12aff73868669a46a84ea617801beea47dda0b581David Chisnall/*===-- atomic.c - Implement support functions for atomic operations.------=== 22aff73868669a46a84ea617801beea47dda0b581David Chisnall * 32aff73868669a46a84ea617801beea47dda0b581David Chisnall * The LLVM Compiler Infrastructure 42aff73868669a46a84ea617801beea47dda0b581David Chisnall * 52aff73868669a46a84ea617801beea47dda0b581David Chisnall * This file is dual licensed under the MIT and the University of Illinois Open 62aff73868669a46a84ea617801beea47dda0b581David Chisnall * Source Licenses. See LICENSE.TXT for details. 72aff73868669a46a84ea617801beea47dda0b581David Chisnall * 82aff73868669a46a84ea617801beea47dda0b581David Chisnall *===----------------------------------------------------------------------=== 92aff73868669a46a84ea617801beea47dda0b581David Chisnall * 102aff73868669a46a84ea617801beea47dda0b581David Chisnall * atomic.c defines a set of functions for performing atomic accesses on 112aff73868669a46a84ea617801beea47dda0b581David Chisnall * arbitrary-sized memory locations. This design uses locks that should 122aff73868669a46a84ea617801beea47dda0b581David Chisnall * be fast in the uncontended case, for two reasons: 132aff73868669a46a84ea617801beea47dda0b581David Chisnall * 142aff73868669a46a84ea617801beea47dda0b581David Chisnall * 1) This code must work with C programs that do not link to anything 152aff73868669a46a84ea617801beea47dda0b581David Chisnall * (including pthreads) and so it should not depend on any pthread 162aff73868669a46a84ea617801beea47dda0b581David Chisnall * functions. 172aff73868669a46a84ea617801beea47dda0b581David Chisnall * 2) Atomic operations, rather than explicit mutexes, are most commonly used 182aff73868669a46a84ea617801beea47dda0b581David Chisnall * on code where contended operations are rate. 192aff73868669a46a84ea617801beea47dda0b581David Chisnall * 202aff73868669a46a84ea617801beea47dda0b581David Chisnall * To avoid needing a per-object lock, this code allocates an array of 212aff73868669a46a84ea617801beea47dda0b581David Chisnall * locks and hashes the object pointers to find the one that it should use. 222aff73868669a46a84ea617801beea47dda0b581David Chisnall * For operations that must be atomic on two locations, the lower lock is 232aff73868669a46a84ea617801beea47dda0b581David Chisnall * always acquired first, to avoid deadlock. 242aff73868669a46a84ea617801beea47dda0b581David Chisnall * 252aff73868669a46a84ea617801beea47dda0b581David Chisnall *===----------------------------------------------------------------------=== 262aff73868669a46a84ea617801beea47dda0b581David Chisnall */ 272aff73868669a46a84ea617801beea47dda0b581David Chisnall 282aff73868669a46a84ea617801beea47dda0b581David Chisnall#include <stdint.h> 292aff73868669a46a84ea617801beea47dda0b581David Chisnall#include <string.h> 302aff73868669a46a84ea617801beea47dda0b581David Chisnall 312aff73868669a46a84ea617801beea47dda0b581David Chisnall// Clang objects if you redefine a builtin. This little hack allows us to 322aff73868669a46a84ea617801beea47dda0b581David Chisnall// define a function with the same name as an intrinsic. 