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/* Copyright (c) 2006, Google Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Google Inc. nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* ---
* Author: Sanjay Ghemawat
*/
// Implementation of atomic operations using Windows API
// functions. This file should not be included directly. Clients
// should instead include "base/atomicops.h".
#ifndef BASE_ATOMICOPS_INTERNALS_WINDOWS_H_
#define BASE_ATOMICOPS_INTERNALS_WINDOWS_H_
#include <stdio.h>
#include <stdlib.h>
#include "base/basictypes.h" // For COMPILE_ASSERT
typedef int32 Atomic32;
#if defined(_WIN64)
#define BASE_HAS_ATOMIC64 1 // Use only in tests and base/atomic*
#endif
namespace base {
namespace subtle {
typedef int64 Atomic64;
// 32-bit low-level operations on any platform
extern "C" {
// We use windows intrinsics when we can (they seem to be supported
// well on MSVC 8.0 and above). Unfortunately, in some
// environments, <windows.h> and <intrin.h> have conflicting
// declarations of some other intrinsics, breaking compilation:
// http://connect.microsoft.com/VisualStudio/feedback/details/262047
// Therefore, we simply declare the relevant intrinsics ourself.
// MinGW has a bug in the header files where it doesn't indicate the
// first argument is volatile -- they're not up to date. See
// http://readlist.com/lists/lists.sourceforge.net/mingw-users/0/3861.html
// We have to const_cast away the volatile to avoid compiler warnings.
// TODO(csilvers): remove this once MinGW has updated MinGW/include/winbase.h
#if defined(__MINGW32__)
inline LONG FastInterlockedCompareExchange(volatile LONG* ptr,
LONG newval, LONG oldval) {
return ::InterlockedCompareExchange(const_cast<LONG*>(ptr), newval, oldval);
}
inline LONG FastInterlockedExchange(volatile LONG* ptr, LONG newval) {
return ::InterlockedExchange(const_cast<LONG*>(ptr), newval);
}
inline LONG FastInterlockedExchangeAdd(volatile LONG* ptr, LONG increment) {
return ::InterlockedExchangeAdd(const_cast<LONG*>(ptr), increment);
}
#elif _MSC_VER >= 1400 // intrinsics didn't work so well before MSVC 8.0
// Unfortunately, in some environments, <windows.h> and <intrin.h>
// have conflicting declarations of some intrinsics, breaking
// compilation. So we declare the intrinsics we need ourselves. See
// http://connect.microsoft.com/VisualStudio/feedback/details/262047
LONG _InterlockedCompareExchange(volatile LONG* ptr, LONG newval, LONG oldval);
#pragma intrinsic(_InterlockedCompareExchange)
inline LONG FastInterlockedCompareExchange(volatile LONG* ptr,
LONG newval, LONG oldval) {
return _InterlockedCompareExchange(ptr, newval, oldval);
}
LONG _InterlockedExchange(volatile LONG* ptr, LONG newval);
#pragma intrinsic(_InterlockedExchange)
inline LONG FastInterlockedExchange(volatile LONG* ptr, LONG newval) {
return _InterlockedExchange(ptr, newval);
}
LONG _InterlockedExchangeAdd(volatile LONG* ptr, LONG increment);
#pragma intrinsic(_InterlockedExchangeAdd)
inline LONG FastInterlockedExchangeAdd(volatile LONG* ptr, LONG increment) {
return _InterlockedExchangeAdd(ptr, increment);
}
#else
inline LONG FastInterlockedCompareExchange(volatile LONG* ptr,
LONG newval, LONG oldval) {
return ::InterlockedCompareExchange(ptr, newval, oldval);
}
inline LONG FastInterlockedExchange(volatile LONG* ptr, LONG newval) {
return ::InterlockedExchange(ptr, newval);
}
inline LONG FastInterlockedExchangeAdd(volatile LONG* ptr, LONG increment) {
return ::InterlockedExchangeAdd(ptr, increment);
}
#endif // ifdef __MINGW32__
} // extern "C"
inline Atomic32 NoBarrier_CompareAndSwap(volatile Atomic32* ptr,
Atomic32 old_value,
Atomic32 new_value) {
LONG result = FastInterlockedCompareExchange(
reinterpret_cast<volatile LONG*>(ptr),
static_cast<LONG>(new_value),
static_cast<LONG>(old_value));
return static_cast<Atomic32>(result);
}
inline Atomic32 NoBarrier_AtomicExchange(volatile Atomic32* ptr,
Atomic32 new_value) {
LONG result = FastInterlockedExchange(
reinterpret_cast<volatile LONG*>(ptr),
static_cast<LONG>(new_value));
return static_cast<Atomic32>(result);
}
inline Atomic32 Acquire_AtomicExchange(volatile Atomic32* ptr,
Atomic32 new_value) {
// FastInterlockedExchange has both acquire and release memory barriers.
