mimalloc/include/mimalloc-atomic.h
Jim Huang b1d299b35b Clarify top-level license file
To be consistent with other Microsoft open source projects, each source
file points to the file "LICENSE" in top-level directory.
2019-06-23 19:53:34 +08:00

191 lines
7.3 KiB
C++

/* ----------------------------------------------------------------------------
Copyright (c) 2018, Microsoft Research, Daan Leijen
This is free software; you can redistribute it and/or modify it under the
terms of the MIT license. A copy of the license can be found in the file
"LICENSE" at the root of this distribution.
-----------------------------------------------------------------------------*/
#pragma once
#ifndef __MIMALLOC_ATOMIC_H
#define __MIMALLOC_ATOMIC_H
// ------------------------------------------------------
// Atomics
// ------------------------------------------------------
// Atomically increment a value; returns the incremented result.
static inline uintptr_t mi_atomic_increment(volatile uintptr_t* p);
// Atomically increment a value; returns the incremented result.
static inline uint32_t mi_atomic_increment32(volatile uint32_t* p);
// Atomically decrement a value; returns the decremented result.
static inline uintptr_t mi_atomic_decrement(volatile uintptr_t* p);
// Atomically add a 64-bit value; returns the added result.
static inline int64_t mi_atomic_add(volatile int64_t* p, int64_t add);
// Atomically subtract a value; returns the subtracted result.
static inline uintptr_t mi_atomic_subtract(volatile uintptr_t* p, uintptr_t sub);
// Atomically subtract a value; returns the subtracted result.
static inline uint32_t mi_atomic_subtract32(volatile uint32_t* p, uint32_t sub);
// Atomically compare and exchange a value; returns `true` if successful.
static inline bool mi_atomic_compare_exchange32(volatile uint32_t* p, uint32_t exchange, uint32_t compare);
// Atomically compare and exchange a value; returns `true` if successful.
static inline bool mi_atomic_compare_exchange(volatile uintptr_t* p, uintptr_t exchange, uintptr_t compare);
// Atomically exchange a value.
static inline uintptr_t mi_atomic_exchange(volatile uintptr_t* p, uintptr_t exchange);
static inline void mi_atomic_yield();
// Atomically compare and exchange a pointer; returns `true` if successful.
static inline bool mi_atomic_compare_exchange_ptr(volatile void** p, void* newp, void* compare) {
return mi_atomic_compare_exchange((volatile uintptr_t*)p, (uintptr_t)newp, (uintptr_t)compare);
}
// Atomically exchange a pointer value.
static inline void* mi_atomic_exchange_ptr(volatile void** p, void* exchange) {
return (void*)mi_atomic_exchange((volatile uintptr_t*)p, (uintptr_t)exchange);
}
#define mi_atomic_locked(mutex) for(bool _mheld = mi_mutex_lock(mutex); _mheld; _mheld = mi_mutex_unlock(mutex))
#ifdef _MSC_VER
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#include <intrin.h>
#if (MI_INTPTR_SIZE==8)
#define RC64(f) f##64
#else
#define RC64(f) f
#endif
static inline uintptr_t mi_atomic_increment(volatile uintptr_t* p) {
return (uintptr_t)RC64(_InterlockedIncrement)((volatile intptr_t*)p);
}
static inline uint32_t mi_atomic_increment32(volatile uint32_t* p) {
return (uint32_t)_InterlockedIncrement((volatile int32_t*)p);
}
static inline uintptr_t mi_atomic_decrement(volatile uintptr_t* p) {
return (uintptr_t)RC64(_InterlockedDecrement)((volatile intptr_t*)p);
}
static inline uintptr_t mi_atomic_subtract(volatile uintptr_t* p, uintptr_t sub) {
return (uintptr_t)RC64(_InterlockedExchangeAdd)((volatile intptr_t*)p, -((intptr_t)sub)) - sub;
}
static inline uint32_t mi_atomic_subtract32(volatile uint32_t* p, uint32_t sub) {
return (uint32_t)_InterlockedExchangeAdd((volatile int32_t*)p, -((int32_t)sub)) - sub;
}
