summaryrefslogtreecommitdiff
path: root/src/atomic.hpp
blob: e581593d417a6d6719e167e7905d2b26e7b35db5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
/*
    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 <http://www.gnu.org/licenses/>.
*/

#ifndef __ZMQ_ATOMIC_HPP_INCLUDED__
#define __ZMQ_ATOMIC_HPP_INCLUDED__

#include "stdint.hpp"

#if defined ZMQ_FORCE_MUTEXES
#define ZMQ_ATOMIC_MUTEX
#elif (defined __i386__ || defined __x86_64__) && defined __GNUC__
#define ZMQ_ATOMIC_X86
#elif defined ZMQ_HAVE_WINDOWS
#define ZMQ_ATOMIC_WINDOWS
#elif defined ZMQ_HAVE_SOLARIS
#define ZMQ_ATOMIC_SOLARIS
#else
#define ZMQ_ATOMIC_MUTEX
#endif

namespace zmq
{

    //  Atomic assignement.
    inline void atomic_uint32_set (volatile uint32_t *p_, uint32_t value_)
    {
        *p_ = value_;
        //  StoreLoad memory barrier should go here on platforms with
        //  memory models that require it.
    }

    //  Atomic retrieval of an integer.
    inline uint32_t atomic_uint32_get (volatile uint32_t *p_)
    {
        //  StoreLoad memory barrier should go here on platforms with
        //  memory models that require it.
        return *p_;
    }

    //  Atomic addition. Returns the old value.
    inline uint32_t atomic_uint32_add (volatile uint32_t *p_, uint32_t delta_)
    {
#if defined ZMQ_ATOMIC_WINDOWS
        return InterlockedExchangeAdd ((LONG*) &value, increment_);
#elif defined ZMQ_ATOMIC_SOLARIS
        return atomic_add_32_nv (&value, increment_) - delta_;
#elif defined ZMQ_ATOMIC_X86
        uint32_t old;
        __asm__ volatile (
            "lock; xadd %0, %1\n\t"
            : "=r" (old), "=m" (*p_)
            : "0" (delta_), "m" (*p_)
            : "cc", "memory");
        return old;
#else
#error // TODO: 
        sync.lock ();
        uint32_t old = *p_;
        *p_ += delta_;
        sync.unlock ();
#endif
    }

    //  Atomic subtraction. Returns the old value.
    inline uint32_t atomic_uint32_sub (volatile uint32_t *p_, uint32_t delta_)
    {
#if defined ZMQ_ATOMIC_WINDOWS
        LONG delta = - ((LONG) delta_);
        return InterlockedExchangeAdd ((LONG*) &value, delta);
#elif defined ZMQ_ATOMIC_SOLARIS
        int32_t delta = - ((int32_t) delta_);
        return atomic_add_32_nv (&value, delta) + delta_;
#elif defined ZMQ_ATOMIC_X86
        uint32_t old = -delta_;
        __asm__ volatile ("lock; xaddl %0,%1"
            : "=r" (old), "=m" (*p_)
            : "0" (old), "m" (*p_)
            : "cc");
        return old;
#else
#error // TODO: 
        sync.lock ();
        uint32_t old = *p_;
        *p_ -= delta_;
        sync.unlock ();
        return old;
#endif
    }

    //  Atomic assignement.
    template <typename T>
    inline void atomic_ptr_set (volatile T **p_, T *value_)
    {
        *p_ = value_;
        //  StoreLoad memory barrier should go here on platforms with
        //  memory models that require it.
    }

    //  Perform atomic 'exchange pointers' operation. Old value is returned.
    template <typename T>
    inline void *atomic_ptr_xchg (volatile T **p_, T *value_)
    {
#if defined ZMQ_ATOMIC_WINDOWS
        return InterlockedExchangePointer (p_, value_);
#elif defined ZMQ_ATOMIC_SOLARIS
        return atomic_swap_ptr (p_, value_);
#elif defined ZMQ_ATOMIC_X86
        void *old;
        __asm__ volatile (
            "lock; xchg %0, %2"
            : "=r" (old), "=m" (*p_)
            : "m" (*p_), "0" (value_));
        return old;
#else
#error //  TODO:
        sync.lock ();
        void *old = *p_;
        *p_ = value_;
        sync.unlock ();
        return old;
#endif
    }

    //  Perform atomic 'compare and swap' operation on the pointer.
    //  The pointer is compared to 'cmp' argument and if they are
    //  equal, its value is set to 'value'. Old value of the pointer
    //  is returned.
    template <typename T>
    inline void *atomic_ptr_cas (volatile T **p_, T *cmp_, T *value_)
    {
#if defined ZMQ_ATOMIC_WINDOWS
        return InterlockedCompareExchangePointer (p_, value_, cmp_);
#elif defined ZMQ_ATOMIC_SOLARIS
        return atomic_cas_ptr (p_, cmp_, value_);
#elif defined ZMQ_ATOMIC_X86
        void *old;
        __asm__ volatile (
            "lock; cmpxchg %2, %3"
            : "=a" (old), "=m" (*p_)
            : "r" (value_), "m" (*p_), "0" (cmp_)
            : "cc");
        return old;
#else
#error //  TODO:
        sync.lock ();
        void *old = *p_;
        if (old == cmp_)
            *p_ = value_;
        sync.unlock ();
        return old;
#endif
    }

