Class: Garcon::MutexCountDownLatch
- Defined in:
- lib/garcon/task/count_down_latch.rb
Overview
A synchronization object that allows one thread to wait on multiple other threads. The thread that will wait creates a ‘CountDownLatch` and sets the initial value (normally equal to the number of other threads). The initiating thread passes the latch to the other threads then waits for the other threads by calling the `#wait` method. Each of the other threads calls `#count_down` when done with its work. When the latch counter reaches zero the waiting thread is unblocked and continues with its work. A `CountDownLatch` can be used only once. Its value cannot be reset.
Direct Known Subclasses
Instance Method Summary collapse
-
#count ⇒ Fixnum
The current value of the counter.
-
#count_down ⇒ Object
Signal the latch to decrement the counter.
-
#initialize(count = 1) ⇒ MutexCountDownLatch
constructor
Create a new ‘CountDownLatch` with the initial `count`.
-
#wait(timeout = nil) ⇒ Boolean
Block on the latch until the counter reaches zero or until ‘timeout` is reached.
Constructor Details
#initialize(count = 1) ⇒ MutexCountDownLatch
Create a new ‘CountDownLatch` with the initial `count`.
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# File 'lib/garcon/task/count_down_latch.rb', line 43 def initialize(count = 1) unless count.is_a?(Fixnum) && count >= 0 raise ArgumentError, 'count must be greater than or equal zero' end @mutex = Mutex.new @condition = Condition.new @count = count end |
Instance Method Details
#count ⇒ Fixnum
The current value of the counter.
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# File 'lib/garcon/task/count_down_latch.rb', line 86 def count @mutex.synchronize { @count } end |
#count_down ⇒ Object
Signal the latch to decrement the counter. Will signal all blocked threads when the ‘count` reaches zero.
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# File 'lib/garcon/task/count_down_latch.rb', line 74 def count_down @mutex.synchronize do @count -= 1 if @count > 0 @condition.broadcast if @count == 0 end end |
#wait(timeout = nil) ⇒ Boolean
Block on the latch until the counter reaches zero or until ‘timeout` is reached.
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# File 'lib/garcon/task/count_down_latch.rb', line 61 def wait(timeout = nil) @mutex.synchronize do remaining = Condition::Result.new(timeout) while @count > 0 && remaining.can_wait? remaining = @condition.wait(@mutex, remaining.remaining_time) end @count == 0 end end |