33bc7ab9ce95a703ef732beb4ca4d0ea8778a60fddDavid Chisnall#pragma redefine_extname __atomic_load_c __atomic_load 34bc7ab9ce95a703ef732beb4ca4d0ea8778a60fddDavid Chisnall#pragma redefine_extname __atomic_store_c __atomic_store 35bc7ab9ce95a703ef732beb4ca4d0ea8778a60fddDavid Chisnall#pragma redefine_extname __atomic_exchange_c __atomic_exchange 36bc7ab9ce95a703ef732beb4ca4d0ea8778a60fddDavid Chisnall#pragma redefine_extname __atomic_compare_exchange_c __atomic_compare_exchange 372aff73868669a46a84ea617801beea47dda0b581David Chisnall 382aff73868669a46a84ea617801beea47dda0b581David Chisnall/// Number of locks. This allocates one page on 32-bit platforms, two on 392aff73868669a46a84ea617801beea47dda0b581David Chisnall/// 64-bit. This can be specified externally if a different trade between 402aff73868669a46a84ea617801beea47dda0b581David Chisnall/// memory usage and contention probability is required for a given platform. 412aff73868669a46a84ea617801beea47dda0b581David Chisnall#ifndef SPINLOCK_COUNT 422aff73868669a46a84ea617801beea47dda0b581David Chisnall#define SPINLOCK_COUNT (1<<10) 432aff73868669a46a84ea617801beea47dda0b581David Chisnall#endif 442aff73868669a46a84ea617801beea47dda0b581David Chisnallstatic const long SPINLOCK_MASK = SPINLOCK_COUNT - 1; 452aff73868669a46a84ea617801beea47dda0b581David Chisnall 462aff73868669a46a84ea617801beea47dda0b581David Chisnall//////////////////////////////////////////////////////////////////////////////// 472aff73868669a46a84ea617801beea47dda0b581David Chisnall// Platform-specific lock implementation. Falls back to spinlocks if none is 482aff73868669a46a84ea617801beea47dda0b581David Chisnall// defined. Each platform should define the Lock type, and corresponding 492aff73868669a46a84ea617801beea47dda0b581David Chisnall// lock() and unlock() functions. 502aff73868669a46a84ea617801beea47dda0b581David Chisnall//////////////////////////////////////////////////////////////////////////////// 512aff73868669a46a84ea617801beea47dda0b581David Chisnall#ifdef __FreeBSD__ 522aff73868669a46a84ea617801beea47dda0b581David Chisnall#include <errno.h> 532aff73868669a46a84ea617801beea47dda0b581David Chisnall#include <sys/types.h> 542aff73868669a46a84ea617801beea47dda0b581David Chisnall#include <machine/atomic.h> 552aff73868669a46a84ea617801beea47dda0b581David Chisnall#include <sys/umtx.h> 562aff73868669a46a84ea617801beea47dda0b581David Chisnalltypedef struct _usem Lock; 572aff73868669a46a84ea617801beea47dda0b581David Chisnallinline static void unlock(Lock *l) { 58bc7ab9ce95a703ef732beb4ca4d0ea8778a60fddDavid Chisnall __c11_atomic_store((_Atomic(uint32_t)*)&l->_count, 1, __ATOMIC_RELEASE); 59bc7ab9ce95a703ef732beb4ca4d0ea8778a60fddDavid Chisnall __c11_atomic_thread_fence(__ATOMIC_SEQ_CST); 602aff73868669a46a84ea617801beea47dda0b581David Chisnall if (l->_has_waiters) 612aff73868669a46a84ea617801beea47dda0b581David Chisnall _umtx_op(l, UMTX_OP_SEM_WAKE, 1, 0, 0); 622aff73868669a46a84ea617801beea47dda0b581David Chisnall} 632aff73868669a46a84ea617801beea47dda0b581David Chisnallinline static void lock(Lock *l) { 642aff73868669a46a84ea617801beea47dda0b581David Chisnall uint32_t old = 1; 65bc7ab9ce95a703ef732beb4ca4d0ea8778a60fddDavid Chisnall while (!__c11_atomic_compare_exchange_weak((_Atomic(uint32_t)*)&l->_count, &old, 662aff73868669a46a84ea617801beea47dda0b581David Chisnall 0, __ATOMIC_ACQUIRE, __ATOMIC_RELAXED)) { 672aff73868669a46a84ea617801beea47dda0b581David Chisnall _umtx_op(l, UMTX_OP_SEM_WAIT, 0, 0, 0); 682aff73868669a46a84ea617801beea47dda0b581David Chisnall old = 1; 692aff73868669a46a84ea617801beea47dda0b581David Chisnall } 702aff73868669a46a84ea617801beea47dda0b581David Chisnall} 712aff73868669a46a84ea617801beea47dda0b581David Chisnall/// locks for atomic operations 722aff73868669a46a84ea617801beea47dda0b581David Chisnallstatic Lock locks[SPINLOCK_COUNT] = { [0 ... SPINLOCK_COUNT-1] = {0,1,0} }; 732aff73868669a46a84ea617801beea47dda0b581David Chisnall#else 742aff73868669a46a84ea617801beea47dda0b581David Chisnalltypedef _Atomic(uintptr_t) Lock; 752aff73868669a46a84ea617801beea47dda0b581David Chisnall/// Unlock a lock. This is a release operation. 