1 //===-- TimeValue.h - Declare OS TimeValue Concept ---------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by Reid Spencer and is distributed under the
6 // University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This header file declares the operating system TimeValue concept.
12 //===----------------------------------------------------------------------===//
14 #include <llvm/Support/DataTypes.h>
16 #ifndef LLVM_SYSTEM_TIMEVALUE_H
17 #define LLVM_SYSTEM_TIMEVALUE_H
21 /// This class is used where a precise fixed point in time is required. The
22 /// range of TimeValue spans many hundreds of billions of years both past and
23 /// present. The precision of TimeValue is to the nanosecond. However, the
24 /// actual precision of its values will be determined by the resolution of
25 /// the system clock. The TimeValue class is used in conjunction with several
26 /// other lib/System interfaces to specify the time at which a call should
29 /// @brief Provides an abstraction for a fixed point in time.
36 /// A constant TimeValue representing the smallest time
37 /// value permissable by the class. MinTime is some point
38 /// in the distant past, about 300 billion years BCE.
39 /// @brief The smallest possible time value.
40 static const TimeValue MinTime;
42 /// A constant TimeValue representing the largest time
43 /// value permissable by the class. MaxTime is some point
44 /// in the distant future, about 300 billion years AD.
45 /// @brief The largest possible time value.
46 static const TimeValue MaxTime;
48 /// A constant TimeValue representing the base time,
49 /// or zero time of 00:00:00 (midnight) January 1st, 2000.
50 /// @brief 00:00:00 Jan 1, 2000 UTC.
51 static const TimeValue ZeroTime;
53 /// A constant TimeValue for the Posix base time which is
54 /// 00:00:00 (midnight) January 1st, 1970.
55 /// @brief 00:00:00 Jan 1, 1970 UTC.
56 static const TimeValue PosixZeroTime;
58 /// A constant TimeValue for the Win32 base time which is
59 /// 00:00:00 (midnight) January 1st, 1601.
60 /// @brief 00:00:00 Jan 1, 1601 UTC.
61 static const TimeValue Win32ZeroTime;
67 typedef int64_t SecondsType; ///< Type used for representing seconds.
68 typedef int32_t NanoSecondsType; ///< Type used for representing nanoseconds.
70 enum TimeConversions {
71 NANOSECONDS_PER_SECOND = 1000000000, ///< One Billion
72 MICROSECONDS_PER_SECOND = 1000000, ///< One Million
73 MILLISECONDS_PER_SECOND = 1000, ///< One Thousand
74 NANOSECONDS_PER_MICROSECOND = 1000, ///< One Thousand
75 NANOSECONDS_PER_MILLISECOND = 1000000,///< One Million
76 NANOSECONDS_PER_POSIX_TICK = 100, ///< Posix tick is 100 Hz (10ms)
77 NANOSECONDS_PER_WIN32_TICK = 100, ///< Win32 tick is 100 Hz (10ms)
81 /// @name Constructors
84 /// Caller provides the exact value in seconds and nanoseconds. The
85 /// \p nanos argument defaults to zero for convenience.
86 /// @brief Explicit constructor
87 explicit TimeValue (SecondsType seconds, NanoSecondsType nanos = 0)
89 , nanos_( nanos ) { this->normalize(); }
91 /// Caller provides the exact value as a double in seconds with the
92 /// fractional part representing nanoseconds.
93 /// @brief Double Constructor.
94 explicit TimeValue( double new_time )
95 : seconds_( 0 ) , nanos_ ( 0 ) {
96 SecondsType integer_part = static_cast<SecondsType>( new_time );
97 seconds_ = integer_part;
98 nanos_ = static_cast<NanoSecondsType>( (new_time -
99 static_cast<double>(integer_part)) * NANOSECONDS_PER_SECOND );
103 /// This is a static constructor that returns a TimeValue that represents
104 /// the current time.
105 /// @brief Creates a TimeValue with the current time (UTC).
106 static TimeValue now();
112 /// Add \p that to \p this.
114 /// @brief Incrementing assignment operator.
115 TimeValue& operator += (const TimeValue& that ) {
116 this->seconds_ += that.seconds_ ;
117 this->nanos_ += that.nanos_ ;
122 /// Subtract \p that from \p this.
