llvm-6502/include/Support/SlowOperationInformer.h
2003-12-31 05:40:02 +00:00

57 lines
2.4 KiB
C++

//===- SlowOperationInformer.h - Keep the user informed ---------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file was developed by the LLVM research group and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// 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
// 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).
//
// 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
// operation was cancelled. As such, client code must be exception safe around
// 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.
//
//===----------------------------------------------------------------------===//
#ifndef SUPPORT_SLOW_OPERATION_INFORMER_H
#define SUPPORT_SLOW_OPERATION_INFORMER_H
#include <string>
namespace llvm {
class SlowOperationInformer {
std::string OperationName;
unsigned LastPrintAmount;
SlowOperationInformer(const SlowOperationInformer&); // DO NOT IMPLEMENT
void operator=(const SlowOperationInformer&); // DO NOT IMPLEMENT
public:
SlowOperationInformer(const std::string &Name);
~SlowOperationInformer();
/// progress - Clients should periodically call this method when they are in
/// an exception-safe state. The Amount variable should indicate how far
/// 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);
};
} // end namespace llvm
#endif /* SLOW_OPERATION_INFORMER_H */