762aff73868669a46a84ea617801beea47dda0b581David Chisnallinline static void unlock(Lock *l) { 77bc7ab9ce95a703ef732beb4ca4d0ea8778a60fddDavid Chisnall __c11_atomic_store(l, 0, __ATOMIC_RELEASE); 782aff73868669a46a84ea617801beea47dda0b581David Chisnall} 792aff73868669a46a84ea617801beea47dda0b581David Chisnall/// Locks a lock. In the current implementation, this is potentially 802aff73868669a46a84ea617801beea47dda0b581David Chisnall/// unbounded in the contended case. 812aff73868669a46a84ea617801beea47dda0b581David Chisnallinline static void lock(Lock *l) { 822aff73868669a46a84ea617801beea47dda0b581David Chisnall uintptr_t old = 0; 83bc7ab9ce95a703ef732beb4ca4d0ea8778a60fddDavid Chisnall while (!__c11_atomic_compare_exchange_weak(l, &old, 1, __ATOMIC_ACQUIRE, 842aff73868669a46a84ea617801beea47dda0b581David Chisnall __ATOMIC_RELAXED)) 852aff73868669a46a84ea617801beea47dda0b581David Chisnall old = 0; 862aff73868669a46a84ea617801beea47dda0b581David Chisnall} 872aff73868669a46a84ea617801beea47dda0b581David Chisnall/// locks for atomic operations 882aff73868669a46a84ea617801beea47dda0b581David Chisnallstatic Lock locks[SPINLOCK_COUNT]; 892aff73868669a46a84ea617801beea47dda0b581David Chisnall#endif 902aff73868669a46a84ea617801beea47dda0b581David Chisnall 912aff73868669a46a84ea617801beea47dda0b581David Chisnall 922aff73868669a46a84ea617801beea47dda0b581David Chisnall/// Returns a lock to use for a given pointer. 932aff73868669a46a84ea617801beea47dda0b581David Chisnallstatic inline Lock *lock_for_pointer(void *ptr) { 942aff73868669a46a84ea617801beea47dda0b581David Chisnall intptr_t hash = (intptr_t)ptr; 952aff73868669a46a84ea617801beea47dda0b581David Chisnall // Disregard the lowest 4 bits. We want all values that may be part of the 962aff73868669a46a84ea617801beea47dda0b581David Chisnall // same memory operation to hash to the same value and therefore use the same 972aff73868669a46a84ea617801beea47dda0b581David Chisnall // lock. 982aff73868669a46a84ea617801beea47dda0b581David Chisnall hash >>= 4; 992aff73868669a46a84ea617801beea47dda0b581David Chisnall // Use the next bits as the basis for the hash 1002aff73868669a46a84ea617801beea47dda0b581David Chisnall intptr_t low = hash & SPINLOCK_MASK; 1012aff73868669a46a84ea617801beea47dda0b581David Chisnall // Now use the high(er) set of bits to perturb the hash, so that we don't 1022aff73868669a46a84ea617801beea47dda0b581David Chisnall // get collisions from atomic fields in a single object 1032aff73868669a46a84ea617801beea47dda0b581David Chisnall hash >>= 16; 1042aff73868669a46a84ea617801beea47dda0b581David Chisnall hash ^= low; 1052aff73868669a46a84ea617801beea47dda0b581David Chisnall // Return a pointer to the word to use 1062aff73868669a46a84ea617801beea47dda0b581David Chisnall return locks + (hash & SPINLOCK_MASK); 1072aff73868669a46a84ea617801beea47dda0b581David Chisnall} 1082aff73868669a46a84ea617801beea47dda0b581David Chisnall 1092aff73868669a46a84ea617801beea47dda0b581David Chisnall/// Macros for determining whether a size is lock free. Clang can not yet 1102aff73868669a46a84ea617801beea47dda0b581David Chisnall/// codegen __atomic_is_lock_free(16), so for now we assume 16-byte values are 1112aff73868669a46a84ea617801beea47dda0b581David Chisnall/// not lock free. 112bc7ab9ce95a703ef732beb4ca4d0ea8778a60fddDavid