124 /// @brief Decrementing assignment operator.
125 TimeValue& operator -= (const TimeValue &that ) {
126 this->seconds_ -= that.seconds_ ;
127 this->nanos_ -= that.nanos_ ;
132 /// Determine if \p this is less than \p that.
133 /// @returns True iff *this < that.
134 /// @brief True if this < that.
135 int operator < (const TimeValue &that) const { return that > *this; }
137 /// Determine if \p this is greather than \p that.
138 /// @returns True iff *this > that.
139 /// @brief True if this > that.
140 int operator > (const TimeValue &that) const {
141 if ( this->seconds_ > that.seconds_ ) {
143 } else if ( this->seconds_ == that.seconds_ ) {
144 if ( this->nanos_ > that.nanos_ ) return 1;
149 /// Determine if \p this is less than or equal to \p that.
150 /// @returns True iff *this <= that.
151 /// @brief True if this <= that.
152 int operator <= (const TimeValue &that) const { return that >= *this; }
154 /// Determine if \p this is greater than or equal to \p that.
155 /// @returns True iff *this >= that.
156 /// @brief True if this >= that.
157 int operator >= (const TimeValue &that) const {
158 if ( this->seconds_ > that.seconds_ ) {
160 } else if ( this->seconds_ == that.seconds_ ) {
161 if ( this->nanos_ >= that.nanos_ ) return 1;
166 /// Determines if two TimeValue objects represent the same moment in time.
167 /// @brief True iff *this == that.
168 /// @brief True if this == that.
169 int operator == (const TimeValue &that) const {
170 return (this->seconds_ == that.seconds_) &&
171 (this->nanos_ == that.nanos_);
174 /// Determines if two TimeValue objects represent times that are not the
176 /// @return True iff *this != that.
177 /// @brief True if this != that.
178 int operator != (const TimeValue &that) const { return !(*this == that); }
180 /// Adds two TimeValue objects together.
181 /// @returns The sum of the two operands as a new TimeValue
182 /// @brief Addition operator.
183 friend TimeValue operator + (const TimeValue &tv1, const TimeValue &tv2);
185 /// Subtracts two TimeValue objects.
186 /// @returns The difference of the two operands as a new TimeValue
187 /// @brief Subtraction operator.
188 friend TimeValue operator - (const TimeValue &tv1, const TimeValue &tv2);
195 /// Returns only the seconds component of the TimeValue. The nanoseconds
196 /// portion is ignored. No rounding is performed.
197 /// @brief Retrieve the seconds component
198 SecondsType seconds( void ) const { return seconds_; }
200 /// Returns only the nanoseconds component of the TimeValue. The seconds
201 /// portion is ignored.
202 /// @brief Retrieve the nanoseconds component.
203 NanoSecondsType nanoseconds( void ) const { return nanos_; }
205 /// Returns only the fractional portion of the TimeValue rounded down to the
206 /// nearest microsecond (divide by one thousand).
207 /// @brief Retrieve the fractional part as microseconds;
208 uint32_t microseconds( void ) const {
209 return nanos_ / NANOSECONDS_PER_MICROSECOND;
212 /// Returns only the fractional portion of the TimeValue rounded down to the
213 /// nearest millisecond (divide by one million).
214 /// @brief Retrieve the fractional part as milliseconds;
215 uint32_t milliseconds( void ) const {
216 return nanos_ / NANOSECONDS_PER_MILLISECOND;
219 /// Returns the TimeValue as a number of microseconds. Note that the value
220 /// returned can overflow because the range of a uint64_t is smaller than
221 /// the range of a TimeValue. Nevertheless, this is useful on some operating
222 /// systems and is therefore provided.
223 /// @brief Convert to a number of microseconds (can overflow)
224 uint64_t usec( void ) const {
225 return seconds_ * MICROSECONDS_PER_SECOND +
226 ( nanos_ / NANOSECONDS_PER_MICROSECOND );
229 /// Returns the TimeValue as a number of milliseconds. Note that the value
230 /// returned can overflow because the range of a uint64_t is smaller than
231 /// the range of a TimeValue. Nevertheless, this is useful on some operating
232 /// systems and is therefore provided.
