/*
- * Copyright 2012 Facebook, Inc.
+ * Copyright 2016 Facebook, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
// Functions to provide smarter use of jemalloc, if jemalloc is being used.
// http://www.canonware.com/download/jemalloc/jemalloc-latest/doc/jemalloc.html
-#ifndef FOLLY_MALLOC_H_
+#pragma once
#define FOLLY_MALLOC_H_
-// If using fbstring from libstdc++, then just define stub code
-// here to typedef the fbstring type into the folly namespace.
+/**
+ * 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++ (see comment in FBString.h), 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;
using std::usingJEMalloc;
using std::smartRealloc;
+ using std::checkedMalloc;
+ using std::checkedCalloc;
+ using std::checkedRealloc;
}
#else // !defined(_GLIBCXX_USE_FB) || defined(_LIBSTDCXX_FBSTRING)
#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" void sdallocx(void*, size_t, 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__));
+extern "C" int mallctlnametomib(const char*, size_t*, size_t*)
+__attribute__((__weak__));
+extern "C" int mallctlbymib(const size_t*, size_t, void*, size_t*, void*,
+ size_t)
+__attribute__((__weak__));
+
+#include <bits/functexcept.h>
#define FOLLY_HAVE_MALLOC_H 1
#else
-#include "folly-config.h"
+#include <folly/detail/Malloc.h> /* nolint */
#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 <cassert>
#include <cstddef>
+#include <cstdint>
#include <cstdlib>
#include <cstring>
-/**
- * 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 the ALLOCM_SUCCESS, ALLOCM_ZERO, and ALLOCM_NO_MOVE constants
- * 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
-#endif
+#include <new>
#ifdef _LIBSTDCXX_FBSTRING
namespace std _GLIBCXX_VISIBILITY(default) {
namespace folly {
#endif
+// Cannot depend on Portability.h when _LIBSTDCXX_FBSTRING.
+// Disabled for nvcc because it fails on attributes on lambdas.
+#if defined(__GNUC__) && !defined(__NVCC__)
+#define FOLLY_MALLOC_NOINLINE __attribute__((__noinline__))
+#else
+#define FOLLY_MALLOC_NOINLINE
+#endif
/**
* Determine if we are using jemalloc or not.
*/
-inline bool usingJEMalloc() {
- return rallocm != NULL;
+inline bool usingJEMalloc() noexcept {
+ // 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.
+ // How do we determine that we're using jemalloc? In the hackiest
+ // way possible. We allocate memory using malloc() and see if the
+ // per-thread counter of allocated memory increases. This makes me
+ // feel dirty inside. Also note that this requires jemalloc to have
+ // been compiled with --enable-stats.
+ static const bool result = [] () FOLLY_MALLOC_NOINLINE noexcept {
+ // Some platforms (*cough* OSX *cough*) require weak symbol checks to be
+ // in the form if (mallctl != nullptr). Not if (mallctl) or if (!mallctl)
+ // (!!). http://goo.gl/xpmctm
+ if (mallocx == nullptr || rallocx == nullptr || xallocx == nullptr
+ || sallocx == nullptr || dallocx == nullptr || sdallocx == nullptr
+ || nallocx == nullptr || mallctl == nullptr
+ || mallctlnametomib == nullptr || mallctlbymib == nullptr) {
+ return false;
+ }
+
+ // "volatile" because gcc optimizes out the reads from *counter, because
+ // it "knows" malloc doesn't modify global state...
+ /* nolint */ volatile uint64_t* counter;
+ size_t counterLen = sizeof(uint64_t*);
+
+ if (mallctl("thread.allocatedp", static_cast<void*>(&counter), &counterLen,
+ nullptr, 0) != 0) {
+ return false;
+ }
+
+ if (counterLen != sizeof(uint64_t*)) {
+ return false;
+ }
+
+ uint64_t origAllocated = *counter;
+
+ // Static because otherwise clever compilers will find out that
+ // the ptr is not used and does not escape the scope, so they will
+ // just optimize away the malloc.
+ static void* ptr = malloc(1);
+ if (!ptr) {
+ // wtf, failing to allocate 1 byte
+ return false;
+ }
+
+ return (origAllocated != *counter);
+ }();
+
+ 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 (minSize == 0) {
+ return 0;
+ }
+
if (!usingJEMalloc()) {
// Not using jemalloc - no smarts
return minSize;
}
- 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) {
- // 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);
- }
- // Holy Moly
- // Round up to the next multiple of 4MB
- return (minSize + 4194303) & ~size_t(4194303);
+
+ return nallocx(minSize, 0);
}
// We always request "good" sizes for allocation, so jemalloc can
// expanded in place, and this constant reflects that.
static const size_t jemallocMinInPlaceExpandable = 4096;
+/**
+ * Trivial wrappers around malloc, calloc, realloc that check for allocation
+ * failure and throw std::bad_alloc in that case.
+ */
+inline void* checkedMalloc(size_t size) {
+ void* p = malloc(size);
+ if (!p) std::__throw_bad_alloc();
+ return p;
+}
+
+inline void* checkedCalloc(size_t n, size_t size) {
+ void* p = calloc(n, size);
+ if (!p) std::__throw_bad_alloc();
+ return p;
+}
+
+inline void* checkedRealloc(void* ptr, size_t size) {
+ void* p = realloc(ptr, size);
+ if (!p) std::__throw_bad_alloc();
+ return p;
+}
+
/**
* This function tries to reallocate a buffer of which only the first
* currentSize bytes are used. The problem with using realloc is that
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;
}
// Cannot expand; must move
- auto const result = malloc(newCapacity);
+ auto const result = checkedMalloc(newCapacity);
std::memcpy(result, p, currentSize);
free(p);
return result;
auto const slack = currentCapacity - currentSize;
if (slack * 2 > currentSize) {
// Too much slack, malloc-copy-free cycle:
- auto const result = malloc(newCapacity);
+ auto const result = checkedMalloc(newCapacity);
std::memcpy(result, p, currentSize);
free(p);
return result;
}
// If there's not too much slack, we realloc in hope of coalescing
- return realloc(p, newCapacity);
+ return checkedRealloc(p, newCapacity);
}
#ifdef _LIBSTDCXX_FBSTRING
} // folly
#endif // !defined(_GLIBCXX_USE_FB) || defined(_LIBSTDCXX_FBSTRING)
-
-#endif // FOLLY_MALLOC_H_
projects / folly.git / blobdiff