trait FiberRef[A] extends Serializable
A FiberRef
is ZIO's equivalent of Java's ThreadLocal
. The value of a
FiberRef
is automatically propagated to child fibers when they are forked
and merged back in to the value of the parent fiber after they are joined.
for { fiberRef <- FiberRef.make("Hello world!") child <- fiberRef.set("Hi!").fork _ <- child.join result <- fiberRef.get } yield result
Here result
will be equal to "Hi!" since changes made by a child fiber are
merged back in to the value of the parent fiber on join.
By default the value of the child fiber will replace the value of the parent fiber on join but you can specify your own logic for how values should be merged.
for { fiberRef <- FiberRef.make(0, identity[Int], math.max) child <- fiberRef.update(_ + 1).fork _ <- fiberRef.update(_ + 2) _ <- child.join value <- fiberRef.get } yield value
Here value
will be 2 as the value in the joined fiber is lower and we
specified max
as our combining function.
- Self Type
- FiberRef[A]
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- FiberRef
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Type Members
-
abstract
type
Patch
The type of the patch that describes updates to the value of the
FiberRef
.The type of the patch that describes updates to the value of the
FiberRef
. In the simple case this will just be a function that sets the value of theFiberRef
. In more complex cases this will describe an update to a piece of a whole value, allowing updates to the value by different fibers to be combined in a compositional way when those fibers are joined. -
type
Value = A
The type of the value of the
FiberRef
.
Abstract Value Members
-
abstract
def
combine(first: Patch, second: Patch): Patch
Combines two patches to produce a new patch that describes the updates of the first patch and then the updates of the second patch.
Combines two patches to produce a new patch that describes the updates of the first patch and then the updates of the second patch. The combine operation should be associative. In addition, if the combine operation is commutative then joining multiple fibers concurrently will result in deterministic
FiberRef
values. -
abstract
def
diff(oldValue: Value, newValue: Value): Patch
Constructs a patch describing the updates to a value from an old value and a new value.
-
abstract
def
fork: Patch
The initial patch that is applied to the value of the
FiberRef
when a new fiber is forked. -
abstract
def
initial: Value
The initial value of the
FiberRef
. - abstract def join(oldValue: Value, newValue: Value): Value
-
abstract
def
patch(patch: Patch)(oldValue: Value): Value
Applies a patch to an old value to produce a new value that is equal to the old value with the updates described by the patch.
Concrete Value Members
-
final
def
!=(arg0: Any): Boolean
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-
final
def
##(): Int
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-
final
def
==(arg0: Any): Boolean
- Definition Classes
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-
final
def
asInstanceOf[T0]: T0
- Definition Classes
- Any
-
def
asThreadLocal(implicit trace: Trace, unsafe: Unsafe): UIO[ThreadLocal[A]]
Returns a
ThreadLocal
that can be used to interact with thisFiberRef
from side effecting code.Returns a
ThreadLocal
that can be used to interact with thisFiberRef
from side effecting code.This feature is meant to be used for integration with side effecting code, that needs to access fiber specific data, like MDC contexts and the like. The returned
ThreadLocal
will be backed by thisFiberRef
on all threads that are currently managed by ZIO when this feature is enabled using Runtime.enableCurrentFiber, and behave like an ordinaryThreadLocal
on all other threads. -
def
clone(): AnyRef
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- protected[lang]
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- @throws( ... ) @native()
- def delete(implicit trace: Trace): UIO[Unit]
-
final
def
eq(arg0: AnyRef): Boolean
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-
def
equals(arg0: Any): Boolean
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-
def
finalize(): Unit
- Attributes
- protected[lang]
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- @throws( classOf[java.lang.Throwable] )
-
def
get(implicit trace: Trace): UIO[A]
Reads the value associated with the current fiber.
Reads the value associated with the current fiber. Returns initial value if no value was
set
or inherited from parent. -
final
def
getAndSet(newValue: A)(implicit trace: Trace): UIO[A]
Atomically sets the value associated with the current fiber and returns the old value.
