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StreamBase.h
1/* -*- mode: c++; indent-tabs-mode: nil -*- */
2/*
3 StreamBase.h
4
5 Qore Programming Language
6
7 Copyright (C) 2016 - 2024 Qore Technologies, s.r.o.
8
9 Permission is hereby granted, free of charge, to any person obtaining a
10 copy of this software and associated documentation files (the "Software"),
11 to deal in the Software without restriction, including without limitation
12 the rights to use, copy, modify, merge, publish, distribute, sublicense,
13 and/or sell copies of the Software, and to permit persons to whom the
14 Software is furnished to do so, subject to the following conditions:
15
16 The above copyright notice and this permission notice shall be included in
17 all copies or substantial portions of the Software.
18
19 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
20 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
21 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
22 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
23 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
24 FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
25 DEALINGS IN THE SOFTWARE.
26
27 Note that the Qore library is released under a choice of three open-source
28 licenses: MIT (as above), LGPL 2+, or GPL 2+; see README-LICENSE for more
29 information.
30*/
31
32#ifndef _QORE_STREAMBASE_H
33#define _QORE_STREAMBASE_H
34
35#include "qore/AbstractPrivateData.h"
36#include "qore/qore_thread.h"
37#include "qore/QoreString.h"
38#include "qore/ExceptionSink.h"
39#include "qore/BinaryNode.h"
40
41#include <atomic>
42
43DLLEXPORT extern QoreClass* QC_STREAMBASE;
44
49public:
57 DLLLOCAL bool check(ExceptionSink *xsink) {
58 if (tid.load(std::memory_order_relaxed) != q_gettid()) {
59 xsink->raiseException("STREAM-THREAD-ERROR", "this %s object was created in TID %d; it is an error " \
60 "to access it from any other thread (accessed from TID %d)", getName(),
61 tid.load(std::memory_order_relaxed), q_gettid());
62 return false;
63 }
64 return true;
65 }
66
72 DLLLOCAL void reassignThread(ExceptionSink *xsink) {
73 // use an atomic compare and exchange to ensure that we only update a stream where the thread is unassigned
74 int chktid = -1;
75 if (!tid.compare_exchange_strong(chktid, q_gettid(), std::memory_order_consume, std::memory_order_relaxed)) {
76 // do not raise an exception if reassigning to the same thread
77 if (chktid != q_gettid()) {
78 xsink->raiseException("STREAM-THREAD-ERROR", "this %s object is assigned to TID %d; it is an error " \
79 "to access it from any other thread (accessed from TID %d)", getName(), chktid, q_gettid());
80 }
81 }
82 }
83
89 DLLLOCAL void unassignThread(ExceptionSink *xsink) {
90 // use an atomic compare and exchange to ensure that we only update a stream where the thread is assigned to this thread
91 int chktid = q_gettid();
92 if (!tid.compare_exchange_strong(chktid, -1, std::memory_order_release, std::memory_order_relaxed)) {
93 // do not raise an exception if already unassigned
94 if (chktid != -1) {
95 xsink->raiseException("STREAM-THREAD-ERROR", "this %s object is assigned to TID %d; unassignment may " \
96 "be processed from that thread (accessed from TID %d)", getName(), chktid, q_gettid());
97 }
98 }
99 }
100
104 DLLLOCAL int getThreadId() {
105 return tid.load(std::memory_order_relaxed);
106 }
107
112 DLLLOCAL virtual const char *getName() = 0;
113
114protected:
118 StreamBase() : tid(q_gettid()) {
119 }
120
121private:
123
127 std::atomic<int> tid;
128};
129
130#endif // _QORE_STREAMBASE_H
the base class for all data to be used as private data of Qore objects
Definition AbstractPrivateData.h:44
container for holding Qore-language exception information and also for registering a "thread_exit" ca...
Definition ExceptionSink.h:50
DLLEXPORT AbstractQoreNode * raiseException(const char *err, const char *fmt,...)
appends a Qore-language exception to the list
defines a Qore-language class
Definition QoreClass.h:310
Base class for private data of stream implementations in C++.
Definition StreamBase.h:48
DLLLOCAL int getThreadId()
Get currently assigned thread id.
Definition StreamBase.h:104
StreamBase()
Constructor.
Definition StreamBase.h:118
DLLLOCAL bool check(ExceptionSink *xsink)
Checks that the current thread is the same as when the instance was created or assigned via unassignT...
Definition StreamBase.h:57
DLLLOCAL void reassignThread(ExceptionSink *xsink)
Reassigns current thread as thread used for stream manipulation, see check()
Definition StreamBase.h:72
virtual DLLLOCAL const char * getName()=0
Returns the name of the class.
DLLLOCAL void unassignThread(ExceptionSink *xsink)
Unassigns current thread as thread used for stream manipulation, see check()
Definition StreamBase.h:89
DLLEXPORT int q_gettid() noexcept
returns the current TID number