Init is an overridden procedure in TIdSchedulerOfThreadPool used to initialize the pre-allocated internal pool of threads for the thread-based scheduler. 

Init calls the inherited method, and creates the TIdThreadSafeList member used for internal storage of the threads. At runtime, Init uses the value in PoolSize is used to create the specified number of threads in the thread pool by calling NewThread. 

Calling Init at design-time has no effect. 

Threads allocated to the thread pool are extracted for use in the AcquireYarn method. Thread instances are returned to the thread pool in the ReleaseYarn, TerminateYarn, and TerminateAllYearns methods.

TIdTCPServer.Scheduler 

TIdTCPServer.Contexts 

TIdTCPServer.ContextClass 

TIdThreadSafeList 

TIdThreadWithTask 

TIdYarnOfThread