Changeset fc2c57a9

Timestamp:

Jun 27, 2022, 1:13:47 PM (17 months ago)

Author:

Thierry Delisle <tdelisle@…>

Branches:

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

Children:

06bdba4

Parents:

e4ea4b8d

Message:

Fixed assert in waitctx.
Removed unnecessary loop in retract.

File:

• libcfa/src/concurrency/kernel/fwd.hfa (modified) (2 diffs)

libcfa/src/concurrency/kernel/fwd.hfa

@@ -254 +254 @@
                         // intented to be use by wait, wait_any, waitfor, etc. rather than used directly
                         bool setup( future_t & this, oneshot & wait_ctx ) {
-                                /* paranoid */ verify( wait_ctx.ptr == 0p );
+                                /* paranoid */ verify( wait_ctx.ptr == 0p || wait_ctx.ptr == 1p );
                                 // The future needs to set the wait context
                                 for() {
@@ -274 +274 @@
                         // intented to be use by wait, wait_any, waitfor, etc. rather than used directly
                         bool retract( future_t & this, oneshot & wait_ctx ) {
-                                for() {
-                                        struct oneshot * expected = this.ptr;
-
-                                        // expected == 0p: future was never actually setup, just return
-                                        if( expected == 0p ) return false;
-
-                                        // expected == 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( expected == 1p ) return true;
-
-                                        // expected == 2p: the future is ready but the context hasn't fully been consumed
-                                        // spin until it is safe to move on
-                                        if( expected == 2p ) {
-                                                while( this.ptr != 1p ) Pause();
-                                                /* paranoid */ verify( this.ptr == 1p );
-                                                return true;
-                                        }
-
-                                        // expected != wait_ctx: the future was setup with a different context ?!?!
-                                        // something went wrong here, abort
-                                        if( expected != &wait_ctx ) abort("Future in unexpected state");
-
+                                struct oneshot * expected = this.ptr;
+
+                                // attempt to remove the context so it doesn't get consumed.
+                                if(__atomic_compare_exchange_n( &this.ptr, &expected, 0p, false, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST)) {
                                         // we still have the original context, then no one else saw it
-                                        // attempt to remove the context so it doesn't get consumed.
-                                        if(__atomic_compare_exchange_n( &this.ptr, &expected, 0p, false, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST)) {
-                                                return false;
-                                        }
-                                }
+                                        return false;
+                                }
+
+                                // expected == 0p: future was never actually setup, just return
+                                if( expected == 0p ) return false;
+
+                                // expected == 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( expected == 1p ) return true;
+
+                                // expected == 2p: the future is ready but the context hasn't fully been consumed
+                                // spin until it is safe to move on
+                                if( expected == 2p ) {
+                                        while( this.ptr != 1p ) Pause();
+                                        /* paranoid */ verify( this.ptr == 1p );
+                                        return true;
+                                }
+
+                                // anything else: the future was setup with a different context ?!?!
+                                // something went wrong here, abort
+                                abort("Future in unexpected state");
                         }