Commit Graph

456 Commits

Author SHA1 Message Date
Norman Maurer
182c91f06c 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 11:30:31 +01:00
Idel Pivnitskiy
35db3c6710 Small performance improvements
Motivation:

Found performance issues via FindBugs and PMD.

Modifications:

- Removed unnecessary boxing/unboxing operations in DefaultTextHeaders.convertToInt(CharSequence) and DefaultTextHeaders.convertToLong(CharSequence). A boxed primitive is created from a string, just to extract the unboxed primitive value.
- Added a static modifier for DefaultHttp2Connection.ParentChangedEvent class. This class is an inner class, but does not use its embedded reference to the object which created it. This reference makes the instances of the class larger, and may keep the reference to the creator object alive longer than necessary.
- Added a static compiled Pattern to avoid compile it each time it is used when we need to replace some part of authority.
- Improved using of StringBuilders.

Result:

Performance improvements.
2014-11-20 00:10:06 -05:00
Norman Maurer
48f1398869 Disable caching of PooledByteBuf for different threads.
Motivation:

We introduced a PoolThreadCache which is used in our PooledByteBufAllocator to reduce the synchronization overhead on PoolArenas when allocate / deallocate PooledByteBuf instances. This cache is used for both the allocation path and deallocation path by:
  - Look for cached memory in the PoolThreadCache for the Thread that tries to allocate a new PooledByteBuf and if one is found return it.
  - Add the memory that is used by a PooledByteBuf to the PoolThreadCache of the Thread that release the PooledByteBuf

This works out very well when all allocation / deallocation is done in the EventLoop as the EventLoop will be used for read and write. On the otherside this can lead to surprising side-effects if the user allocate from outside the EventLoop and and pass the ByteBuf over for writing. The problem here is that the memory will be added to the PoolThreadCache that did the actual write on the underlying transport and not on the Thread that previously allocated the buffer.

Modifications:

Don't cache if different Threads are used for allocating/deallocating

Result:

Less confusing behavior for users that allocate PooledByteBufs from outside the EventLoop.
2014-09-22 13:39:31 +02:00
Norman Maurer
858de5699b [#2924] Correctly update head in MemoryRegionCache.trim()
Motivation:
When MemoryRegionCache.trim() is called, some unused cache entries will be freed (started from head). However, in MeoryRegionCache.trim() the head is not updated, which make entry list's head point to an entry whose chunk is null now and following allocate of MeoryRegionCache will return false immediately.

In other word, cache is no longer usable once trim happen.

Modifications:

Update head to correct idx after free entries in trim().

Result:

MemoryRegionCache behaves correctly even after calling trim().
2014-09-22 11:04:21 +02:00
Norman Maurer
4e62b51c6d [#2843] Add test-case to show correct behavior of ByteBuf.refCnt() and ByteBuf.release(...)
Motivation:

We received a bug-report that the ByteBuf.refCnt() does sometimes not show the correct value when release() and refCnt() is called from different Threads.

Modifications:

Add test-case which shows that all is working like expected

Result:

Test-case added which shows everything is ok.
2014-09-01 08:50:21 +02:00
Trustin Lee
b5f61d0de5 [maven-release-plugin] prepare for next development iteration 2014-08-16 03:27:42 +09:00
Trustin Lee
76ac3b21a5 [maven-release-plugin] prepare release netty-4.1.0.Beta3 2014-08-16 03:27:37 +09:00
Trustin Lee
b3c1904cc9 [maven-release-plugin] prepare for next development iteration 2014-08-15 09:31:03 +09:00
Trustin Lee
e013b2400f [maven-release-plugin] prepare release netty-4.1.0.Beta2 2014-08-15 09:30:59 +09:00
Trustin Lee
0dc6a8dccf Use heap buffers for Unpooled.copiedBuffer()
Related issue: #2028

Motivation:

Some copiedBuffer() methods in Unpooled allocated a direct buffer.  An
allocation of a direct buffer is an expensive operation, and thus should
be avoided for unpooled buffers.

