Intel® oneAPI Threading Building Blocks Developer Guide and API Reference
A newer version of this document is available. Customers should click here to go to the newest version.
Visible to Intel only — GUID: GUID-90DA3B18-4DE7-410B-A17E-D9D676A64E24
Visible to Intel only — GUID: GUID-90DA3B18-4DE7-410B-A17E-D9D676A64E24
Cancellation Without An Exception
To cancel an algorithm but not throw an exception, use the expression current_context()->cancel_group_execution(). The part current_context() references the task_group_context* of the currently executing task if any on the current thread. Calling cancel_group_execution() cancels all tasks in its task_group_context, which is explained in more detail in Cancellation and Nested Parallelism. The method returns true if it actually causes cancellation, false if the task_group_context was already cancelled.
The example below shows how to use current_context()->cancel_group_execution().
#include "oneapi/tbb.h"
#include <vector>
#include <iostream>
using namespace oneapi::tbb;
using namespace std;
vector<int> Data;
struct Update {
void operator()( const blocked_range<int>& r ) const {
for( int i=r.begin(); i!=r.end(); ++i )
if( i<Data.size() ) {
++Data[i];
} else {
// Cancel related tasks.
if( current_context()->cancel_group_execution() )
cout << "Index " << i << " caused cancellation\n";
return;
}
}
};
int main() {
Data.resize(1000);
parallel_for( blocked_range<int>(0, 2000), Update());
return 0;
}