/*
Copyright (c) 2007-2009 FastMQ Inc.
This file is part of 0MQ.
0MQ is free software; you can redistribute it and/or modify it under
the terms of the Lesser GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
0MQ is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
Lesser GNU General Public License for more details.
You should have received a copy of the Lesser GNU General Public License
along with this program. If not, see .
*/
#ifndef __ZMQ_ATOMIC_BITMAP_HPP_INCLUDED__
#define __ZMQ_ATOMIC_BITMAP_HPP_INCLUDED__
#include "stdint.hpp"
#include "platform.hpp"
// These are the conditions to choose between different implementations
// of atomic_bitmap.
#if defined ZMQ_FORCE_MUTEXES
#define ZMQ_ATOMIC_BITMAP_MUTEX
#elif (defined __i386__ || defined __x86_64__) && defined __GNUC__
#define ZMQ_ATOMIC_BITMAP_X86
#elif 0 && defined __sparc__ && defined __GNUC__
#define ZMQ_ATOMIC_BITMAP_SPARC
#elif defined ZMQ_HAVE_WINDOWS
#define ZMQ_ATOMIC_BITMAP_WINDOWS
#elif defined ZMQ_HAVE_SOLARIS
#define ZMQ_ATOMIC_BITMAP_SOLARIS
#else
#define ZMQ_ATOMIC_BITMAP_MUTEX
#endif
#if defined ZMQ_ATOMIC_BITMAP_MUTEX
#include "mutex.hpp"
#elif defined ZMQ_ATOMIC_BITMAP_WINDOWS
#include "windows.hpp"
#elif defined ZMQ_ATOMIC_BITMAP_SOLARIS
#include
#endif
namespace zmq
{
// This class encapuslates several bitwise atomic operations on unsigned
// integer. Selection of operations is driven specifically by the needs
// of ypollset implementation.
class atomic_bitmap_t
{
public:
#if (defined ZMQ_ATOMIC_BITMAP_X86 || defined ZMQ_FORCE_MUTEXES) \
&& defined __x86_64__
typedef uint64_t bitmap_t;
#else
typedef uint32_t bitmap_t;
#endif
inline atomic_bitmap_t (bitmap_t value_ = 0) :
value (value_)
{
}
inline ~atomic_bitmap_t ()
{
}
// Bit-test-set-and-reset. Sets one bit of the value and resets
// another one. Returns the original value of the reset bit.
inline bool btsr (int set_index_, int reset_index_)
{
#if defined ZMQ_ATOMIC_BITMAP_WINDOWS
while (true) {
bitmap_t oldval = value;
bitmap_t newval = (oldval | (bitmap_t (1) << set_index_)) &
~(bitmap_t (1) << reset_index_);
if (InterlockedCompareExchange ((volatile LONG*) &value, newval,
oldval) == (LONG) oldval)
return (oldval & (bitmap_t (1) << reset_index_)) ?
true : false;
}
#elif defined ZMQ_ATOMIC_BITMAP_SOLARIS
while (true) {
bitmap_t oldval = value;
bitmap_t newval = (oldval | (bitmap_t (1) << set_index_)) &
~(bitmap_t (1) << reset_index_);
if (atomic_cas_32 (&value, oldval, newval) == oldval)
return (oldval & (bitmap_t (1) << reset_index_)) ?
true : false;
}
#elif defined ZMQ_ATOMIC_BITMAP_X86
bitmap_t oldval, dummy;
__asm__ volatile (
"mov %0, %1\n\t"
"1:"
"mov %1, %2\n\t"
"bts %3, %2\n\t"
"btr %4, %2\n\t"
"lock cmpxchg %2, %0\n\t"
"jnz 1b\n\t"
: "+m" (value), "=&a" (oldval), "=&r" (dummy)
: "r" (bitmap_t(set_index_)), "r" (bitmap_t(reset_index_))
: "cc");
return (bool) (oldval & (bitmap_t(1) << reset_index_));
#elif defined ZMQ_ATOMIC_BITMAP_SPARC
volatile bitmap_t* valptr = &value;
bitmap_t set_val = bitmap_t(1) << set_index_;
bitmap_t reset_val = ~(bitmap_t(1) << reset_index_);
bitmap_t tmp;
bitmap_t oldval;
__asm__ volatile(
"ld [%5], %2 \n\t"
"1: \n\t"
"or %2, %0, %3 \n\t"
"and %3, %1, %3 \n\t"
"cas [%5], %2, %3 \n\t"
"cmp %2, %3 \n\t"
"bne,a,pn %%icc, 1b \n\t"
"mov %3, %2 \n\t"
: "+r" (set_val), "+r" (reset_val), "=&r" (tmp),
"=&r" (oldval), "+m" (*valptr)
: "r" (valptr)
: "cc");
return oldval;
#elif defined ZMQ_ATOMIC_BITMAP_MUTEX
sync.lock ();
bitmap_t oldval = value;
value = (oldval | (bitmap_t (1) << set_index_)) &
~(bitmap_t (1) << reset_index_);
sync.unlock ();
return (oldval & (bitmap_t (1) << reset_index_)) ? true : false;
#else
#error
#endif
}
// Sets value to newval. Returns the original value.
