Module locking

source code

Module implementing the Ganeti locking code.

Classes

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_SingleNotifyPipeConditionWaiter
Helper class for SingleNotifyPipeCondition

_BaseCondition
Base class containing common code for conditions.

SingleNotifyPipeCondition
Condition which can only be notified once.

PipeCondition
Group-only non-polling condition with counters.

_PipeConditionWithMode

SharedLock
Implements a shared lock.

_AcquireTimeout
Internal exception to abort an acquire on a timeout.

Functions

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ssynchronized(mylock, shared=0)
Shared Synchronization decorator.

source code

_TimeoutZero()
Returns the number zero.

source code

Variables

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_EXCLUSIVE_TEXT = "exclusive"

_SHARED_TEXT = "shared"

_DELETED_TEXT = "deleted"

_DEFAULT_PRIORITY = 0

_LOCK_ACQUIRE_MIN_TIMEOUT = 1.0/ 1000
Minimum timeout required to consider scheduling a pending acquisition (seconds)

ALL_SET = None
hash(x)

LOCKSET_NAME = "[lockset]"

LEVELS = [LEVEL_CLUSTER, LEVEL_INSTANCE, LEVEL_NODE_ALLOC, LEV...

LEVELS_MOD = compat.UniqueFrozenset([LEVEL_NODE_RES, LEVEL_NOD...

LEVEL_NAMES = {LEVEL_CLUSTER: "cluster", LEVEL_INSTANCE: "inst...
Lock level names (make sure to use singular form)

BGL = "BGL"

NAL = "NAL"
Node allocation lock

Imports: os, select, threading, errno, logging, heapq, time, errors, utils, compat, query

Function Details

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ssynchronized(mylock, shared=0)

source code

Shared Synchronization decorator.

Calls the function holding the given lock, either in exclusive or shared mode. It requires the passed lock to be a SharedLock (or support its semantics).

Parameters:

mylock (lockable object or string) - lock to acquire or class member name of the lock to acquire

Variables Details

[hide private]

LEVELS

Value:

[LEVEL_CLUSTER, LEVEL_INSTANCE, LEVEL_NODE_ALLOC, LEVEL_NODEGROUP, LEV
EL_NODE, LEVEL_NODE_RES, LEVEL_NETWORK,]

LEVELS_MOD

Value:

compat.UniqueFrozenset([LEVEL_NODE_RES, LEVEL_NODE, LEVEL_NODEGROUP, L
EVEL_INSTANCE, LEVEL_NETWORK,])

LEVEL_NAMES

Lock level names (make sure to use singular form)

Value:

{LEVEL_CLUSTER: "cluster", LEVEL_INSTANCE: "instance", LEVEL_NODE_ALLO
C: "node-alloc", LEVEL_NODEGROUP: "nodegroup", LEVEL_NODE: "node", LEV
EL_NODE_RES: "node-res", LEVEL_NETWORK: "network",}