80 lines
1.8 KiB
C++
80 lines
1.8 KiB
C++
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// 2020/08/28 - Created by netcan: https://github.com/netcan
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// Task DSL demo
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// The example creates the following cyclic graph:
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//
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// A
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// |
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// v
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// B<---|
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// | |
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// v |
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// C----|
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// |
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// v
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// D
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//
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// - A is a task that initializes a counter to zero
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// - B is a task that increments the counter
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// - C is a condition task that loops around B until the counter
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// reaches a breaking number
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// - D is a task that wraps up the result
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#include <taskflow/taskflow.hpp>
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#include <taskflow/dsl.hpp>
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int main() {
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tf::Executor executor;
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tf::Taskflow taskflow("Conditional Tasking Demo");
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int counter; // owner
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// use context to pass args
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// context must copyable
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struct Context {
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int &rcounter; // use counter(borrow)
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} context{counter};
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make_task((A, Context), {
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std::cout << "initializes the counter to zero\n";
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rcounter = 0;
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});
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make_task((B, Context), {
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std::cout << "loops to increment the counter\n";
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rcounter++;
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});
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make_task((C, Context), {
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std::cout << "counter is " << rcounter << " -> ";
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if (rcounter != 5) {
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std::cout << "loops again (goes to B)\n";
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return 0;
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}
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std::cout << "breaks the loop (goes to D)\n";
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return 1;
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});
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make_task((D, Context), {
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std::cout << "done with counter equal to " << rcounter << '\n';
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});
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auto tasks = build_taskflow(
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task(A)
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-> task(B)
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-> task(C),
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task(C)
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-> fork_tasks(B, D)
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)(taskflow, context);
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tasks.get_task<A>().name("A");
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tasks.get_task<B>().name("B");
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tasks.get_task<C>().name("C");
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tasks.get_task<D>().name("D");
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// visualizes the taskflow
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taskflow.dump(std::cout);
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// executes the taskflow
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executor.run(taskflow).wait();
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assert(counter == 5);
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return 0;
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}
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