Chisnall#define IS_LOCK_FREE_1 __c11_atomic_is_lock_free(1) 113bc7ab9ce95a703ef732beb4ca4d0ea8778a60fddDavid Chisnall#define IS_LOCK_FREE_2 __c11_atomic_is_lock_free(2) 114bc7ab9ce95a703ef732beb4ca4d0ea8778a60fddDavid Chisnall#define IS_LOCK_FREE_4 __c11_atomic_is_lock_free(4) 115bc7ab9ce95a703ef732beb4ca4d0ea8778a60fddDavid Chisnall#define IS_LOCK_FREE_8 __c11_atomic_is_lock_free(8) 1162aff73868669a46a84ea617801beea47dda0b581David Chisnall#define IS_LOCK_FREE_16 0 1172aff73868669a46a84ea617801beea47dda0b581David Chisnall 1182aff73868669a46a84ea617801beea47dda0b581David Chisnall/// Macro that calls the compiler-generated lock-free versions of functions 1192aff73868669a46a84ea617801beea47dda0b581David Chisnall/// when they exist. 1202aff73868669a46a84ea617801beea47dda0b581David Chisnall#define LOCK_FREE_CASES() \ 1212aff73868669a46a84ea617801beea47dda0b581David Chisnall do {\ 1222aff73868669a46a84ea617801beea47dda0b581David Chisnall switch (size) {\ 1232aff73868669a46a84ea617801beea47dda0b581David Chisnall case 2:\ 1242aff73868669a46a84ea617801beea47dda0b581David Chisnall if (IS_LOCK_FREE_2) {\ 1252aff73868669a46a84ea617801beea47dda0b581David Chisnall LOCK_FREE_ACTION(uint16_t);\ 1262aff73868669a46a84ea617801beea47dda0b581David Chisnall }\ 1272aff73868669a46a84ea617801beea47dda0b581David Chisnall case 4:\ 1282aff73868669a46a84ea617801beea47dda0b581David Chisnall if (IS_LOCK_FREE_4) {\ 1292aff73868669a46a84ea617801beea47dda0b581David Chisnall LOCK_FREE_ACTION(uint32_t);\ 1302aff73868669a46a84ea617801beea47dda0b581David Chisnall }\ 1312aff73868669a46a84ea617801beea47dda0b581David Chisnall case 8:\ 1322aff73868669a46a84ea617801beea47dda0b581David Chisnall if (IS_LOCK_FREE_8) {\ 1332aff73868669a46a84ea617801beea47dda0b581David Chisnall LOCK_FREE_ACTION(uint64_t);\ 1342aff73868669a46a84ea617801beea47dda0b581David Chisnall }\ 1352aff73868669a46a84ea617801beea47dda0b581David Chisnall case 16:\ 1362aff73868669a46a84ea617801beea47dda0b581David Chisnall if (IS_LOCK_FREE_16) {\ 137fa3eee4101f39661b4a88ac0bc7f184ca8c1ecb1Benjamin Kramer /* FIXME: __uint128_t isn't available on 32 bit platforms. 138fa3eee4101f39661b4a88ac0bc7f184ca8c1ecb1Benjamin Kramer LOCK_FREE_ACTION(__uint128_t);*/\ 1392aff73868669a46a84ea617801beea47dda0b581David Chisnall }\ 1402aff73868669a46a84ea617801beea47dda0b581David Chisnall }\ 1412aff73868669a46a84ea617801beea47dda0b581David Chisnall } while (0) 1422aff73868669a46a84ea617801beea47dda0b581David Chisnall 1432aff73868669a46a84ea617801beea47dda0b581David Chisnall 1442aff73868669a46a84ea617801beea47dda0b581David Chisnall/// An atomic load operation. This is atomic with respect to the source 1452aff73868669a46a84ea617801beea47dda0b581David Chisnall/// pointer only. 146bc7ab9ce95a703ef732beb4ca4d0ea8778a60fddDavid Chisnallvoid __atomic_load_c(int size, void *src, void *dest, int model) { 1472aff73868669a46a84ea617801beea47dda0b581David Chisnall#define LOCK_FREE_ACTION(type) \ 148bc7ab9ce95a703ef732beb4ca4d0ea8778a60fddDavid Chisnall *((type*)dest) = __c11_atomic_load((_Atomic(type)*)src, model);\ 1492aff73868669a46a84ea617801beea47dda0b581David Chisnall return; 1502aff73868669a46a84ea617801beea47dda0b581David Chisnall LOCK_FREE_CASES(); 1512aff73868669a46a84ea617801beea47dda0b581David Chisnall#undef LOCK_FREE_ACTION 1522aff73868669a46a84ea617801beea47dda0b581David Chisnall Lock *l = lock_for_pointer(src); 1532aff73868669a46a84ea617801beea47dda0b581David Chisnall lock(l); 1542aff73868669a46a84ea617801beea47dda0b581David Chisnall