static inline bool mi_atomic_compare_exchange32(volatile uint32_t* p, uint32_t exchange, uint32_t compare) {
return ((int32_t)compare == _InterlockedCompareExchange((volatile int32_t*)p, (int32_t)exchange, (int32_t)compare));
}
static inline bool mi_atomic_compare_exchange(volatile uintptr_t* p, uintptr_t exchange, uintptr_t compare) {
return (compare == RC64(_InterlockedCompareExchange)((volatile intptr_t*)p, (intptr_t)exchange, (intptr_t)compare));
}
static inline uintptr_t mi_atomic_exchange(volatile uintptr_t* p, uintptr_t exchange) {
return (uintptr_t)RC64(_InterlockedExchange)((volatile intptr_t*)p, (intptr_t)exchange);
}
static inline void mi_atomic_yield() {
YieldProcessor();
}
static inline int64_t mi_atomic_add(volatile int64_t* p, int64_t add) {
#if (MI_INTPTR_SIZE==8)
return _InterlockedExchangeAdd64(p, add) + add;
#else
int64_t current;
int64_t sum;
do {
current = *p;
sum = current + add;
} while (_InterlockedCompareExchange64(p, sum, current) != current);
return sum;
#endif
}
#else
#ifdef __cplusplus
#include <atomic>
#define MI_USING_STD using namespace std;
#define _Atomic(tp) atomic<tp>
#else
#include <stdatomic.h>
#define MI_USING_STD
#endif
static inline uintptr_t mi_atomic_increment(volatile uintptr_t* p) {
MI_USING_STD
return atomic_fetch_add_explicit((volatile atomic_uintptr_t*)p, (uintptr_t)1, memory_order_relaxed) + 1;
}
static inline uint32_t mi_atomic_increment32(volatile uint32_t* p) {
MI_USING_STD
return atomic_fetch_add_explicit((volatile _Atomic(uint32_t)*)p, (uint32_t)1, memory_order_relaxed) + 1;
}
static inline uintptr_t mi_atomic_decrement(volatile uintptr_t* p) {
MI_USING_STD
return atomic_fetch_sub_explicit((volatile atomic_uintptr_t*)p, (uintptr_t)1, memory_order_relaxed) - 1;
}
static inline int64_t mi_atomic_add(volatile int64_t* p, int64_t add) {
MI_USING_STD
return atomic_fetch_add_explicit((volatile _Atomic(int64_t)*)p, add, memory_order_relaxed) + add;
}
static inline uintptr_t mi_atomic_subtract(volatile uintptr_t* p, uintptr_t sub) {
MI_USING_STD
return atomic_fetch_sub_explicit((volatile atomic_uintptr_t*)p, sub, memory_order_relaxed) - sub;
}
static inline uint32_t mi_atomic_subtract32(volatile uint32_t* p, uint32_t sub) {
MI_USING_STD
return atomic_fetch_sub_explicit((volatile _Atomic(uint32_t)*)p, sub, memory_order_relaxed) - sub;
}
static inline bool mi_atomic_compare_exchange32(volatile uint32_t* p, uint32_t exchange, uint32_t compare) {
MI_USING_STD
return atomic_compare_exchange_weak_explicit((volatile _Atomic(uint32_t)*)p, &compare, exchange, memory_order_relaxed, memory_order_seq_cst);
}
static inline bool mi_atomic_compare_exchange(volatile uintptr_t* p, uintptr_t exchange, uintptr_t compare) {
MI_USING_STD
return atomic_compare_exchange_weak_explicit((volatile atomic_uintptr_t*)p, &compare, exchange, memory_order_relaxed, memory_order_seq_cst);
}
static inline uintptr_t mi_atomic_exchange(volatile uintptr_t* p, uintptr_t exchange) {
MI_USING_STD
return atomic_exchange_explicit((volatile atomic_uintptr_t*)p, exchange, memory_order_relaxed);
}
#if defined(__cplusplus)
#include <thread>
static inline void mi_atomic_yield() {
std::this_thread::yield();
}
#elif (defined(__GNUC__) || defined(__clang__)) && (defined(__x86_64__) || defined(__i386__))
static inline void mi_atomic_yield() {
asm volatile ("pause" ::: "memory");
}
#else
#include <unistd.h>
static inline void mi_atomic_yield() {
sleep(0);
}
#endif
#endif
// Light weight mutex for low contention situations
typedef struct mi_mutex_s {
volatile uint32_t value;
} mi_mutex_t;
static inline bool mi_mutex_lock(mi_mutex_t* mutex) {
while(!mi_atomic_compare_exchange32(&mutex->value, 1, 0)) {
mi_atomic_yield();
}
return true;
}
static inline bool mi_mutex_unlock(mi_mutex_t* mutex) {
mutex->value = 0;
return false;
}
#endif // __MIMALLOC_ATOMIC_H