Remove all observers associated with this object.
Return the number of observers associated with this object.
Notify observers of a change in state if this object’s changed state is true.
This will invoke the method named in add_observer, passing *arg. The changed state is then set to false.
*arg
Any arguments to pass to the observers.
Returns a clock time as determined by POSIX function clock_gettime():
Process.clock_gettime(:CLOCK_PROCESS_CPUTIME_ID) # => 198.650379677
Argument clock_id should be a symbol or a constant that specifies the clock whose time is to be returned; see below.
Optional argument unit should be a symbol that specifies the unit to be used in the returned clock time; see below.
Argument clock_id
Argument clock_id specifies the clock whose time is to be returned; it may be a constant such as Process::CLOCK_REALTIME, or a symbol shorthand such as :CLOCK_REALTIME.
The supported clocks depend on the underlying operating system; this method supports the following clocks on the indicated platforms (raises Errno::EINVAL if called with an unsupported clock):
:CLOCK_BOOTTIME: Linux 2.6.39.
:CLOCK_BOOTTIME_ALARM: Linux 3.0.
:CLOCK_MONOTONIC: SUSv3 to 4, Linux 2.5.63, FreeBSD 3.0, NetBSD 2.0, OpenBSD 3.4, macOS 10.12, Windows-2000.
:CLOCK_MONOTONIC_COARSE: Linux 2.6.32.
:CLOCK_MONOTONIC_FAST: FreeBSD 8.1.
:CLOCK_MONOTONIC_PRECISE: FreeBSD 8.1.
:CLOCK_MONOTONIC_RAW: Linux 2.6.28, macOS 10.12.
:CLOCK_MONOTONIC_RAW_APPROX: macOS 10.12.
:CLOCK_PROCESS_CPUTIME_ID: SUSv3 to 4, Linux 2.5.63, FreeBSD 9.3, OpenBSD 5.4, macOS 10.12.
:CLOCK_PROF: FreeBSD 3.0, OpenBSD 2.1.
:CLOCK_REALTIME: SUSv2 to 4, Linux 2.5.63, FreeBSD 3.0, NetBSD 2.0, OpenBSD 2.1, macOS 10.12, Windows-8/Server-2012. Time.now is recommended over +:CLOCK_REALTIME:.
:CLOCK_REALTIME_ALARM: Linux 3.0.
:CLOCK_REALTIME_COARSE: Linux 2.6.32.
:CLOCK_REALTIME_FAST: FreeBSD 8.1.
:CLOCK_REALTIME_PRECISE: FreeBSD 8.1.
:CLOCK_SECOND: FreeBSD 8.1.
:CLOCK_TAI: Linux 3.10.
:CLOCK_THREAD_CPUTIME_ID: SUSv3 to 4, Linux 2.5.63, FreeBSD 7.1, OpenBSD 5.4, macOS 10.12.
:CLOCK_UPTIME: FreeBSD 7.0, OpenBSD 5.5.
:CLOCK_UPTIME_FAST: FreeBSD 8.1.
:CLOCK_UPTIME_PRECISE: FreeBSD 8.1.
:CLOCK_UPTIME_RAW: macOS 10.12.
:CLOCK_UPTIME_RAW_APPROX: macOS 10.12.
:CLOCK_VIRTUAL: FreeBSD 3.0, OpenBSD 2.1.
Note that SUS stands for Single Unix Specification. SUS contains POSIX and clock_gettime is defined in the POSIX part. SUS defines :CLOCK_REALTIME as mandatory but :CLOCK_MONOTONIC, :CLOCK_PROCESS_CPUTIME_ID, and :CLOCK_THREAD_CPUTIME_ID are optional.
Certain emulations are used when the given clock_id is not supported directly:
Emulations for :CLOCK_REALTIME:
:GETTIMEOFDAY_BASED_CLOCK_REALTIME: Use gettimeofday() defined by SUS (deprecated in SUSv4). The resolution is 1 microsecond.
:TIME_BASED_CLOCK_REALTIME: Use time() defined by ISO C. The resolution is 1 second.
Emulations for :CLOCK_MONOTONIC:
:MACH_ABSOLUTE_TIME_BASED_CLOCK_MONOTONIC: Use mach_absolute_time(), available on Darwin. The resolution is CPU dependent.
:TIMES_BASED_CLOCK_MONOTONIC: Use the result value of times() defined by POSIX, thus:
Upon successful completion, times() shall return the elapsed real time, in clock ticks, since an arbitrary point in the past (for example, system start-up time).
For example, GNU/Linux returns a value based on jiffies and it is monotonic. However, 4.4BSD uses gettimeofday() and it is not monotonic. (FreeBSD uses :CLOCK_MONOTONIC instead, though.)
The resolution is the clock tick. “getconf CLK_TCK” command shows the clock ticks per second. (The clock ticks-per-second is defined by HZ macro in older systems.) If it is 100 and clock_t is 32 bits integer type, the resolution is 10 millisecond and cannot represent over 497 days.
Emulations for :CLOCK_PROCESS_CPUTIME_ID:
:GETRUSAGE_BASED_CLOCK_PROCESS_CPUTIME_ID: Use getrusage() defined by SUS. getrusage() is used with RUSAGE_SELF to obtain the time only for the calling process (excluding the time for child processes). The result is addition of user time (ru_utime) and system time (ru_stime). The resolution is 1 microsecond.
:TIMES_BASED_CLOCK_PROCESS_CPUTIME_ID: Use times() defined by POSIX. The result is addition of user time (tms_utime) and system time (tms_stime). tms_cutime and tms_cstime are ignored to exclude the time for child processes. The resolution is the clock tick. “getconf CLK_TCK” command shows the clock ticks per second. (The clock ticks per second is defined by HZ macro in older systems.) If it is 100, the resolution is 10 millisecond.
