Commit Graph

6465 Commits

Author SHA1 Message Date
Norman Maurer
deb1dfb5b0 Allow to enable client authentication on the OpenSslEngine
Motivation:

At the moment there is no way to enable client authentication when using OpenSslEngine. This limits the uses of OpenSslEngine.

Modifications:

Add support for different authentication modes.

Result:

OpenSslEngine can now also be used when client authenticiation is needed.
2014-12-22 20:19:14 +01:00
Norman Maurer
9ff689331c More complete OpenSslEngine SSLSession implementation
Motivation:

The current SSLSession implementation used by OpenSslEngine does not support various operations and so may not be a good replacement by the SSLEngine provided by the JDK implementation.

Modifications:

- Add SSLSession.getCreationTime()
- Add SSLSession.getLastAccessedTime()
- Add SSLSession.putValue(...), getValue(...), removeValue(...), getValueNames()
- Add correct SSLSession.getProtocol()
- Ensure OpenSSLEngine.getSession() is thread-safe
- Use optimized AtomicIntegerFieldUpdater when possible

Result:

More complete OpenSslEngine SSLSession implementation
2014-12-22 20:13:00 +01:00
Norman Maurer
6600ea3fac Add OpenSslClientContext to allow creating SslEngine for client side
Motivation:

We only support openssl for server side at the moment but it would be also useful for client side.

Modification:

* Upgrade to new netty-tcnative snapshot to support client side openssl support
* Add OpenSslClientContext which can be used to create SslEngine for client side usage
* Factor out common logic between OpenSslClientContext and OpenSslServerContent into new abstract base class called OpenSslContext
* Correctly detect handshake failures as soon as possible
* Guard against segfault caused by multiple calls to destroyPools(). This can happen if OpenSslContext throws an exception in the constructor and the finalize() method is called later during GC

Result:

openssl can be used for client and servers now.
2014-12-22 20:10:24 +01:00
Trustin Lee
7aa9480cc6 Remove thepiratebay.se from the test domain list
.. due to its instability
2014-12-22 22:35:58 +09:00
Norman Maurer
64065e84f5 Efficiently handle writing ( wrap(...) ) of CompositeByteBuf when using SslHandler
Motivation:

SslHandler.wrap(...) does a poor job when handling CompositeByteBuf as it always call ByteBuf.nioBuffer() which will do a memory copy when a CompositeByteBuf is used that is backed by multiple ByteBuf.

Modifications:

- Use SslEngine.wrap(ByteBuffer[]...) to allow wrap CompositeByteBuf in an efficient manner
- Reduce object allocation in unwrapNonAppData(...)

Result:

Performance improvement when a CompositeByteBuf is written and the SslHandler is in the ChannelPipeline.
2014-12-22 12:15:38 +01:00
Norman Maurer
95a75da00a CompositeByteBuf.nioBuffers(...) must not return an empty ByteBuffer array
Motivation:

CompositeByteBuf.nioBuffers(...) returns an empty ByteBuffer array if the specified length is 0. This is not consistent with other ByteBuf implementations which return an ByteBuffer array of size 1 with an empty ByteBuffer included.

Modifications:

Make CompositeByteBuf.nioBuffers(...) consistent with other ByteBuf implementations.

Result:

Consistent and correct behaviour of nioBufffers(...)
2014-12-22 11:18:57 +01:00
Norman Maurer
b2fca0cf18 Always return SliceByteBuf on slice(...) to eliminate possible leak
Motivation:

When calling slice(...) on a ByteBuf the returned ByteBuf should be the slice of a ByteBuf and shares it's reference count. This is important as it is perfect legal to use buf.slice(...).release() and have both, the slice and the original ByteBuf released. At the moment this is only the case if the requested slice size is > 0. This makes the behavior inconsistent and so may lead to a memory leak.

Modifications:

- Never return Unpooled.EMPTY_BUFFER when calling slice(...).
- Adding test case for buffer.slice(...).release() and buffer.duplicate(...).release()

Result:

Consistent behaviour and so no more leaks possible.
2014-12-22 11:16:09 +01:00
Norman Maurer
6e5ab465d9 Fix memory leak in OpenSslEngine
Motivation:

When a remote peer did open a connection and only do the handshake without sending any data and then directly close the connection we did not call shutdown() in the OpenSslEngine. This leads to a native memory leak. Beside this it also was not fireed when a OpenSslEngine was created but never used.

