src/share/vm/logging/logTag.hpp

rev 8933 : 8046148.01

@@ -21,21 +21,19 @@
  * questions.
  *
  */
 #ifndef SHARE_VM_LOGGING_LOGTAG_HPP
 #define SHARE_VM_LOGGING_LOGTAG_HPP
+
+#include "memory/allocation.hpp"
 #include "utilities/globalDefinitions.hpp"
 
 // List of available logging tags. New tags should be added here.
 // (The tags 'all', 'disable' and 'help' are special tags that can
 // not be used in log calls, and should not be listed below.)
 #define LOG_TAG_LIST \
-  LOG_TAG(gc) \
-  LOG_TAG(rt) \
-  LOG_TAG(svc) \
-  LOG_TAG(logging) \
-  LOG_TAG(comp)
+  LOG_TAG(logging)
 
 #define PREFIX_LOG_TAG(T) (LogTag::T)
 
 // Expand a set of log tags to their prefixed names.
 // For error detection purposes, the macro passes one more tag than what is supported.

@@ -44,12 +42,20 @@
                                                         PREFIX_LOG_TAG(T3), PREFIX_LOG_TAG(T4), PREFIX_LOG_TAG(T5)
 // The EXPAND_VARARGS macro is required for MSVC, or it will resolve the LOG_TAGS_EXPANDED macro incorrectly.
 #define EXPAND_VARARGS(x) x
 #define LOG_TAGS(...) EXPAND_VARARGS(LOG_TAGS_EXPANDED(__VA_ARGS__, __NO_TAG, __NO_TAG, __NO_TAG, __NO_TAG, __NO_TAG, __NO_TAG))
 
-class LogTag {
+// Log tags are used to classify log messages.
+// Each log message can be assigned between 1 to LogTag::MaxTags number of tags.
+// Specifying multiple tags for a log message means that only outputs configured
+// for those exact tags, or a subset of the tags with a wildcard, will see the logging.
+// Multiple tags should be comma separated, e.g. log_error(tag1, tag2)("msg").
+class LogTag : public AllStatic {
  public:
+  // The maximum number of tags that a single log message can have.
+  // E.g. there might be hundreds of different tags available,
+  // but a specific log message can only be tagged with up to MaxTags of those.
   static const size_t MaxTags = 5;
 
   enum type {
     __NO_TAG,
 #define LOG_TAG(name) name,

@@ -68,6 +74,6 @@
   static const char* _name[];
 };
 
 typedef LogTag::type LogTagType;
 
-#endif
+#endif // SHARE_VM_LOGGING_LOGTAG_HPP