trait STMImpl extends RefFactory with TxnContext with TxnExecutor
STMImpl
gathers all of the functionality required to plug an STM
implementation into scala.concurrent.stm
. See the STMImpl
companion
object for information on controlling which STMImpl
is selected at run
time.
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Abstract Value Members
-
abstract
def
apply[Z](block: (InTxn) ⇒ Z)(implicit mt: MaybeTxn): Z
Executes
block
one or more times until an atomic execution is achieved, buffering and/or locking writes so they are not visible until success.Executes
block
one or more times until an atomic execution is achieved, buffering and/or locking writes so they are not visible until success.- Z
the return type of the atomic block
- block
code to execute atomically
- returns
the value returned from
block
after a successful optimistic concurrency attempt
- Definition Classes
- TxnExecutor
-
abstract
def
compareAndSet[A, B](a: Ref[A], a0: A, a1: A, b: Ref[B], b0: B, b1: B): Boolean
Atomically compares and sets two
Ref
s, probably more efficiently then the corresponding transaction.Atomically compares and sets two
Ref
s, probably more efficiently then the corresponding transaction. Equivalent toatomic { implicit t => a() == a0 && b() == b0 && { a() = a1 ; b() = b1 ; true } }
- Definition Classes
- TxnExecutor
-
abstract
def
compareAndSetIdentity[A <: AnyRef, B <: AnyRef](a: Ref[A], a0: A, a1: A, b: Ref[B], b0: B, b1: B): Boolean
Atomically compares and sets two
Ref
s using identity comparison, probably more efficiently then the corresponding transaction.Atomically compares and sets two
Ref
s using identity comparison, probably more efficiently then the corresponding transaction. Equivalent toatomic { implicit t => val f = (a() eq a0) && (b() eq b0) if (f && (a0 ne a1)) a() = a1 if (f && (b0 ne b1)) b() = b1 f }
- Definition Classes
- TxnExecutor
-
abstract
def
dynCurrentOrNull: InTxn
Returns the current
InTxn
instance if it is active or in the process of committing on the current thread,null
otherwise.Returns the current
InTxn
instance if it is active or in the process of committing on the current thread,null
otherwise. Always performs a dynamic lookup.- Definition Classes
- TxnContext
-
abstract
def
findCurrent(implicit mt: MaybeTxn): Option[InTxn]
Returns
Some(txn)
iftxn
is theInTxn
active or in the process of committing on the current thread,None
otherwise.Returns
Some(txn)
iftxn
is theInTxn
active or in the process of committing on the current thread,None
otherwise.- Definition Classes
- TxnContext
-
abstract
def
isControlFlow(x: Throwable): Boolean
Returns true if
x
should be treated as a transfer of control, rather than an error.Returns true if
x
should be treated as a transfer of control, rather than an error. Atomic blocks that end with an uncaught control flow exception are committed, while atomic blocks that end with an uncaught error exception are rolled back.All implementations of this method must return true for instances that implement
scala.util.control.ControlThrowable
.- Definition Classes
- TxnExecutor
-
abstract
def
newCommitBarrier(timeout: Long, unit: TimeUnit): CommitBarrier
Returns a new commit barrier suitable for coordinating commits by this STM implementation.
-
abstract
def
newRef[A](v0: A)(implicit arg0: ClassManifest[A]): Ref[A]
T
will not be one of the primitive types (for which anewRef
specialization exists).T
will not be one of the primitive types (for which anewRef
specialization exists).- Definition Classes
- RefFactory
-
abstract
def
newRef(v0: Unit): Ref[Unit]
- Definition Classes
- RefFactory
-
abstract
def
newRef(v0: Double): Ref[Double]
- Definition Classes
- RefFactory
-
abstract
def
newRef(v0: Long): Ref[Long]
- Definition Classes
- RefFactory
-
abstract
def
newRef(v0: Float): Ref[Float]
- Definition Classes
- RefFactory
-
abstract
def
newRef(v0: Int): Ref[Int]
- Definition Classes
- RefFactory
-
abstract
def
newRef(v0: Char): Ref[Char]
- Definition Classes
- RefFactory
-
abstract
def
newRef(v0: Short): Ref[Short]
- Definition Classes
- RefFactory
-
abstract
def
newRef(v0: Byte): Ref[Byte]
- Definition Classes
- RefFactory
-
abstract
def
newRef(v0: Boolean): Ref[Boolean]
- Definition Classes
- RefFactory
-
abstract
def
newTArray[A](xs: TraversableOnce[A])(implicit arg0: ClassManifest[A]): TArray[A]
- Definition Classes
- RefFactory
-
abstract
def
newTArray[A](length: Int)(implicit arg0: ClassManifest[A]): TArray[A]
