The Low Level Persistence Library offers access to blocks of persistent memory allocated on a persistent heap.
This Java library uses the Persistent Memory Development Kit (PMDK). For more information on PMDK, please visit http://pmem.io and https://github.com/pmem/pmdk.
The following are the prerequisites for building this Java library:
- Linux operating system
- Persistent Memory Development Kit (PMDK)
- Java 8 or above
- Build tools -
g++
compiler,CMake
andMaven
This library assumes the availability of hardware persistent memory or emulated persistent memory. Instructions for creating emulated persistent memory are shown below.
The preferred way is to create an in-memory DAX file system. This requires Linux kernel 4.2 or greater. Please follow the steps at:
http://pmem.io/2016/02/22/pm-emulation.html
Alternatively, for use with older kernels, create a tmpfs partition as follows (as root):
$ mount -t tmpfs -o size=4G tmpfs /mnt/mem # creates a 4GB tmpfs partition
$ chmod -R a+rw /mnt/mem # enables read/write permissions to all users
Once all the prerequisites have been satisfied:
$ git clone https://github.com/pmem/llpl.git
$ cd llpl
$ mvn compile
$ mvn test -Dtest.heap.path=<path to persistent memory mount point>
Available Maven commands include:
compile
- builds sourcestest
- builds and runs testsjavadoc:javadoc
- builds javadocs intotarget/site/apidocs
package
- builds jar file intotarget
directory
LLPL is available from the Maven central repository. Add the following dependency to your pom.xml:
<dependency>
<groupId>com.intel.pmem</groupId>
<artifactId>llpl</artifactId>
<version>1.1.0-release</version>
<type>jar</type>
</dependency>
To import this library into an existing Java application, include the project's target/classes
directory in your Java classpath and the project's target/cppbuild
directory in your
java.library.path
. For example:
$ javac -cp .:<path>/llpl/target/classes <source>
$ java -cp .:<path>/llpl/target/classes -Djava.library.path=<path>/llpl/target/cppbuild <class>
Thanks for your interest! Please see the CONTRIBUTING.md document for information on how to contribute.
We would love to hear your comments and suggestions via https://github.com/pmem/llpl/issues.
For more information on this library, contact Olasoji Denloye ([email protected]) or Steve Dohrmann ([email protected]).