memcpy(dest, src, size); 1552aff73868669a46a84ea617801beea47dda0b581David Chisnall unlock(l); 1562aff73868669a46a84ea617801beea47dda0b581David Chisnall} 1572aff73868669a46a84ea617801beea47dda0b581David Chisnall 1582aff73868669a46a84ea617801beea47dda0b581David Chisnall/// An atomic store operation. This is atomic with respect to the destination 1592aff73868669a46a84ea617801beea47dda0b581David Chisnall/// pointer only. 160bc7ab9ce95a703ef732beb4ca4d0ea8778a60fddDavid Chisnallvoid __atomic_store_c(int size, void *dest, void *src, int model) { 1612aff73868669a46a84ea617801beea47dda0b581David Chisnall#define LOCK_FREE_ACTION(type) \ 162bc7ab9ce95a703ef732beb4ca4d0ea8778a60fddDavid Chisnall __c11_atomic_store((_Atomic(type)*)dest, *(type*)dest, model);\ 1632aff73868669a46a84ea617801beea47dda0b581David Chisnall return; 1642aff73868669a46a84ea617801beea47dda0b581David Chisnall LOCK_FREE_CASES(); 1652aff73868669a46a84ea617801beea47dda0b581David Chisnall#undef LOCK_FREE_ACTION 1662aff73868669a46a84ea617801beea47dda0b581David Chisnall Lock *l = lock_for_pointer(dest); 1672aff73868669a46a84ea617801beea47dda0b581David Chisnall lock(l); 1682aff73868669a46a84ea617801beea47dda0b581David Chisnall memcpy(dest, src, size); 1692aff73868669a46a84ea617801beea47dda0b581David Chisnall unlock(l); 1702aff73868669a46a84ea617801beea47dda0b581David Chisnall} 1712aff73868669a46a84ea617801beea47dda0b581David Chisnall 1722aff73868669a46a84ea617801beea47dda0b581David Chisnall/// Atomic compare and exchange operation. If the value at *ptr is identical 1732aff73868669a46a84ea617801beea47dda0b581David Chisnall/// to the value at *expected, then this copies value at *desired to *ptr. If 1742aff73868669a46a84ea617801beea47dda0b581David Chisnall/// they are not, then this stores the current value from *ptr in *expected. 1752aff73868669a46a84ea617801beea47dda0b581David Chisnall/// 1762aff73868669a46a84ea617801beea47dda0b581David Chisnall/// This function returns 1 if the exchange takes place or 0 if it fails. 177bc7ab9ce95a703ef732beb4ca4d0ea8778a60fddDavid Chisnallint __atomic_compare_exchange_c(int size, void *ptr, void *expected, 1782aff73868669a46a84ea617801beea47dda0b581David Chisnall void *desired, int success, int failure) { 1792aff73868669a46a84ea617801beea47dda0b581David Chisnall#define LOCK_FREE_ACTION(type) \ 180bc7ab9ce95a703ef732beb4ca4d0ea8778a60fddDavid Chisnall return __c11_atomic_compare_exchange_strong((_Atomic(type)*)ptr, (type*)expected,\ 1812aff73868669a46a84ea617801beea47dda0b581David Chisnall *(type*)desired, success, failure) 1822aff73868669a46a84ea617801beea47dda0b581David Chisnall LOCK_FREE_CASES(); 1832aff73868669a46a84ea617801beea47dda0b581David Chisnall#undef LOCK_FREE_ACTION 1842aff73868669a46a84ea617801beea47dda0b581David Chisnall Lock *l = lock_for_pointer(ptr); 1852aff73868669a46a84ea617801beea47dda0b581David Chisnall lock(l); 1862aff73868669a46a84ea617801beea47dda0b581David Chisnall if (memcmp(ptr, expected, size) == 0) { 1872aff73868669a46a84ea617801beea47dda0b581David Chisnall memcpy(ptr, desired, size); 1882aff73868669a46a84ea617801beea47dda0b581David Chisnall unlock(l); 1892aff73868669a46a84ea617801beea47dda0b581David Chisnall return 1; 1902aff73868669a46a84ea617801beea47dda0b581David Chisnall } 1912aff73868669a46a84ea617801beea47dda0b581David Chisnall memcpy(expected, ptr, size); 1922aff73868669a46a84ea617801beea47dda0b581David Chisnall unlock(l); 1932aff73868669a46a84ea617801beea47dda0b581David Chisnall return 0; 1942aff73868669a46a84ea617801beea47dda0b581David Chisnall} 1952aff73868669a46a84ea617801beea47dda0b581David Chisnall 1962aff73868669a46a84ea617801beea47dda0b581David Chisnall/// Performs an atomic exchange operation between two pointers. This is atomic 1972aff73868669a46a84ea617801beea47dda0b581David Chisnall/// with respect to the target address. 