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align vmb.h with the varnish version #86

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Merged
nigoroll merged 1 commit into from
Apr 21, 2022
Merged

align vmb.h with the varnish version #86

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2 changes: 2 additions & 0 deletions configure.ac
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Original file line number Diff line number Diff line change
Expand Up @@ -13,6 +13,8 @@ AM_PROG_AR
LT_PREREQ([2.2.6])
LT_INIT([dlopen disable-static])

AC_CHECK_HEADERS([stdatomic.h])

AC_ARG_WITH([rst2man],
AS_HELP_STRING(
[--with-rst2man=PATH],
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52 changes: 16 additions & 36 deletions src/vmb.h
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Original file line number Diff line number Diff line change
Expand Up @@ -4,6 +4,8 @@
*
* Author: Poul-Henning Kamp <phk@phk.freebsd.dk>
*
* SPDX-License-Identifier: BSD-2-Clause
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
Expand All @@ -27,60 +29,38 @@
*
* Memory barriers
*
* XXX: It is utterly braindamaged, that no standard facility for this
* XXX: is available. The "just use pthreads locking" excuse does not
* XXX: make sense, and does not apply to two unthreaded programs sharing
* XXX: a memory segment.
*/

#ifndef VMB_H_INCLUDED
#define VMB_H_INCLUDED

#if defined(__FreeBSD__)
#include <sys/param.h>
#endif

#if defined(__FreeBSD__) && __FreeBSD_version >= 800058
#if defined(HAVE_STDATOMIC_H) && !defined(__FLEXELINT__)

#include <sys/types.h>
#include <machine/atomic.h>
#define VMB() mb()
#define VWMB() wmb()
#define VRMB() rmb()
# include <stdatomic.h>
# define VWMB() atomic_thread_fence(memory_order_release)
# define VRMB() atomic_thread_fence(memory_order_acquire)

#elif defined(__amd64__) && defined(__GNUC__)

#define VMB() __asm __volatile("mfence;" : : : "memory")
#define VWMB() __asm __volatile("sfence;" : : : "memory")
#define VRMB() __asm __volatile("lfence;" : : : "memory")

#elif defined(__arm__)

#define VMB()
#define VWMB()
#define VRMB()
# define VWMB() __asm __volatile("sfence;" : : : "memory")
# define VRMB() __asm __volatile("lfence;" : : : "memory")

#elif defined(__i386__) && defined(__GNUC__)

#define VMB() __asm __volatile("lock; addl $0,(%%esp)" : : : "memory")
#define VWMB() __asm __volatile("lock; addl $0,(%%esp)" : : : "memory")
#define VRMB() __asm __volatile("lock; addl $0,(%%esp)" : : : "memory")
# define VWMB() __asm __volatile("lock; addl $0,(%%esp)" : : : "memory")
# define VRMB() __asm __volatile("lock; addl $0,(%%esp)" : : : "memory")

#elif defined(__sparc64__) && defined(__GNUC__)

#define VMB() __asm__ __volatile__ ("membar #MemIssue": : :"memory")
#define VWMB() VMB()
#define VRMB() VMB()
# define VWMB() __asm__ __volatile__ ("membar #MemIssue": : :"memory")
# define VRMB() __asm__ __volatile__ ("membar #MemIssue": : :"memory")

#else

#define VMB_NEEDS_PTHREAD_WORKAROUND_THIS_IS_BAD_FOR_PERFORMANCE 1

void vmb_pthread(void);

#define VMB() vmb_pthread()
#define VWMB() vmb_pthread()
#define VRMB() vmb_pthread()
# define VMB_NEEDS_PTHREAD_WORKAROUND_THIS_IS_BAD_FOR_PERFORMANCE 1
void vmb_pthread(void);
# define VWMB() vmb_pthread()
# define VRMB() vmb_pthread()

#endif

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