/usr/lib/ruby/vendor_ruby/thread_safe/mri_cache_backend.rb is in ruby-thread-safe 0.3.6-1.
This file is owned by root:root, with mode 0o644.
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 | module ThreadSafe
class MriCacheBackend < NonConcurrentCacheBackend
# We can get away with a single global write lock (instead of a per-instance
# one) because of the GVL/green threads.
#
# NOTE: a neat idea of writing a c-ext to manually perform atomic
# put_if_absent, while relying on Ruby not releasing a GVL while calling a
# c-ext will not work because of the potentially Ruby implemented `#hash`
# and `#eql?` key methods.
WRITE_LOCK = Mutex.new
def []=(key, value)
WRITE_LOCK.synchronize { super }
end
def compute_if_absent(key)
if stored_value = _get(key) # fast non-blocking path for the most likely case
stored_value
else
WRITE_LOCK.synchronize { super }
end
end
def compute_if_present(key)
WRITE_LOCK.synchronize { super }
end
def compute(key)
WRITE_LOCK.synchronize { super }
end
def merge_pair(key, value)
WRITE_LOCK.synchronize { super }
end
def replace_pair(key, old_value, new_value)
WRITE_LOCK.synchronize { super }
end
def replace_if_exists(key, new_value)
WRITE_LOCK.synchronize { super }
end
def get_and_set(key, value)
WRITE_LOCK.synchronize { super }
end
def delete(key)
WRITE_LOCK.synchronize { super }
end
def delete_pair(key, value)
WRITE_LOCK.synchronize { super }
end
def clear
WRITE_LOCK.synchronize { super }
end
end
end
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