return NoBarrier_AtomicExchange(ptr, new_value);
}
inline Atomic32 Release_AtomicExchange(volatile Atomic32* ptr,
Atomic32 new_value) {
// FastInterlockedExchange has both acquire and release memory barriers.
return NoBarrier_AtomicExchange(ptr, new_value);
}
inline Atomic32 Barrier_AtomicIncrement(volatile Atomic32* ptr,
Atomic32 increment) {
return FastInterlockedExchangeAdd(
reinterpret_cast<volatile LONG*>(ptr),
static_cast<LONG>(increment)) + increment;
}
inline Atomic32 NoBarrier_AtomicIncrement(volatile Atomic32* ptr,
Atomic32 increment) {
return Barrier_AtomicIncrement(ptr, increment);
}
} // namespace base::subtle
} // namespace base
// In msvc8/vs2005, winnt.h already contains a definition for
// MemoryBarrier in the global namespace. Add it there for earlier
// versions and forward to it from within the namespace.
#if !(defined(_MSC_VER) && _MSC_VER >= 1400)
inline void MemoryBarrier() {
Atomic32 value = 0;
base::subtle::NoBarrier_AtomicExchange(&value, 0);
// actually acts as a barrier in thisd implementation
}
#endif
namespace base {
namespace subtle {
inline void MemoryBarrier() {
::MemoryBarrier();
}
inline Atomic32 Acquire_CompareAndSwap(volatile Atomic32* ptr,
Atomic32 old_value,
Atomic32 new_value) {
return NoBarrier_CompareAndSwap(ptr, old_value, new_value);
}
inline Atomic32 Release_CompareAndSwap(volatile Atomic32* ptr,
Atomic32 old_value,
Atomic32 new_value) {
return NoBarrier_CompareAndSwap(ptr, old_value, new_value);
}
inline void NoBarrier_Store(volatile Atomic32* ptr, Atomic32 value) {
*ptr = value;
}
inline void Acquire_Store(volatile Atomic32* ptr, Atomic32 value) {
Acquire_AtomicExchange(ptr, value);
}
inline void Release_Store(volatile Atomic32* ptr, Atomic32 value) {
*ptr = value; // works w/o barrier for current Intel chips as of June 2005
// See comments in Atomic64 version of Release_Store() below.
}
inline Atomic32 NoBarrier_Load(volatile const Atomic32* ptr) {
return *ptr;
}
inline Atomic32 Acquire_Load(volatile const Atomic32* ptr) {
Atomic32 value = *ptr;
return value;
}
inline Atomic32 Release_Load(volatile const Atomic32* ptr) {
MemoryBarrier();
return *ptr;
}
// 64-bit operations
#if defined(_WIN64) || defined(__MINGW64__)
// 64-bit low-level operations on 64-bit platform.
COMPILE_ASSERT(sizeof(Atomic64) == sizeof(PVOID), atomic_word_is_atomic);
// These are the intrinsics needed for 64-bit operations. Similar to the
// 32-bit case above.
extern "C" {
#if defined(__MINGW64__)
inline PVOID FastInterlockedCompareExchangePointer(volatile PVOID* ptr,
PVOID newval, PVOID oldval) {
return ::InterlockedCompareExchangePointer(const_cast<PVOID*>(ptr),
newval, oldval);
}
inline PVOID FastInterlockedExchangePointer(volatile PVOID* ptr, PVOID newval) {
return ::InterlockedExchangePointer(const_cast<PVOID*>(ptr), newval);
}
inline LONGLONG FastInterlockedExchangeAdd64(volatile LONGLONG* ptr,
LONGLONG increment) {
return ::InterlockedExchangeAdd64(const_cast<LONGLONG*>(ptr), increment);
}
#elif _MSC_VER >= 1400 // intrinsics didn't work so well before MSVC 8.0
// Like above, we need to declare the intrinsics ourselves.
