Active Record Connection Pool Queue
Threadsafe, fair, LIFO queue. Meant to be used by ConnectionPool
with which it shares a Monitor.
Methods
Class Public methods
new(lock = Monitor.new)
π Source code
# File activerecord/lib/active_record/connection_adapters/abstract/connection_pool/queue.rb, line 13
def initialize(lock = Monitor.new)
@lock = lock
@cond = @lock.new_cond
@num_waiting = 0
@queue = []
end
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Instance Public methods
add(element)
Add element
to the queue. Never blocks.
π Source code
# File activerecord/lib/active_record/connection_adapters/abstract/connection_pool/queue.rb, line 36
def add(element)
synchronize do
@queue.push element
@cond.signal
end
end
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any_waiting?()
Test if any threads are currently waiting on the queue.
π Source code
# File activerecord/lib/active_record/connection_adapters/abstract/connection_pool/queue.rb, line 21
def any_waiting?
synchronize do
@num_waiting > 0
end
end
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clear()
Remove all elements from the queue.
π Source code
# File activerecord/lib/active_record/connection_adapters/abstract/connection_pool/queue.rb, line 51
def clear
synchronize do
@queue.clear
end
end
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delete(element)
If element
is in the queue, remove and return it, or nil
.
π Source code
# File activerecord/lib/active_record/connection_adapters/abstract/connection_pool/queue.rb, line 44
def delete(element)
synchronize do
@queue.delete(element)
end
end
π See on GitHub
num_waiting()
Returns the number of threads currently waiting on this queue.
π Source code
# File activerecord/lib/active_record/connection_adapters/abstract/connection_pool/queue.rb, line 29
def num_waiting
synchronize do
@num_waiting
end
end
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poll(timeout = nil)
Remove the head of the queue.
If timeout
is not given, remove and return the head of the queue if the number of available elements is strictly greater than the number of threads currently waiting (that is, donβt jump ahead in line). Otherwise, return nil
.
If timeout
is given, block if there is no element available, waiting up to timeout
seconds for an element to become available.
Raises:
-
ActiveRecord::ConnectionTimeoutError
iftimeout
is given and no element
becomes available within timeout
seconds,
π Source code
# File activerecord/lib/active_record/connection_adapters/abstract/connection_pool/queue.rb, line 71
def poll(timeout = nil)
synchronize { internal_poll(timeout) }
end
π See on GitHub