[
https://issues.apache.org/jira/browse/KAFKA-9156?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16969820#comment-16969820
]
shilin Lu commented on KAFKA-9156:
----------------------------------
[~guozhang] i think only use val AtomicReference can't perform as well.
{code:java}
// code placeholder
class LazyTimeIndex(@volatile private var _file: File, baseOffset: Long,
maxIndexSize: Int = -1, writable: Boolean = true) {
@volatile private var timeIndex: Option[TimeIndex] = None
def file: File = {
if (timeIndex.isDefined)
timeIndex.get.file
else
_file
}
def file_=(f: File) {
if (timeIndex.isDefined)
timeIndex.get.file = f
else
_file = f
}
def get: TimeIndex = {
if (timeIndex.isEmpty) {
this synchronized {
if (timeIndex.isEmpty) {
timeIndex = Some(new TimeIndex(_file, baseOffset, maxIndexSize,
writable))
}
}
}
timeIndex.get
}
}{code}
the file will rename by def file_=(f: File) this function. we should keep it
Multi-thread safe. i think this code can work.i use synchronized because i
think this function is lightweight. if you think has some problem, i will
modify it. thanks
{code:java}
// code placeholder
class LazyTimeIndex(@volatile private var _file: File, baseOffset: Long,
maxIndexSize: Int = -1, writable: Boolean = true) {
@volatile private var timeIndex: Option[TimeIndex] = None
def file: File = {
this synchronized {
if (timeIndex.isDefined)
timeIndex.get.file
else
_file
}
}
def file_=(f: File) {
this synchronized {
if (timeIndex.isDefined)
timeIndex.get.file = f
else
_file = f
}
}
def get: TimeIndex = {
if (timeIndex.isEmpty) {
this synchronized {
if (timeIndex.isEmpty) {
timeIndex = Some(new TimeIndex(_file, baseOffset, maxIndexSize,
writable))
}
}
}
timeIndex.get
}
}{code}
> LazyTimeIndex & LazyOffsetIndex may cause niobufferoverflow in concurrent
> state
> -------------------------------------------------------------------------------
>
> Key: KAFKA-9156
> URL: https://issues.apache.org/jira/browse/KAFKA-9156
> Project: Kafka
> Issue Type: Bug
> Components: core
> Affects Versions: 2.3.0
> Reporter: shilin Lu
> Priority: Critical
> Attachments: image-2019-11-07-17-42-13-852.png,
> image-2019-11-07-17-44-05-357.png, image-2019-11-07-17-46-53-650.png
>
>
> !image-2019-11-07-17-42-13-852.png!
> this timeindex get function is not thread safe ,may cause create some
> timeindex.
> !image-2019-11-07-17-44-05-357.png!
> When create timeindex not exactly one ,may cause mappedbytebuffer position to
> end. Then write index entry to this mmap file will cause
> java.nio.BufferOverflowException.
>
> !image-2019-11-07-17-46-53-650.png!
>
>
>
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
