Changeset 50aeb6f for doc/theses/thierry_delisle_PhD/code/processor_list.hpp

Timestamp:

Sep 26, 2019, 4:25:04 PM (5 years ago)

Author:

Thierry Delisle <tdelisle@…>

Branches:

ADT, arm-eh, ast-experimental, enum, forall-pointer-decay, jacob/cs343-translation, jenkins-sandbox, master, new-ast, new-ast-unique-expr, pthread-emulation, qualifiedEnum

Children:

1e24d13

Parents:

b2a37b0

Message:

Small tweaks to the memory layout

File:

• doc/theses/thierry_delisle_PhD/code/processor_list.hpp (modified) (1 diff)

doc/theses/thierry_delisle_PhD/code/processor_list.hpp

@@ -188 +188 @@
         }
 
+        //-----------------------------------------------------------------------
+        // Checking support
+        uint_fast32_t epoch_check() {
+                // Step 1 : lock global lock
+                // It is needed to avoid processors that register mid Critical-Section
+                //   to simply lock their own lock and enter.
+                while(lock.load(std::memory_order_relaxed))
+                        asm volatile("pause");
+
+                // Step 2 : lock per-proc lock
+                // Processors that are currently being registered aren't counted
+                //   but can't be in read_lock or in the critical section.
+                // All other processors are counted
+                uint_fast32_t s = ready;
+                for(uint_fast32_t i = 0; i < s; i++) {
+                        while(data[i].lock.load(std::memory_order_relaxed))
+                                asm volatile("pause");
+                }
+
+                return s;
+        }
+
 public:
 };