- Definition Classes
- RefFactory
-
abstract
def
newTMap[A, B]: TMap[A, B]
- Definition Classes
- RefFactory
-
abstract
def
newTMapBuilder[A, B]: Builder[(A, B), TMap[A, B]]
- Definition Classes
- RefFactory
-
abstract
def
newTSet[A]: TSet[A]
- Definition Classes
- RefFactory
-
abstract
def
newTSetBuilder[A]: Builder[A, TSet[A]]
- Definition Classes
- RefFactory
-
abstract
def
newTxnLocal[A](init: ⇒ A, initialValue: (InTxn) ⇒ A, beforeCommit: (InTxn) ⇒ Unit, whilePreparing: (InTxnEnd) ⇒ Unit, whileCommitting: (InTxnEnd) ⇒ Unit, afterCommit: (A) ⇒ Unit, afterRollback: (Status) ⇒ Unit, afterCompletion: (Status) ⇒ Unit): TxnLocal[A]
- Definition Classes
- RefFactory
-
abstract
def
oneOf[Z](blocks: (InTxn) ⇒ Z*)(implicit mt: MaybeTxn): Z
Atomically executes a transaction that is composed from
blocks
by joining with a left-biasedorAtomic
operator.Atomically executes a transaction that is composed from
blocks
by joining with a left-biasedorAtomic
operator. The following two examples are equivalent. UsingorAtomic
:atomic { implicit t => // body A } orAtomic { implicit t => // body B } ...
Using
oneOf
:atomic.oneOf( { implicit t: InTxn => // body A }, { implicit t: InTxn => // body B } )
The first block will be attempted in an optimistic transaction until it either succeeds, fails with no retry possible (in which case the causing exception will be rethrown), or performs a call to
retry
. If a retry is requested, then the next block will be attempted in the same fashion. If all blocks are explicitly retried then execution resumes at the first block, but only after another context has changed some value read by one of the attempts.The left-biasing of the
orAtomic
composition guarantees that if the first block does not callretry
, no other blocks will be executed.- Definition Classes
- TxnExecutor
-
abstract
def
postDecisionFailureHandler: (Status, Throwable) ⇒ Unit
Returns a function that records, reports or discards exceptions that were thrown from a while-committing, after-commit or after-rollback life-cycle callback.
Returns a function that records, reports or discards exceptions that were thrown from a while-committing, after-commit or after-rollback life-cycle callback.
- Definition Classes
- TxnExecutor
-
abstract
def
pushAlternative[Z](mt: MaybeTxn, block: (InTxn) ⇒ Z): Boolean
(rare) Associates an alternative atomic block with the current thread.
(rare) Associates an alternative atomic block with the current thread. The next call to
apply
will considerblock
to be an alternative. Multiple alternatives may be associated before callingapply
. Returns true if this is the first pushed alternative, false otherwise. This method is not usually called directly. Alternative atomic blocks are only attempted if the previous alternatives callretry
.Note that it is not required that
pushAlternative
be called on the same instance ofTxnExecutor
asapply
, just that they have been derived from the same original executor.- Definition Classes
- TxnExecutor
-
abstract
def
retryTimeoutNanos: Option[Long]
Returns
Some(t)
ift
is the retry timeout in nanoseconds used by thisTxnExecutor
, orNone
otherwise.Returns
Some(t)
ift
is the retry timeout in nanoseconds used by thisTxnExecutor
, orNone
otherwise. If the retry timeout isSome(t)
and an atomic block executed by the returned executor blocks withretry
orretryFor
for more thant
nanoseconds the retry will be cancelled with anInterruptedException
.The retry timeout has essentially the same effect as replacing calls to
retry
with{ retryFor(timeout, NANOS) ; throw new InterruptedException }
. Alternately,retryFor(timeout)
has roughly the same effect astry { atomic.withRetryTimeout(timeout) { implicit txn => retry } } catch { case _: InterruptedException => }
- Definition Classes
- TxnExecutor
-
abstract
def
unrecorded[Z](block: (InTxn) ⇒ Z, outerFailure: (RollbackCause) ⇒ Z = null)(implicit mt: MaybeTxn): Z
Performs a computation in a transaction and returns the result, but always rolls back the transaction.
Performs a computation in a transaction and returns the result, but always rolls back the transaction. No writes performed by
block
will be committed or exposed to other threads. This may be useful for heuristic decisions or for debugging, as for the variousdbgStr
implementations.The caller is responsible for correctness: It is a code smell if Z is a type that is constructed from Ref
,
TMap,
TSet, .....
