Motivation:
Netty provides a adaptor from ByteBuf to Java's InputStream interface. The JDK Stream interfaces have an explicit lifetime because they implement the Closable interface. This lifetime may be differnt than the ByteBuf which is wrapped, and controlled by the interface which accepts the JDK Stream. However Netty's ByteBufInputStream currently does not take reference count ownership of the underlying ByteBuf. There may be no way for existing classes which only accept the InputStream interface to communicate when they are done with the stream, other than calling close(). This means that when the stream is closed it may be appropriate to release the underlying ByteBuf, as the ownership of the underlying ByteBuf resource may be transferred to the Java Stream.
Motivation:
- ByteBufInputStream.close() supports taking reference count ownership of the underyling ByteBuf
Result:
ByteBufInputStream can assume reference count ownership so the underlying ByteBuf can be cleaned up when the stream is closed.
Motivation:
In some ByteBuf implementations we not correctly implement getBytes(index, ByteBuffer).
Modifications:
Correct code to do what is defined in the javadocs and adding test.
Result:
Implementation works as described.
Motivation:
the build doesnt seem to enforce this, so they piled up
Modifications:
removed unused import lines
Result:
less unused imports
Signed-off-by: radai-rosenblatt <radai.rosenblatt@gmail.com>
Motivation:
We introduced a regression in 1abdbe6f67 which let the iteration start from the wrong index.
Modifications:
Fix start index and add tests.
Result:
Fix regression.
Motivation:
Result of ByteBufUtil.compare(ByteBuf a, ByteBuf b) is dependent on ByteOrder of supplied ByteBufs which should not be the case (as stated in the javadocs).
Modifications:
Ensure we get a consistent behavior when calling ByteBufUtil.compare(ByteBuf a, ByteBuf b) and not depend on ByteOrder.
Result:
ByteBufUtil.compare(ByteBuf a, ByteBuf b) and so AbstractByteBuf.compare(...) works correctly as stated in the javadocs.
Motivation:
Sometimes it is useful to be able to wrap an existing memory address (a.k.a pointer) and create a ByteBuf from it. This way its easier to interopt with other libraries.
Modifications:
Add a new Unpooled.wrappedBuffer(....) method that takes a memory address.
Result:
Be able to wrap an existing memory address into a ByteBuf.
Motivation:
We used incorrect assumeTrue(...) checks.
Modifications:
Fix check.
Result:
Be able to run tests also if java.nio.DirectByteBuffer.<init>(long, int) could not be accessed.
Motivation:
We not need to do an extra conditional check in retain(...) as we can just check for overflow after we did the increment.
Modifications:
- Remove extra conditional check
- Add test code.
Result:
One conditional check less.
Motivation:
When Unpooled.wrappedBuffer(...) is called with an array of ByteBuf with length >= 2 and the first ByteBuf is not readable it will result in double releasing of these empty buffers when release() is called on the returned buffer.
Modifications:
- Ensure we only wrap readable buffers.
- Add unit test
Result:
No double release of buffers.
Motivation:
retainSlice() currently does not unwrap the ByteBuf when creating the ByteBuf wrapper. This effectivley forms a linked list of ByteBuf when it is only necessary to maintain a reference to the unwrapped ByteBuf.
Modifications:
- retainSlice() and retainDuplicate() variants should only maintain a reference to the unwrapped ByteBuf
- create new unit tests which generally verify the retainSlice() behavior
- Remove unecessary generic arguments from AbstractPooledDerivedByteBuf
- Remove unecessary int length member variable from the unpooled sliced ByteBuf implementation
- Rename the unpooled sliced/derived ByteBuf to include Unpooled in their name to be more consistent with the Pooled variants
Result:
Fixes https://github.com/netty/netty/issues/5582
Motivation:
At the moment the Recyler is very sensitive to allocation bursts which means that if there is a need for X objects for only one time these will most likely end up in the Recycler and sit there forever as the normal workload only need a subset of this number.
Modifications:
Add a ratio which sets how many objects should be pooled for each new allocation. This allows to slowly increase the number of objects in the Recycler while not be to sensitive for bursts.
Result:
Less unused objects in the Recycler if allocation rate sometimes bursts.
Motivation:
SwappedByteBuf.retainedSlice(...) did not return a retained buffer.
Modifications:
Correctly delegate to retainedSlice(..) calls.
