[infinispan-issues] [JBoss JIRA] Issue Comment Edited: (ISPN-1131) Locking optimization: acquire (write) locks at prepare time

[ https://issues.jboss.org/browse/ISPN-1131?page=com.atlassian.jira.plugin.... ] Mircea Markus edited comment on ISPN-1131 at 5/23/11 4:15 PM: -------------------------------------------------------------- Suggested design. On first release this is an experimental feature disabled by default. In ordert to enable it use the following configuration element: {code:xml} <locking isolationLevel="READ_COMMITTED" lockAtPrepareTime="true" /> {code} In order to preserve the existing functionality and also support *lockAtPrepareTime* a new interceptor is added: {{PrepareTimeLockingInterceptor}}: * it extends {{LockingInterceptor}} * when *lockAtPrepareTime* is enabled it takes {{LockingInterceptor}}'s place is the interceptor chain * it overrides all {{LockingInterceptor}}'s {{visit<WriteCommand>}} methods (e.g. visitpPutKeyValueCommand) and does not acquire write locks on these invocations but read locks * read locks are acquired similar to {{LockingInterceptor.visitGetKeyValueCommand()}}: {code:java} public Object visitGetKeyValueCommand(InvocationContext ctx, GetKeyValueCommand command) throws Throwable { try { entryFactory.wrapEntryForReading(ctx, command.getKey()); return invokeNextInterceptor(ctx, command); } finally { doAfterCall(ctx); } } {code} * {{PrepareTimeLockingInterceptor.visitPrepareCommand}} overrides {{LockingInterceptor.visitPrepareCommand}}: {code:java} @Override public Object visitPrepareCommand(TxInvocationContext ctx, PrepareCommand command) throws Throwable { super.visitPrepareCommand(ctx, command); if (ctx.isOriginLocal()) { for (WriteCommand wc : command.getModifications()) { acquireLock(wc); } } return invokeNextInterceptor(ctx, command); } {code} * {{acquireLock()}} in the code above acquires locks *exactly* the same way {{LockingInterceptor}} would do for a given command. ** E.g. {{acquireLock(PutKeyValueCommand)}} is equivalent with {{LockingInterceptor.visitPutKeyValueCommand(..)}} ** if in distributed mode, the acquire lock *only* acquires a lock if the key(s) within {{WriteCommand}} map to the local node was (Author: mircea.markus): Suggested design. When first released, this will be an experimental feature disabled by default. It will be possible to enable it by using the following configuration element: {code:xml} <locking isolationLevel="READ_COMMITTED" lockAtPrepareTime="true" /> {code} In order to preserve the existing functionality and also support *lockAtPrepareTime* a new interceptor will be added: {{PrepareTimeLockingInterceptor}}: * it extends {{LockingInterceptor}} * when *lockAtPrepareTime* is enabled it takes {{LockingInterceptor}}'s place is the interceptor chain * it overrides the all {{LockingInterceptor}}'s {{visit<WriteCommand>}} methods (e.g. visitpPutKeyValueCommand) and does not acquire write locks on these invocations but read locks * read locks are acquired similar to {{LockingInterceptor.visitGetKeyValueCommand()}}: {code:java} public Object visitGetKeyValueCommand(InvocationContext ctx, GetKeyValueCommand command) throws Throwable { try { entryFactory.wrapEntryForReading(ctx, command.getKey()); return invokeNextInterceptor(ctx, command); } finally { doAfterCall(ctx); } } {code} * {{PrepareTimeLockingInterceptor.visitPrepareCommand}} also overrides the same method from {{LockingInterceptor}}: {code:java} @Override public Object visitPrepareCommand(TxInvocationContext ctx, PrepareCommand command) throws Throwable { super.visitPrepareCommand(ctx, command); if (ctx.isOriginLocal()) { for (WriteCommand wc : command.getModifications()) { acquireLock(wc); } } return invokeNextInterceptor(ctx, command); } {code} * {{acquireLock()}} in the code above acquires locks *exactly* the same way {{LockingInterceptor}} would do for a given command. ** E.g. {{acquireLock(PutKeyValueCommand}} is equivalent with {{LockingInterceptor.visitPutKeyValueCommand(..)}} ** if in distributed mode, the acquire lock *only* acquires a lock if the key(s) within {{WriteCommand}} map to the local node -- This message is automatically generated by JIRA. For more information on JIRA, see: http://www.atlassian.com/software/jira