- return (minSize + 4194303) & ~size_t(4194303);
+ assert(nallocx(goodSize, 0) == goodSize);
+ return goodSize;
}
// We always request "good" sizes for allocation, so jemalloc can
if (usingJEMalloc()) {
// using jemalloc's API. Don't forget that jemalloc can never grow
// in place blocks smaller than 4096 bytes.
+ //
+ // NB: newCapacity may not be precisely equal to a jemalloc size class,
+ // i.e. newCapacity is not guaranteed to be the result of a
+ // goodMallocSize() call, therefore xallocx() may return more than
+ // newCapacity bytes of space. Use >= rather than == to check whether
+ // xallocx() successfully expanded in place.
if (currentCapacity >= jemallocMinInPlaceExpandable &&
- rallocm(&p, NULL, newCapacity, 0, ALLOCM_NO_MOVE) == ALLOCM_SUCCESS) {
+ xallocx(p, newCapacity, 0, 0) >= newCapacity) {
// Managed to expand in place
return p;
}
projects / folly.git / blobdiff