Result:
Correctly return retained slice.
Motivation:
Because of a bug we missed to include the first PoolSubpage when collection metrics.
Modifications:
- Correctly include all subpages
- Add unit test
Result:
Correctly include all subpages
Motivation:
In order to prevent a regression, add test case for a bug that caused a CompositeByteBuf to not release its components.
Modifications:
Add a test case that asserts a CompositeByteBuf's component buffers have indeed been released.
Result:
AbstractCompositeByteBuf gains a test case that will prevent future regressions.
Motivation:
See #82.
Modifications:
- Added `isText` to validate if the given ByteBuf is compliant with the specified charset.
- Optimized for UTF-8 and ASCII. For other cases, `CharsetDecoder.decoder` is used.
Result:
Users can validate ByteBuf with given charset.
Motivation:
Using the Cleaner to release the native memory has a few drawbacks:
- Cleaner.clean() uses static synchronized internally which means it can be a performance bottleneck
- It put more load on the GC
Modifications:
Add new buffer implementations that can be enabled with a system flag as optimizations. In this case no Cleaner is used at all and the user must ensure everything is always released.
Result:
Less performance impact by direct buffers when need to be allocated and released.
Motivation:
At the moment the user is responsible to increase the writer index of the composite buffer when a new component is added. We should add some methods that handle this for the user as this is the most popular usage of the composite buffer.
Modifications:
Add new methods that autoamtically increase the writerIndex when buffers are added.
Result:
Easier usage of CompositeByteBuf.
Motivation:
We missed to override a few methods and so some actions on the ByteBuf failed.
Modifications:
- Override all methods
- Add unit tests to ensure all is fixed.
Result:
All *LeakAware*ByteBuf have correct implementations
Motivation:
Some tests in PooledByteBufAllocatorTest are blocking on a CountDownLatch. We should use a timeout on these tests so these will not block forever on a failure.
Modifications:
Add timeout param to @Test annotation
Result:
Have sane timeouts on tests.
Motivation:
DefaultByteBufHolder.equals(...) and hashCode() should be implemented so it works correctly with instances that share the same content.
Modifications:
Add implementations and a unit-test.
Result:
Have correctly working equals(...) and hashCode() method
Related: #4333#4421#5128
Motivation:
slice(), duplicate() and readSlice() currently create a non-recyclable
derived buffer instance. Under heavy load, an application that creates a
lot of derived buffers can put the garbage collector under pressure.
Modifications:
- Add the following methods which creates a non-recyclable derived buffer
- retainedSlice()
- retainedDuplicate()
- readRetainedSlice()
- Add the new recyclable derived buffer implementations, which has its
own reference count value
- Add ByteBufHolder.retainedDuplicate()
- Add ByteBufHolder.replace(ByteBuf) so that..
- a user can replace the content of the holder in a consistent way
- copy/duplicate/retainedDuplicate() can delegate the holder
construction to replace(ByteBuf)
- Use retainedDuplicate() and retainedSlice() wherever possible
- Miscellaneous:
- Rename DuplicateByteBufTest to DuplicatedByteBufTest (missing 'D')
- Make ReplayingDecoderByteBuf.reject() return an exception instead of
throwing it so that its callers don't need to add dummy return
statement
Result:
Derived buffers are now recycled when created via retainedSlice() and
retainedDuplicate() and derived from a pooled buffer
Motivation:
PooledByteBufAllocatorTest.testNumThreadCachesWithNoDirrectArenas() had a race as it just used LockSupport.parkNanos(). We should better use a CountdownLatch and so be sure we really have init everything.
Modifications:
Replace LockSupport.parkNanos(...) with CountdownLatch usage
Result:
No more race in test.
Motivation:
When FixedCompositeByteBuf was constructed with new ByteBuf[0] and IndexOutOfboundsException was thrown.
Modifications:
Fix constructor
Result:
No more exception
Motivation:
We should not cache the SwappedByteBuf in AbstractByteBuf to reduce the memory footprint.
Modifications:
Not cache the SwappedByteBuf.
Result:
Less memory footprint.
Motivation:
ByteBuf.readBytes(...) uses Unpooled.buffer(...) internally which will use a heap ByteBuf and also not able to make use of the allocator which may be pooled. We should better make use of the allocator.
Modifications:
Use the allocator for thenew buffer.