PVOID _InterlockedCompareExchangePointer(volatile PVOID* ptr,
PVOID newval, PVOID oldval);
#pragma intrinsic(_InterlockedCompareExchangePointer)
inline PVOID FastInterlockedCompareExchangePointer(volatile PVOID* ptr,
PVOID newval, PVOID oldval) {
return _InterlockedCompareExchangePointer(const_cast<PVOID*>(ptr),
newval, oldval);
}
PVOID _InterlockedExchangePointer(volatile PVOID* ptr, PVOID newval);
#pragma intrinsic(_InterlockedExchangePointer)
inline PVOID FastInterlockedExchangePointer(volatile PVOID* ptr, PVOID newval) {
return _InterlockedExchangePointer(const_cast<PVOID*>(ptr), newval);
}
LONGLONG _InterlockedExchangeAdd64(volatile LONGLONG* ptr, LONGLONG increment);
#pragma intrinsic(_InterlockedExchangeAdd64)
inline LONGLONG FastInterlockedExchangeAdd64(volatile LONGLONG* ptr,
LONGLONG increment) {
return _InterlockedExchangeAdd64(const_cast<LONGLONG*>(ptr), increment);
}
#else
inline PVOID FastInterlockedCompareExchangePointer(volatile PVOID* ptr,
PVOID newval, PVOID oldval) {
return ::InterlockedCompareExchangePointer(ptr, newval, oldval);
}
inline PVOID FastInterlockedExchangePointer(volatile PVOID* ptr, PVOID newval) {
return ::InterlockedExchangePointer(ptr, newval);
}
inline LONGLONG FastInterlockedExchangeAdd64(volatile LONGLONG* ptr,
LONGLONG increment) {
return ::InterlockedExchangeAdd64(ptr, increment);
}
#endif // ifdef __MINGW64__
} // extern "C"
inline Atomic64 NoBarrier_CompareAndSwap(volatile Atomic64* ptr,
Atomic64 old_value,
Atomic64 new_value) {
PVOID result = FastInterlockedCompareExchangePointer(
reinterpret_cast<volatile PVOID*>(ptr),
reinterpret_cast<PVOID>(new_value), reinterpret_cast<PVOID>(old_value));
return reinterpret_cast<Atomic64>(result);
}
inline Atomic64 NoBarrier_AtomicExchange(volatile Atomic64* ptr,
Atomic64 new_value) {
PVOID result = FastInterlockedExchangePointer(
reinterpret_cast<volatile PVOID*>(ptr),
reinterpret_cast<PVOID>(new_value));
return reinterpret_cast<Atomic64>(result);
}
inline Atomic64 Barrier_AtomicIncrement(volatile Atomic64* ptr,
Atomic64 increment) {
return FastInterlockedExchangeAdd64(
reinterpret_cast<volatile LONGLONG*>(ptr),
static_cast<LONGLONG>(increment)) + increment;
}
inline Atomic64 NoBarrier_AtomicIncrement(volatile Atomic64* ptr,
Atomic64 increment) {
return Barrier_AtomicIncrement(ptr, increment);
}
inline void NoBarrier_Store(volatile Atomic64* ptr, Atomic64 value) {
*ptr = value;
}
inline void Acquire_Store(volatile Atomic64* ptr, Atomic64 value) {
NoBarrier_AtomicExchange(ptr, value);
// acts as a barrier in this implementation
}
inline void Release_Store(volatile Atomic64* ptr, Atomic64 value) {
*ptr = value; // works w/o barrier for current Intel chips as of June 2005
// When new chips come out, check:
// IA-32 Intel Architecture Software Developer's Manual, Volume 3:
// System Programming Guide, Chatper 7: Multiple-processor management,
// Section 7.2, Memory Ordering.
// Last seen at:
// http://developer.intel.com/design/pentium4/manuals/index_new.htm
}
inline Atomic64 NoBarrier_Load(volatile const Atomic64* ptr) {
return *ptr;
}
inline Atomic64 Acquire_Load(volatile const Atomic64* ptr) {
Atomic64 value = *ptr;
return value;
}
inline Atomic64 Release_Load(volatile const Atomic64* ptr) {
MemoryBarrier();
return *ptr;
}
#else // defined(_WIN64) || defined(__MINGW64__)
// 64-bit low-level operations on 32-bit platform
// TODO(vchen): The GNU assembly below must be converted to MSVC inline
// assembly. Then the file should be renamed to ...-x86-msvc.h, probably.
inline void NotImplementedFatalError(const char *function_name) {
fprintf(stderr, "64-bit %s() not implemented on this platform\n",
function_name);
abort();
}
inline Atomic64 NoBarrier_CompareAndSwap(volatile Atomic64* ptr,
Atomic64 old_value,
Atomic64 new_value) {
#if 0 // Not implemented
Atomic64 prev;
__asm__ __volatile__("movl (%3), %%ebx\n\t" // Move 64-bit new_value into
"movl 4(%3), %%ecx\n\t" // ecx:ebx
"lock; cmpxchg8b %1\n\t" // If edx:eax (old_value) same
: "=A" (prev) // as contents of ptr:
: "m" (*ptr), // ecx:ebx => ptr
"0" (old_value), // else:
"r" (&new_value) // old *ptr => edx:eax
: "memory", "%ebx", "%ecx");
return prev;
#else
NotImplementedFatalError("NoBarrier_CompareAndSwap");
return 0;
#endif
}
inline Atomic64 NoBarrier_AtomicExchange(volatile Atomic64* ptr,
Atomic64 new_value) {
#if 0 // Not implemented
__asm__ __volatile__(
"movl (%2), %%ebx\n\t" // Move 64-bit new_value into
"movl 4(%2), %%ecx\n\t" // ecx:ebx
"0:\n\t"
"movl %1, %%eax\n\t" // Read contents of ptr into
"movl 4%1, %%edx\n\t" // edx:eax
"lock; cmpxchg8b %1\n\t" // Attempt cmpxchg; if *ptr
"jnz 0b\n\t" // is no longer edx:eax, loop
: "=A" (new_value)
: "m" (*ptr),
"r" (&new_value)
: "memory", "%ebx", "%ecx");
return new_value; // Now it's the previous value.
