run dispatcher context at scheduler destruction

src/context.cpp

@@ -6,7 +6,6 @@
 
 #include "boost/fiber/context.hpp"
 
-#include "boost/fiber/fixedsize_stack.hpp"
 #include "boost/fiber/scheduler.hpp"
 
 #ifdef BOOST_HAS_ABI_HEADERS
@@ -16,25 +15,23 @@
 namespace boost {
 namespace fibers {
 
-static context * main_context() {
+static context * make_main_context() {
     // main fiber context for this thread
-    static thread_local context main_ctx;
+    static thread_local context main_ctx( main_context);
     // scheduler for this thread
     static thread_local scheduler sched;
     // attach scheduler to main fiber context
     main_ctx.set_scheduler( & sched);
     // attach main fiber context to scheduler
-    sched.main_context( & main_ctx);
-    // attach dispatching fiber context to scheduler
-    sched.dispatching_context(
-        make_context(
-            fixedsize_stack(),
-            & scheduler::dispatch, & sched) );
+    sched.set_main_context( & main_ctx);
+    // create and attach dispatching fiber context to scheduler
+    sched.set_dispatching_context(
+        make_dispatcher_context( & sched) );
     return & main_ctx;
 }
 
 thread_local context *
-context::active_ = main_context();
+context::active_ = make_main_context();
 
 context *
 context::active() noexcept {
@@ -47,6 +44,47 @@ context::active( context * active) noexcept {
     active_ = active;
 }
 
+void
+context::set_terminated_() noexcept {
+    scheduler_->set_terminated( this);
+}
+
+void
+context::suspend_() noexcept {
+    scheduler_->re_schedule( this);
+}
+
+// main fiber context
+context::context( main_context_t) :
+    ready_hook_(),
+    terminated_hook_(),
+    wait_hook_(),
+    use_count_( 1), // allocated on main- or thread-stack
+    flags_( flag_main_context),
+    scheduler_( nullptr),
+    ctx_( boost::context::execution_context::current() ),
+    wait_queue_() {
+}
+
+// dispatcher fiber context
+context::context( dispatcher_context_t, boost::context::preallocated const& palloc,
+                  fixedsize_stack const& salloc, scheduler * sched) :
+    ready_hook_(),
+    terminated_hook_(),
+    wait_hook_(),
+    use_count_( 0), // scheduler will own dispatcher context
+    flags_( flag_dispatcher_context),
+    scheduler_( nullptr),
+    ctx_( palloc, salloc,
+          [=] () -> void {
+            // execute scheduler::dispatch()
+            sched->dispatch();
+            // dispatcher context should never return from scheduler::dispatch()
+            BOOST_ASSERT_MSG( false, "disatcher fiber already terminated");
+          }),
+    wait_queue_() {
+}
+
 context::~context() {
     BOOST_ASSERT( ! wait_is_linked() );
     BOOST_ASSERT( wait_queue_.empty() );
@@ -71,13 +109,12 @@ context::get_id() const noexcept {
 
 void
 context::resume() {
-    BOOST_ASSERT( is_running() ); // set by the scheduler-algorithm
     ctx_();
 }
 
 void
 context::release() noexcept {
-    BOOST_ASSERT( is_terminated() );
+    BOOST_ASSERT( terminated_is_linked() );
 
     // notify all waiting fibers
     wait_queue_t::iterator e = wait_queue_.end();
@@ -93,16 +130,21 @@ context::wait_is_linked() {
     return wait_hook_.is_linked();
 }
 
-void
-context::wait_unlink() {
-    wait_hook_.unlink();
-}
-
 bool
 context::ready_is_linked() {
     return ready_hook_.is_linked();
 }
 
+bool
+context::terminated_is_linked() {
+    return terminated_hook_.is_linked();
+}
+
+void
+context::wait_unlink() {
+    wait_hook_.unlink();
+}
+
 }}
 
 #ifdef BOOST_HAS_ABI_HEADERS