Changeset c06551b

Timestamp:

Jun 9, 2022, 4:30:00 PM (2 years ago)

Author:

caparsons <caparson@…>

Branches:

ADT, ast-experimental, master, pthread-emulation, qualifiedEnum

Children:

6d41f66

Parents:

aeb20a4

Message:

added wait_any to fwd.cfa for future_t

Files:

• libcfa/src/concurrency/kernel/fwd.hfa (modified) (6 diffs)
• tests/concurrent/futures/.expect/wait_any.txt (added)
• tests/concurrent/futures/wait_any.cfa (added)

libcfa/src/concurrency/kernel/fwd.hfa

@@ -200 +200 @@
                                         struct thread$ * expected = this.ptr;
                                         if(expected == 1p) return false;
-                                        /* paranoid */ verify( expected == 0p );
                                         if(__atomic_compare_exchange_n(&this.ptr, &expected, active_thread(), false, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST)) {
                                                 park();
@@ -213 +212 @@
                         thread$ * post(oneshot & this, bool do_unpark = true) {
                                 struct thread$ * got = __atomic_exchange_n( &this.ptr, 1p, __ATOMIC_SEQ_CST);
-                                if( got == 0p ) return 0p;
+                                if( got == 0p || got == 1p ) return 0p;
                                 if(do_unpark) unpark( got );
                                 return got;
@@ -263 +262 @@
 
                                         // The future is not fulfilled, try to setup the wait context
-                                        /* paranoid */ verify( expected == 0p );
                                         if(__atomic_compare_exchange_n(&this.ptr, &expected, &wait_ctx, false, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST)) {
                                                 return true;
@@ -275 +273 @@
                         // should retract the wait ctx
                         // intented to be use by wait, wait_any, waitfor, etc. rather than used directly
-                        void retract( future_t & this, oneshot & wait_ctx ) {
+                        bool retract( future_t & this, oneshot & wait_ctx ) {
                                 // Remove the wait context
                                 struct oneshot * got = __atomic_exchange_n( &this.ptr, 0p, __ATOMIC_SEQ_CST);
 
                                 // got == 0p: future was never actually setup, just return
-                                if( got == 0p ) return;
+                                if( got == 0p ) return false;
 
                                 // got == wait_ctx: since fulfil does an atomic_swap,
                                 // if we got back the original then no one else saw context
                                 // It is safe to delete (which could happen after the return)
-                                if( got == &wait_ctx ) return;
+                                if( got == &wait_ctx ) return false;
 
                                 // got == 1p: the future is ready and the context was fully consumed
                                 // the server won't use the pointer again
                                 // It is safe to delete (which could happen after the return)
-                                if( got == 1p ) return;
+                                if( got == 1p ) return true;
 
                                 // got == 2p: the future is ready but the context hasn't fully been consumed
@@ -296 +294 @@
                                 if( got == 2p ) {
                                         while( this.ptr != 1p ) Pause();
-                                        return;
+                                        return false;
                                 }
 
@@ -379 +377 @@
                                 return ret;
                         }
+
+                        // Wait for any future to be fulfilled
+                        future_t & wait_any( future_t * futures, size_t num_futures ) {
+                                oneshot temp;
+
+                                // setup all futures
+                                // if any are already satisfied return
+                                for ( i; num_futures ) {
+                                        if( !setup(futures[i], temp) ) return futures[i];
+                                }
+                                
+                                // Wait context is setup, just wait on it
+                                wait( temp );
+                                
+                                size_t ret;
+                                // attempt to retract all futures
+                                for ( i; num_futures ) {
+                                        if ( retract( futures[i], temp ) ) ret = i;
+                                }
+                                
+                                return futures[ret];
+                        }
                 }