Danny Robson
f6056153e3
This places, at long last, the core library code into the same namespace as the extended library code.
79 lines
1.9 KiB
C++
79 lines
1.9 KiB
C++
#include "thread/flag.hpp"
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#include "tap.hpp"
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#include <thread>
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int
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main ()
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{
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cruft::TAP::logger tap;
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cruft::thread::flag f;
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std::atomic<int> value = 0;
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std::thread t1 ([&] () {
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f.wait ();
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value = 1;
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});
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std::this_thread::sleep_for (std::chrono::milliseconds (100));
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tap.expect_eq (value, 0, "value hasn't been set during wait");
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tap.expect_eq (f.notify (), 1, "notify reports one thread woke");
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t1.join ();
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tap.expect_eq (value, 1, "value has been changed after wait");
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std::thread t2 ([&] () {
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f.wait ();
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value = 2;
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});
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std::this_thread::sleep_for (std::chrono::milliseconds (100));
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tap.expect_eq (value, 2, "second wait didn't appear to block");
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t2.join ();
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{
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// perform a stress test to (hopefully) discover deadlocks
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//
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// * create a large matrix of flag variables
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// * create a bank of threads which:
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// * wait on each flag of each row, or
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// * notify if the flag index matches the thread index
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constexpr int iterations = 1024;
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constexpr int parallelism = 16;
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std::vector<
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std::array<cruft::thread::flag,parallelism>
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> flags (iterations);
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const auto func = [&flags] (const int idx) {
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for (auto &row: flags) {
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for (int i = 0; i < parallelism; ++i) {
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if (i == idx)
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row[i].notify ();
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else
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row[i].wait ();
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}
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}
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};
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std::vector<std::thread> workers;
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std::generate_n (
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std::back_inserter (workers),
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parallelism,
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[&, i = 0] () mutable
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{
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return std::thread { func, i++ };
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});
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for (auto &t: workers)
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t.join ();
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tap.expect (true, "flag sequence did not block");
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}
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return tap.status ();
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}
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