-
final
def
getAndUpdate(f: (A) ⇒ A)(implicit trace: Trace): UIO[A]
Atomically modifies the
FiberRef
with the specified function and returns the old value. -
final
def
getAndUpdateSome(pf: PartialFunction[A, A])(implicit trace: Trace): UIO[A]
Atomically modifies the
FiberRef
with the specified partial function and returns the old value.Atomically modifies the
FiberRef
with the specified partial function and returns the old value. If the function is undefined on the current value it doesn't change it. -
final
def
getClass(): Class[_]
- Definition Classes
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- Annotations
- @native()
-
def
getWith[R, E, B](f: (A) ⇒ ZIO[R, E, B])(implicit trace: Trace): ZIO[R, E, B]
Gets the value associated with the current fiber and uses it to run the specified effect.
-
def
hashCode(): Int
- Definition Classes
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- @native()
-
final
def
isInstanceOf[T0]: Boolean
- Definition Classes
- Any
-
def
locally[R, E, B](newValue: A)(zio: ZIO[R, E, B])(implicit trace: Trace): ZIO[R, E, B]
Returns a
ZIO
that runs withvalue
bound to the current fiber.Returns a
ZIO
that runs withvalue
bound to the current fiber.Guarantees that fiber data is properly restored via
acquireRelease
. -
final
def
locallyScoped(value: A)(implicit trace: Trace): ZIO[Scope, Nothing, Unit]
Returns a scoped workflow that sets the value associated with the curent fiber to the specified value and restores it to its original value when the scope is closed.
-
final
def
locallyScopedWith(f: (A) ⇒ A)(implicit trace: Trace): ZIO[Scope, Nothing, Unit]
Returns a scoped workflow that updates the value associated with the current fiber using the specified function and restores it to its original value when the scope is closed.
-
final
def
locallyWith[R, E, B](f: (A) ⇒ A)(zio: ZIO[R, E, B])(implicit trace: Trace): ZIO[R, E, B]
Returns a
ZIO
that runs withf
applied to the current fiber.Returns a
ZIO
that runs withf
applied to the current fiber.Guarantees that fiber data is properly restored via
acquireRelease
. -
def
modify[B](f: (A) ⇒ (B, A))(implicit trace: Trace): UIO[B]
Atomically modifies the
FiberRef
with the specified function, which computes a return value for the modification.Atomically modifies the
FiberRef
with the specified function, which computes a return value for the modification. This is a more powerful version ofupdate
. -
final
def
modifySome[B](default: B)(pf: PartialFunction[A, (B, A)])(implicit trace: Trace): UIO[B]
Atomically modifies the
FiberRef
with the specified partial function, which computes a return value for the modification if the function is defined in the current value otherwise it returns a default value.Atomically modifies the
FiberRef
with the specified partial function, which computes a return value for the modification if the function is defined in the current value otherwise it returns a default value. This is a more powerful version ofupdateSome
. -
final
def
ne(arg0: AnyRef): Boolean
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final
def
notify(): Unit
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- @native()
-
final
def
notifyAll(): Unit
- Definition Classes
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- Annotations
- @native()
- final def reset(implicit trace: Trace): UIO[Unit]
-
def
set(value: A)(implicit trace: Trace): UIO[Unit]
Sets the value associated with the current fiber.
-
final
def
synchronized[T0](arg0: ⇒ T0): T0
- Definition Classes
- AnyRef
-
def
toString(): String
- Definition Classes
- AnyRef → Any
-
def
update(f: (A) ⇒ A)(implicit trace: Trace): UIO[Unit]
Atomically modifies the
FiberRef
with the specified function. -
final
def
updateAndGet(f: (A) ⇒ A)(implicit trace: Trace): UIO[A]
Atomically modifies the
FiberRef
with the specified function and returns the result. -
final
def
updateSome(pf: PartialFunction[A, A])(implicit trace: Trace): UIO[Unit]
Atomically modifies the
FiberRef
with the specified partial function.Atomically modifies the
FiberRef
with the specified partial function. If the function is undefined on the current value it doesn't change it. -
final
def
updateSomeAndGet(pf: PartialFunction[A, A])(implicit trace: Trace): UIO[A]
Atomically modifies the
FiberRef
with the specified partial function.Atomically modifies the
FiberRef
with the specified partial function. If the function is undefined on the current value it returns the old value without changing it. -
final
def
wait(): Unit
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- @throws( ... )
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final
def
wait(arg0: Long, arg1: Int): Unit
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- @throws( ... )
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final
def
wait(arg0: Long): Unit
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- @throws( ... ) @native()