inline bitmap_t xchg (bitmap_t newval_)
{
bitmap_t oldval;
#if defined ZMQ_ATOMIC_BITMAP_WINDOWS
oldval = InterlockedExchange ((volatile LONG*) &value, newval_);
#elif defined ZMQ_ATOMIC_BITMAP_SOLARIS
oldval = atomic_swap_32 (&value, newval_);
#elif defined ZMQ_ATOMIC_BITMAP_X86
oldval = newval_;
__asm__ volatile (
"lock; xchg %0, %1"
: "=r" (oldval)
: "m" (value), "0" (oldval)
: "memory");
#elif defined ZMQ_ATOMIC_BITMAP_SPARC
oldval = value;
volatile bitmap_t* ptrin = &value;
bitmap_t tmp;
bitmap_t prev;
__asm__ __volatile__(
"ld [%4], %1\n\t"
"1:\n\t"
"mov %0, %2\n\t"
"cas [%4], %1, %2\n\t"
"cmp %1, %2\n\t"
"bne,a,pn %%icc, 1b\n\t"
"mov %2, %1\n\t"
: "+r" (newval_), "=&r" (tmp), "=&r" (prev), "+m" (*ptrin)
: "r" (ptrin)
: "cc");
return prev;
#elif defined ZMQ_ATOMIC_BITMAP_MUTEX
sync.lock ();
oldval = value;
value = newval_;
sync.unlock ();
#else
#error
#endif
return oldval;
}
// izte is "if-zero-then-else" atomic operation - if the value is zero
// it substitutes it by 'thenval' else it rewrites it by 'elseval'.
// Original value of the integer is returned from this function.
inline bitmap_t izte (bitmap_t thenval_,
bitmap_t elseval_)
{
#if defined ZMQ_ATOMIC_BITMAP_WINDOWS
while (true) {
bitmap_t oldval = value;
bitmap_t newval = oldval == 0 ? thenval_ : elseval_;
if (InterlockedCompareExchange ((volatile LONG*) &value,
newval, oldval) == (LONG) oldval)
return oldval;
}
#elif defined ZMQ_ATOMIC_BITMAP_SOLARIS
while (true) {
bitmap_t oldval = value;
bitmap_t newval = oldval == 0 ? thenval_ : elseval_;
if (atomic_cas_32 (&value, oldval, newval) == oldval)
return oldval;
}
#elif defined ZMQ_ATOMIC_BITMAP_X86
bitmap_t oldval;
bitmap_t dummy;
__asm__ volatile (
"mov %0, %1\n\t"
"1:"
"mov %3, %2\n\t"
"test %1, %1\n\t"
"jz 2f\n\t"
"mov %4, %2\n\t"
"2:"
"lock cmpxchg %2, %0\n\t"
"jnz 1b\n\t"
: "+m" (value), "=&a" (oldval), "=&r" (dummy)
: "r" (thenval_), "r" (elseval_)
: "cc");
return oldval;
#elif defined ZMQ_ATOMIC_BITMAP_SPARC
volatile bitmap_t* ptrin = &value;
bitmap_t tmp;
bitmap_t prev;
__asm__ __volatile__(
"ld [%3], %0 \n\t"
"mov 0, %1 \n\t"
"cas [%3], %1, %4 \n\t"
"cmp %0, %1 \n\t"
"be,a,pn %%icc,1f \n\t"
"ld [%3], %0 \n\t"
"cas [%3], %0, %5 \n\t"
"1: \n\t"
: "=&r" (tmp), "=&r" (prev), "+m" (*ptrin)
: "r" (ptrin), "r" (thenval_), "r" (elseval_)
: "cc");
return prev;
#elif defined ZMQ_ATOMIC_BITMAP_MUTEX
sync.lock ();
bitmap_t oldval = value;
value = oldval ? elseval_ : thenval_;
sync.unlock ();
return oldval;
#else
#error
#endif
}
private:
volatile bitmap_t value;
#if defined ZMQ_ATOMIC_BITMAP_MUTEX
mutex_t sync;
#endif
atomic_bitmap_t (const atomic_bitmap_t&);
void operator = (const atomic_bitmap_t&);
};
}
// Remove macros local to this file.
#if defined ZMQ_ATOMIC_BITMAP_WINDOWS
#undef ZMQ_ATOMIC_BITMAP_WINDOWS
#endif
#if defined ZMQ_ATOMIC_BITMAP_SOLARIS
#undef ZMQ_ATOMIC_BITMAP_SOLARIS
#endif
#if defined ZMQ_ATOMIC_BITMAP_X86
#undef ZMQ_ATOMIC_BITMAP_X86
#endif
#if defined ZMQ_ATOMIC_BITMAP_SPARC
#undef ZMQ_ATOMIC_BITMAP_SPARC
#endif
#if defined ZMQ_ATOMIC_BITMAP_MUTEX
#undef ZMQ_ATOMIC_BITMAP_MUTEX
#endif
#endif