Class: Thread

When set to true, all threads will abort if an exception is raised. Returns the new state.

Thread.abort_on_exception = true
t1 = Thread.new do
  puts  "In new thread"
  raise "Exception from thread"
end
sleep(1)
puts "not reached"

produces:

In new thread
prog.rb:4: Exception from thread (RuntimeError)
 from prog.rb:2:in `initialize'
 from prog.rb:2:in `new'
 from prog.rb:2

Returns the currently executing thread.

Thread.current   #=> #<Thread:0x401bdf4c run>

Returns the thread debug level. Available only if compiled with THREAD_DEBUG=-1.

Sets the thread debug level. Available only if compiled with THREAD_DEBUG=-1.

Terminates the currently running thread and schedules another thread to be run. If this thread is already marked to be killed, exit returns the Thread. If this is the main thread, or the last thread, exit the process.

Basically the same as Thread::new. However, if class Thread is subclassed, then calling start in that subclass will not invoke the subclass's initialize method.

Causes the given thread to exit (see Thread::exit).

count = 0
a = Thread.new { loop { count += 1 } }
sleep(0.1)       #=> 0
Thread.kill(a)   #=> #<Thread:0x401b3d30 dead>
count            #=> 93947
a.alive?         #=> false

Returns an array of Thread objects for all threads that are either runnable or stopped.

Thread.new { sleep(200) }
Thread.new { 1000000.times {|i| i*i } }
Thread.new { Thread.stop }
Thread.list.each {|t| p t}

produces:

#<Thread:0x401b3e84 sleep>
#<Thread:0x401b3f38 run>
#<Thread:0x401b3fb0 sleep>
#<Thread:0x401bdf4c run>

Returns the main thread.

:nodoc:

Give the thread scheduler a hint to pass execution to another thread. A running thread may or may not switch, it depends on OS and processor.

Basically the same as Thread::new. However, if class Thread is subclassed, then calling start in that subclass will not invoke the subclass's initialize method.

Stops execution of the current thread, putting it into a "sleep" state, and schedules execution of another thread.

a = Thread.new { print "a"; Thread.stop; print "c" }
sleep 0.1 while a.status!='sleep'
print "b"
a.run
a.join

produces:

abc

Attribute Assignment---Sets or creates the value of a thread-local variable, using either a symbol or a string. See also Thread#[].

Returns the status of the thread-local "abort on exception" condition for thr. The default is false. See also Thread::abort_on_exception=.

When set to true, causes all threads (including the main program) to abort if an exception is raised in thr. The process will effectively exit(0).

Adds proc as a handler for tracing. See Thread#set_trace_func and set_trace_func.

Returns true if thr is running or sleeping.

thr = Thread.new { }
thr.join                #=> #<Thread:0x401b3fb0 dead>
Thread.current.alive?   #=> true
thr.alive?              #=> false

Returns the current back trace of the thr.

Terminates thr and schedules another thread to be run. If this thread is already marked to be killed, exit returns the Thread. If this is the main thread, or the last thread, exits the process.

Returns the ThreadGroup which contains thr, or nil if the thread is not a member of any group.

Thread.main.group   #=> #<ThreadGroup:0x4029d914>

Dump the name, id, and status of thr to a string.

The calling thread will suspend execution and run thr. Does not return until thr exits or until limit seconds have passed. If the time limit expires, nil will be returned, otherwise thr is returned.

Any threads not joined will be killed when the main program exits. If thr had previously raised an exception and the abort_on_exception and $DEBUG flags are not set (so the exception has not yet been processed) it will be processed at this time.

a = Thread.new { print "a"; sleep(10); print "b"; print "c" }
x = Thread.new { print "x"; Thread.pass; print "y"; print "z" }
x.join # Let x thread finish, a will be killed on exit.

produces:

axyz

The following example illustrates the limit parameter.

y = Thread.new { 4.times { sleep 0.1; puts 'tick... ' }}
puts "Waiting" until y.join(0.15)

produces:

tick...
Waiting
tick...
Waitingtick...

tick...

Returns true if the given string (or symbol) exists as a thread-local variable.

me = Thread.current
me[:oliver] = "a"
me.key?(:oliver)    #=> true
me.key?(:stanley)   #=> false

Returns an an array of the names of the thread-local variables (as Symbols).

thr = Thread.new do
  Thread.current[:cat] = 'meow'
  Thread.current["dog"] = 'woof'
end
thr.join   #=> #<Thread:0x401b3f10 dead>
thr.keys   #=> [:dog, :cat]

Terminates thr and schedules another thread to be run. If this thread is already marked to be killed, exit returns the Thread. If this is the main thread, or the last thread, exits the process.

Returns the priority of thr. Default is inherited from the current thread which creating the new thread, or zero for the initial main thread; higher-priority thread will run more frequently than lower-priority threads (but lower-priority threads can also run).

This is just hint for Ruby thread scheduler. It may be ignored on some platform.

Thread.current.priority   #=> 0

Sets the priority of thr to integer. Higher-priority threads will run more frequently than lower-priority threads (but lower-priority threads can also run).

This is just hint for Ruby thread scheduler. It may be ignored on some platform.

count1 = count2 = 0
a = Thread.new do
      loop { count1 += 1 }
    end
a.priority = -1

b = Thread.new do
      loop { count2 += 1 }
    end
b.priority = -2
sleep 1   #=> 1
count1    #=> 622504
count2    #=> 5832

Raises an exception (see Kernel::raise) from thr. The caller does not have to be thr.

Thread.abort_on_exception = true
a = Thread.new { sleep(200) }
a.raise("Gotcha")

produces:

prog.rb:3: Gotcha (RuntimeError)
 from prog.rb:2:in `initialize'
 from prog.rb:2:in `new'
 from prog.rb:2

Wakes up thr, making it eligible for scheduling.

a = Thread.new { puts "a"; Thread.stop; puts "c" }
sleep 0.1 while a.status!='sleep'
puts "Got here"
a.run
a.join

produces:

a
Got here
c

Returns the safe level in effect for thr. Setting thread-local safe levels can help when implementing sandboxes which run insecure code.

thr = Thread.new { $SAFE = 3; sleep }
Thread.current.safe_level   #=> 0
thr.safe_level              #=> 3

Establishes proc on thr as the handler for tracing, or disables tracing if the parameter is nil. See set_trace_func.

Returns the status of thr: "sleep" if thr is sleeping or waiting on I/O, "run" if thr is executing, "aborting" if thr is aborting, false if thr terminated normally, and nil if thr terminated with an exception.

a = Thread.new { raise("die now") }
b = Thread.new { Thread.stop }
c = Thread.new { Thread.exit }
d = Thread.new { sleep }
d.kill                  #=> #<Thread:0x401b3678 aborting>
a.status                #=> nil
b.status                #=> "sleep"
c.status                #=> false
d.status                #=> "aborting"
Thread.current.status   #=> "run"

Returns true if thr is dead or sleeping.

a = Thread.new { Thread.stop }
b = Thread.current
a.stop?   #=> true
b.stop?   #=> false

Terminates thr and schedules another thread to be run. If this thread is already marked to be killed, exit returns the Thread. If this is the main thread, or the last thread, exits the process.

Waits for thr to complete (via Thread#join) and returns its value.

a = Thread.new { 2 + 2 }
a.value   #=> 4

Marks thr as eligible for scheduling (it may still remain blocked on I/O, however). Does not invoke the scheduler (see Thread#run).

c = Thread.new { Thread.stop; puts "hey!" }
sleep 0.1 while c.status!='sleep'
c.wakeup
c.join

produces:

hey!