198bc7ab9ce95a703ef732beb4ca4d0ea8778a60fddDavid Chisnallvoid __atomic_exchange_c(int size, void *ptr, void *val, void *old, int model) { 1992aff73868669a46a84ea617801beea47dda0b581David Chisnall#define LOCK_FREE_ACTION(type) \ 200bc7ab9ce95a703ef732beb4ca4d0ea8778a60fddDavid Chisnall *(type*)old = __c11_atomic_exchange((_Atomic(type)*)ptr, *(type*)val,\ 2012aff73868669a46a84ea617801beea47dda0b581David Chisnall model);\ 2022aff73868669a46a84ea617801beea47dda0b581David Chisnall return; 2032aff73868669a46a84ea617801beea47dda0b581David Chisnall LOCK_FREE_CASES(); 2042aff73868669a46a84ea617801beea47dda0b581David Chisnall#undef LOCK_FREE_ACTION 2052aff73868669a46a84ea617801beea47dda0b581David Chisnall Lock *l = lock_for_pointer(ptr); 2062aff73868669a46a84ea617801beea47dda0b581David Chisnall lock(l); 2072aff73868669a46a84ea617801beea47dda0b581David Chisnall memcpy(old, ptr, size); 2082aff73868669a46a84ea617801beea47dda0b581David Chisnall memcpy(ptr, val, size); 2092aff73868669a46a84ea617801beea47dda0b581David Chisnall unlock(l); 2102aff73868669a46a84ea617801beea47dda0b581David Chisnall} 2112aff73868669a46a84ea617801beea47dda0b581David Chisnall 2122aff73868669a46a84ea617801beea47dda0b581David Chisnall//////////////////////////////////////////////////////////////////////////////// 2132aff73868669a46a84ea617801beea47dda0b581David Chisnall// Where the size is known at compile time, the compiler may emit calls to 2142aff73868669a46a84ea617801beea47dda0b581David Chisnall// specialised versions of the above functions. 2152aff73868669a46a84ea617801beea47dda0b581David Chisnall//////////////////////////////////////////////////////////////////////////////// 2162aff73868669a46a84ea617801beea47dda0b581David Chisnall#define OPTIMISED_CASES\ 2172aff73868669a46a84ea617801beea47dda0b581David Chisnall OPTIMISED_CASE(1, IS_LOCK_FREE_1, uint8_t)\ 2182aff73868669a46a84ea617801beea47dda0b581David Chisnall OPTIMISED_CASE(2, IS_LOCK_FREE_2, uint16_t)\ 2192aff73868669a46a84ea617801beea47dda0b581David Chisnall OPTIMISED_CASE(4, IS_LOCK_FREE_4, uint32_t)\ 2202aff73868669a46a84ea617801beea47dda0b581David Chisnall OPTIMISED_CASE(8, IS_LOCK_FREE_8, uint64_t)\ 221fa3eee4101f39661b4a88ac0bc7f184ca8c1ecb1Benjamin Kramer /* FIXME: __uint128_t isn't available on 32 bit platforms. 222fa3eee4101f39661b4a88ac0bc7f184ca8c1ecb1Benjamin Kramer OPTIMISED_CASE(16, IS_LOCK_FREE_16, __uint128_t)*/\ 2232aff73868669a46a84ea617801beea47dda0b581David Chisnall 2242aff73868669a46a84ea617801beea47dda0b581David Chisnall#define OPTIMISED_CASE(n, lockfree, type)\ 2252aff73868669a46a84ea617801beea47dda0b581David Chisnalltype __atomic_load_##n(type *src, int model) {\ 2262aff73868669a46a84ea617801beea47dda0b581David Chisnall if (lockfree)\ 227bc7ab9ce95a703ef732beb4ca4d0ea8778a60fddDavid Chisnall return __c11_atomic_load((_Atomic(type)*)src, model);\ 2282aff73868669a46a84ea617801beea47dda0b581David Chisnall Lock *l = lock_for_pointer(src);\ 2292aff73868669a46a84ea617801beea47dda0b581David Chisnall lock(l);\ 2302aff73868669a46a84ea617801beea47dda0b581David Chisnall type val = *src;\ 2312aff73868669a46a84ea617801beea47dda0b581David Chisnall unlock(l);\ 2322aff73868669a46a84ea617801beea47dda0b581David Chisnall return val;\ 