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
|
/*
* This file is part of KDevelop
*
* Copyright 2007-2009 David Nolden <david.nolden.kdevelop@art-master.de>
* Copyright 2016 Milian Wolff <mail@milianw.de>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Library 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.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#include "urlparselock.h"
#include <QHash>
#include <QMutex>
using namespace KDevelop;
namespace {
struct PerUrlData
{
PerUrlData()
// TODO: make this non-recursive
: mutex(QMutex::Recursive)
{}
QMutex mutex;
// how many people are (trying to) parse this url
// we use this to delete the entry once no-one needs it anymore
uint ref = 0;
};
// this mutex protects the parsingUrls
// NOTE: QBasicMutex is safe to initialize statically
QBasicMutex parsingUrlsMutex;
// Hash of urls that are currently being parsed and their protection data
using ParsingUrls = QHash<IndexedString, PerUrlData*>;
ParsingUrls& parsingUrls()
{
// delay initialization of the hash until it's needed
static ParsingUrls parsingUrls;
return parsingUrls;
}
}
UrlParseLock::UrlParseLock(const IndexedString& url)
: m_url(url)
{
QMutexLocker lock(&parsingUrlsMutex);
// NOTE: operator[] default-initializes the ptr to zero for us when not available
auto& perUrlData = parsingUrls()[url];
if (!perUrlData) {
// if that was the case, we are the first to parse this url, create an entry
perUrlData = new PerUrlData;
}
// always increment the refcount
++perUrlData->ref;
// now lock the url, but don't do so while blocking the global mutex
auto& mutex = perUrlData->mutex;
lock.unlock();
mutex.lock();
}
UrlParseLock::~UrlParseLock()
{
QMutexLocker lock(&parsingUrlsMutex);
// find the entry for this url
auto& urls = parsingUrls();
auto it = urls.find(m_url);
Q_ASSERT(it != urls.end()); // it must exist
auto& perUrlData = it.value();
// unlock the per-url mutex
perUrlData->mutex.unlock();
// decrement the refcount
--perUrlData->ref;
if (perUrlData->ref == 0) {
// and cleanup, if possible
delete perUrlData;
urls.erase(it);
}
}
|
