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# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
require 'atomic/concurrent_update_error'
# Define update methods that delegate to @ref field
class Atomic
# Pass the current value to the given block, replacing it
# with the block's result. May retry if the value changes
# during the block's execution.
def update
true until @ref.compare_and_set(old_value = @ref.get, new_value = yield(old_value))
new_value
end
def try_update
old_value = @ref.get
new_value = yield old_value
unless @ref.compare_and_set(old_value, new_value)
if $VERBOSE
raise ConcurrentUpdateError, "Update failed"
else
raise ConcurrentUpdateError, "Update failed", ConcurrentUpdateError::CONC_UP_ERR_BACKTRACE
end
end
new_value
end
end
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