Changes between Version 58 and Version 59 of Next-GenOpenMPTransformation

Timestamp:

11/12/19 13:20:57 (7 years ago)

Author:

wuwenhao

Comment:

--

Next-GenOpenMPTransformation

@@ -611 +611 @@
 
 Basically, use a lock for each critical name, plus one for the "no name".  All threads must obtain lock to enter the critical section, then release it.
-I.e., if there are critical sections name a, b, and c, there should be global root-scope variables of boolean type named `_critical_noname`, `_critical_a`, etc.
+i.e., if there are critical sections name a, b, and c, there should be global root-scope variables of boolean type named `_critical_noname`, `_critical_a`, etc. \\
+The translation pattern is:
+* '''update R/W sets''' for the caller thread that calls `$read_and_write_set_update(team)`
+* '''wait''' for other threads until they finish updating their R/W sets, by calling `$yield()`
+* '''acquire the lock''', which bonds to this `critical` region.
+* '''check data-race''' by calling `$check_data_race(team)` at each synchronizing point. 
+* '''explore''' the  translated `critical` region.
+* '''update R/W sets''' 
+* '''wait''' for other threads
+* '''release the lock'''
+* '''check data-race'''
 
 {{{
@@ -632 +642 @@
 
 // critical block with unspecified name
+  $read_and_write_set_update(team);
   $yield();
-  $check_data_race(team);
   $omp_helper_semaphore_p(critical_, 0);
   $omp_helper_semaphore_v(critical_, 1);
+  $check_data_race(team);
+
   translate(BLOCK_A)
+
+  $read_and_write_set_update(team);
+  $yield();
   $omp_helper_semaphore_v(critical_, 0);
+  $check_data_race(team);
 
 // critical block with specified name
+
+  $read_and_write_set_update(team);
   $yield();
-  $check_data_race(team);
   $omp_helper_semaphore_p(critical_x, 0);
   $omp_helper_semaphore_v(critical_x, 1);
+  $check_data_race(team);
+
   translate(BLOCK_X);
+
+  $read_and_write_set_update(team);
+  $yield();
   $omp_helper_semaphore_v(critical_x, 0);
+  $check_data_race(team);
 }}}
 
@@ -692 +715 @@
     int i_next = i + I_INCR;
     ...
+    $read_and_write_set_update(team);
     $yield();
-    $check_data_race(team);
     // wait until hs0->val is i
     $omp_helper_semaphore_p(ordered_0, i);
+    $check_data_race(team);
+
     translate(BLOCK);
+
+    $read_and_write_set_update(team);
+    $yield();
     // set hs0->val as i_next
     $omp_helper_semaphore_v(ordered_0, i_next);
+    $check_data_race(team);
     ...
   }
@@ -704 +733 @@
 }}}
 
-==== Case 1: ordered for-loop with a collapse clause ====
+==== Case 2: ordered for-loop with a collapse clause ====
+The transformation pattern is:
+* '''record next iteration value''' for all loop variables in the entry of the loop body.
+* '''update R/W sets''' for the current thread.
+* '''wait for other threads''' finishing R/W set updates.
+* '''semaphore P operations''' from the outer-most to the inner-most loop variable.
+  (This operation waits for a "signal" send when its sequentially previous iteration is completed.) 
+* '''check data-race''' at any synchronizing point.
+* '''explore''' the translated `ordered` region
+* '''update R/W sets'''
+* '''wait for others'''
+* '''semaphore V operations''' from the inner-most to the outer-most loop variable;
+  (This operation issues a "signal" to enable the execution of its sequentially next iteration.) 
+* '''check data-race'''
 
 {{{
@@ -731 +773 @@
     int k_next = k + K_INCR;
 
+    $read_and_write_set_update(team);
     $yield();
+    $omp_helper_semaphore_p(ordered_0, i);
+    $omp_helper_semaphore_p(ordered_1, j);
+    $omp_helper_semaphore_p(ordered_2, k);
     $check_data_race(team);
-    $omp_helper_semaphore_p(ordered_0, i); 
-    $omp_helper_semaphore_p(ordered_1, j); 
-    $omp_helper_semaphore_p(ordered_2, k); 
 
     translate(BLOCK);
 
-    if (k_next < K_COND) // hit bound
-      $omp_helper_semaphore_v(ordered_2, k_next); // incr
+    $read_and_write_set_update(team);
+    $yield();
+    if (k_next < K_COND) // 'k' deos NOT hit its bound
+      $omp_helper_semaphore_v(ordered_2, k_next); // incr 'k'
     else { 
-      $omp_helper_semaphore_v(ordered_2, K_INIT); // reset
-
-      if (j_next < J_COND) // hit bound
-        $omp_helper_semaphore_v(ordered_1, j_next); // incr
+      $omp_helper_semaphore_v(ordered_2, K_INIT); // reset 'k'
+
+      if (j_next < J_COND) // 'j' deos NOT hit its bound
+        $omp_helper_semaphore_v(ordered_1, j_next); // incr 'j'
       else {
-        $omp_helper_semaphore_v(ordered_1, J_INIT); // reset
-
-        $omp_helper_semaphore_v(ordered_0, i_next); // incr
+        $omp_helper_semaphore_v(ordered_1, J_INIT); // reset 'j'
+
+        $omp_helper_semaphore_v(ordered_0, i_next); // incr 'i'
       }
     }
+    $check_data_race(team);
   }
   ..