C++ containers are supposed to be thread-safe by default. I must be using queue
to multithread incorrectly because for this code:
#include <thread>
using std::thread;
#include <iostream>
using std::cout;
using std::endl;
#include <queue>
using std::queue;
#include <string>
using std::string;
using std::to_string;
#include <functional>
using std::ref;
void fillWorkQueue(queue<string>& itemQueue) {
int size = 40000;
for(int i = 0; i < size; i++)
itemQueue.push(to_string(i));
}
void doWork(queue<string>& itemQueue) {
while(!itemQueue.empty()) {
itemQueue.pop();
}
}
void singleThreaded() {
queue<string> itemQueue;
fillWorkQueue(itemQueue);
doWork(itemQueue);
cout << "done\n";
}
void multiThreaded() {
queue<string> itemQueue;
fillWorkQueue(itemQueue);
thread t1(doWork, ref(itemQueue));
thread t2(doWork, ref(itemQueue));
t1.join();
t2.join();
cout << "done\n";
}
int main() {
cout << endl;
// Single Threaded
cout << "singleThreaded\n";
singleThreaded();
cout << endl;
// Multi Threaded
cout << "multiThreaded\n";
multiThreaded();
cout << endl;
}
I'm getting:
singleThreaded
done
multiThreaded
main(32429,0x10e530000) malloc: *** error for object 0x7fe4e3883e00: pointer being freed was not allocated
*** set a breakpoint in malloc_error_break to debug
make: *** [run] Abort trap: 6
What am I doing wrong here?
EDIT
Apparently I misread the link above. Is there a thread-safe queue implementation available that does what I am trying to do? I know this is a common thread organization strategy.