Modifications:

- Use heap buffers in all copiedBuffer() methods

Result:

Unpooled.copiedBuffers() are less expensive now.
2014-08-13 15:10:11 -07:00
Norman Maurer
ef572d859d Change back default allocator to pooled.
Motivation:

While porting some changes from 4.0 to 4.1 and master branch I changed the default allocator from pooled to unpooled by mistake. This should be reverted. The guilty commit is 4a3ef90381.

Thanks to @blucas for spotting this.

Modifications:

Revert changes related to allocator.

Result:

Use the correct default allocator again.
2014-08-13 12:07:06 +02:00
Norman Maurer
869687bd71 Port ChannelOutboundBuffer and related changes from 4.0
Motivation:

We did various changes related to the ChannelOutboundBuffer in 4.0 branch. This commit port all of them over and so make sure our branches are synced in terms of these changes.

Related to [#2734], [#2709], [#2729], [#2710] and [#2693] .

Modification:
Port all changes that was done on the ChannelOutboundBuffer.

This includes the port of the following commits:
 - 73dfd7c01b
 - 997d8c32d2
 - e282e504f1
 - 5e5d1a58fd
 - 8ee3575e72
 - d6f0d12a86
 - 16e50765d1
 - 3f3e66c31a

Result:
 - Less memory usage by ChannelOutboundBuffer
 - Same code as in 4.0 branch
 - Make it possible to use ChannelOutboundBuffer with Channel implementation that not extends AbstractChannel
2014-08-05 15:00:45 +02:00
Trustin Lee
9a654d8a61 Remove duplicate range check in AbstractByteBuf.skipBytes() 2014-07-29 15:58:28 -07:00
Idel Pivnitskiy
ad1389be9d Small performance improvements
Modifications:

- Added a static modifier for CompositeByteBuf.Component.
This class is an inner class, but does not use its embedded reference to the object which created it. This reference makes the instances of the class larger, and may keep the reference to the creator object alive longer than necessary.
- Removed unnecessary boxing/unboxing operations in HttpResponseDecoder, RtspResponseDecoder, PerMessageDeflateClientExtensionHandshaker and PerMessageDeflateServerExtensionHandshaker
A boxed primitive is created from a String, just to extract the unboxed primitive value.
- Removed unnecessary 3 times calculations in DiskAttribute.addContent(...).
- Removed unnecessary checks if file exists before call mkdirs() in NativeLibraryLoader and PlatformDependent.
Because the method mkdirs() has this check inside.
- Removed unnecessary `instanceof AsciiString` check in StompSubframeAggregator.contentLength(StompHeadersSubframe) and StompSubframeDecoder.getContentLength(StompHeaders, long).
Because StompHeaders.get(CharSequence) always returns java.lang.String.
2014-07-20 09:26:04 +02:00
Norman Maurer
f88dfd0430 [#2653] Remove unnecessary ensureAccessible() calls
Motivation:

I introduced ensureAccessible() class as part of 6c47cc9711 in some places. Unfortunally I also added some where these are not needed and so caused a performance regression.

Modification:

Remove calls where not needed.

Result:

Fixed performance regression.
2014-07-14 21:04:12 +02:00
Norman Maurer
93c306602a [#2653] Remove uncessary range checks for performance reasons
Motivation:

I introduced range checks as part of 6c47cc9711 in some places. Unfortunally I also added some where these are not needed and so caused a performance regression.

Modification:

Remove range checks where not needed

Result:

Fixed performance regression.
2014-07-14 11:43:19 +02:00
Brendt Lucas
ac8ac59148 [#2642] CompositeByteBuf.deallocate memory/GC improvement
Motivation:

CompositeByteBuf.deallocate generates unnecessary GC pressure when using the 'foreach' loop, as a 'foreach' loop creates an iterator when looping.