:CLOCK_BASED_CLOCK_PROCESS_CPUTIME_ID: Use clock() defined by ISO C. The resolution is 1/CLOCKS_PER_SEC. CLOCKS_PER_SEC is the C-level macro defined by time.h. SUS defines CLOCKS_PER_SEC as 1000000; other systems may define it differently. If CLOCKS_PER_SEC is 1000000 (as in SUS), the resolution is 1 microsecond. If CLOCKS_PER_SEC is 1000000 and clock_t is a 32-bit integer type, it cannot represent over 72 minutes.
Argument unit
Optional argument unit (default :float_second) specifies the unit for the returned value.
:float_microsecond: Number of microseconds as a float.
:float_millisecond: Number of milliseconds as a float.
:float_second: Number of seconds as a float.
:microsecond: Number of microseconds as an integer.
:millisecond: Number of milliseconds as an integer.
:nanosecond: Number of nanoseconds as an integer.
::second: Number of seconds as an integer.
Examples:
Process.clock_gettime(:CLOCK_PROCESS_CPUTIME_ID, :float_microsecond) # => 203605054.825 Process.clock_gettime(:CLOCK_PROCESS_CPUTIME_ID, :float_millisecond) # => 203643.696848 Process.clock_gettime(:CLOCK_PROCESS_CPUTIME_ID, :float_second) # => 203.762181929 Process.clock_gettime(:CLOCK_PROCESS_CPUTIME_ID, :microsecond) # => 204123212 Process.clock_gettime(:CLOCK_PROCESS_CPUTIME_ID, :millisecond) # => 204298 Process.clock_gettime(:CLOCK_PROCESS_CPUTIME_ID, :nanosecond) # => 204602286036 Process.clock_gettime(:CLOCK_PROCESS_CPUTIME_ID, :second) # => 204
The underlying function, clock_gettime(), returns a number of nanoseconds. Float object (IEEE 754 double) is not enough to represent the return value for :CLOCK_REALTIME. If the exact nanoseconds value is required, use :nanosecond as the unit.
The origin (time zero) of the returned value is system-dependent, and may be, for example, system start up time, process start up time, the Epoch, etc.
The origin in :CLOCK_REALTIME is defined as the Epoch: 1970-01-01 00:00:00 UTC; some systems count leap seconds and others don’t, so the result may vary across systems.
Returns a clock resolution as determined by POSIX function clock_getres():
Process.clock_getres(:CLOCK_REALTIME) # => 1.0e-09
See Process.clock_gettime for the values of clock_id and unit.
Examples:
Process.clock_getres(:CLOCK_PROCESS_CPUTIME_ID, :float_microsecond) # => 0.001 Process.clock_getres(:CLOCK_PROCESS_CPUTIME_ID, :float_millisecond) # => 1.0e-06 Process.clock_getres(:CLOCK_PROCESS_CPUTIME_ID, :float_second) # => 1.0e-09 Process.clock_getres(:CLOCK_PROCESS_CPUTIME_ID, :microsecond) # => 0 Process.clock_getres(:CLOCK_PROCESS_CPUTIME_ID, :millisecond) # => 0 Process.clock_getres(:CLOCK_PROCESS_CPUTIME_ID, :nanosecond) # => 1 Process.clock_getres(:CLOCK_PROCESS_CPUTIME_ID, :second) # => 0
In addition to the values for unit supported in Process.clock_gettime, this method supports :hertz, the integer number of clock ticks per second (which is the reciprocal of :float_second):
Process.clock_getres(:TIMES_BASED_CLOCK_PROCESS_CPUTIME_ID, :hertz) # => 100.0 Process.clock_getres(:TIMES_BASED_CLOCK_PROCESS_CPUTIME_ID, :float_second) # => 0.01
Accuracy: Note that the returned resolution may be inaccurate on some platforms due to underlying bugs. Inaccurate resolutions have been reported for various clocks including :CLOCK_MONOTONIC and :CLOCK_MONOTONIC_RAW on Linux, macOS, BSD or AIX platforms, when using ARM processors, or when using virtualization.
Returns a non-lazy Enumerator converted from the lazy enumerator.
Creates a new Socket::Option object for SOL_SOCKET/SO_LINGER.
onoff should be an integer or a boolean.
secs should be the number of seconds.
p Socket::Option.linger(true, 10) #=> #<Socket::Option: UNSPEC SOCKET LINGER on 10sec>
Returns the linger data in sockopt as a pair of boolean and integer.
sockopt = Socket::Option.linger(true, 10) p sockopt.linger => [true, 10]
Creates a singleton RingFinger and looks for a RingServer. Returns the created RingFinger.
Merges the requirements of other into this dependency
Destructive form of merge.
require 'uri' uri = URI.parse("http://my.example.com") uri.merge!("/main.rbx?page=1") uri.to_s # => "http://my.example.com/main.rbx?page=1"
Merges two URIs.
require 'uri' uri = URI.parse("http://my.example.com") uri.merge("/main.rbx?page=1") # => "http://my.example.com/main.rbx?page=1"
Create a new AlternationPatternNode node
Create a new BackReferenceReadNode node
Create a new BlockLocalVariableNode node
Create a new BlockParameterNode node
Create a new BlockParametersNode node
Create a new CallOperatorWriteNode node
Create a new GlobalVariableOperatorWriteNode node
Create a new GlobalVariableReadNode node
Create a new GlobalVariableTargetNode node
Create a new IntegerNode node
Create a new LocalVariableOperatorWriteNode node