libmdbx/barriers.h

157 lines
4.8 KiB
C

/*
* Copyright 2015-2017 Leonid Yuriev <leo@yuriev.ru>.
* Copyright 2015,2016 Peter-Service R&D LLC.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted only as authorized by the OpenLDAP
* Public License.
*
* A copy of this license is available in the file LICENSE in the
* top-level directory of the distribution or, alternatively, at
* <http://www.OpenLDAP.org/license.html>.
*/
/*****************************************************************************
* Properly compiler/memory/coherence barriers
* in the most portable way for libmdbx project.
*
* Feedback and comments are welcome.
* https://gist.github.com/leo-yuriev/ba186a6bf5cf3a27bae7 */
#pragma once
/* *INDENT-OFF* */
/* clang-format off */
#if defined(__mips) && defined(__linux)
/* Only MIPS has explicit cache control */
# include <asm/cachectl.h>
#endif
#if defined(__GNUC__) || defined(__clang__)
# define MDBX_INLINE __inline
#elif defined(__INTEL_COMPILER) /* LY: Intel Compiler may mimic GCC and MSC */
# include <intrin.h>
# if defined(__ia64__) || defined(__ia64) || defined(_M_IA64)
# pragma intrinsic(__mf)
# elif defined(__i386__) || defined(__x86_64__)
# pragma intrinsic(_mm_mfence)
# endif
# define MDBX_INLINE __inline
#elif defined(__SUNPRO_C) || defined(__sun) || defined(sun)
# include <mbarrier.h>
# define MDBX_INLINE inline
#elif (defined(_HPUX_SOURCE) || defined(__hpux) || defined(__HP_aCC)) \
&& (defined(HP_IA64) || defined(__ia64))
# include <machine/sys/inline.h>
# define MDBX_INLINE
#elif defined(__IBMC__) && defined(__powerpc)
# include <atomic.h>
# define MDBX_INLINE
#elif defined(_AIX)
# include <builtins.h>
# include <sys/atomic_op.h>
# define MDBX_INLINE
#elif (defined(__osf__) && defined(__DECC)) || defined(__alpha)
# include <machine/builtins.h>
# include <c_asm.h>
# define MDBX_INLINE
#elif defined(__MWERKS__)
/* CodeWarrior - troubles ? */
# pragma gcc_extensions
# define MDBX_INLINE
#elif defined(__SNC__)
/* Sony PS3 - troubles ? */
# define MDBX_INLINE
#else
# define MDBX_INLINE
#endif
#if defined(__i386__) || defined(__x86_64__) \
|| defined(_M_AMD64) || defined(_M_IX86) \
|| defined(__i386) || defined(__amd64) \
|| defined(i386) || defined(__x86_64) \
|| defined(_AMD64_) || defined(_M_X64)
# define MDB_CACHE_IS_COHERENT 1
#elif defined(__hppa) || defined(__hppa__)
# define MDB_CACHE_IS_COHERENT 1
#endif
#ifndef MDB_CACHE_IS_COHERENT
# define MDB_CACHE_IS_COHERENT 0
#endif
#define MDBX_BARRIER_COMPILER 0
#define MDBX_BARRIER_MEMORY 1
static MDBX_INLINE void mdbx_barrier(int type) {
#if defined(__clang__)
__asm__ __volatile__ ("" ::: "memory");
if (type > MDBX_BARRIER_COMPILER)
# if __has_extension(c_atomic) || __has_extension(cxx_atomic)
__c11_atomic_thread_fence(__ATOMIC_SEQ_CST);
# else
__sync_synchronize();
# endif
#elif defined(__GNUC__)
__asm__ __volatile__ ("" ::: "memory");
if (type > MDBX_BARRIER_COMPILER)
# if defined(__ATOMIC_SEQ_CST)
__atomic_thread_fence(__ATOMIC_SEQ_CST);
# else
__sync_synchronize();
# endif
#elif defined(__INTEL_COMPILER) /* LY: Intel Compiler may mimic GCC and MSC */
__memory_barrier();
if (type > MDBX_BARRIER_COMPILER)
# if defined(__ia64__) || defined(__ia64) || defined(_M_IA64)
__mf();
# elif defined(__i386__) || defined(__x86_64__)
_mm_mfence();
# else
# error "Unknown target for Intel Compiler, please report to us."
# endif
#elif defined(__SUNPRO_C) || defined(__sun) || defined(sun)
__compiler_barrier();
if (type > MDBX_BARRIER_COMPILER)
__machine_rw_barrier();
#elif (defined(_HPUX_SOURCE) || defined(__hpux) || defined(__HP_aCC)) \
&& (defined(HP_IA64) || defined(__ia64))
_Asm_sched_fence(/* LY: no-arg meaning 'all expect ALU', e.g. 0x3D3D */);
if (type > MDBX_BARRIER_COMPILER)
_Asm_mf();
#elif defined(_AIX) || defined(__ppc__) || defined(__powerpc__) \
|| defined(__ppc64__) || defined(__powerpc64__)
__fence();
if (type > MDBX_BARRIER_COMPILER)
__lwsync();
#elif (defined(__osf__) && defined(__DECC)) || defined(__alpha)
__PAL_DRAINA(); /* LY: excessive ? */
__MB();
#else
# error "Could not guess the kind of compiler, please report to us."
#endif
}
#define mdbx_compiler_barrier() \
mdbx_barrier(MDBX_BARRIER_COMPILER)
#define mdbx_memory_barrier() \
mdbx_barrier(MDBX_BARRIER_MEMORY)
#define mdbx_coherent_barrier() \
mdbx_barrier(MDB_CACHE_IS_COHERENT ? MDBX_BARRIER_COMPILER : MDBX_BARRIER_MEMORY)
static MDBX_INLINE void mdbx_invalidate_cache(void *addr, int nbytes) {
mdbx_coherent_barrier();
#if defined(__mips) && defined(__linux)
/* MIPS has cache coherency issues.
* Note: for any nbytes >= on-chip cache size, entire is flushed. */
cacheflush(addr, nbytes, DCACHE);
#elif defined(_M_MRX000) || defined(_MIPS_)
# error "Sorry, cacheflush() for MIPS not implemented"
#else
/* LY: assume no mmap/dcache issues. */
(void) addr;
(void) nbytes;
#endif
}