Modification:

Convert 'foreach' loop into regular 'for' loop.

Result:

Less GC pressure (and possibly more throughput) as the 'for' loop does not create an iterator
2014-07-08 21:08:14 +02:00
Trustin Lee
e167b02d52 [maven-release-plugin] prepare for next development iteration 2014-07-04 17:26:02 +09:00
Trustin Lee
ba50cb829b [maven-release-plugin] prepare release netty-4.1.0.Beta1 2014-07-04 17:25:54 +09:00
Trustin Lee
787663a644 [maven-release-plugin] rollback the release of netty-4.1.0.Beta1 2014-07-04 17:11:14 +09:00
Trustin Lee
83eae705e1 [maven-release-plugin] prepare release netty-4.1.0.Beta1 2014-07-04 17:02:17 +09:00
Trustin Lee
fbf1bdbef1 Fix the build timeout when 'leak' profile is active
Motivation:

AbstractByteBufTest.testInternalBuffer() uses writeByte() operations to
populate the sample data.  Usually, this isn't a problem, but it starts
to take a lot of time when the resource leak detection level gets
higher.

In our CI machine, testInternalBuffer() takes more than 30 minutes,
causing the build timeout when the 'leak' profile is active (paranoid
level resource detection.)

Modification:

Populate the sample data using ThreadLocalRandom.nextBytes() instead of
using millions of writeByte() operations.

Result:

Test runs much faster when leak detection level is high.
2014-07-03 17:55:10 +09:00
Trustin Lee
d0912f2709 Fix most inspector warnings
Motivation:

It's good to minimize potentially broken windows.

Modifications:

Fix most inspector warnings from our profile
Update IntObjectHashMap

Result:

Cleaner code
2014-07-02 19:55:07 +09:00
Norman Maurer
9594a81b95 [#2622] Correctly check reference count before try to work on the underlying memory
Motivation:

Because of how we use reference counting we need to check for the reference count before each operation that touches the underlying memory. This is especially true as we use sun.misc.Cleaner.clean() to release the memory ASAP when possible. Because of this the user may cause a SEGFAULT if an operation is called that tries to access the backing memory after it was released.

Modification:

Correctly check the reference count on all methods that access the underlying memory or expose it via a ByteBuffer.

Result:

Safer usage of ByteBuf
2014-06-30 07:14:25 +02:00
Trustin Lee
c0462c0c3b Optimize PoolChunk
- Using short[] for memoryMap did not improve performance. Reverting
  back to the original dual-byte[] structure in favor of simplicity.
- Optimize allocateRun() which yields small performence improvement
- Use local variable when member fields are accessed more than once
2014-06-26 17:06:10 +09:00
Trustin Lee
dbc011c3f4 Fix inspector warnings 2014-06-26 17:06:10 +09:00
Pavan Kumar
69a6ad940a Improve the allocation algorithm in PoolChunk
Motivation:

Depth-first search is not always efficient for buddy allocation.

Modification:

Employ a new faster search algorithm with different memoryMap layout.

Result:

With thread-local cache disabled, we see a lot of performance
improvment, especially when the size of the allocation is as small as
the page size, which had the largest search space previously.
2014-06-26 17:06:10 +09:00
Trustin Lee
41d44a8161 Remove 'get' prefix from all HTTP/SPDY messages
Motivation:

Persuit for the consistency in method naming

Modifications:

- Remove the 'get' prefix from all HTTP/SPDY message classes
- Fix some inspector warnings

Result:

Consistency
2014-06-24 18:03:33 +09:00
Norman Maurer
12a3e23e47 MessageToByteEncoder always starts with ByteBuf that use initalCapacity == 0
Motivation:

MessageToByteEncoder always starts with ByteBuf that use initalCapacity == 0 when preferDirect is used. This is really wasteful in terms of performance as every first write into the buffer will cause an expand of the buffer itself.

