source: vscpl/src/hu/varadiistvan/scpl/io/_posix/WaitableEvent.cc@ 21:22a8774452ac

Last change on this file since 21:22a8774452ac was 7:e0118c752a06, checked in by István Váradi <ivaradi@…>, 12 years ago

Imported the WaitableEvent class

File size: 3.8 KB
Line 
1// Copyright (c) 2013 by István Váradi
2
3// This file is part of VSCPL, a simple cross-platform utility library
4
5// Redistribution and use in source and binary forms, with or without
6// modification, are permitted provided that the following conditions are met:
7
8// 1. Redistributions of source code must retain the above copyright notice, this
9// list of conditions and the following disclaimer.
10// 2. Redistributions in binary form must reproduce the above copyright notice,
11// this list of conditions and the following disclaimer in the documentation
12// and/or other materials provided with the distribution.
13
14// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
15// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
16// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
17// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
18// ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
19// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
20// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
21// ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
23// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24
25// The views and conclusions contained in the software and documentation are those
26// of the authors and should not be interpreted as representing official policies,
27// either expressed or implied, of the FreeBSD Project.
28
29//------------------------------------------------------------------------------
30
31#include "WaitableEvent.h"
32
33#include <poll.h>
34#include <unistd.h>
35
36#include <sys/eventfd.h>
37
38//------------------------------------------------------------------------------
39
40using hu::varadiistvan::scpl::io::WaitableEvent;
41
42//------------------------------------------------------------------------------
43
44WaitableEvent::WaitableEvent(Waiter* waiter) :
45 Waitable(waiter, eventfd(0, (waiter==0) ? 0 : EFD_NONBLOCK), POLLIN),
46 fired(false)
47{
48 if (fd<0) {
49 setErrorCodeFromErrno();
50 }
51}
52
53//------------------------------------------------------------------------------
54
55WaitableEvent::~WaitableEvent()
56{
57 close(fd);
58}
59
60//------------------------------------------------------------------------------
61
62void WaitableEvent::fire()
63{
64 static const uint64_t one = 1;
65 if (write(fd, &one, sizeof(one))<0) {
66 if (errno!=EAGAIN) {
67 setErrorCodeFromErrno();
68 }
69 }
70}
71
72//------------------------------------------------------------------------------
73
74bool WaitableEvent::check()
75{
76 if (doCheck()) {
77 fired = false;
78 return true;
79 } else {
80 return false;
81 }
82}
83
84//------------------------------------------------------------------------------
85
86bool WaitableEvent::isReady()
87{
88 return fired;
89}
90
91//------------------------------------------------------------------------------
92
93void WaitableEvent::handleEvents(short events)
94{
95 if ((events&POLLIN)==POLLIN) {
96 doCheck();
97 }
98}
99
100//------------------------------------------------------------------------------
101
102bool WaitableEvent::doCheck(bool fromHandleEvents)
103{
104 if (failed()) return false;
105 if (!fromHandleEvents && fired) return true;
106
107 uint64_t value = 0;
108 if (read(fd, &value, sizeof(value))<0) {
109 if (errno!=EAGAIN) {
110 setErrorCodeFromErrno();
111 }
112 } else {
113 fired = fired || value>0;
114 }
115
116 return fired;
117}
118
119//------------------------------------------------------------------------------
120//------------------------------------------------------------------------------
121
122// Local Variables:
123// mode: C++
124// c-basic-offset: 4
125// indent-tabs-mode: nil
126// End:
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