memory optimization, free some memory in terminated coroutine

src/co/scheduler.cc

@@ -35,7 +35,6 @@ void SchedulerImpl::stop() {
 void SchedulerImpl::main_func(tb_context_from_t from) {
     ((Coroutine*)from.priv)->ctx = from.ctx;
     gSched->running()->cb->run(); // run the coroutine function
-    gSched->recycle();            // recycle the current coroutine
     tb_context_jump(from.ctx, 0); // jump back to the from context
 }
 
@@ -86,11 +85,14 @@ void SchedulerImpl::resume(Coroutine* co) {
         from = tb_context_jump(co->ctx, _main_co); // jump back to where the user called yiled()
     }
 
-    // yiled() was called in coroutine, the scheduler will jump back to resume()
     if (from.priv) {
+        // yiled() was called in the coroutine, update context for it
         assert(_running == from.priv);
-        _running->ctx = from.ctx;   // update context for the coroutine
+        _running->ctx = from.ctx;
         CO_DBG_LOG << "yield co: " << _running << " id: " << _running->id;
+    } else {
+        // the coroutine has terminated, recycle it
+        this->recycle();
     }
 }
 

src/co/scheduler.h

@@ -120,6 +120,7 @@ class Copool {
 
     void push(Coroutine* co) {
         _ids.push_back(co->id);
+        if (_ids.size() >= 1024) co->stack.reset();
     }
 
     Coroutine* operator[](size_t i) {
@@ -300,7 +301,10 @@ class SchedulerImpl : public co::Scheduler {
     static void main_func(tb_context_from_t from);
 
     // push a coroutine back to the pool, so it can be reused later.
-    void recycle() { _co_pool.push(_running); }
+    void recycle() {
+        _stack[_running->sid].co = 0;
+        _co_pool.push(_running);
+    }
 
     // start the scheduler thread
     void start() { Thread(&SchedulerImpl::loop, this).detach(); }
@@ -313,8 +317,10 @@ class SchedulerImpl : public co::Scheduler {
 
     // save stack for the coroutine
     void save_stack(Coroutine* co) {
-        co->stack.clear();
-        co->stack.append(co->ctx, _stack[co->sid].top - (char*)co->ctx);
+        if (co) {
+            co->stack.clear();
+            co->stack.append(co->ctx, _stack[co->sid].top - (char*)co->ctx);
+        }
     }
 
     // pop a Coroutine from the pool

test/nco.cc

@@ -1,7 +1,7 @@
 #include "co/co.h"
 
 DEF_uint32(n, 1000000, "coroutine number");
-DEF_uint32(t, 7, "seconds to sleep in coroutines");
+DEF_uint32(t, 60, "seconds to sleep in coroutines");
 
 DEF_main(argc, argv) {
     for (int i = 0; i < FLG_n; ++i) {