If this method is executed inside an outer transaction that has status
Txn.RolledBack
thenblock
can't complete. The default behavior (ifouterFailure
is null) in that case is to immediately roll back the outer transaction. If a non-nullouterFailure
handler has been provided, however, it allow this method to return. This is useful when the unrecorded transaction is being used for debugging or logging.atomic.unrecorded { implicit txn => code }
is roughly equivalent to the following, except that the rollback cause used will beTxn.UnrecordedTxnCause
:case class Tunnel(z: Z) extends Exception {} try { atomic.withControlFlowRecognizer({ case Tunnel(_) => false }) { implicit txn => throw Tunnel(code) } } catch { case Tunnel(z) => z }
- Definition Classes
- TxnExecutor
-
abstract
def
withControlFlowRecognizer(pf: PartialFunction[Throwable, Boolean]): TxnExecutor
Returns a
TxnExecutor e
that is identical to this one, except thate.isControlFlow(x)
will returnpf(x)
ifpf.isDefined(x)
.Returns a
TxnExecutor e
that is identical to this one, except thate.isControlFlow(x)
will returnpf(x)
ifpf.isDefined(x)
. For exceptions for whichpf
is not defined the decision will be deferred to the previous implementation.This function may be combined with
TxnExecutor.transformDefault
to add system-wide recognition of a control-transfer exception that does not extendscala.util.control.ControlThrowable
. For example, to modify the default behavior of allTxnExecutor.isControlFlow
calls to acceptDSLNonLocalControlTransferException
:TxnExecutor.transformDefault { e => e.withControlFlowRecognizer { case _: DSLNonLocalControlTransferException => true } }
- Definition Classes
- TxnExecutor
-
abstract
def
withPostDecisionFailureHandler(handler: (Status, Throwable) ⇒ Unit): TxnExecutor
Returns a
TxnExecutor e
that is identical to this one, except thate.postDecisionFailureHandler
will returnhandler
.Returns a
TxnExecutor e
that is identical to this one, except thate.postDecisionFailureHandler
will returnhandler
. This function may be called from inside a function passed toTxnExecutor.transformDefault
to change the system-wide post-decision failure handler.- Definition Classes
- TxnExecutor
-
abstract
def
withRetryTimeoutNanos(timeoutNanos: Option[Long]): TxnExecutor
Returns a
TxnExecutor
that is identical to this one, except that it has aretryTimeout
oftimeoutNanos
.Returns a
TxnExecutor
that is identical to this one, except that it has aretryTimeout
oftimeoutNanos
.- Definition Classes
- TxnExecutor
Concrete Value Members
-
final
def
!=(arg0: Any): Boolean
- Definition Classes
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-
final
def
##(): Int
- Definition Classes
- AnyRef → Any
-
final
def
==(arg0: Any): Boolean
- Definition Classes
- AnyRef → Any
-
final
def
asInstanceOf[T0]: T0
- Definition Classes
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def
clone(): AnyRef
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- @throws( ... )
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final
def
eq(arg0: AnyRef): Boolean
- Definition Classes
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def
equals(arg0: Any): Boolean
- Definition Classes
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-
def
finalize(): Unit
- Attributes
- protected[java.lang]
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- @throws( classOf[java.lang.Throwable] )
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final
def
getClass(): Class[_]
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def
hashCode(): Int
- Definition Classes
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-
final
def
isInstanceOf[T0]: Boolean
- Definition Classes
- Any
-
final
def
ne(arg0: AnyRef): Boolean
- Definition Classes
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final
def
notify(): Unit
- Definition Classes
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final
def
notifyAll(): Unit
- Definition Classes
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final
def
synchronized[T0](arg0: ⇒ T0): T0
- Definition Classes
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def
toString(): String
- Definition Classes
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-
final
def
wait(): Unit
- Definition Classes
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- Annotations
- @throws( ... )
-
final
def
wait(arg0: Long, arg1: Int): Unit
- Definition Classes
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- @throws( ... )
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final
def
wait(arg0: Long): Unit
- Definition Classes
- AnyRef
- Annotations
- @throws( ... )
-
def
withRetryTimeout(timeout: Long, unit: TimeUnit = TimeUnit.MILLISECONDS): TxnExecutor
Returns a
TxnExecutor
that is identical to this one except that it has the specified retry timeout.Returns a
TxnExecutor
that is identical to this one except that it has the specified retry timeout. The default time unit is milliseconds. If the retry timeout expires the retry will be cancelled with anInterruptedException
.- Definition Classes
- TxnExecutor