Intel® oneAPI Threading Building Blocks Developer Guide and API Reference
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Visible to Intel only — GUID: GUID-AF2A24AF-C129-4555-89DC-222350529002
Visible to Intel only — GUID: GUID-AF2A24AF-C129-4555-89DC-222350529002
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; }