def __init__(self, value=None):
"""
Creates a new Atomic with the given initial value.
:param value: initial value
"""
self.ref = Reference(value)
def __init__(self, value=None):
"""
Creates a new Atomic with the given initial value.
:param value: initial value
"""
self.ref = Reference(value)
class Atomic(object):
"""
An atomic class that guarantees atomic updates to its contained value.
"""
def __init__(self, value=None):
"""
Creates a new Atomic with the given initial value.
:param value: initial value
"""
self.ref = Reference(value)
def get_value(self):
return self.ref.get()
def set_value(self, value):
return self.ref.set(value)
value = property(get_value, set_value, doc="""Get or set current value""")
def get_and_set(self, new_value):
"""Atomically sets to the given value and returns the old value
:param new_value: the new value
"""
return self.ref.get_and_set(new_value)
def swap(self, new_value):
return self.get_and_set(new_value)
def compare_and_set(self, expect_value, new_value):
"""
Atomically sets the value to the given value if the current value is
equal to the expected value.
:param expect_value: the expected value
:param new_value: the new value
"""
return self.ref.compare_and_set(expect_value, new_value)
def compare_and_swap(self, expect_value, new_value):
return self.compare_and_set(expect_value, new_value)
def update(self, update_func):
"""
Update value based on the given function.
It may run the block repeatedly if there are other concurrent
updates in progress.
:param update_func: a function that given the current value
return the new value
:type update_func: func
"""
update = False
while not update:
old_value = self.ref.get()
new_value = update_func(old_value)
update = self.ref.compare_and_set(old_value, new_value)
return new_value
def try_update(self, update_func):
"""
Update value based on the given function.
If the value changes before the update can happen,
it will raise a :class:`ConcurrentUpdateException`.
:param update_func: a function that given the current
value return the new value
:type update_func: func
:raises: ConcurrentUpdateException
"""
old_value = self.ref.get()
new_value = update_func(old_value)
while not self.ref.compare_and_set(old_value, new_value):
raise ConcurrentUpdateException("Updating reference failed")
return new_value
class Atomic(object):
"""
An atomic class that guarantees atomic updates to its contained value.
"""
def __init__(self, value=None):
"""
Creates a new Atomic with the given initial value.
:param value: initial value
"""
self.ref = Reference(value)
def get_value(self):
return self.ref.get()
def set_value(self, value):
return self.ref.set(value)
value = property(get_value, set_value, doc="""Get or set current value""")
def get_and_set(self, new_value):
"""Atomically sets to the given value and returns the old value
:param new_value: the new value
"""
return self.ref.get_and_set(new_value)
def swap(self, new_value):
return self.get_and_set(new_value)
def compare_and_set(self, expect_value, new_value):
"""
Atomically sets the value to the given value if the current value is
equal to the expected value.
:param expect_value: the expected value
:param new_value: the new value
"""
return self.ref.compare_and_set(expect_value, new_value)
def compare_and_swap(self, expect_value, new_value):
return self.compare_and_set(expect_value, new_value)
def update(self, update_func):
"""
Update value based on the given function.
It may run the block repeatedly if there are other concurrent
updates in progress.
:param update_func: a function that given the current value
return the new value
:type update_func: func
"""
update = False
while not update:
old_value = self.ref.get()
new_value = update_func(old_value)
update = self.ref.compare_and_set(old_value, new_value)
return new_value
def try_update(self, update_func):
"""
Update value based on the given function.
If the value changes before the update can happen,
it will raise a :class:`ConcurrentUpdateException`.
:param update_func: a function that given the current
value return the new value
:type update_func: func
:raises: ConcurrentUpdateException
"""
old_value = self.ref.get()
new_value = update_func(old_value)
while not self.ref.compare_and_set(old_value, new_value):
raise ConcurrentUpdateException("Updating reference failed")
return new_value