Changeset 7770cc8 for libcfa/src/concurrency/kernel_private.hfa

Timestamp:

Nov 24, 2021, 9:47:56 PM (4 years ago)

Author:

Michael Brooks <mlbrooks@…>

Branches:

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

Children:

5235d49

Parents:

94647b0b (diff), 3cc1111 (diff)
Note: this is a merge changeset, the changes displayed below correspond to the merge itself.
Use the (diff) links above to see all the changes relative to each parent.

Message:

Merge branch 'master' of plg.uwaterloo.ca:software/cfa/cfa-cc

File:

• libcfa/src/concurrency/kernel_private.hfa (modified) (4 diffs)

libcfa/src/concurrency/kernel_private.hfa

@@ -39 +39 @@
 }
 
+// #define IO_URING_IDLE
+
 //-----------------------------------------------------------------------------
 // Scheduler
@@ -149 +151 @@
         __atomic_store_n(ll, (bool)false, __ATOMIC_RELEASE);
 }
-
-
-
-
 
 //-----------------------------------------------------------------------
@@ -268 +266 @@
         ready_schedule_lock();
 
-        // Simple counting lock, acquired, acquired by incrementing the counter
-        // to an odd number
-        for() {
-                uint64_t l = this.lock;
-                if(
-                        (0 == (l % 2))
-                        && __atomic_compare_exchange_n(&this.lock, &l, l + 1, false, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST)
-                ) return;
-                Pause();
-        }
-
-        /* paranoid */ verify( ! __preemption_enabled() );
+        lock( this.lock __cfaabi_dbg_ctx2 );
+
+        /* paranoid */ verify( ! __preemption_enabled() );
+}
+
+static inline bool try_lock(__cluster_proc_list & this) {
+        /* paranoid */ verify( ! __preemption_enabled() );
+
+        // Start by locking the global RWlock so that we know no-one is
+        // adding/removing processors while we mess with the idle lock
+        ready_schedule_lock();
+
+        if(try_lock( this.lock __cfaabi_dbg_ctx2 )) {
+                // success
+                /* paranoid */ verify( ! __preemption_enabled() );
+                return true;
+        }
+
+        // failed to lock
+        ready_schedule_unlock();
+
+        /* paranoid */ verify( ! __preemption_enabled() );
+        return false;
 }
 
@@ -285 +294 @@
         /* paranoid */ verify( ! __preemption_enabled() );
 
-        /* paranoid */ verify( 1 == (this.lock % 2) );
-        // Simple couting lock, release by incrementing to an even number
-        __atomic_fetch_add( &this.lock, 1, __ATOMIC_SEQ_CST );
+        unlock(this.lock);
 
         // Release the global lock, which we acquired when locking