Result:
Take allocator into account when copy bytes.
Motivation:
When a PoolChunk needs to get moved to the previous PoolChunkList because of the minUsage / maxUsage constraints we always just moved it one level which is incorrect and so could lead to have PoolChunks in the wrong PoolChunkList (in respect to their minUsage / maxUsage settings). This then could have the effect that PoolChunks are not released / freed in a timely fashion and so.
Modifications:
- Correctly move PoolChunks between PoolChunkLists, which includes moving it multiple "levels".
- Add unit test
Result:
Correctlty move the PoolChunk to PoolChunkList when it is freed, even if its multiple layers.
Motivation:
The PoolChunkList.minUsage() and maxUsage() needs to take special action to translate Integer.MIN_VALUE / MAX_VALUE as these are used internal for tail and head of the linked-list structure.
Modifications:
- Correct the minUsage() and maxUsage() methods.
- Add unit test.
Result:
Correct metrics
Motivation:
The method setBytes creates temporary heap buffer when source buffer is read-only.
But this temporary buffer is not used correctly and may lead to data corruption.
This problem occurs when target buffer is pooled and temporary buffer
arrayOffset() is not zero.
Modifications:
Use correct arrayOffset when calling PlatformDependent.copyMemory.
Unit test was added to test this case.
Result:
Setting buffer content works correctly when target is pooled buffer and source
is read-only ByteBuffer.
Motivation:
My previous commit b88a980482 introduced a flawed unit test,
that executes an assertion in a different thread than the test thread.
If this assertion fails, the test doesn't fail.
Modifications:
Replace the assertion by a proper workaround.
Result:
More correct unit test
Motivation:
Circular assignment of arenas to thread caches can lead to less than optimal
mappings in cases where threads are (frequently) shutdown and started.
Example Scenario:
There are a total of 2 arenas. The first two threads performing an allocation
would lead to the following mapping:
Thread 0 -> Arena 0
Thread 1 -> Arena 1
Now, assume Thread 1 is shut down and another Thread 2 is started. The current
circular assignment algorithm would lead to the following mapping:
Thread 0 -> Arena 0
Thread 2 -> Arena 0
Ideally, we want Thread 2 to use Arena 1 though.
Presumably, this is not much of an issue for most Netty applications that do all
the allocations inside the eventloop, as eventloop threads are seldomly shut down
and restarted. However, applications that only use the netty-buffer package
or implement their own threading model outside the eventloop might suffer from
increased contention. For example, gRPC Java when using the blocking stub
performs some allocations outside the eventloop and within its own thread pool
that is dynamically sized depending on system load.
Modifications:
Implement a linear scan algorithm that assigns a new thread cache to the arena
that currently backs the fewest thread caches.
Result:
Closer to ideal mappings between thread caches and arenas. In order to always
get an ideal mapping, we would have to re-balance the mapping whenever a thread
dies. However, that's difficult because of deallocation.
Motivation
See ##3229
Modifications:
Add methods with position independent FileChannel calls to ByteBuf and its subclasses.
Results:
The user can use these new methods to read/write ByteBuff without updating FileChannel's position.
Motivation:
f750d6e36c added support for surrogates in the writeUtf8 conversion. However exceptions are thrown if invalid input is detected, but the JDK (and slow path of writeUtf8) uses a replacement character and does not throw. We should behave the same way.
Modificiations:
- Don't throw in ByteBufUtil.writeUtf8, and instead use a replacement character consistent with the JDK
Result:
ByteBufUtil.writeUtf8 behavior is consistent with the JDK UTF_8 conversion.
Motivation:
There are a few buffer leaks related to how Unpooled.wrapped and Base64.encode is used.
Modifications:
- Fix usages of Bas64.encode to correct leaks
- Clarify interface of Unpooled.wrapped* to ensure reference count ownership is clearly defined.
Result:
Reference count code is more clearly defined and less leaks are possible.
Motivation:
UTF-16 can not represent the full range of Unicode characters, and thus has the concept of Surrogate Pair (http://unicode.org/glossary/#surrogate_pair) where 2 16-bit code units can be used to represent the missing characters. ByteBufUtil.writeUtf8 is currently does not support this and is thus incomplete.
Modifications:
- Add support for surrogate pairs in ByteBufUtil.writeUtf8
Result:
ByteBufUtil.writeUtf8 now supports surrogate pairs and is correctly converting to UTF-8.