Modifications:

- Make sure shutdown() is called in all cases when closeInbound() is called
- Call shutdown() also in the finalize() method to ensure we release native memory when the OpenSslEngine is GC'ed

Result:

No more memory leak when using OpenSslEngine
2014-12-21 09:51:57 +01:00
Trustin Lee
7bb7b8742f Do not use SLF4J/Logback API directly
Motivation:

TrafficShapingHandlerTest uses Logback API directly, which is
discouraged.  Also, it overrides the global default log level, which
silences the DEBUG messages from other tests.

Modifications:

Remove the direct use of Logback API

Result:

The tests executed after TrafficShapingHandlerTest logs their DEBUG
messages correctly.
2014-12-17 10:20:13 +09:00
Scott Mitchell
f879614c61 Java ALPN provider version update
Motivation:

There was a bug in the Java ALPN library we are using.  A new version was released to fix this bug and we should update our pom.xml to use the new version.

Modifications:

Update pom.xml to use new ALPN library.

Result:

Newer versions of JDK (1.7_u71, 1.7_u72, 1.8_u25) have the bug fixed.
2014-12-16 16:25:01 -05:00
Trustin Lee
770126f707 Fix checkstyle 2014-12-16 20:34:01 +09:00
Trustin Lee
1ecb3fe88c Log detailed information about renegotiation and traffic
Motivation:

We need more information to understand why SocketSslEchoTest fails
sporadically in the CI machine.

Modifications:

- Refactor SocketSslEchoTest so that it is easier to retrieve the
  information about renegotiation and the current progress

Result:

We will get more information when the test fails.
2014-12-16 17:40:00 +09:00
Trustin Lee
0b9fff906e Compress the heap dump after tests are finished
Motivation:

Tests sometimes time out because it took too long to compress the
generated heap dump.

Modifications:

- Move the compression logic to a new method 'compressHeapDumps()'
- Call TestUtils.compressHeapDumps() at the end of the tests, so that
  the tests do not fail because of timeout

Result:

JUnit reports the real cause of the test failure instead of timeout
exception.
2014-12-16 16:16:03 +09:00
Leonardo Freitas Gomes
75aa8475e1 Motivation: Sonar points out an equals comparison, where the types compared are different and don't share any common parent http://clinker.netty.io/sonar/drilldown/issues/io.netty:netty-parent:master?severity=CRITICAL#
Modifications:
Converted AsciiString into a String by calling toString() method before comparing with equals(). Also added a unit-test to show that it works.

Result:
Major violation is gone. Code is correct.
2014-12-16 06:59:48 +01:00
zcourts
a7a1b8e561 ensure getRawQuery is not null before appending
Motivation:

without this check then given a URI with path /path the resulting URL will be /path?null=

Modifications:

check that getRawQuery doesn't return null and only append if not

Result:

urls of the form /path will not have a null?= appended
2014-12-16 06:39:28 +01:00
Trustin Lee
2668944e0b Generate non-test JAR for netty-testsuite
Motivation:

So far, we generated and deployed test JARs to Maven repositories. The
deployed JAR had the classifier 'test-jar'.  The test JAR is consumed by
transport-native-epoll as a test dependency.

The problem is, when netty-transport-native-epoll pulls the test JAR as
a dependency, that Maven resolves its transitive dependencies at
'compile' and 'runtime' scope only, which is incorrect.

I was bitten by this problem recently while trying to add a new
dependency to netty-testsuite.  Because I added a new dependency at the
'test' scope, the new dependency was not pulled transitively by
transport-native-epoll and caused an unexpected build failure.

- d6160208c3
- bf77bb4c3a

Modifications:

- Move all classes in netty-testsuite from src/test to src/main
- Update the 'compile' scope dependencies of netty-testsuite
- Override the test directory configuration properties of the surefire
  plugin
- Do not generate the test JAR anymore
- Update the dependency of netty-transport-native-epoll

Result:

It is less error-prone to add a new dependency to netty-testsuite.
2014-12-15 09:17:51 +09:00
Trustin Lee
bf77bb4c3a Fix build errors due to missing dependency 2014-12-14 21:29:26 +09:00
Trustin Lee
d6160208c3 Compress the heap dump generated by TestUtils.dump()
Motivation:

It takes too long to download the heap dump from the CI server.

Modifications:

Compress the heap dump as much as possible.