Modifications:

 - Change ByteBufAllocator.ioBuffer() use the same default initialCapacity as heapBuffer() and directBuffer()
 - Add new allocateBuffer method to MessageToByteEncoder that allow the user to do some smarter allocation based on the message that will be encoded.

Result:

Less expanding of buffer and more flexibilty when allocate the buffer for encoding.
2014-06-24 13:55:21 +09:00
Trustin Lee
37b07a04d4 Revert "Improve the allocation algorithm in PoolChunk"
This reverts commit 36305d7dce, which
seems to cause an assertion failure on our CI machine.
2014-06-21 19:19:35 +09:00
Pavan Kumar
6bd8c5d4d0 Improve the allocation algorithm in PoolChunk
Motivation:

Depth-first search is not always efficient for buddy allocation.

Modification:

Employ a new faster search algorithm with different memoryMap layout.

Result:

With thread-local cache disabled, we see a lot of performance
improvment, especially when the size of the allocation is as small as
the page size, which had the largest search space previously:

-- master head --
Benchmark                (size) Mode    Score  Error Units
pooledDirectAllocAndFree  8192 thrpt  215.392  1.565 ops/ms
pooledDirectAllocAndFree 16384 thrpt  594.625  2.154 ops/ms
pooledDirectAllocAndFree 65536 thrpt 1221.520 18.965 ops/ms
pooledHeapAllocAndFree    8192 thrpt  217.175  1.653 ops/ms
pooledHeapAllocAndFree   16384 thrpt  587.250 14.827 ops/ms
pooledHeapAllocAndFree   65536 thrpt 1217.023 44.963 ops/ms

-- changes --
Benchmark                (size) Mode    Score  Error Units
pooledDirectAllocAndFree  8192 thrpt 3656.744 94.093 ops/ms
pooledDirectAllocAndFree 16384 thrpt 4087.152 22.921 ops/ms
pooledDirectAllocAndFree 65536 thrpt 4058.814 29.276 ops/ms
pooledHeapAllocAndFree    8192 thrpt 3640.355 44.418 ops/ms
pooledHeapAllocAndFree   16384 thrpt 4030.206 24.365 ops/ms
pooledHeapAllocAndFree   65536 thrpt 4103.991 70.991 ops/ms
2014-06-21 13:20:25 +09:00
Norman Maurer
f05510063e Remove System.out.println(...) debug messages 2014-06-20 19:42:38 +02:00
Norman Maurer
371f8066d2 [#2580] [#2587] Fix buffer corruption regression when ByteBuf.order(LITTLE_ENDIAN) is used
Motivation:

To improve the speed of ByteBuf with order LITTLE_ENDIAN and where the native order is also LITTLE_ENDIAN (intel) we introduces a new special SwappedByteBuf before in commit 4ad3984c8b. Unfortunally the commit has a flaw which does not handle correctly the case when a ByteBuf expands. This was caused because the memoryAddress was cached and never changed again even if the underlying buffer expanded. This can lead to corrupt data or even to SEGFAULT the JVM if you are lucky enough.

Modification:

Always lookup the actual memoryAddress of the wrapped ByteBuf.

Result:

No more data-corruption for ByteBuf with order LITTLE_ENDIAN and no JVM crashes.
2014-06-20 18:24:44 +02:00
Trustin Lee
085a61a310 Refactor FastThreadLocal to simplify TLV management
Motivation:

When Netty runs in a managed environment such as web application server,
Netty needs to provide an explicit way to remove the thread-local
variables it created to prevent class loader leaks.

FastThreadLocal uses different execution paths for storing a
thread-local variable depending on the type of the current thread.
It increases the complexity of thread-local removal.

