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Why does the main thread crashes when a child thread invokes call back function of main thread

Member 13508014 asked:

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I am trying to understand some basics of multi threading. I have written a simple program as shown below. When the child thread invokes a call back function, a crash is seen in the main thread (here the scope of call back function is in main thread. That's what I understand the scope is. But I am guessing it is something related to scope that is leading to crash)

#include <iostream>
#include <thread>

using namespace std;

void t1_exec(void (*notfiy_func)());
void main_observer();

int main()
	std::thread t1(t1_exec, main_observer);
	int i = 0;
	while (i < 200)
		cout << "In main thread" << endl;

	return (0);

void t1_exec(void (*notify_func)())
	int i = 0;
	while (i < 5)
		cout << "Inside T1" << endl;


void main_observer()
	cout << "Inside Observer" << endl;


What I have tried:

Tried to increase the time of execution of main thread by increasing the number of loop (i.e increased i to 2000). Still didn't help stopping crash.
Tags: C++, multi-threading


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