#if defined ZMQ_ATOMIC_X86 && defined __x86_64__
    typedef uint64_t atomic_bitmap_t;
#else
    typedef uint32_t atomic_bitmap_t;
#endif

    //  Atomic assignement.
    inline void atomic_bitmap_set (volatile atomic_bitmap_t *p_,
        atomic_bitmap_t value_)
    {
        *p_ = value_;
        //  StoreLoad memory barrier should go here on platforms with
        //  memory models that require it.
    }

    //  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 atomic_bitmap_btsr (volatile atomic_bitmap_t *p_,
        int set_index_, int reset_index_)
    {
#if defined ZMQ_ATOMIC_WINDOWS
        while (true) {
            atomic_bitmap_t oldval = *p_;
            atomic_bitmap_t newval = (oldval | (atomic_bitmap_t (1) <<
                set_index_)) & ~(integer_t (1) << reset_index_);
            if (InterlockedCompareExchange ((volatile LONG*) p_, newval,
                  oldval) == (LONG) oldval)
                return (oldval & (atomic_bitmap_t (1) << reset_index_)) ?
                    true : false; 
        }
#elif defined ZMQ_ATOMIC_SOLARIS
        while (true) {
            atomic_bitmap_t oldval = *p_;
            atomic_bitmap_t newval = (oldval | (atomic_bitmap_t (1) <<
                set_index_)) & ~(integer_t (1) << reset_index_);
            if (atomic_cas_32 (p_, oldval, newval) == oldval)
                return (oldval & (atomic_bitmap_t (1) << reset_index_)) ?
                    true : false; 
        }
#elif defined ZMQ_ATOMIC_X86
        atomic_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" (*p_), "=&a" (oldval), "=&r" (dummy)
            : "r" (atomic_bitmap_t (set_index_)),
                "r" (atomic_bitmap_t (reset_index_))
            : "cc");
        return (bool) (oldval & (atomic_bitmap_t (1) << reset_index_)); 
#else
#error // TODO:
        sync.lock ();
        atomic_bitmap_t oldval = *p_;
        *p_ = (oldval | (atomic_bitmap_t (1) << set_index_)) &
            ~(atomic_bitmap_t (1) << reset_index_);
        sync.unlock ();
        return (oldval & (atomic_bitmap_t (1) << reset_index_)) ? true : false;
#endif
    }

    //  Sets value to newval. Returns the original value.
    inline atomic_bitmap_t atomic_bitmap_xchg (volatile atomic_bitmap_t *p_,
        atomic_bitmap_t newval_)
    {
#if defined ZMQ_ATOMIC_WINDOWS
        return InterlockedExchange ((volatile LONG*) p_, newval_);
#elif defined ZMQ_ATOMIC_SOLARIS
        return atomic_swap_32 (p_, newval_);
#elif defined ZMQ_ATOMIC_X86
        atomic_bitmap_t oldval = newval_;
        __asm__ volatile (
            "lock; xchg %0, %1"
            : "=r" (oldval)
            : "m" (*p_), "0" (oldval)
            : "memory");
        return oldval; 
#else
#error //  TODO:
        sync.lock ();
        atomic_bitmap_t oldval = *p_;
        *p_ = newval_;
        sync.unlock ();
#endif
    }

    //  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 atomic_bitmap_t atomic_bitmap_izte (volatile atomic_bitmap_t *p_,
            atomic_bitmap_t thenval_,  atomic_bitmap_t elseval_)
    {
#if defined ZMQ_ATOMIC_WINDOWS
        while (true) {
            atomic_bitmap_t oldval = *p_;
            atomic_bitmap_t newval = (oldval ? elseval_ : thenval_); 
            if (InterlockedCompareExchange ((volatile LONG*) p_, newval,
                  oldval) == (LONG) oldval)
                return oldval;
        }
#elif defined ZMQ_ATOMIC_SOLARIS
        while (true) {
            atomic_bitmap_t oldval = *p_;
            atomic_bitmap_t newval = (oldval ? elseval_ : thenval_); 
            if (atomic_cas_32 (p_, oldval, newval) == oldval)
                return oldval;
        }
#elif defined ZMQ_ATOMIC_X86
        atomic_bitmap_t oldval;
        atomic_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" (*p_), "=&a" (oldval), "=&r" (dummy)
            : "r" (thenval_), "r" (elseval_)
            : "cc");
        return oldval;
#else
#error //  TODO:
        sync.lock ();
        atomic_bitmap_t oldval = *p_;
        *p_ = oldval ? elseval_ : thenval_;
        sync.unlock ();
        return oldval;
#endif
    }

}

#endif