2332aff73868669a46a84ea617801beea47dda0b581David Chisnall} 2342aff73868669a46a84ea617801beea47dda0b581David ChisnallOPTIMISED_CASES 2352aff73868669a46a84ea617801beea47dda0b581David Chisnall#undef OPTIMISED_CASE 2362aff73868669a46a84ea617801beea47dda0b581David Chisnall 2372aff73868669a46a84ea617801beea47dda0b581David Chisnall#define OPTIMISED_CASE(n, lockfree, type)\ 2382aff73868669a46a84ea617801beea47dda0b581David Chisnallvoid __atomic_store_##n(type *dest, type val, int model) {\ 2392aff73868669a46a84ea617801beea47dda0b581David Chisnall if (lockfree) {\ 240bc7ab9ce95a703ef732beb4ca4d0ea8778a60fddDavid Chisnall __c11_atomic_store((_Atomic(type)*)dest, val, model);\ 2412aff73868669a46a84ea617801beea47dda0b581David Chisnall return;\ 2422aff73868669a46a84ea617801beea47dda0b581David Chisnall }\ 2432aff73868669a46a84ea617801beea47dda0b581David Chisnall Lock *l = lock_for_pointer(dest);\ 2442aff73868669a46a84ea617801beea47dda0b581David Chisnall lock(l);\ 2452aff73868669a46a84ea617801beea47dda0b581David Chisnall *dest = val;\ 2462aff73868669a46a84ea617801beea47dda0b581David Chisnall unlock(l);\ 2472aff73868669a46a84ea617801beea47dda0b581David Chisnall return;\ 2482aff73868669a46a84ea617801beea47dda0b581David Chisnall} 2492aff73868669a46a84ea617801beea47dda0b581David ChisnallOPTIMISED_CASES 2502aff73868669a46a84ea617801beea47dda0b581David Chisnall#undef OPTIMISED_CASE 2512aff73868669a46a84ea617801beea47dda0b581David Chisnall 2522aff73868669a46a84ea617801beea47dda0b581David Chisnall#define OPTIMISED_CASE(n, lockfree, type)\ 2532aff73868669a46a84ea617801beea47dda0b581David Chisnalltype __atomic_exchange_##n(type *dest, type val, int model) {\ 2542aff73868669a46a84ea617801beea47dda0b581David Chisnall if (lockfree)\ 255bc7ab9ce95a703ef732beb4ca4d0ea8778a60fddDavid Chisnall return __c11_atomic_exchange((_Atomic(type)*)dest, val, model);\ 2562aff73868669a46a84ea617801beea47dda0b581David Chisnall Lock *l = lock_for_pointer(dest);\ 2572aff73868669a46a84ea617801beea47dda0b581David Chisnall lock(l);\ 2582aff73868669a46a84ea617801beea47dda0b581David Chisnall type tmp = *dest;\ 2592aff73868669a46a84ea617801beea47dda0b581David Chisnall *dest = val;\ 2602aff73868669a46a84ea617801beea47dda0b581David Chisnall unlock(l);\ 2612aff73868669a46a84ea617801beea47dda0b581David Chisnall return tmp;\ 2622aff73868669a46a84ea617801beea47dda0b581David Chisnall} 2632aff73868669a46a84ea617801beea47dda0b581David ChisnallOPTIMISED_CASES 2642aff73868669a46a84ea617801beea47dda0b581David Chisnall#undef OPTIMISED_CASE 2652aff73868669a46a84ea617801beea47dda0b581David Chisnall 2662aff73868669a46a84ea617801beea47dda0b581David Chisnall#define OPTIMISED_CASE(n, lockfree, type)\ 2672aff73868669a46a84ea617801beea47dda0b581David Chisnallint __atomic_compare_exchange_##n(type *ptr, type *expected, type desired,\ 2682aff73868669a46a84ea617801beea47dda0b581David Chisnall int success, int failure) {\ 2692aff73868669a46a84ea617801beea47dda0b581David Chisnall if (lockfree)\ 270bc7ab9ce95a703ef732beb4ca4d0ea8778a60fddDavid Chisnall return __c11_atomic_compare_exchange_strong((_Atomic(type)*)ptr, expected, desired,\ 2712aff73868669a46a84ea617801beea47dda0b581David Chisnall success, failure);\ 2722aff73868669a46a84ea617801beea47dda0b581David Chisnall Lock *l = lock_for_pointer(ptr);\ 2732aff73868669a46a84ea617801beea47dda0b581David Chisnall lock(l);\ 2742aff73868669a46a84ea617801beea47dda0b581David Chisnall if (*ptr == *expected) {\ 2752aff73868669a46a84ea617801beea47dda0b581David Chisnall *ptr = desired;\ 