Result:

When heap dump is generated by certain test failure, the generated heap
dump file is about 3 times smaller than before, although the compression
time will increase the build time when the test fails.
2014-12-14 12:01:17 +09:00
Norman Maurer
99a703be88 Revert "Suppress channelReadComplete until MessageAggregator completes aggregating a message. https://github.com/netty/netty/issues/3168"
This reverts commit cb95a1331d.
2014-12-13 09:19:04 +01:00
Sam Young
cb95a1331d Suppress channelReadComplete until MessageAggregator completes aggregating a message. https://github.com/netty/netty/issues/3168
Motivation:
This fixes issue 3168 where HttpObjectAggregator does not suppress
channelReadComplete() when aggregation is not yet finished.

Modifications:
Ignore channelReadComplete until a message completes aggregation.
MessageAggregator currently tracks the currentMessage being aggregated.
This variable transitions to non-null when aggregation begins and back
to null when aggregation completes or fails. When the currentMessage is
null, it is safe to issue a channelReadComplete because the
corresponding channelRead will have completed aggregation.

Result:
channelReadComplete will only fire one time on each completed message
aggregation.
2014-12-13 07:58:19 +01:00
Scott Mitchell
cc8140b41c HTTP/2 unit test failure race condition
Motivation:
HttpToHttp2ConnectionHandler is awaiting on a future and a latch that may be competed before the buffers actually get released.  This test is attempting to validate that the buffer's refCnt() is 0 but there is no mechanism to wait on for a buffer's release() method to be called.

Modifications:
Remove the buffer refCnt() check.  The leak profile is designed to pick these up.

Result:
Unit tests that no longer have a race condition.
2014-12-12 14:44:38 -05:00
Scott Mitchell
83427022bf HTTP/2 stress test timeout
Motivation:
The stress tests have been observed to fail on the CI server. The average run time of the stress tests has recently been 26+ seconds.  Our timeout is currently set to 30 seconds.

Modifications:
Increase the timeout for the stress test so when the leak profile is active we will have more time to complete the test (with the additional overhead).

Result:
Stress tests fail less frequently (hopefully not at all).
2014-12-12 14:38:46 -05:00
ysammy
139fda2fea Fix documentation for ChannelHandlerContext#fireChannelReadComplete
Motivation:
Fix a minor documentation bug in
ChannelHandlerContext#fireChannelReadComplete.

Modifications:
ChannelHandlerContext#fireChannelReadComplete no longer references an
incorrect method in its javadoc.

Results:
Documentation is correct.
2014-12-12 18:34:40 +01:00
Norman Maurer
bb3aed78cd Remove bottleneck while create InetSocketAddress in native transport
Motivation:

Everytime a new connection is accepted via EpollSocketServerChannel it will create a new EpollSocketChannel that needs to get the remote and local addresses in the constructor. The current implementation uses new InetSocketAddress(String, int) to create these. This is quite slow due the implementation in oracle and openjdk.

Modifications:

Encode all needed informations into a byte array before return from jni layer and then use new InetSocketAddress(InetAddress, int) to create the socket addresses. This allows to create the InetAddress via a byte[] and so reduce the overhead, this is done either by using InetAddress.getByteAddress(byte[]) or by Inet6Address.getByteAddress(String, byte[], int).

Result:

Reduce performance overhead while accept new connections with native transport
2014-12-12 18:23:18 +01:00
Trustin Lee
9a0be053c4 Add more assertions related with TLS renegotiation 2014-12-12 18:01:36 +09:00
Trustin Lee
d838b19b6f Test TLS renegotiation with explicit cipher suite change
Motivation:

So far, our TLS renegotiation test did not test changing cipher suite
during renegotiation explicitly.

Modifications:

- Switch the cipher suite during renegotiation

Result:

We are now sure the cipher suite change works.
2014-12-12 17:43:23 +09:00
Trustin Lee
61eddd5b74 Add log messages when dump starts
.. to make it easier to find the right dump file for a test when there
are multiple dump files.
2014-12-12 11:55:34 +09:00
Trustin Lee
94a64c09cd Make sure to notify handshake success even if SSLEngine is closed
Related:

e9685ea45a

Motivation:

SslHandler.unwrap() does not evaluate the handshake status of
SSLEngine.unwrap() when the status of SSLEngine.unwrap() is CLOSED.

It is not correct because the status does not reflect the state of the
handshake currently in progress, accoding to the API documentation of
SSLEngineResult.Status.