Motivation:
We missed to check if the dst is ready only before using unsafe to copy data into it which lead to data-corruption. We need to ensure we respect ready only ByteBuffer.
Modifications:
- Correctly check if the dst is ready only before copy data into it in UnsafeByteBufUtil
- Also make it work for buffers that are not direct and not have an array
Result:
No more data corruption possible if the dst buffer is readonly and unsafe buffer implementation is used.
As discussed in #3209, this PR adds Little Endian accessors
to ByteBuf and descendants.
Corresponding accessors were added to UnsafeByteBufUtil,
HeapByteBufferUtil to avoid calling `reverseBytes`.
Deprecate `order()`, `order(buf)` and `SwappedByteBuf`.
Motivation:
The method setBytes did not work correctly because read-only ByteBuffer
does not allow access to its underlying array.
Modifications:
New case was added for ByteBuffer's that are not direct and do not have an array.
These must be handled by copying the data into a temporary array. Unit test was
added to test this case.
Result:
It is now possible to use read-only ByteBuffer as the source
for the setBytes method.
Motivation:
Fix a race condition that was introduced by f18990a8a5 that could lead to a NPE when allocate from the PooledByteBufAllocator concurrently by many threads.
Modifications:
Correctly synchronize on the PoolSubPage head.
Result:
No more race.
Motivation:
SlicedByteBuf did double reference count checking for various bulk operations, which affects performance.
Modifications:
- Add package private method to AbstractByteBuf that can be used to check indexes without check the reference count
- Use this new method in the bulk operation os SlicedByteBuf as the reference count checks take place on the wrapped buffer anyway
- Fix test-case to not try to read data that is out of the bounds of the buffer.
Result:
Better performance on bulk operations when using SlicedByteBuf (and sub-classes)
Motivation:
Some of the tests in the buffer module contained unused code. Some of the tests also used unnecessary inheritance which could be avoided to simplify code.
Modifications:
Cleanup the test cases.
Result:
Cleaner code, less cruft.
Motivation:
We need to always return a real slice even when the requested length is 0. This is needed as otherwise we not correctly share the reference count and so may leak a buffer if the user call release() on the returned slice and expect it to decrement the reference count of the "parent" buffer.
Modifications:
- Always return a real slice
- Add unit test for the bug.
Result:
No more leak possible when a user requests a slice of length 0 of a SlicedByteBuf.
Motivation:
Calling AbstractByteBuf.toString(..., Charset) is used quite frequently by users but produce a lot of GC.
Modification:
- Use a FastThreadLocal to store the CharBuffer that are needed for decoding.
- Use internalNioBuffer(...) when possible
Result:
Less object creation / Less GC
Motivation:
ByteBufUtil.writeUtf8(...) / writeUsAscii(...) can use a fast-path when writing into AbstractByteBuf. We should try to unwrap WrappedByteBuf implementations so
we are able to do the same on wrapped AbstractByteBuf instances.
Modifications:
- Try to unwrap WrappedByteBuf to use the fast-path
Result:
Faster writing of utf8 and usascii for WrappedByteBuf instances.
Motivation:
As toString() is often used while logging we need to ensure this produces no exception.
Modifications:
Ensure we never throw an IllegalReferenceCountException.
Result:
Be able to log without produce exceptions.
Motivation:
The logic in ByteBufUtilTest.ByteBufUtilTest is wrong. It is attempting to ensure at least 1 byte is different in the ranges that will be subsequently compared, but does so before the copy operation.
Modifications:
- Move the code which ensures there is a difference to after the copy
- Simplify the logic which ensures there is a difference
Result:
Unit test now operates as designed.
Motivation:
ByteBufUtilTest.notEqualsBufferSubsections is testing non-equality but just uses random numbers to assume they will not be equal. Even after the random bytes are generated we should check they are infact not equal so the test has no chance of failing when it should not.
Modifications:
- Loop through bytes in notEqualsBufferSubsections after they are randomly generated to ensure there is atleast 1 difference.
Result:
More reliable unit tests.
Motivation:
We need to ensure all markers are reset when doing an allocation via the PooledByteBufAllocator. This was not the always the case.
Modifications:
Move all logic that needs to get executed when reuse a PooledByteBuf into one place and call it.
Result:
Correct behavior
