MutexLock

public final class MutexLock

Locks a mutex resource. The output is the lock. So long as the lock tensor

is alive, any other request to use `MutexLock` with this mutex will wait.

This is particularly useful for creating a critical section when used in conjunction with `MutexLockIdentity`: 

mutex = mutex_v2(
   shared_name=handle_name, container=container, name=name)
 
 def execute_in_critical_section(fn, *args, **kwargs):
   lock = gen_resource_variable_ops.mutex_lock(mutex)
 
   with ops.control_dependencies([lock]):
     r = fn(*args, **kwargs)
 
   with ops.control_dependencies(nest.flatten(r)):
     with ops.colocate_with(mutex):
       ensure_lock_exists = mutex_lock_identity(lock)
 
     # Make sure that if any element of r is accessed, all of
     # them are executed together.
     r = nest.map_structure(tf.identity, r)
 
   with ops.control_dependencies([ensure_lock_exists]):
     return nest.map_structure(tf.identity, r)
While `fn` is running in the critical section, no other functions which wish to use this critical section may run.

Often the use case is that two executions of the same graph, in parallel, wish to run `fn`; and we wish to ensure that only one of them executes at a time. This is especially important if `fn` modifies one or more variables at a time.

It is also useful if two separate functions must share a resource, but we wish to ensure the usage is exclusive.

Public Methods

Output<Object>
asOutput()
Returns the symbolic handle of a tensor.
static MutexLock
create(Scope scope, Operand<?> mutex)
Factory method to create a class wrapping a new MutexLock operation.
Output<?>
mutexLock()
A tensor that keeps a shared pointer to a lock on the mutex; when the Tensor is destroyed, the use count on the shared pointer is decreased by 1.

Inherited Methods

Public Methods

public Output<Object> asOutput ()

Returns the symbolic handle of a tensor.

Inputs to TensorFlow operations are outputs of another TensorFlow operation. This method is used to obtain a symbolic handle that represents the computation of the input.

public static MutexLock create (Scope scope, Operand<?> mutex)

Factory method to create a class wrapping a new MutexLock operation.

Parameters
scope current scope
mutex The mutex resource to lock.
Returns
  • a new instance of MutexLock

public Output<?> mutexLock ()

A tensor that keeps a shared pointer to a lock on the mutex; when the Tensor is destroyed, the use count on the shared pointer is decreased by 1. When it reaches 0, the lock is released.