Gabriele Cosmo
81 lines
1.9 KiB
Markdown
81 lines
1.9 KiB
Markdown
# Parallel Tasking Library (PTL)
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Lightweight C++11 multithreading tasking system featuring thread-pool, task-groups, and lock-free task queue
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## Basic Interface
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```cpp
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#include "PTL/PTL.hh"
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#include <cassert>
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inline long
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fibonacci(long n)
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{
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return (n < 2) ? n : (fibonacci(n - 1) + fibonacci(n - 2));
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}
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int main()
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{
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bool use_tbb = false;
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auto num_threads = 4;
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auto run_manager = PTL::TaskRunManager(use_tbb);
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run_manager.Initialize(num_threads);
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auto* task_manager = run_manager.GetTaskManager();
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// add a task via the task manager
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auto baz = task_manager->async<long>(fibonacci, 40);
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// functor to combine results
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auto join = [](long& lhs, long rhs) { return lhs += rhs; };
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// create a task group for 10 fibonacci calculations
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PTL::TaskGroup<long> foo(join);
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for(uint64_t i = 0; i < 10; ++i)
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foo.exec(fibonacci, 40);
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// create a task group for 10 fibonacci calculations
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PTL::TaskGroup<void> bar{};
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long ret_bar = 0;
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auto run = [&ret_bar](long n) { ret_bar += fibonacci(n); };
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for(uint64_t i = 0; i < 10; ++i)
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bar.exec(run, 40);
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auto ret_baz = baz->get();
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auto ret_foo = foo.join();
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bar.join();
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assert(ret_baz * 10 == ret_foo);
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assert(ret_baz * 10 == ret_bar);
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assert(ret_foo == ret_bar);
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}
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```
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## Explicit Thread-Pool
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Using `PTL::TaskRunManager` is not necessary with task-groups.
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You can create new thread-pools directly and pass them to task-groups:
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```cpp
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long example()
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{
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// create a new thread-pool explicitly
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PTL::ThreadPool tp(4);
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// combines results
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auto join = [](long& lhs, long rhs) { return lhs += rhs; };
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// specify thread-pool explicitly
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PTL::TaskGroup<long> foo(join, &tp);
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for(int i = 0; i < 10; ++i)
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foo.exec(fibonacci, 40);
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// blocks until tasks in group are completed
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// thread-pool is destroyed after function returns
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return foo.get();
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}
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```
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