Also, sslCloseFuture can be notified earlier than handshake notification
because we call sslCloseFuture.trySuccess() before evaluating handshake
status.

Modifications:

- Notify sslCloseFuture after the unwrap loop is finished
- Add more assertions to SocketSslEchoTest

Result:

Potentially fix the regression caused by:
- e9685ea45a
2014-12-12 11:55:34 +09:00
Trustin Lee
ed7cc5bee6 Generate heap and thread dump when some tests fail
Motivation:

We have a few sporadic test failures which are only easily reproduceable
in our CI machine.  To get more information about the failure, we need
heap and full thread dump at the moment of failure.

Modifications:

- Add TestUtils.dump() method to dump heap and threads
- Modify SocketGatheringWriteTest and SocketSslEchoTest to call
  TestUtils.dump() on failure

Result:

We get more information about the test failure.
2014-12-12 10:35:19 +09:00
Scott Mitchell
1293aba28e HTTP/2 Draft 16
Motivation:
HTTP/2 draft 16 has been released https://tools.ietf.org/html/draft-ietf-httpbis-http2-16.

Modifications:
The HTTP/2 codec should be updated to support draft 16.

Result:
HTTP/2 codec is draft 16 compliant.
2014-12-11 18:58:59 -05:00
Scott Mitchell
2cf4ee9322 HTTP/2 Sonar Bugs
Motivation:
Clinker provides a Sonar tool which detects potential bugs or problems in the code.  These problems were reported here http://clinker.netty.io/sonar/drilldown/issues/io.netty:netty-parent:master?

Modifications:
Make the recommended changes as reported by Sonar

Result:
Better or more standard code.  Less Sonar problem reports for HTTP/2 codec.
2014-12-11 08:10:27 -05:00
Norman Maurer
140a32bcb3 Allow to lazy create a DefaultFileRegion from a File
Motivation:

We only provided a constructor in DefaultFileRegion that takes a FileChannel which means the File itself needs to get opened on construction. This has the problem that if you want to write a lot of Files very fast you may end up with may open FD's even if they are not needed yet. This can lead to hit the open FD limit of the OS.

Modifications:

Add a new constructor to DefaultFileRegion which allows to construct it from a File. The FileChannel will only be obtained when transferTo(...) is called or the DefaultFileRegion is explicit open'ed via open() (this is needed for the native epoll transport)

Result:

Less resource usage when writing a lot of DefaultFileRegion.
2014-12-11 12:06:52 +01:00
Norman Maurer
398e7a9b08 Ensure buffer is not released when call array() / memoryAddress()
Motivation:

Before we missed to check if a buffer was released before we return the backing byte array or memoryaddress. This could lead to JVM crashes when someone tried various bulk operations on the Unsafe*ByteBuf implementations.

Modifications:

Always check if the buffer is released before all to return the byte array and memoryaddress.

Result:

No more JVM crashes because of released buffers when doing bulk operations on Unsafe*ByteBuf implementations.
2014-12-11 11:31:05 +01:00
Trustin Lee
a0862bc5fb Make SslHandler work when autoRead is turned off
Related: #2958

Motivation:

SslHandler currently does not issue a read() request when it is
handshaking. It makes a connection with autoRead off stall, because a
user's read() request can be used to read the handshake response which
is invisible to the user.

Modifications:

- SslHandler now issues a read() request when:
  - the current handshake is in progress and channelReadComplete() is
    invoked
  - the current handshake is complete and a user issued a read() request
    during handshake
- Rename flushedBeforeHandshakeDone to flushedBeforeHandshake for
  consistency with the new variable 'readDuringHandshake'

Result:

SslHandler should work regardless whether autoRead is on or off.
2014-12-11 17:54:39 +09:00
Trustin Lee
d1612f67ad Add SslHandler.renegotiate()
Related: #3125

Motivation:

We did not expose a way to initiate TLS renegotiation and to get
notified when the renegotiation is done.