Modifications:

- Moved FastThreadLocal and FastThreadLocalThread out of the internal
  package so that a user can use it.
- FastThreadLocal now keeps track of all thread local variables it has
  initialized, and calling FastThreadLocal.removeAll() will remove all
  thread-local variables of the caller thread.
- Added FastThreadLocal.size() for diagnostics and tests
- Introduce InternalThreadLocalMap which is a mixture of hard-wired
  thread local variable fields and extensible indexed variables
- FastThreadLocal now uses InternalThreadLocalMap to implement a
  thread-local variable.
- Added ThreadDeathWatcher.unwatch() so that PooledByteBufAllocator
  tells it to stop watching when its thread-local cache has been freed
  by FastThreadLocal.removeAll().
- Added FastThreadLocalTest to ensure that removeAll() works
- Added microbenchmark for FastThreadLocal and JDK ThreadLocal
- Upgraded to JMH 0.9

Result:

- A user can remove all thread-local variables Netty created, as long as
  he or she did not exit from the current thread. (Note that there's no
  way to remove a thread-local variable from outside of the thread.)
- FastThreadLocal exposes more useful operations such as isSet() because
  we always implement a thread local variable via InternalThreadLocalMap
  instead of falling back to JDK ThreadLocal.
- FastThreadLocalBenchmark shows that this change improves the
  performance of FastThreadLocal even more.
2014-06-19 21:13:55 +09:00
Norman Maurer
ad86ec798d Move calculateNewCapacity(...) to ByteBufAllocator
Motivation:

Currently we have the algorithm of calculate the new capacity of a ByteBuf implemented in AbstractByteBuf. The problem with this is that it is impossible for a user to change it if it not fits well it's use-case. We should better move it to ByteBufAllocator and so let the user implement it's own by either write his/her own ByteBufAllocator or just override the default implementation in one of our provided ByteBufAllocators.

Modifications:

Move calculateNewCapacity(...) to ByteBufAllocator and move the implementation (which was part of AbstractByteBuf) to AbstractByteBufAllocator.

Result:

The user can now override the default calculation algorithm when needed.
2014-06-17 09:35:45 +02:00
Norman Maurer
066f95d047 [#2573] UnpooledUnsafeDirectByteBuf.setBytes(int,ByteBuf,int,int) fails to use fast-path when src has array
Motivation:

UnpooledUnsafeDirectByteBuf.setBytes(int,ByteBuf,int,int) fails to use fast-path when src uses an array as backing storage. This is because the if else uses the wrong ByteBuf for its check.

Modifications:

- Use correct ByteBuf when check for array as backing storage
- Also eliminate unecessary check in UnpooledDirectByteBuf which always fails anyway

Result:

Faster setBytes(...) when src ByteBuf is backed by an array.

No more IndexOutOfBoundsException or data-corruption.
2014-06-16 11:11:41 +02:00
belliottsmith
2a2a21ec59 Introduce FastThreadLocal which uses an EnumMap and a predefined fixed set of possible thread locals
Motivation:
Provide a faster ThreadLocal implementation

Modification:
Add a "FastThreadLocal" which uses an EnumMap and a predefined fixed set of possible thread locals (all of the static instances created by netty) that is around 10-20% faster than standard ThreadLocal in my benchmarks (and can be seen having an effect in the direct PooledByteBufAllocator benchmark that uses the DEFAULT ByteBufAllocator which uses this FastThreadLocal, as opposed to normal instantiations that do not, and in the new RecyclableArrayList benchmark);

Result:
Improved performance
2014-06-13 10:56:18 +02:00
Norman Maurer
61dbc353ca [#2436] Unsafe*ByteBuf implementation should only invert bytes if ByteOrder differ from native ByteOrder
Motivation:
Our Unsafe*ByteBuf implementation always invert bytes when the native ByteOrder is LITTLE_ENDIAN (this is true on intel), even when the user calls order(ByteOrder.LITTLE_ENDIAN). This is not optimal for performance reasons as the user should be able to set the ByteOrder to LITTLE_ENDIAN and so write bytes without the extra inverting.

