Changeset b93bf85 for libcfa

Timestamp:

Jul 11, 2023, 2:27:58 PM (22 months ago)

Author:

caparsons <caparson@…>

Branches:

master

Children:

bbecdd4

Parents:

4c8ce47

Message:

fixed spurious channel close waituntil error case. Was caused by a race condition causing an exception to be thrown while another was in flight

Location:

libcfa/src/concurrency

Files:

• channel.hfa (modified) (2 diffs)
• future.hfa (modified) (1 diff)
• invoke.h (modified) (1 diff)
• kernel.cfa (modified) (1 diff)
• locks.cfa (modified) (1 diff)
• locks.hfa (modified) (3 diffs)
• select.cfa (modified) (1 diff)
• select.hfa (modified) (2 diffs)

libcfa/src/concurrency/channel.hfa ¶

@@ -444 +444 @@
 }
 static inline bool unregister_select( chan_read(T) & this, select_node & node ) { return unregister_chan( this.chan, node ); }
-static inline void on_selected( chan_read(T) & this, select_node & node ) with(this) {
-    if ( node.extra == 0p ) // check if woken up due to closed channel
-        __closed_remove( chan, ret );
+static inline bool on_selected( chan_read(T) & this, select_node & node ) with(this) {
+    if ( unlikely(node.extra == 0p) ) {
+        if ( !exception_in_flight() ) __closed_remove( chan, ret ); // check if woken up due to closed channel
+        else return false;
+    }
     // This is only reachable if not closed or closed exception was handled
+    return true;
 }
 
@@ -536 +539 @@
 static inline bool unregister_select( chan_write(T) & this, select_node & node ) { return unregister_chan( this.chan, node ); }
 
-static inline void on_selected( chan_write(T) & this, select_node & node ) with(this) { 
-    if ( node.extra == 0p ) // check if woken up due to closed channel
-        __closed_insert( chan, elem );
-
+static inline bool on_selected( chan_write(T) & this, select_node & node ) with(this) { 
+    if ( unlikely(node.extra == 0p) ) {
+        if ( !exception_in_flight() ) __closed_insert( chan, elem ); // check if woken up due to closed channel
+        else return false;
+    }
     // This is only reachable if not closed or closed exception was handled
+    return true;
 }
 

libcfa/src/concurrency/future.hfa ¶

@@ -180 +180 @@
         }
                 
-        void on_selected( future(T) & this, select_node & node ) {}
+        bool on_selected( future(T) & this, select_node & node ) { return true; }
         }
 }

libcfa/src/concurrency/invoke.h ¶

@@ -255 +255 @@
         #ifdef __cforall
         extern "Cforall" {
+        static inline bool exception_in_flight() {
+            return __get_stack( &active_thread()->self_cor )->exception_context.current_exception != 0p;
+        }
+
                 static inline thread$ * volatile & ?`next ( thread$ * this ) {
                         return this->user_link.next;

libcfa/src/concurrency/kernel.cfa ¶

@@ -569 +569 @@
                 returnToKernel();
         __enable_interrupts_checked();
-
 }
 

libcfa/src/concurrency/locks.cfa ¶

@@ -239 +239 @@
 }
 
-void on_selected( blocking_lock & this, select_node & node ) {}
+bool on_selected( blocking_lock & this, select_node & node ) { return true; }
 
 //-----------------------------------------------------------------------------

libcfa/src/concurrency/locks.hfa ¶

@@ -112 +112 @@
 static inline bool   register_select( single_acquisition_lock & this, select_node & node ) { return register_select( (blocking_lock &)this, node ); }
 static inline bool   unregister_select( single_acquisition_lock & this, select_node & node ) { return unregister_select( (blocking_lock &)this, node ); }
-static inline void   on_selected( single_acquisition_lock & this, select_node & node ) { on_selected( (blocking_lock &)this, node ); }
+static inline bool   on_selected( single_acquisition_lock & this, select_node & node ) { return on_selected( (blocking_lock &)this, node ); }
 
 //----------
@@ -129 +129 @@
 static inline bool   register_select( owner_lock & this, select_node & node ) { return register_select( (blocking_lock &)this, node ); }
 static inline bool   unregister_select( owner_lock & this, select_node & node ) { return unregister_select( (blocking_lock &)this, node ); }
-static inline void   on_selected( owner_lock & this, select_node & node ) { on_selected( (blocking_lock &)this, node ); }
+static inline bool   on_selected( owner_lock & this, select_node & node ) { return on_selected( (blocking_lock &)this, node ); }
 
 //-----------------------------------------------------------------------------
@@ -619 +619 @@
 }
 
-static inline void on_selected( simple_owner_lock & this, select_node & node ) {}
+static inline bool on_selected( simple_owner_lock & this, select_node & node ) { return true; }
 
 

libcfa/src/concurrency/select.cfa ¶

@@ -49 +49 @@
     return false;
 }
-void on_selected( select_timeout_node & this, select_node & node ) {}
+bool on_selected( select_timeout_node & this, select_node & node ) { return true; }
 
 // Gateway routine to wait on duration

libcfa/src/concurrency/select.hfa ¶

@@ -96 +96 @@
     //    passed as an arg to this routine
     // If on_selected returns false, the statement is not run, if it returns true it is run.
-    void on_selected( T &, select_node & );
+    bool on_selected( T &, select_node & );
 };
 
@@ -208 +208 @@
 bool register_select( select_timeout_node & this, select_node & node );
 bool unregister_select( select_timeout_node & this, select_node & node );
-void on_selected( select_timeout_node & this, select_node & node );
+bool on_selected( select_timeout_node & this, select_node & node );
 
 // Gateway routines to waituntil on duration