llvm-6502/include/llvm/Support/Process.h
2013-01-10 00:45:19 +00:00

253 lines
9.4 KiB
C++

//===- llvm/Support/Process.h -----------------------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
/// \file
///
/// Provides a library for accessing information about this process and other
/// processes on the operating system. Also provides means of spawning
/// subprocess for commands. The design of this library is modeled after the
/// proposed design of the Boost.Process library, and is design specifically to
/// follow the style of standard libraries and potentially become a proposal
/// for a standard library.
///
/// This file declares the llvm::sys::Process class which contains a collection
/// of legacy static interfaces for extracting various information about the
/// current process. The goal is to migrate users of this API over to the new
/// interfaces.
///
//===----------------------------------------------------------------------===//
#ifndef LLVM_SUPPORT_PROCESS_H
#define LLVM_SUPPORT_PROCESS_H
#include "llvm/Config/llvm-config.h"
#include "llvm/Support/DataTypes.h"
#include "llvm/Support/TimeValue.h"
namespace llvm {
namespace sys {
class self_process;
/// \brief Generic base class which exposes information about an operating
/// system process.
///
/// This base class is the core interface behind any OS process. It exposes
/// methods to query for generic information about a particular process.
///
/// Subclasses implement this interface based on the mechanisms available, and
/// can optionally expose more interfaces unique to certain process kinds.
class process {
protected:
/// \brief Only specific subclasses of process objects can be destroyed.
virtual ~process();
public:
/// \brief Operating system specific type to identify a process.
///
/// Note that the windows one is defined to 'void *' as this is the
/// documented type for HANDLE on windows, and we don't want to pull in the
/// Windows headers here.
#if defined(LLVM_ON_UNIX)
typedef pid_t id_type;
#elif defined(LLVM_ON_WIN32)
typedef void *id_type; // Must match the type of HANDLE.
#else
#error Unsupported operating system.
#endif
/// \brief Get the operating system specific identifier for this process.
virtual id_type get_id() = 0;
/// \brief Get the user time consumed by this process.
///
/// Note that this is often an approximation and may be zero on platforms
/// where we don't have good support for the functionality.
virtual TimeValue get_user_time() const = 0;
/// \brief Get the system time consumed by this process.
///
/// Note that this is often an approximation and may be zero on platforms
/// where we don't have good support for the functionality.
virtual TimeValue get_system_time() const = 0;
/// \brief Get the wall time consumed by this process.
///
/// Note that this is often an approximation and may be zero on platforms
/// where we don't have good support for the functionality.
virtual TimeValue get_wall_time() const = 0;
/// \name Static factory routines for processes.
/// @{
/// \brief Get the process object for the current process.
static self_process *get_self();
/// @}
};
/// \brief The specific class representing the current process.
///
/// The current process can both specialize the implementation of the routines
/// and can expose certain information not available for other OS processes.
class self_process : public process {
friend class process;
/// \brief Private destructor, as users shouldn't create objects of this
/// type.
virtual ~self_process();
public:
virtual id_type get_id();
virtual TimeValue get_user_time() const;
virtual TimeValue get_system_time() const;
virtual TimeValue get_wall_time() const;
/// \name Process configuration (sysconf on POSIX)
/// @{
/// \brief Get the virtual memory page size.
///
/// Query the operating system for this process's page size.
size_t page_size() const { return PageSize; };
/// @}
private:
/// \name Cached process state.
/// @{
/// \brief Cached page size, this cannot vary during the life of the process.
size_t PageSize;
/// @}
/// \brief Constructor, used by \c process::get_self() only.
self_process();
};
/// \brief A collection of legacy interfaces for querying information about the
/// current executing process.
class Process {
public:
/// \brief Return process memory usage.
/// This static function will return the total amount of memory allocated
/// by the process. This only counts the memory allocated via the malloc,
/// calloc and realloc functions and includes any "free" holes in the
/// allocated space.
static size_t GetMallocUsage();
/// This static function will set \p user_time to the amount of CPU time
/// spent in user (non-kernel) mode and \p sys_time to the amount of CPU
/// time spent in system (kernel) mode. If the operating system does not
/// support collection of these metrics, a zero TimeValue will be for both
/// values.
/// \param elapsed Returns the TimeValue::now() giving current time
/// \param user_time Returns the current amount of user time for the process
/// \param sys_time Returns the current amount of system time for the process
static void GetTimeUsage(TimeValue &elapsed, TimeValue &user_time,
TimeValue &sys_time);
/// This static function will return the process' current user id number.
/// Not all operating systems support this feature. Where it is not
/// supported, the function should return 65536 as the value.
static int GetCurrentUserId();
/// This static function will return the process' current group id number.
/// Not all operating systems support this feature. Where it is not
/// supported, the function should return 65536 as the value.
static int GetCurrentGroupId();
/// This function makes the necessary calls to the operating system to
/// prevent core files or any other kind of large memory dumps that can
/// occur when a program fails.
/// @brief Prevent core file generation.
static void PreventCoreFiles();
/// This function determines if the standard input is connected directly
/// to a user's input (keyboard probably), rather than coming from a file
/// or pipe.
static bool StandardInIsUserInput();
/// This function determines if the standard output is connected to a
/// "tty" or "console" window. That is, the output would be displayed to
/// the user rather than being put on a pipe or stored in a file.
static bool StandardOutIsDisplayed();
/// This function determines if the standard error is connected to a
/// "tty" or "console" window. That is, the output would be displayed to
/// the user rather than being put on a pipe or stored in a file.
static bool StandardErrIsDisplayed();
/// This function determines if the given file descriptor is connected to
/// a "tty" or "console" window. That is, the output would be displayed to
/// the user rather than being put on a pipe or stored in a file.
static bool FileDescriptorIsDisplayed(int fd);
/// This function determines if the given file descriptor is displayd and
/// supports colors.
static bool FileDescriptorHasColors(int fd);
/// This function determines the number of columns in the window
/// if standard output is connected to a "tty" or "console"
/// window. If standard output is not connected to a tty or
/// console, or if the number of columns cannot be determined,
/// this routine returns zero.
static unsigned StandardOutColumns();
/// This function determines the number of columns in the window
/// if standard error is connected to a "tty" or "console"
/// window. If standard error is not connected to a tty or
/// console, or if the number of columns cannot be determined,
/// this routine returns zero.
static unsigned StandardErrColumns();
/// This function determines whether the terminal connected to standard
/// output supports colors. If standard output is not connected to a
/// terminal, this function returns false.
static bool StandardOutHasColors();
/// This function determines whether the terminal connected to standard
/// error supports colors. If standard error is not connected to a
/// terminal, this function returns false.
static bool StandardErrHasColors();
/// Whether changing colors requires the output to be flushed.
/// This is needed on systems that don't support escape sequences for
/// changing colors.
static bool ColorNeedsFlush();
/// This function returns the colorcode escape sequences.
/// If ColorNeedsFlush() is true then this function will change the colors
/// and return an empty escape sequence. In that case it is the
/// responsibility of the client to flush the output stream prior to
/// calling this function.
static const char *OutputColor(char c, bool bold, bool bg);
/// Same as OutputColor, but only enables the bold attribute.
static const char *OutputBold(bool bg);
/// This function returns the escape sequence to reverse forground and
/// background colors.
static const char *OutputReverse();
/// Resets the terminals colors, or returns an escape sequence to do so.
static const char *ResetColor();
/// Get the result of a process wide random number generator. The
/// generator will be automatically seeded in non-deterministic fashion.
static unsigned GetRandomNumber();
};
}
}
#endif