Modification:
- Introduce a new special SwappedByteBuf (called UnsafeDirectSwappedByteBuf) that is used by all the Unsafe*ByteBuf implementation and allows to write without inverting the bytes.
- Add benchmark
- Upgrade jmh to 0.8

Result:
The user is be able to get the max performance even on servers that have ByteOrder.LITTLE_ENDIAN as their native ByteOrder.
2014-06-05 10:59:22 +02:00
Trustin Lee
7d9374a582 Use Java 5 foreach for arrays for brevity at no cost 2014-06-02 18:25:25 +09:00
Trustin Lee
af4c30fa56 Remove the deprecated constructor 2014-06-02 18:24:19 +09:00
Trustin Lee
e79ca269b8 Introduce ThreadDeathWatcher
Motivation:

PooledByteBufAllocator's thread local cache and
ReferenceCountUtil.releaseLater() are in need of a way to run an
arbitrary logic when a certain thread is terminated.

Modifications:

- Add ThreadDeathWatcher, which spawns a low-priority daemon thread
  that watches a list of threads periodically (every second) and
  invokes the specified tasks when the associated threads are not alive
  anymore
  - Start-stop logic based on CAS operation proposed by @tea-dragon
- Add debug-level log messages to see if ThreadDeathWatcher works

Result:

- Fixes #2519 because we don't use GlobalEventExecutor anymore
- Cleaner code
2014-06-02 18:23:23 +09:00
Trustin Lee
ea3dac0753 Do not use a pseudo random for tree traversal
Motivation:

If we make allocateRun/SubpageSimple() always try the left node first and make allocateRun/Subpage() always tries the right node first,  it is more likely that allocateRun/Subpage() will find a node with ST_UNUSED sooner.

Modifications:

- Make allocateRunSimple() and allocateSubpageSimple() always try the left node first.
- Make allocateRun() and allocateSubpage() always try the right node first.
- Remove randome

Result:

We get the same performance without using random numbers.
2014-05-30 11:24:16 +09:00
Trustin Lee
e5ed69241b Optimize PooledByteBufAllocator
Motivation:

We still have a room for improvement in PoolChunk.allocateRun() and
Subpage.allocate().

Modifications:

- Unroll the recursion in PoolChunk.allocateRun()
- Subpage.allocate() makes use of the 'nextAvail' value set by previous
  free().

Result:

- PoolChunk.allocateRun() optimization yields 10%+ improvements in
  allocation throughput for non-subpage allocations.
- Subpage.allocate() optimization makes the subpage allocations for
  tiny buffers as fast as non-tiny buffers even when the pageSize is
  huge (e.g. 1048576) because it doesn't need to perform a linear search
  in most cases.
2014-05-30 10:51:21 +09:00
Jake Luciani
d547b5d51d Fix capacity check bug affecting offheap buffers 2014-05-13 07:25:15 +02:00
Trustin Lee
db3709e652 Synchronized between 4.1 and master
Motivation:

4 and 5 were diverged long time ago and we recently reverted some of the
early commits in master.  We must make sure 4.1 and master are not very
different now.

Modification:

Fix found differences

Result:

4.1 and master got closer.
2014-04-25 00:38:02 +09:00
ian
15d11289b0 Fix error that causes (up to) double memory usage
Motivation:

PoolArena's 'normalizeCapacity' function was micro-optimized some
time ago to remove a while loop. However, there was a change of
behavior in the function as a result. Capacities passed into it
that are already powers of 2 (and >= 512) are doubled in size. So
if I ask for a buffer with a capacity of 1024, I will get back one
that actually uses 2048 bytes (stored in maxLength).

Aligning to powers of two for book keeping ease is reasonable,
and if someone tries to expand a buffer, you might as well use some
of the previously wasted space. However, since this distinction
between 'easily expanded' and 'costly to expand' space is not
supported at all by the APIs, I cannot imagine this change to
doubling is desirable or intentional.

