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
|
/*
SuperCollider real time audio synthesis system
Copyright (c) 2002 James McCartney. All rights reserved.
http://www.audiosynth.com
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program 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
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifndef _IntFifo_
#define _IntFifo_
#ifdef SC_DARWIN
# include <CoreServices/CoreServices.h>
#endif
template <int N>
class IntFifo
{
public:
IntFifo()
: mMask(N - 1), mReadHead(0), mWriteHead(0)
{}
void MakeEmpty() { mReadHead = mWriteHead; }
bool IsEmpty() { return mReadHead == mWriteHead; }
bool HasData() { return mReadHead != mWriteHead; }
bool Put(int data)
{
long next = NextPos(mWriteHead);
if (next == mReadHead) return false; // fifo is full
mItems[next] = data;
#ifdef SC_DARWIN
// we don't really need a compare and swap, but this happens to call
// the PowerPC memory barrier instruction lwsync.
CompareAndSwap(mWriteHead, next, &mWriteHead);
#elif defined SC_WIN32
InterlockedExchange(reinterpret_cast<volatile LONG*>(&mWriteHead),next);
#else
mWriteHead = next;
#endif
return true;
}
int32 Get()
{
//assert(HasData());
long next = NextPos(mReadHead);
out = mItems[next].Perform();
#ifdef SC_DARWIN
// we don't really need a compare and swap, but this happens to call
// the PowerPC memory barrier instruction lwsync.
CompareAndSwap(mReadHead, next, &mReadHead);
#elif defined SC_WIN32
InterlockedExchange(reinterpret_cast<volatile LONG*>(&mReadHead),next);
#else
mReadHead = next;
#endif
}
private:
int NextPos(int inPos) { return (inPos + 1) & mMask; }
long mMask;
#ifdef SC_DARWIN
UInt32 mReadHead, mWriteHead;
#else
volatile int mReadHead, mWriteHead;
#endif
int32 mItems[N];
};
#endif
|
