Changeset ae6b6cf

Timestamp:

Mar 26, 2019, 2:12:57 PM (5 years ago)

Author:

tdelisle <tdelisle@…>

Branches:

ADT, arm-eh, ast-experimental, cleanup-dtors, enum, forall-pointer-decay, jacob/cs343-translation, jenkins-sandbox, master, new-ast, new-ast-unique-expr, pthread-emulation, qualifiedEnum

Children:

8dbfb7e

Parents:

1bb2488

Message:

Implemented ProdCons? using C++20 coroutines and a dispatcher pattern, it works but is also a lovecraftian horror

File:

• doc/papers/concurrency/examples/ProdCons.cpp (modified) (10 diffs)

doc/papers/concurrency/examples/ProdCons.cpp

@@ -12 +12 @@
 struct Cons;
 
-struct Prod {
+struct resumable {
+        virtual resumable * resume() = 0;
+};
+
+struct Prod : public resumable {
         struct local {
                 Cons * c;
@@ -20 +24 @@
         struct promise_type {
                 local _l;
+                resumable * next;
 
                 Prod get_return_object() {
@@ -69 +74 @@
         static Prod main();
 
-        auto payment(int money) {
-                _coroutine.promise()._l.money = money;
-                struct ret {
-                        int _receipt;
-                        bool await_ready() { return false; }
-                        void await_suspend(std::experimental::coroutine_handle<>) {}
-                        int await_resume() { return _receipt; }
-                };
-                return ret{ _coroutine.promise()._l.receipt };
-        }
+        struct payment_return;
+
+        payment_return payment(int money);
 
         auto start(int N, Cons & c) {
@@ -84 +82 @@
                 _coroutine.promise()._l.N = N;
                 _coroutine.promise()._l.receipt = 0;
+        }
+
+        virtual resumable * resume() override final {
                 _coroutine.resume();
-        }
-};
-
-struct Cons {
+                return _coroutine.promise().next;
+        }
+};
+
+struct Cons : public resumable {
         struct local {
                 Prod * p;
@@ -97 +99 @@
         struct promise_type {
                 local _l;
+                resumable * next;
 
                 Cons get_return_object() {
@@ -154 +157 @@
                 struct ret {
                         int _status;
+                        Cons * c;
                         bool await_ready() { return false; }
-                        void await_suspend(std::experimental::coroutine_handle<>) {}
+                        void await_suspend(std::experimental::coroutine_handle<Prod::promise_type> _coroutine) {
+                                _coroutine.promise().next = c;
+                        }
                         int await_resume() { return _status; }
                 };
-                return ret{ _coroutine.promise()._l.status };
+                return ret{ _coroutine.promise()._l.status, this };
         }
 
@@ -164 +170 @@
                 _coroutine.promise()._l.done = true;
                 struct ret {
+                        Cons * c;
+                        Prod::promise_type * _promise;
                         bool await_ready() { return false; }
-                        void await_suspend(std::experimental::coroutine_handle<>) {}
-                        void await_resume() {}
+                        void await_suspend(std::experimental::coroutine_handle<Prod::promise_type> _coroutine) {
+                                _promise = &_coroutine.promise();
+                                _promise->next = c;
+                        }
+                        void await_resume() {
+                                _promise->next = nullptr;
+                        }
                 };
-                return ret{};
-        }
-};
+                return ret{this, nullptr};
+        }
+
+        virtual resumable * resume() override final {
+                _coroutine.resume();
+                return _coroutine.promise().next;
+        }
+};
+
+struct Prod::payment_return {
+        int _receipt;
+        Prod * p;
+        bool await_ready() { return false; }
+        void await_suspend(std::experimental::coroutine_handle<Cons::promise_type> _coroutine) {
+                _coroutine.promise().next = p;
+        }
+        int await_resume() { return _receipt; }
+};
+
+Prod::payment_return Prod::payment(int money)  {
+        _coroutine.promise()._l.money = money;
+        return payment_return{ _coroutine.promise()._l.receipt, this };
+}
 
 Prod Prod::main() {
@@ -176 +209 @@
         for(int i = 0; i < p.N; i++) {
                 int p1 = random(100), p2 = random(100);
-                std::cout << p1 << " " << p2;
+                std::cout << p1 << " " << p2 << std::endl;
                 int status = co_await p.c->deliver(p1, p2);
-                std::cout << " $" << p.money << std::endl << status;
+                std::cout << " $" << p.money << std::endl << status << std::endl;
                 p.receipt += 1;
         }
         co_await p.c->stop();
-        std::cout << "prod stops";
+        std::cout << "prod stops" << std::endl;
 }
 
@@ -189 +222 @@
         int money = 1, receipt;
         for(;!c.done ;) {
-                std::cout << c.p1 << " " << c.p2 << std::endl << " $" << money;
+                std::cout << c.p1 << " " << c.p2 << std::endl;
+                std::cout << " $ " << money << std::endl;
                 c.status += 1;
                 receipt = co_await c.p->payment( money );
-                std::cout << " #" << receipt;
+                std::cout << " # " << receipt << std::endl;
                 money += 1;
         }
-        std::cout << "const stops";
+        std::cout << "cons stops" << std::endl;
+}
+
+void dispatch(resumable * r) {
+        while((r = r->resume()));
 }
 
@@ -203 +241 @@
         srandom( getpid() );
         prod.start(5, cons);
-}
+        dispatch(&prod);
+}