Modifications:

- Add SslHandler.renegotiate() so that a user can initiate TLS
  renegotiation and get the future that's notified on completion
- Make SslHandler.handshakeFuture() return the future for the most
  recent handshake so that a user can get the future of the last
  renegotiation
- Add the test for renegotiation to SocketSslEchoTest

Result:

Both client-initiated and server-initiated renegotiations are now
supported properly.
2014-12-10 18:47:53 +09:00
Trustin Lee
85ec4d9cc4 Trigger channelWritabilityChanged() later to avoid reentrance
Related: #3212

Motivation:

When SslHandler and ChunkedWriteHandler exists in a pipeline together,
it is possible that ChunkedWriteHandler.channelWritabilityChanged()
invokes SslHandler.flush() and vice versa. Because they can feed each
other (i.e. ChunkedWriteHandler.channelWritabilityChanged() ->
SslHandler.flush() -> ChunkedWriteHandler.channelWritabilityChanged() ->
..), they can fall into an inconsistent state due to reentrance (e.g.
bad MAC record at the remote peer due to incorrect ordering.)

Modifications:

- Trigger channelWritabilityChanged() using EventLoop.execute() when
  there's a chance where channelWritabilityChanged() can cause a
  reentrance issue
- Fix test failures caused by the modification

Result:

Fix the handler reentrance issues related with a
channelWritabilityChanged() event
2014-12-10 18:36:53 +09:00
Scott Mitchell
7f9fb95702 HTTP/2 Unit Test race condition
Motivation:
The Http2ConnectionRoundtripTest.noMoreStreamIdsShouldSendGoAway unit test had a race condition where it would sometimes receive a SETINGS_ACK message that was not anticipated. This caused the test to fail because of bad test code.

Modifications:
The bad unit test should be updated to handle the message exchange for a good connection setup, and then the GO_AWAY frame.

Result:
Http2ConnectionRoundtripTest.noMoreStreamIdsShouldSendGoAway should no longer sporadically fail.
2014-12-09 16:24:21 -05:00
Trustin Lee
047176bc3f Call ctx.flush() at least once in ChunkedWriteHandler.flush()
Related: #3219

Motivation:

ChunkedWriteHandler.flush() does not call ctx.flush() when channel is
not writable. This can be a problem when other handler / non-Netty
thread writes messages simultaneously, because
ChunkedWriteHandler.flush() might have no chance to observe
channel.isWritable() returns true and thus the channel is never flushed.

Modifications:

- Ensure that ChunkedWriteHandler.flush() calls ctx.flush() at least
  once.

Result:

A stall connection issue, that occurs when certain combination of
handlers exist in a pipeline, has been fixed. (e.g. SslHandler and
ChunkedWriteHandler)
2014-12-09 18:17:23 +09:00
nmittler
124983afb5 Refactoring HTTP/2 Flow Control interfaces.
Motivation:

The terminology used with inbound/outbound is a little confusing since
it's not discussed in the spec. We should switch to using local/remote
instead. Also there is some asymmetry between the inbound/outbound
interfaces which could probably be cleaned up.

Modifications:

Changing the interface names and making a common Http2FlowController
interface for most of the methods.

Result:

The HTTP/2 flow control interfaces should be more clear.
2014-12-08 09:16:06 -08:00
Daniel Bevenius
ed09fb10bc Fixing minor typo in FastThreadLocal javadoc. 2014-12-08 14:24:07 +01:00
Frederic Bregier
cb6646da13 Fix AbstractDiskHttpData int conversion from long
Motivations:
The chunkSize might be oversized after comparison (size being > of int
capacity) if file size is bigger than an integer.

Modifications:
Change it to long.

Result:
There is no more int oversized.

Same fix for 4.1 and Master
2014-12-08 07:18:09 +01:00
Trustin Lee
69e25d21f6 Make PendingWriteQueue.recycle() update its state before triggering an event
Related: #3212

Motivation:

PendingWriteQueue.recycle() updates its data structure after triggering
a channelWritabilityChanged() event. It causes a rare corruption such as
double free when channelWritabilityChanged() method accesses the
PendingWriteQueue.

Modifications:

Update the state of PendingWriteQueue before triggering an event.

Result:

Fix a rare double-free problem
2014-12-07 23:24:19 +09:00
Trustin Lee
a337589c91 Trigger exceptionCaught() when VoidChannelPromise fails
Related: #3190

Motivation:

When an outbound handler method raises an exception, its promise is
marked as failed.  If the promise is done already, the exception is
logged.

When the promise is void, exceptionCaught() must be triggered to notify
a user. However, ChannelHandlerInvokerUtil simply swallows it.

Modifications:

Do not swallow an exception when the promise is void.