2762aff73868669a46a84ea617801beea47dda0b581David Chisnall unlock(l);\ 2772aff73868669a46a84ea617801beea47dda0b581David Chisnall return 1;\ 2782aff73868669a46a84ea617801beea47dda0b581David Chisnall }\ 2792aff73868669a46a84ea617801beea47dda0b581David Chisnall *expected = *ptr;\ 2802aff73868669a46a84ea617801beea47dda0b581David Chisnall unlock(l);\ 2812aff73868669a46a84ea617801beea47dda0b581David Chisnall return 0;\ 2822aff73868669a46a84ea617801beea47dda0b581David Chisnall} 2832aff73868669a46a84ea617801beea47dda0b581David ChisnallOPTIMISED_CASES 2842aff73868669a46a84ea617801beea47dda0b581David Chisnall#undef OPTIMISED_CASE 2852aff73868669a46a84ea617801beea47dda0b581David Chisnall 2862aff73868669a46a84ea617801beea47dda0b581David Chisnall//////////////////////////////////////////////////////////////////////////////// 2872aff73868669a46a84ea617801beea47dda0b581David Chisnall// Atomic read-modify-write operations for integers of various sizes. 2882aff73868669a46a84ea617801beea47dda0b581David Chisnall//////////////////////////////////////////////////////////////////////////////// 2892aff73868669a46a84ea617801beea47dda0b581David Chisnall#define ATOMIC_RMW(n, lockfree, type, opname, op) \ 2902aff73868669a46a84ea617801beea47dda0b581David Chisnalltype __atomic_fetch_##opname##_##n(type *ptr, type val, int model) {\ 2912aff73868669a46a84ea617801beea47dda0b581David Chisnall if (lockfree) \ 292bc7ab9ce95a703ef732beb4ca4d0ea8778a60fddDavid Chisnall return __c11_atomic_fetch_##opname((_Atomic(type)*)ptr, val, model);\ 2932aff73868669a46a84ea617801beea47dda0b581David Chisnall Lock *l = lock_for_pointer(ptr);\ 2942aff73868669a46a84ea617801beea47dda0b581David Chisnall lock(l);\ 2952aff73868669a46a84ea617801beea47dda0b581David Chisnall type tmp = *ptr;\ 2962aff73868669a46a84ea617801beea47dda0b581David Chisnall *ptr = tmp op val;\ 2972aff73868669a46a84ea617801beea47dda0b581David Chisnall unlock(l);\ 2982aff73868669a46a84ea617801beea47dda0b581David Chisnall return tmp;\ 2992aff73868669a46a84ea617801beea47dda0b581David Chisnall} 3002aff73868669a46a84ea617801beea47dda0b581David Chisnall 3012aff73868669a46a84ea617801beea47dda0b581David Chisnall#define OPTIMISED_CASE(n, lockfree, type) ATOMIC_RMW(n, lockfree, type, add, +) 3022aff73868669a46a84ea617801beea47dda0b581David ChisnallOPTIMISED_CASES 3032aff73868669a46a84ea617801beea47dda0b581David Chisnall#undef OPTIMISED_CASE 3042aff73868669a46a84ea617801beea47dda0b581David Chisnall#define OPTIMISED_CASE(n, lockfree, type) ATOMIC_RMW(n, lockfree, type, sub, -) 3052aff73868669a46a84ea617801beea47dda0b581David ChisnallOPTIMISED_CASES 3062aff73868669a46a84ea617801beea47dda0b581David Chisnall#undef OPTIMISED_CASE 3072aff73868669a46a84ea617801beea47dda0b581David Chisnall#define OPTIMISED_CASE(n, lockfree, type) ATOMIC_RMW(n, lockfree, type, and, &) 3082aff73868669a46a84ea617801beea47dda0b581David ChisnallOPTIMISED_CASES 3092aff73868669a46a84ea617801beea47dda0b581David Chisnall#undef OPTIMISED_CASE 3102aff73868669a46a84ea617801beea47dda0b581David Chisnall#define OPTIMISED_CASE(n, lockfree, type) ATOMIC_RMW(n, lockfree, type, or, |) 3112aff73868669a46a84ea617801beea47dda0b581David ChisnallOPTIMISED_CASES 3122aff73868669a46a84ea617801beea47dda0b581David Chisnall#undef OPTIMISED_CASE 3132aff73868669a46a84ea617801beea47dda0b581David Chisnall#define OPTIMISED_CASE(n, lockfree, type) ATOMIC_RMW(n, lockfree, type, xor, ^) 3142aff73868669a46a84ea617801beea47dda0b581David ChisnallOPTIMISED_CASES 3152aff73868669a46a84ea617801beea47dda0b581David Chisnall#undef OPTIMISED_CASE 316