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_SYSTEM_PROCESS_H
26 #define LLVM_SYSTEM_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;
68 /// \name Static factory routines for processes.
71 /// \brief Get the process object for the current process.
72 static self_process *get_self();
78 /// \brief The specific class representing the current process.
80 /// The current process can both specialize the implementation of the routines
81 /// and can expose certain information not available for other OS processes.
82 class self_process : public process {
85 /// \brief Private destructor, as users shouldn't create objects of this
87 virtual ~self_process();
90 virtual id_type get_id();
96 /// \brief A collection of legacy interfaces for querying information about the
97 /// current executing process.
100 /// \brief Get the virtual memory page size
101 /// This static function will return the operating system's virtual memory
103 /// \returns The number of bytes in a virtual memory page.
104 static unsigned GetPageSize();
106 /// \brief Return process memory usage.
107 /// This static function will return the total amount of memory allocated
108 /// by the process. This only counts the memory allocated via the malloc,
109 /// calloc and realloc functions and includes any "free" holes in the
111 static size_t GetMallocUsage();
113 /// This static function will set \p user_time to the amount of CPU time
114 /// spent in user (non-kernel) mode and \p sys_time to the amount of CPU
115 /// time spent in system (kernel) mode. If the operating system does not
116 /// support collection of these metrics, a zero TimeValue will be for both
118 /// \param elapsed Returns the TimeValue::now() giving current time
119 /// \param user_time Returns the current amount of user time for the process
120 /// \param sys_time Returns the current amount of system time for the process
121 static void GetTimeUsage(TimeValue &elapsed, TimeValue &user_time,
122 TimeValue &sys_time);
124 /// This static function will return the process' current user id number.
125 /// Not all operating systems support this feature. Where it is not
126 /// supported, the function should return 65536 as the value.
127 static int GetCurrentUserId();
129 /// This static function will return the process' current group id number.
130 /// Not all operating systems support this feature. Where it is not
131 /// supported, the function should return 65536 as the value.
132 static int GetCurrentGroupId();
134 /// This function makes the necessary calls to the operating system to
135 /// prevent core files or any other kind of large memory dumps that can
136 /// occur when a program fails.
137 /// @brief Prevent core file generation.
138 static void PreventCoreFiles();
140 /// This function determines if the standard input is connected directly
141 /// to a user's input (keyboard probably), rather than coming from a file
143 static bool StandardInIsUserInput();
145 /// This function determines if the standard output is connected to a
146 /// "tty" or "console" window. That is, the output would be displayed to
147 /// the user rather than being put on a pipe or stored in a file.
148 static bool StandardOutIsDisplayed();
150 /// This function determines if the standard error is connected to a
151 /// "tty" or "console" window. That is, the output would be displayed to
152 /// the user rather than being put on a pipe or stored in a file.
153 static bool StandardErrIsDisplayed();
155 /// This function determines if the given file descriptor is connected to
156 /// a "tty" or "console" window. That is, the output would be displayed to
157 /// the user rather than being put on a pipe or stored in a file.
158 static bool FileDescriptorIsDisplayed(int fd);
160 /// This function determines if the given file descriptor is displayd and
162 static bool FileDescriptorHasColors(int fd);
164 /// This function determines the number of columns in the window
165 /// if standard output is connected to a "tty" or "console"
166 /// window. If standard output is not connected to a tty or
167 /// console, or if the number of columns cannot be determined,
168 /// this routine returns zero.
169 static unsigned StandardOutColumns();
171 /// This function determines the number of columns in the window
172 /// if standard error is connected to a "tty" or "console"
173 /// window. If standard error is not connected to a tty or
174 /// console, or if the number of columns cannot be determined,
175 /// this routine returns zero.
176 static unsigned StandardErrColumns();
178 /// This function determines whether the terminal connected to standard
179 /// output supports colors. If standard output is not connected to a
180 /// terminal, this function returns false.
181 static bool StandardOutHasColors();
183 /// This function determines whether the terminal connected to standard
184 /// error supports colors. If standard error is not connected to a
185 /// terminal, this function returns false.
186 static bool StandardErrHasColors();
188 /// Whether changing colors requires the output to be flushed.
189 /// This is needed on systems that don't support escape sequences for
191 static bool ColorNeedsFlush();
193 /// This function returns the colorcode escape sequences.
194 /// If ColorNeedsFlush() is true then this function will change the colors
195 /// and return an empty escape sequence. In that case it is the
196 /// responsibility of the client to flush the output stream prior to
197 /// calling this function.
198 static const char *OutputColor(char c, bool bold, bool bg);
200 /// Same as OutputColor, but only enables the bold attribute.
201 static const char *OutputBold(bool bg);
203 /// This function returns the escape sequence to reverse forground and
204 /// background colors.
205 static const char *OutputReverse();
207 /// Resets the terminals colors, or returns an escape sequence to do so.
208 static const char *ResetColor();
210 /// Get the result of a process wide random number generator. The
211 /// generator will be automatically seeded in non-deterministic fashion.
212 static unsigned GetRandomNumber();