src/share/vm/logging/log.cpp

rev 10535 : imported patch 8151438
rev 10536 : [mq]: 8151438.01

*** 157,162 ****
--- 157,207 ----
  
    LogConfiguration::disable_logging();
    assert(Test_logconfiguration_subscribe_triggered == 3, "subscription not triggered (3)");
  }
  
+ void Test_logtagset_duplicates() {
+   for (LogTagSet* ts = LogTagSet::first(); ts != NULL; ts = ts->next()) {
+     char ts_name[512];
+     ts->label(ts_name, sizeof(ts_name), ",");
+ 
+     // verify that NO_TAG is never followed by a real tag
+     for (size_t i = 0; i < LogTag::MaxTags; i++) {
+       if (ts->tag(i) == LogTag::__NO_TAG) {
+         for (i++; i < LogTag::MaxTags; i++) {
+           assert(ts->tag(i) == LogTag::__NO_TAG,
+                  "NO_TAG was followed by a real tag (%s) in tagset %s",
+                  LogTag::name(ts->tag(i)), ts_name);
+         }
+       }
+     }
+ 
+     // verify that there are no duplicate tagsets (same tags in different order)
+     for (LogTagSet* other = ts->next(); other != NULL; other = other->next()) {
+       if (ts->ntags() != other->ntags()) {
+         continue;
+       }
+       bool equal = true;
+       for (size_t i = 0; i < ts->ntags(); i++) {
+         LogTagType tag = ts->tag(i);
+         if (!other->contains(tag)) {
+           equal = false;
+           break;
+         }
+       }
+       // Since tagsets are implemented using template arguments, using both of
+       // the (logically equivalent) tagsets (t1, t2) and (t2, t1) somewhere will
+       // instantiate two different LogTagSetMappings. This causes multiple
+       // tagset instances to be created for the same logical set. We want to
+       // avoid this to save time, memory and prevent any confusion around it.
+       if (equal) {
+         char other_name[512];
+         other->label(other_name, sizeof(other_name), ",");
+         assert(false, "duplicate LogTagSets found: '%s' vs '%s' "
+                "(tags must always be specified in the same order for each tagset)",
+                ts_name, other_name);
+       }
+     }
+   }
+ }
+ 
  #endif // PRODUCT