Raises PStore::Error
if the calling code is not in a PStore#transaction
.
Dup internal hash.
Clone internal hash.
Convenience method for Shell::CommandProcessor.alias_command
. Defines an instance method which will execute a command under an alternative name.
Shell.def_system_command('date') Shell.alias_command('date_in_utc', 'date', '-u') Shell.new.date_in_utc # => Sat Jan 25 16:59:57 UTC 2014
Convenience method for Shell::CommandProcessor.unalias_command
Specifies the threads that this object will wait for, but does not actually wait.
Specifies the threads that this object will wait for, but does not actually wait.
Changes asynchronous interrupt timing.
interrupt means asynchronous event and corresponding procedure by Thread#raise
, Thread#kill
, signal trap (not supported yet) and main thread termination (if main thread terminates, then all other thread will be killed).
The given hash
has pairs like ExceptionClass => :TimingSymbol
. Where the ExceptionClass is the interrupt handled by the given block. The TimingSymbol can be one of the following symbols:
:immediate
Invoke interrupts immediately.
:on_blocking
Invoke interrupts while BlockingOperation.
:never
Never invoke all interrupts.
BlockingOperation means that the operation will block the calling thread, such as read and write. On CRuby implementation, BlockingOperation is any operation executed without GVL.
Masked asynchronous interrupts are delayed until they are enabled. This method is similar to sigprocmask(3).
Asynchronous interrupts are difficult to use.
If you need to communicate between threads, please consider to use another way such as Queue
.
Or use them with deep understanding about this method.
In this example, we can guard from Thread#raise
exceptions.
Using the :never
TimingSymbol the RuntimeError
exception will always be ignored in the first block of the main thread. In the second ::handle_interrupt
block we can purposefully handle RuntimeError
exceptions.
th = Thread.new do Thread.handle_interrupt(RuntimeError => :never) { begin # You can write resource allocation code safely. Thread.handle_interrupt(RuntimeError => :immediate) { # ... } ensure # You can write resource deallocation code safely. end } end Thread.pass # ... th.raise "stop"
While we are ignoring the RuntimeError
exception, it’s safe to write our resource allocation code. Then, the ensure block is where we can safely deallocate your resources.
Timeout::Error
In the next example, we will guard from the Timeout::Error
exception. This will help prevent from leaking resources when Timeout::Error
exceptions occur during normal ensure clause. For this example we use the help of the standard library Timeout
, from lib/timeout.rb
require 'timeout' Thread.handle_interrupt(Timeout::Error => :never) { timeout(10){ # Timeout::Error doesn't occur here Thread.handle_interrupt(Timeout::Error => :on_blocking) { # possible to be killed by Timeout::Error # while blocking operation } # Timeout::Error doesn't occur here } }
In the first part of the timeout
block, we can rely on Timeout::Error
being ignored. Then in the Timeout::Error => :on_blocking
block, any operation that will block the calling thread is susceptible to a Timeout::Error
exception being raised.
It’s possible to stack multiple levels of ::handle_interrupt
blocks in order to control more than one ExceptionClass and TimingSymbol at a time.
Thread.handle_interrupt(FooError => :never) { Thread.handle_interrupt(BarError => :never) { # FooError and BarError are prohibited. } }
All exceptions inherited from the ExceptionClass parameter will be considered.
Thread.handle_interrupt(Exception => :never) { # all exceptions inherited from Exception are prohibited. }
Returns the original name of the method.
Returns the original name of the method.
Return class or module of the method being called.
class C; def foo; end; end trace = TracePoint.new(:call) do |tp| p tp.defined_class #=> C end.enable do C.new.foo end
If method is defined by a module, then that module is returned.
module M; def foo; end; end class C; include M; end; trace = TracePoint.new(:call) do |tp| p tp.defined_class #=> M end.enable do C.new.foo end
Note: defined_class
returns singleton class.
6th block parameter of Kernel#set_trace_func
passes original class of attached by singleton class.
This is a difference between Kernel#set_trace_func and TracePoint.
class C; def self.foo; end; end trace = TracePoint.new(:call) do |tp| p tp.defined_class #=> #<Class:C> end.enable do C.foo end
Returns a pretty printed object as a string.
In order to use this method you must first require the PP
module:
require 'pp'
See the PP
module for more information.
Returns an array containing all elements of enum
for which the given block
returns a true value.
If no block is given, an Enumerator
is returned instead.
(1..10).find_all { |i| i % 3 == 0 } #=> [3, 6, 9] [1,2,3,4,5].select { |num| num.even? } #=> [2, 4]
See also Enumerable#reject
.
Returns a new array with the concatenated results of running block once for every element in enum.
If no block is given, an enumerator is returned instead.
[1, 2, 3, 4].flat_map { |e| [e, -e] } #=> [1, -1, 2, -2, 3, -3, 4, -4] [[1, 2], [3, 4]].flat_map { |e| e + [100] } #=> [1, 2, 100, 3, 4, 100]
Returns the original line from source for from the given object
.
See ::trace_object_allocations
for more information and examples.
Returns the full line that is being edited. This is useful from within the complete_proc for determining the context of the completion request.
The length of Readline.line_buffer
and GNU Readline’s rl_end are same.
Raises NotImplementedError
if the using readline library does not support.
Clear the current input line.
Insert text into the line at the current cursor position.
See GNU Readline’s rl_insert_text function.
Raises NotImplementedError
if the using readline library does not support.
Combine two Adler-32 check values in to one. alder1
is the first Adler-32 value, adler2
is the second Adler-32 value. len2
is the length of the string used to generate adler2
.
Combine two CRC-32 check values in to one. crc1
is the first CRC-32 value, crc2
is the second CRC-32 value. len2
is the length of the string used to generate crc2
.
Returns the number of malloc() allocations.
Only available if ruby was built with CALC_EXACT_MALLOC_SIZE
.