Be a bit more efficient when processing the active and inactive

[oota-llvm.git] / include / Support / SlowOperationInformer.h

diff --git a/include/Support/SlowOperationInformer.h b/include/Support/SlowOperationInformer.h
index f27a05571b4aafc5fff49e37b4c086696cc99a01..67edf7df42b53998e5c53f7e824992e00556e9ff 100644 (file)
--- a/include/Support/SlowOperationInformer.h
+++ b/include/Support/SlowOperationInformer.h
@@ -8,14 +8,13 @@
 //===----------------------------------------------------------------------===//
 //
 // This file defines a simple object which can be used to let the user know what
-// is going on when a slow operation is happening,l and gives them the ability
-// to cancel it.  Potentially slow operations can stack allocate one of these
+// is going on when a slow operation is happening, and gives them the ability to
+// cancel it.  Potentially slow operations can stack allocate one of these
 // objects, and periodically call the "progress" method to update the progress
-// bar.  If the operation takes more than 3 seconds to complete, the progress
-// bar is automatically shown and updated every second.  As such, the slow
-// operation should not print stuff to the screen, and should not be confused if
-// an extra line appears on the screen (ie, the cursor should be at the start of
-// the line).
+// bar.  If the operation takes more than 1 second to complete, the progress bar
+// is automatically shown and updated.  As such, the slow operation should not
+// print stuff to the screen, and should not be confused if an extra line
+// appears on the screen (ie, the cursor should be at the start of the line).
 //
 // If the user presses CTRL-C during the operation, the next invocation of the
 // progress method with throw an std::string object indicating that the
@@ -23,9 +22,9 @@
 // the progress method.
 //
 // Because SlowOperationInformers fiddle around with signals, they cannot be
-// nested.  The SIGINT signal handler is restored after the
-// SlowOperationInformer is destroyed, but the SIGALRM handlers is set back to
-// the default.
+// nested, and interact poorly with threads.  The SIGALRM handler is set back to
+// SIGDFL, but the SIGINT signal handler is restored when the
+// SlowOperationInformer is destroyed.
 //
 //===----------------------------------------------------------------------===//
 
@@ -33,6 +32,7 @@
 #define SUPPORT_SLOW_OPERATION_INFORMER_H
 
 #include <string>
+#include <cassert>
 
 namespace llvm {
   class SlowOperationInformer {
@@ -50,6 +50,15 @@ namespace llvm {
     /// along the operation is, given in 1/10ths of a percent (in other words,
     /// Amount should range from 0 to 1000).
     void progress(unsigned Amount);
+
+    /// progress - Same as the method above, but this performs the division for
+    /// you, and helps you avoid overflow if you are dealing with largish
+    /// numbers.
+    void progress(unsigned Current, unsigned Maximum) {
+      assert(Maximum != 0 &&
+             "Shouldn't be doing work if there is nothing to do!");
+      progress(Current*1000ULL/Maximum);
+    }
   };
 } // end namespace llvm