[weave message frame] [netty Source analysis]7 Unsafe Implementation Class NIOSOCKETCHANNELUNSAFE responsibility and implementation

Last Update:2017-06-21 Source: Internet

Author: User

Tags throwable

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Unsafe is the internal interface of the channel and is responsible for dealing with the underlying socket. It is not publicly available to developers from the writing and naming, until the final implementation of the Niosocketchannelunsafe is not disclosed.<pre> public InterfaceChannelextendsattributemap, channeloutboundinvoker, comparable<channel> { InterfaceUnsafe {recvbytebufallocator.handle Recvbufallochandle (); SocketAddress localaddress (); SocketAddress remoteaddress (); voidRegister (eventloop eventloop, channelpromise promise); voidbind (socketaddress localaddress, channelpromise promise); voidConnect (socketaddress remoteaddress, socketaddress localaddress, channelpromise promise); voidDisconnect (channelpromise promise); voidClose (channelpromise promise); voidcloseforcibly (); voidderegister (channelpromise promise); voidBeginRead (); voidWrite (Object msg, channelpromise promise); voidFlush (); Channelpromise voidpromise (); Channeloutboundbuffer Outboundbuffer (); } public InterfaceNiounsafeextendsUnsafe {selectablechannel Ch (); voidFinishconnect (); voidRead (); voidForceflush (); }}</pre>Niosocketchannelunsafe inheritance: niosocketchannelunsafe, niobyteunsafe, abstractniounsafe, AbstractunsafeAbstractunsafe: responsible for socket link binding, acceptance, shutdown, data fush operationEach operation is handled in approximately four stages<pre>@Override public Final voidBindFinalSocketAddress localaddress,Finalchannelpromise Promise) {asserteventloop (); //pre-execution Check if(!promise.setuncancellable () | | |Ensureopen (promise)) { return; } BooleanWasactive =isActive (); //Call Implementation Try{dobind (localaddress); } Catch(throwable t) {safesetfailure (promise, t); Closeifclosed (); return; } //Call the business, notify pipeline if(!wasactive &&isActive ()) {invokelater ()-pipeline.firechannelactive ();); } //Complete Stage Processingsafesetsuccess (promise); }</pre><pre>@Override public Final voidFlush () {asserteventloop (); Channeloutboundbuffer Outboundbuffer= this. outboundbuffer; if(outboundbuffer = =NULL) { return; } Outboundbuffer.addflush (); Flush0 (); } @SuppressWarnings ("deprecation") protected voidflush0 () {//just finished flush operation if(inFlush0) {return; } FinalChanneloutboundbuffer Outboundbuffer = this. outboundbuffer; if(outboundbuffer = =NULL||Outboundbuffer.isempty ()) { return; } inFlush0=true; //link check before sending data if(!isActive ()) { Try { if(isOpen ()) {//true to notify the handler channelwritabilitychanged methodOutboundbuffer.failflushed (flush0_not_yet_connected_exception,true); } Else{outboundbuffer.failflushed (flush0_closed_channel_exception,false); } } finally{inFlush0=false; } return; } Try { //Call Channel ImplementationDowrite (outboundbuffer); } Catch(throwable T) {if(tinstanceofIOException &&config (). isautoclose ()) {close (voidpromise (), t, flush0_closed_channel_exception,false); } Else{outboundbuffer.failflushed (t,true); } } finally{inFlush0=false; } }</pre>Abstractniounsafe: is the Niounsafe interface template class, Simple packagingNiobyteunsafe: Main to Niounsafe interface read operation implementationNiosocketchannelunsafe: It's just a simple wrapper, which is finally exposed to internal useNiobyteunsafe Read method<pre> public Final voidRead () {FinalChannelconfig config =Config (); FinalChannelpipeline pipeline =Pipeline (); FinalBytebufallocator allocator =Config.getallocator (); FinalRecvbytebufallocator.handle Allochandle =Recvbufallochandle (); Allochandle.reset (config); Bytebuf Bytebuf=NULL; BooleanClose =false; Try { do{bytebuf=allochandle.allocate (allocator); //Fill BYTEBUF call channel implementation intSize =doreadbytes (bytebuf); //record last read lengthAllochandle.lastbytesread (size); //link off, release bytebuf if(allochandle.lastbytesread () <= 0) {bytebuf.release (); Bytebuf=NULL; Close= Allochandle.lastbytesread () < 0; break; } //self-increment message read processing timesAllochandle.incmessagesread (1); //filled BYTEBUF call business pipeline completedReadpending =false; Pipeline.firechannelread (bytebuf); Bytebuf=NULL; } while(allochandle.continuereading ()); Allochandle.readcomplete (); Pipeline.firechannelreadcomplete (); if(close) {closeonread (pipeline); } } Catch(throwable t) {handlereadexception (pipeline, bytebuf, t, close, allochandle); } finally { //if it is not active read to be completed after you want to clean the read op if(!readpending &&!)Config.isautoread ()) {removereadop (); } } } }</pre>Summary: It can be seen that no calculation code, unsafe only to achieve boundary inspection, process control, concrete implementation to the upper processing[weave message frame] [netty Source analysis]7 Unsafe Implementation Class NIOSOCKETCHANNELUNSAFE responsibility and implementation

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