Result:

A user who uses a void promise for an outbound operation will be
notified on failure.
2014-12-07 16:07:33 +09:00
Trustin Lee
7e2ae8758c Fire channelRead() event immediately in OIO message channels
Related: #3189

Motivation:

OIO transport implementations block for at most 1 second to wait for
additional messages (or accepted connections).

However, because AbstractOioMessageChannel defers the channelRead()
events for the messages read so far until there's nothing to read up to
maxMessagesPerRead, any read operation will be followed by a 1-second
delay.

Modifications:

Fire channelRead() events as soon as doRead() returns so that there is
no 1 second delay between the actual read and the channelRead() event.

Result:

No more weird 1-second delay
2014-12-07 12:12:19 +09:00
Scott Mitchell
eb0e127ee9 Headers set/add/contains timeMillis methods
Motivation:
The new Headers interface contains methods to getTimeMillis but no add/set/contains variants.  These should be added for consistency.

Modifications:
- Add three new methods: addTimeMillis, setTimeMillis, containsTimeMillis to the Headers interface.
- Add a new method to the Headers.ValueConverter interface: T convertTimeMillis(long)
- Bring these new interfaces up the class hierarchy

Result:
All Headers classes have setters/getters for timeMillis.
2014-12-06 22:40:45 +09:00
Trustin Lee
216cbd9e31 Fix Java 6 compatibility issue in DnsNameResolver
Related: #3173

Motivation:

DnsNameResolver was using InetSocketAddress.getHostString() which is
only available since Java 7.

Modifications:

Use InetSocketAddress.getHostName() in lieu of getHostString() when the
current Java version is less than 7.

Result:

DnsNameResolver runs fine on Java 6.
2014-12-06 22:33:45 +09:00
Trustin Lee
97bf8a6d61 Change the type of HTTP string properties to AsciiString
Related: #3132

Motivation:

Changing the type of the string properties of HttpVersion and
HttpResponseStatus to AsciiString will give us the performance advantage
when encoding it into the wire.

Modifications:

- Change the type of the following properties to AsciiString:
  - HttpVersion.protocolName()
  - HttpVersion.text()
  - HttpResponseStatus.reasonPhrase()
- Inline their respective encode() methods because they are used only in
  the encoders.
- Fix the test failures incurred by the changes above

Result:

Getting close to the machine
2014-12-06 18:42:58 +09:00
Trustin Lee
377ef31bb1 Change the type of HttpMethod.name() to AsciiString
Related: #3132

Motivation:

Changing the type of HttpMethod.name() gives us the performance
advantage when encoding it into the wire.

Modifications:

- Change the type of HttpMethod.name()
- Inline HttpMethod.encode() because it's used only in a single place
  and it's trivial.

Result:

Getting close to the machine
2014-12-06 18:09:27 +09:00
Trustin Lee
13ad58aed7 Fix a bug where Recycler's capacity can increase beyond its maximum
Related: #3166

Motivation:

When the recyclable object created at one thread is returned at the
other thread, it is stored in a WeakOrderedQueue.

The objects stored in the WeakOrderedQueue is added back to the stack by
WeakOrderedQueue.transfer() when the owner thread ran out of recyclable
objects.

However, WeakOrderedQueue.transfer() does not have any mechanism that
prevents the stack from growing beyond its maximum capacity.

Modifications:

- Make WeakOrderedQueue.transfer() increase the capacity of the stack
  only up to its maximum
- Add tests for the cases where the recyclable object is returned at the
  non-owner thread
- Fix a bug where Stack.scavengeSome() does not scavenge the objects
  when it's the first time it ran out of objects and thus its cursor is
  null.
- Overall clean-up of scavengeSome() and transfer()

Result:

The capacity of Stack never increases beyond its maximum.
2014-12-06 17:58:53 +09:00
Greg Gibeling
47319d3cfc Lazily check for root, avoids unnecessary errors & resources
Motivation:

io.netty.util.internal.PlatformDependent.isRoot() depends on the IS_ROOT field which is filled in during class initialization. This spawns processes and consumes resources, which are not generally necessary to the complete functioning of that class.

Modifications:

This switches the class to use lazy initialization this field inside of the isRoot() method using double-checked locking (http://en.wikipedia.org/wiki/Double-checked_locking).

Result:

The first call to isRoot() will be slightly slower, at a tradeoff that class loading is faster, uses fewer resources and platform errors are avoided unless necessary.
2014-12-05 10:02:39 +01:00