Returns the instance of STMImpl
that should be used to implement all
ScalaSTM functionality.
Returns the instance of STMImpl
that should be used to implement all
ScalaSTM functionality. Calling this method forces the implementation
to be chosen if it has not already been selected.
Installs impl
as the system-wide STM implementation if no STMImpl
has yet been chosen, or verifies that impl
is equal to the previously
selected instance, throwing IllegalStateException
if an STM
implementation has already been selected and impl != instance
Installs Class.forName(implClassName)
as the system-wide STM
implementation if no STMImpl
has yet been chosen, or verifies that
implClassName
was previously selected, throwing
IllegalStateException
if a different STM implementation has already
been selected
If no STMImpl
instance has yet been selected, installs an instance of
Class.forName(implClassName)
as the system-wide STM implementation.
If no STMImpl
instance has yet been selected, installs an instance of
Class.forName(implClassName)
as the system-wide STM implementation.
Returns true if implClassName
was newly or previously selected, or
returns false if another STM implementation was chosen.
STMImpl
gathers all of the functionality required to plug an STM implementation intoscala.concurrent.stm
. Only one implementation can be selected, becauseRef
s and atomic blocks from different STM implementations are not compatible.STMImpl.instance
returns theSTMImpl
instance that has been selected for this program execution.There are two ways to explicitly select the
STMImpl
instance:STMImpl
; or2. arrange for
STMImpl.select
orSTMImpl.trySelect
to be called before anyRef
s are constructed and before any atomic blocks are executed.Setting the JVM system property "scala.stm.impl" is equivalent to making a call to
STMImpl.select(System.getProperty("scala.stm.impl"))
before any otherSTMImpl
selections.If there is no explicitly selected
STMImpl
instance and the classpath contains a classscala.concurrent.stm.impl.DefaultFactory
that extendsscala.concurrent.stm.impl.STMImpl.Factory
, then an instance of that class will be instantiated and used to generate theSTMImpl
instance. ScalaSTM implementations are encouraged to implementDefaultFactory
so that if a user includes the implementation's JAR file, it will be automatically selected.If no explicit selection has been made and there is no definition of
scala.concurrent.stm.impl.DefaultFactory
present in the classpath, then ScalaSTM will fall back to the reference implementation "scala.concurrent.stm.ccstm.CCSTM".