1 //===- llvm/Support/Process.h -----------------------------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
11 /// Provides a library for accessing information about this process and other
12 /// processes on the operating system. Also provides means of spawning
13 /// subprocess for commands. The design of this library is modeled after the
14 /// proposed design of the Boost.Process library, and is design specifically to
15 /// follow the style of standard libraries and potentially become a proposal
16 /// for a standard library.
18 /// This file declares the llvm::sys::Process class which contains a collection
19 /// of legacy static interfaces for extracting various information about the
20 /// current process. The goal is to migrate users of this API over to the new
23 //===----------------------------------------------------------------------===//
25 #ifndef LLVM_SUPPORT_PROCESS_H
26 #define LLVM_SUPPORT_PROCESS_H
28 #include "llvm/Config/llvm-config.h"
29 #include "llvm/Support/DataTypes.h"
30 #include "llvm/Support/TimeValue.h"
37 /// \brief Generic base class which exposes information about an operating
40 /// This base class is the core interface behind any OS process. It exposes
41 /// methods to query for generic information about a particular process.
43 /// Subclasses implement this interface based on the mechanisms available, and
44 /// can optionally expose more interfaces unique to certain process kinds.
47 /// \brief Only specific subclasses of process objects can be destroyed.
51 /// \brief Operating system specific type to identify a process.
53 /// Note that the windows one is defined to 'void *' as this is the
54 /// documented type for HANDLE on windows, and we don't want to pull in the
55 /// Windows headers here.
56 #if defined(LLVM_ON_UNIX)
57 typedef pid_t id_type;
58 #elif defined(LLVM_ON_WIN32)
59 typedef void *id_type; // Must match the type of HANDLE.
61 #error Unsupported operating system.
64 /// \brief Get the operating system specific identifier for this process.
65 virtual id_type get_id() = 0;
67 /// \brief Get the user time consumed by this process.
69 /// Note that this is often an approximation and may be zero on platforms
70 /// where we don't have good support for the functionality.
71 virtual TimeValue get_user_time() const = 0;
73 /// \brief Get the system time consumed by this process.
75 /// Note that this is often an approximation and may be zero on platforms
76 /// where we don't have good support for the functionality.
77 virtual TimeValue get_system_time() const = 0;
79 /// \brief Get the wall time consumed by this process.
81 /// Note that this is often an approximation and may be zero on platforms
82 /// where we don't have good support for the functionality.
83 virtual TimeValue get_wall_time() const = 0;
85 /// \name Static factory routines for processes.
88 /// \brief Get the process object for the current process.
89 static self_process *get_self();
95 /// \brief The specific class representing the current process.
97 /// The current process can both specialize the implementation of the routines
98 /// and can expose certain information not available for other OS processes.
99 class self_process : public process {
100 friend class process;
102 /// \brief Private destructor, as users shouldn't create objects of this
104 virtual ~self_process();
107 virtual id_type get_id();
108 virtual TimeValue get_user_time() const;
109 virtual TimeValue get_system_time() const;
110 virtual TimeValue get_wall_time() const;
112 /// \name Process configuration (sysconf on POSIX)
115 /// \brief Get the virtual memory page size.
117 /// Query the operating system for this process's page size.
118 size_t page_size() const { return PageSize; };
123 /// \name Cached process state.
126 /// \brief Cached page size, this cannot vary during the life of the process.
131 /// \brief Constructor, used by \c process::get_self() only.
136 /// \brief A collection of legacy interfaces for querying information about the
137 /// current executing process.
140 /// \brief Return process memory usage.
