ircd::ctx: Add access to rdtsc through ctx::prof; minor comments.

Author: jevolk

include/ircd/ctx/ctx.h

@@ -115,4 +115,6 @@ namespace ircd
 
 	using ctx::critical_assertion;
 	using ctx::critical_indicator;
+
+	using ctx::prof::rdtsc;
 }

include/ircd/ctx/prof.h

@@ -32,10 +32,15 @@ namespace ircd::ctx::prof
 	enum class event;
 	struct settings extern settings;
 
+	// lowlevel
+	ulong rdtsc();
+
+	// state accessors
 	const ulong &total_slice_cycles();
 	const ulong &cur_slice_start();
 	ulong cur_slice_cycles();
 
+	// called at the appropriate point to mark the event (internal use).
 	void mark(const event &);
 }
 

ircd/ctx.cc

@@ -1231,7 +1231,7 @@ ircd::ctx::prof::mark(const event &e)
 ulong
 ircd::ctx::prof::cur_slice_cycles()
 {
-	return __rdtsc() - cur_slice_start();
+	return rdtsc() - cur_slice_start();
 }
 
 const ulong &
@@ -1274,7 +1274,7 @@ ircd::ctx::prof::handle_cur_continue()
 void
 ircd::ctx::prof::slice_start()
 {
-	_slice_start = __rdtsc();
+	_slice_start = rdtsc();
 }
 
 void
@@ -1335,6 +1335,12 @@ ircd::ctx::prof::check_stack()
 	}
 }
 
+ulong
+ircd::ctx::prof::rdtsc()
+{
+	return __rdtsc();
+}
+
 ///////////////////////////////////////////////////////////////////////////////
 //
 // ctx_ole.h