This is especially costly when using composite buffers. They
frequently allocate components with a capacity that is a power of
2, and they never attempt to expand components themselves. The end
result is that heavy use of pool-backed composite buffers wastes
almost half of the memory pool (the smaller / initial components are
<512 and so are not affected by the off-by-one bug).

Modifications:

Although I find it difficult to believe that such an optimization
is really helpful, I left it in and fixed the off-by-one issue by
decrementing the value at the start.

I also added a simple test to both attempt to verify that the
decrement fixes the issue without introducing any other change, and
to make it easy for a reviewer to test the existing behavior. PoolArena
does not seem to have much testing or testability support though so
the test is kind of a hack and will break for unrelated changes. I
suggest either removing it or factoring out the single non-static
portion of normalizeCapacity so that the fragile dummy PoolArena is
not required.

Result:

Pooled allocators will allocate less resources to the highly
inefficient and undocumented buffer section between length and
maxLength.

Composite buffers of non-trivial size that are backed by pooled
allocators will use about half as much memory.
2014-04-15 07:03:13 +02:00
Norman Maurer
ceffa82d0d [#2370] Periodically check for not alive Threads and free up their ThreadPoolCache
Motivation:
At the moment we create new ThreadPoolCache whenever a Thread tries either allocate or release something on the PooledByteBufAllocator. When something is released we put it then in its ThreadPoolCache. The problem is we never check if a Thread is not alive anymore and so we may end up with memory that is never freed again if a user create many short living Threads that use the PooledByteBufAllocator.

Modifications:
Periodically check if the Thread is still alive that has a ThreadPoolCache assinged and if not free it.

Result:
Memory is freed up correctly even for short living Threads.
2014-04-09 11:45:11 +02:00
Norman Maurer
8429ecfcc4 Implement Thread caches for pooled buffers to minimize conditions. This fixes [#2264] and [#808].
Motivation:
Remove the synchronization bottleneck in PoolArena and so speed up things

Modifications:

This implementation uses kind of the same technics as outlined in the jemalloc paper and jemalloc
blogpost https://www.facebook.com/notes/facebook-engineering/scalable-memory-allocation-using-jemalloc/480222803919.

At the moment we only cache for "known" Threads (that powers EventExecutors) and not for others to keep the overhead
minimal when need to free up unused buffers in the cache and free up cached buffers once the Thread completes. Here
we use multi-level caches for tiny, small and normal allocations. Huge allocations are not cached at all to keep the
memory usage at a sane level. All the different cache configurations can be adjusted via system properties or the constructor
directly where it makes sense.

Result:
Less conditions as most allocations can be served by the cache itself
2014-03-20 09:30:57 -07:00
Trustin Lee
19422972e3 Fix and simplify freeing a direct buffer / Fix Android support
Motivation:

6e8ba291cf introduced a regression in Android because Android does not have sun.nio.ch.DirectBuffer (see #2330.)  I also found PlatformDependent0.freeDirectBuffer() and freeDirectBufferUnsafe() are pretty much same after the commit and the unsafe version should be removed.

Modifications:

- Do not use the pooled allocator in Android because it's too resource hungry for Androids.
- Merge PlatformDependent0.freeDirectBuffer() and freeDirectBufferUnsafe() into one method.
- Make the Unsafe unavailable when sun.nio.ch.DirectBuffer is unavailable.  We could keep the Unsafe available and handle the sun.nio.ch.DirectBuffer case separately, but I don't want to complicate our code just because of that.  All supported JDK versions have sun.nio.ch.DirectBuffer if the Unsafe is available.

Result:

Simpler code. Fixes Android support (#2330)
2014-03-20 11:11:07 +09:00
Jakob Buchgraber
1bce46dbb3 Bit tricks to check for and calculate power of two.
Motivation:
I was studying the code and thought this was simpler and easier to
understand.

Modifications:
Replaced the for loop and if conditions, with a simple implementation.

Result:
Code is easier to understand.
2014-03-18 15:59:34 +09:00