141 /// This static function will return the total amount of memory allocated
142 /// by the process. This only counts the memory allocated via the malloc,
143 /// calloc and realloc functions and includes any "free" holes in the
145 static size_t GetMallocUsage();
147 /// This static function will set \p user_time to the amount of CPU time
148 /// spent in user (non-kernel) mode and \p sys_time to the amount of CPU
149 /// time spent in system (kernel) mode. If the operating system does not
150 /// support collection of these metrics, a zero TimeValue will be for both
152 /// \param elapsed Returns the TimeValue::now() giving current time
153 /// \param user_time Returns the current amount of user time for the process
154 /// \param sys_time Returns the current amount of system time for the process
155 static void GetTimeUsage(TimeValue &elapsed, TimeValue &user_time,
156 TimeValue &sys_time);
158 /// This static function will return the process' current user id number.
159 /// Not all operating systems support this feature. Where it is not
160 /// supported, the function should return 65536 as the value.
161 static int GetCurrentUserId();
163 /// This static function will return the process' current group id number.
164 /// Not all operating systems support this feature. Where it is not
165 /// supported, the function should return 65536 as the value.
166 static int GetCurrentGroupId();
168 /// This function makes the necessary calls to the operating system to
169 /// prevent core files or any other kind of large memory dumps that can
170 /// occur when a program fails.
171 /// @brief Prevent core file generation.
172 static void PreventCoreFiles();
174 /// This function determines if the standard input is connected directly
175 /// to a user's input (keyboard probably), rather than coming from a file
177 static bool StandardInIsUserInput();
179 /// This function determines if the standard output is connected to a
180 /// "tty" or "console" window. That is, the output would be displayed to
181 /// the user rather than being put on a pipe or stored in a file.
182 static bool StandardOutIsDisplayed();
184 /// This function determines if the standard error is connected to a
185 /// "tty" or "console" window. That is, the output would be displayed to
186 /// the user rather than being put on a pipe or stored in a file.
187 static bool StandardErrIsDisplayed();
189 /// This function determines if the given file descriptor is connected to
190 /// a "tty" or "console" window. That is, the output would be displayed to
191 /// the user rather than being put on a pipe or stored in a file.
192 static bool FileDescriptorIsDisplayed(int fd);
194 /// This function determines if the given file descriptor is displayd and
196 static bool FileDescriptorHasColors(int fd);
198 /// This function determines the number of columns in the window
199 /// if standard output is connected to a "tty" or "console"
200 /// window. If standard output is not connected to a tty or
201 /// console, or if the number of columns cannot be determined,
202 /// this routine returns zero.
203 static unsigned StandardOutColumns();
205 /// This function determines the number of columns in the window
206 /// if standard error is connected to a "tty" or "console"
207 /// window. If standard error is not connected to a tty or
208 /// console, or if the number of columns cannot be determined,
209 /// this routine returns zero.
210 static unsigned StandardErrColumns();
212 /// This function determines whether the terminal connected to standard
213 /// output supports colors. If standard output is not connected to a
214 /// terminal, this function returns false.
215 static bool StandardOutHasColors();
217 /// This function determines whether the terminal connected to standard
218 /// error supports colors. If standard error is not connected to a
219 /// terminal, this function returns false.
220 static bool StandardErrHasColors();
222 /// Whether changing colors requires the output to be flushed.
223 /// This is needed on systems that don't support escape sequences for
225 static bool ColorNeedsFlush();
227 /// This function returns the colorcode escape sequences.
228 /// If ColorNeedsFlush() is true then this function will change the colors
229 /// and return an empty escape sequence. In that case it is the
230 /// responsibility of the client to flush the output stream prior to
231 /// calling this function.
232 static const char *OutputColor(char c, bool bold, bool bg);
234 /// Same as OutputColor, but only enables the bold attribute.
235 static const char *OutputBold(bool bg);
237 /// This function returns the escape sequence to reverse forground and
238 /// background colors.
239 static const char *OutputReverse();
241 /// Resets the terminals colors, or returns an escape sequence to do so.
242 static const char *ResetColor();
244 /// Get the result of a process wide random number generator. The
245 /// generator will be automatically seeded in non-deterministic fashion.
246 static unsigned GetRandomNumber();