Linked Questions
61 questions linked to/from Is Meyers' implementation of the Singleton pattern thread safe?
251
votes
2
answers
100k
views
Is local static variable initialization thread-safe in C++11? [duplicate]
I know this is an often asked question, but as there are so many variants, I'd like to re-state it, and hopefully have an answer reflecting the current state. Something like
Logger& g_logger() {
...
- 5,443
35
votes
4
answers
55k
views
Singleton instance declared as static variable of GetInstance method, is it thread-safe? [duplicate]
I've seen implementations of Singleton patterns where instance variable was declared as static variable in GetInstance method. Like this:
SomeBaseClass &SomeClass::GetInstance()
{
static ...
- 14.4k
1
vote
0
answers
316
views
Definition of a static variable inside a parallel region [duplicate]
I have a parallel region, I have a static variable defined inside this region, like this
#pragma omp parallel
{
static int var;
// some stuff
}
Without threadprivate, static variables are ...
- 2,075
0
votes
1
answer
196
views
Thread safe singleton implementation : whats wrong? [duplicate]
This question was closed as duplicate and hence making the question more explicit and reopening the question:
The questions are :
1) Is the implementation below thread safe or not?
2) What are the ...
- 2,788
0
votes
1
answer
86
views
Singleton - multithreaded issue in C++ [duplicate]
I've seen posts about this issue but I'm still trying to figure it out. Is this way alright for implementing a safe singelton? I'm using mutex, static member and return its reference.
#include <...
- 956
1
vote
0
answers
57
views
Does c++11 make sure static local variable be initialized only once in a thread-safe manner? [duplicate]
When class B is used as a static local variable in class A constructor, does c++11 will make sure func() be initialized only once in a thread-safe manner? Are the codes commented out redundant?
void ...
- 1,263
2
votes
0
answers
30
views
Hidden branching when using static variables in functions and thread safety [duplicate]
I encountered a behavior I didn't understand.
Here is test code of a common singleton implementation,
Code from the link:
#include <iostream>
using namespace std;
class CFoo
{
public:
...
- 3,413
920
votes
24
answers
1.0m
views
How do you implement the Singleton design pattern?
Recently I've bumped into a realization/implementation of the Singleton design pattern for C++. It has looked like this (I have adopted it from the real-life example):
// a lot of methods are omitted ...
- 41.3k
66
votes
2
answers
73k
views
How is Meyers' implementation of a Singleton actually a Singleton
I have been reading a lot about Singletons, when they should and shouldn't be used, and how to implement them safely. I am writing in C++11, and have come across the Meyer's lazy initialized ...
- 2,704
47
votes
3
answers
17k
views
Are function-local static mutexes thread-safe?
In the following program I attempt the make the print function thread-safe by using a function-local mutex object:
#include <iostream>
#include <chrono>
#include <mutex>
#include &...
- 35.7k
24
votes
3
answers
3k
views
Race condition on x86
Could someone explain this statement:
shared variables
x = 0, y = 0
Core 1 Core 2
x = 1; y = 1;
r1 = y; r2 = x;
How is it possible to have r1 == 0 and r2 == 0 on x86 processors?
...
- 731
6
votes
4
answers
12k
views
Private constructor and make_shared
I have a singleton class with a private constructor. In the static factory method I do the following:
shared_ptr<MyClass> MyClass::GetInstance()
{
static once_flag onceFlag;
call_once(...
- 677
3
votes
2
answers
3k
views
Singleton implementation using friend class (C++)
I came up with this while trying to create a singleton.
Example: ( I am trying to make MySelf a singleton which is thread safe and without using double checked locking )
class MySelf
{
private:
...
- 815
0
votes
2
answers
2k
views
How to prevent multiple threads to use singleton class instance at same time in cpp
I am writting a thread safe singleton class as follows. The following implementation ensures that only one instance of the class in created. My use case is that I am using this instance in a multi ...
- 1,963
0
votes
6
answers
5k
views
C++ Singleton class creates more than one instance
The static method GetUI is called with mouse events, however noticed from debug that the constructor is called twice in some very rare cases with rush of mouse events.
The question is it the ...
