Move Partition Allocator into Chromium base.

base/allocator/partition_allocator/address_space_randomization.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "wtf/allocator/AddressSpaceRandomization.h"
+#include "base/allocator/partition_allocator/address_space_randomization.h"
 
-#include "wtf/SpinLock.h"
-#include "wtf/allocator/PageAllocator.h"
+#include "base/allocator/partition_allocator/page_allocator.h"
+#include "base/synchronization/spin_lock.h"
+#include "build/build_config.h"
 
-#if OS(WIN)
+#if defined(OS_WIN)
 #include <windows.h>
 #else
 #include <sys/time.h>
 #include <unistd.h>
 #endif
 
-namespace WTF {
+namespace base {
 
 namespace {
 
 // This is the same PRNG as used by tcmalloc for mapping address randomness;
 // see http://burtleburtle.net/bob/rand/smallprng.html
 struct ranctx {
-  SpinLock lock;
+  subtle::SpinLock lock;
   bool initialized;
   uint32_t a;
   uint32_t b;
   uint32_t c;
   uint32_t d;
 };
 
 #define rot(x, k) (((x) << (k)) | ((x) >> (32 - (k))))
 
 uint32_t ranvalInternal(ranctx* x) {
   uint32_t e = x->a - rot(x->b, 27);
   x->a = x->b ^ rot(x->c, 17);
   x->b = x->c + x->d;
   x->c = x->d + e;
   x->d = e + x->a;
   return x->d;
 }
 
 #undef rot
 
 uint32_t ranval(ranctx* x) {
-  SpinLock::Guard guard(x->lock);
+  subtle::SpinLock::Guard guard(x->lock);
   if (UNLIKELY(!x->initialized)) {
     x->initialized = true;
     char c;
     uint32_t seed = static_cast<uint32_t>(reinterpret_cast<uintptr_t>(&c));
     uint32_t pid;
     uint32_t usec;
-#if OS(WIN)
+#if defined(OS_WIN)
     pid = GetCurrentProcessId();
     SYSTEMTIME st;
     GetSystemTime(&st);
     usec = static_cast<uint32_t>(st.wMilliseconds * 1000);
 #else
     pid = static_cast<uint32_t>(getpid());
     struct timeval tv;
     gettimeofday(&tv, 0);
     usec = static_cast<uint32_t>(tv.tv_usec);
 #endif
     seed ^= pid;
     seed ^= usec;
     x->a = 0xf1ea5eed;
     x->b = x->c = x->d = seed;
     for (int i = 0; i < 20; ++i) {
       (void)ranvalInternal(x);
     }
   }
   uint32_t ret = ranvalInternal(x);
   return ret;
 }
 
 static struct ranctx s_ranctx;
 
 }  // namespace
 
-// Calculates a random preferred mapping address. In calculating an
-// address, we balance good ASLR against not fragmenting the address
-// space too badly.
+// Calculates a random preferred mapping address. In calculating an address, we
+// balance good ASLR against not fragmenting the address space too badly.
 void* getRandomPageBase() {
   uintptr_t random;
   random = static_cast<uintptr_t>(ranval(&s_ranctx));
-#if CPU(X86_64)
+#if defined(ARCH_CPU_X86_64)
   random <<= 32UL;
   random |= static_cast<uintptr_t>(ranval(&s_ranctx));
-// This address mask gives a low liklihood of address space collisions.
-// We handle the situation gracefully if there is a collision.
-#if OS(WIN)
-  // 64-bit Windows has a bizarrely small 8TB user address space.
-  // Allocates in the 1-5TB region.
-  // TODO(cevans): I think Win 8.1 has 47-bits like Linux.
+// This address mask gives a low likelihood of address space collisions. We
+// handle the situation gracefully if there is a collision.
+#if defined(OS_WIN)
+  // 64-bit Windows has a bizarrely small 8TB user address space. Allocates in
+  // the 1-5TB region. TODO(palmer): See if Windows >= 8.1 has the full 47 bits,
+  // and use it if so. crbug.com/672219
   random &= 0x3ffffffffffUL;
   random += 0x10000000000UL;
 #elif defined(MEMORY_TOOL_REPLACES_ALLOCATOR)
   // This range is copied from the TSan source, but works for all tools.
   random &= 0x007fffffffffUL;
   random += 0x7e8000000000UL;
 #else
   // Linux and OS X support the full 47-bit user space of x64 processors.
   random &= 0x3fffffffffffUL;
 #endif
-#elif CPU(ARM64)
+#elif defined(ARCH_CPU_ARM64)
   // ARM64 on Linux has 39-bit user space.
   random &= 0x3fffffffffUL;
   random += 0x1000000000UL;
-#else  // !CPU(X86_64) && !CPU(ARM64)
-#if OS(WIN)
+#else  // !defined(ARCH_CPU_X86_64) && !defined(ARCH_CPU_ARM64)
+#if defined(OS_WIN)
   // On win32 host systems the randomization plus huge alignment causes
   // excessive fragmentation. Plus most of these systems lack ASLR, so the
   // randomization isn't buying anything. In that case we just skip it.
   // TODO(jschuh): Just dump the randomization when HE-ASLR is present.
   static BOOL isWow64 = -1;
   if (isWow64 == -1 && !IsWow64Process(GetCurrentProcess(), &isWow64))
     isWow64 = FALSE;
   if (!isWow64)
     return nullptr;
-#endif  // OS(WIN)
+#endif  // defined(OS_WIN)
   // This is a good range on Windows, Linux and Mac.
   // Allocates in the 0.5-1.5GB region.
   random &= 0x3fffffff;
   random += 0x20000000;
-#endif  // CPU(X86_64)
+#endif  // defined(ARCH_CPU_X86_64)
   random &= kPageAllocationGranularityBaseMask;
   return reinterpret_cast<void*>(random);
 }
 
-}  // namespace WTF
+}  // namespace base