#else
NotImplementedFatalError("NoBarrier_AtomicExchange");
return 0;
#endif
}
inline Atomic64 NoBarrier_AtomicIncrement(volatile Atomic64* ptr,
Atomic64 increment) {
#if 0 // Not implemented
Atomic64 temp = increment;
__asm__ __volatile__(
"0:\n\t"
"movl (%3), %%ebx\n\t" // Move 64-bit increment into
"movl 4(%3), %%ecx\n\t" // ecx:ebx
"movl (%2), %%eax\n\t" // Read contents of ptr into
"movl 4(%2), %%edx\n\t" // edx:eax
"add %%eax, %%ebx\n\t" // sum => ecx:ebx
"adc %%edx, %%ecx\n\t" // edx:eax still has old *ptr
"lock; cmpxchg8b (%2)\n\t"// Attempt cmpxchg; if *ptr
"jnz 0b\n\t" // is no longer edx:eax, loop
: "=A"(temp), "+m"(*ptr)
: "D" (ptr), "S" (&increment)
: "memory", "%ebx", "%ecx");
// temp now contains the previous value of *ptr
return temp + increment;
#else
NotImplementedFatalError("NoBarrier_AtomicIncrement");
return 0;
#endif
}
inline Atomic64 Barrier_AtomicIncrement(volatile Atomic64* ptr,
Atomic64 increment) {
#if 0 // Not implemented
Atomic64 new_val = NoBarrier_AtomicIncrement(ptr, increment);
if (AtomicOps_Internalx86CPUFeatures.has_amd_lock_mb_bug) {
__asm__ __volatile__("lfence" : : : "memory");
}
return new_val;
#else
NotImplementedFatalError("Barrier_AtomicIncrement");
return 0;
#endif
}
inline void NoBarrier_Store(volatile Atomic64* ptrValue, Atomic64 value)
{
__asm {
movq mm0, value; // Use mmx reg for 64-bit atomic moves
mov eax, ptrValue;
movq [eax], mm0;
emms; // Empty mmx state to enable FP registers
}
}
inline void Acquire_Store(volatile Atomic64* ptr, Atomic64 value) {
NoBarrier_AtomicExchange(ptr, value);
// acts as a barrier in this implementation
}
inline void Release_Store(volatile Atomic64* ptr, Atomic64 value) {
NoBarrier_Store(ptr, value);
}
inline Atomic64 NoBarrier_Load(volatile const Atomic64* ptrValue)
{
Atomic64 value;
__asm {
mov eax, ptrValue;
movq mm0, [eax]; // Use mmx reg for 64-bit atomic moves
movq value, mm0;
emms; // Empty mmx state to enable FP registers
}
return value;
}
inline Atomic64 Acquire_Load(volatile const Atomic64* ptr) {
Atomic64 value = NoBarrier_Load(ptr);
return value;
}
inline Atomic64 Release_Load(volatile const Atomic64* ptr) {
MemoryBarrier();
return NoBarrier_Load(ptr);
}
#endif // defined(_WIN64) || defined(__MINGW64__)
inline Atomic64 Acquire_AtomicExchange(volatile Atomic64* ptr,
Atomic64 new_value) {
// FastInterlockedExchange has both acquire and release memory barriers.
return NoBarrier_AtomicExchange(ptr, new_value);
}
inline Atomic64 Release_AtomicExchange(volatile Atomic64* ptr,
Atomic64 new_value) {
// FastInterlockedExchange has both acquire and release memory barriers.
return NoBarrier_AtomicExchange(ptr, new_value);
}
inline Atomic64 Acquire_CompareAndSwap(volatile Atomic64* ptr,
Atomic64 old_value,
Atomic64 new_value) {
return NoBarrier_CompareAndSwap(ptr, old_value, new_value);
}
inline Atomic64 Release_CompareAndSwap(volatile Atomic64* ptr,
Atomic64 old_value,
Atomic64 new_value) {
return NoBarrier_CompareAndSwap(ptr, old_value, new_value);
}
} // namespace base::subtle
} // namespace base
#endif // BASE_ATOMICOPS_INTERNALS_WINDOWS_H_