233 /// @brief Convert to a number of milliseconds (can overflow)
234 uint64_t msec( void ) const {
235 return seconds_ * MILLISECONDS_PER_SECOND +
236 ( nanos_ / NANOSECONDS_PER_MILLISECOND );
239 /// Converts the TimeValue into the corresponding number of "ticks" for
240 /// Posix, correcting for the difference in Posix zero time.
241 /// @brief Convert to unix time (100 nanoseconds since 12:00:00a Jan 1,1970)
242 uint64_t ToPosixTime( void ) const {
243 uint64_t result = seconds_ - PosixZeroTime.seconds_;
244 result += nanos_ / NANOSECONDS_PER_POSIX_TICK;
248 /// Converts the TiemValue into the correspodning number of "ticks" for
249 /// Win32 platforms, correcting for the difference in Win32 zero time.
250 /// @brief Convert to windows time (seconds since 12:00:00a Jan 1, 1601)
251 uint64_t ToWin32Time( void ) const {
252 uint64_t result = seconds_ - Win32ZeroTime.seconds_;
253 result += nanos_ / NANOSECONDS_PER_WIN32_TICK;
257 /// Provides the seconds and nanoseconds as results in its arguments after
258 /// correction for the Posix zero time.
259 /// @brief Convert to timespec time (ala POSIX.1b)
260 void GetTimespecTime( uint64_t& seconds, uint32_t& nanos ) const {
261 seconds = seconds_ - PosixZeroTime.seconds_;
269 /// The seconds component of the TimeValue is set to \p sec without
270 /// modifying the nanoseconds part. This is useful for whole second arithmetic.
271 /// @brief Set the seconds component.
272 void seconds (SecondsType sec ) {
273 this->seconds_ = sec;
277 /// The nanoseconds component of the TimeValue is set to \p nanos without
278 /// modifying the seconds part. This is useful for basic computations
279 /// involving just the nanoseconds portion. Note that the TimeValue will be
280 /// normalized after this call so that the fractional (nanoseconds) portion
281 /// will have the smallest equivalent value.
282 /// @brief Set the nanoseconds component using a number of nanoseconds.
283 void nanoseconds ( NanoSecondsType nanos ) {
284 this->nanos_ = nanos;
288 /// The seconds component remains unchanged.
289 /// @brief Set the nanoseconds component using a number of microseconds.
290 void microseconds ( int32_t micros ) {
291 this->nanos_ = micros * NANOSECONDS_PER_MICROSECOND;
295 /// The seconds component remains unchanged.
296 /// @brief Set the nanoseconds component using a number of milliseconds.
297 void milliseconds ( int32_t millis ) {
298 this->nanos_ = millis * NANOSECONDS_PER_MILLISECOND;
302 /// @brief Converts from microsecond format to TimeValue format
303 void usec( int64_t microseconds ) {
304 this->seconds_ = microseconds / MICROSECONDS_PER_SECOND;
305 this->nanos_ = (microseconds % MICROSECONDS_PER_SECOND) *
306 NANOSECONDS_PER_MICROSECOND;
310 /// @brief Converts from millisecond format to TimeValue format
311 void msec( int64_t milliseconds ) {
312 this->seconds_ = milliseconds / MILLISECONDS_PER_SECOND;
313 this->nanos_ = (milliseconds % MILLISECONDS_PER_SECOND) *
314 NANOSECONDS_PER_MILLISECOND;
319 /// @name Implementation
322 /// This causes the values to be represented so that the fractional
323 /// part is minimized, possibly incrementing the seconds part.
324 /// @brief Normalize to canonical form.
325 void normalize (void);
331 /// Store the values as a <timeval>.
332 SecondsType seconds_;///< Stores the seconds part of the TimeVal
333 NanoSecondsType nanos_; ///< Stores the nanoseconds part of the TimeVal
339 inline TimeValue operator + (const TimeValue &tv1, const TimeValue &tv2) {
340 TimeValue sum (tv1.seconds_ + tv2.seconds_, tv1.nanos_ + tv2.nanos_);
345 inline TimeValue operator - (const TimeValue &tv1, const TimeValue &tv2) {
346 TimeValue difference (tv1.seconds_ - tv2.seconds_, tv1.nanos_ - tv2.nanos_ );
347 difference.normalize ();
354 // vim: sw=2 smartindent smarttab tw=80 autoindent expandtab