Changes in libcfa/src/concurrency/ready_queue.cfa [8cd5434:69914cbc]

File:

• libcfa/src/concurrency/ready_queue.cfa (modified) (3 diffs)

libcfa/src/concurrency/ready_queue.cfa

@@ -398 +398 @@
 
                 if(proc->rdq.target == -1u) {
-                        unsigned long long min = ts(lanes.data[proc->rdq.id]);
-                        for(int i = 0; i < READYQ_SHARD_FACTOR; i++) {
-                                unsigned long long tsc = ts(lanes.data[proc->rdq.id + i]);
-                                if(tsc < min) min = tsc;
-                        }
-                        proc->rdq.cutoff = min;
+                        _Static_assert(READYQ_SHARD_FACTOR == 2);
+                        unsigned idx1 = proc->rdq.id + 0;
+                        unsigned idx2 = proc->rdq.id + 1;
+                        unsigned long long tsc1 = ts(lanes.data[idx1]);
+                        unsigned long long tsc2 = ts(lanes.data[idx2]);
                         proc->rdq.target = __tls_rand() % lanes.count;
+
+                        // WARNING: std::min is polymorphic and therefore causes 500% slowdown instead of the expected 2%
+                        proc->rdq.cutoff = tsc1 < tsc2 ? tsc1 : tsc2;
                 }
                 else {
@@ -552 +554 @@
 }
 
-static void assign_list(unsigned & value, dlist(processor, processor) & list, unsigned count) {
+static void assign_list(unsigned & value, dlist(processor) & list, unsigned count) {
         processor * it = &list`first;
         for(unsigned i = 0; i < count; i++) {
@@ -702 +704 @@
         /* paranoid */ verify( ready_mutate_islocked() );
 }
-
-#if !defined(__CFA_NO_STATISTICS__)
-        unsigned cnt(const __ready_queue_t & this, unsigned idx) {
-                /* paranoid */ verify(this.lanes.count > idx);
-                return this.lanes.data[idx].cnt;
-        }
-#endif