A Tutorial Introduction to the ADAPTIVE Communication ...

Developed by HUGHES NETWORK SYSTEMS (HNS) for the benefit of the ACE community at large A Tutorial Introduction to the ADAPTIVE Communication Environment (ACE) Umar Syyid (usyyid@hotmail.com)  Acknowledgments I would like to thank the following people for their assistance in making this tutorial possible, Ambreen Ilyas ambreen@bitsmart.com James CE Johnson jcej@lads.com Aaron Valdivia avaldivia@hns.com Douglas C. Schmidt schmidt@cs.wustl.edu Thomas Jordan ace@programmer.net Erik Koerber erik.koerber@siemens.at Martin Krumpolec krumpo@pobox.sk Fred Kuhns fredk@tango.cs.wustl.edu Susan Liebeskind shl@cc.gatech.edu Andy Bellafaire amba@callisto.eci-esyst.com Marina marina@cs.wustl.edu Jean-Paul Genty jpgenty@sesinsud.com Mike Curtis mccurry@my-deja.com Philippe Perrin perrin@enseirb.fr Gunnar Bason a98gunbu@student.his.se  TABLE OF CONTENTS Acknowledgments....................................................................................................................................................0 TABLE OF CONTENTS ........................................................................................................................................... I THE ADAPTIVE COMMUNICATION ENVIRONMENT.................................................................................1 THE ACE ARCHITECTURE...........................................................................................................................................2 The OS Adaptation Layer .......................................................................................................................................2 The C++ wrappers layer.........................................................................................................3 The ACE Framework Components ........................................................................................................................4 IPC SAP ..........................................................................................................................................................................6 CATEGORIES OF CLASSES IN IPC SAP.6 THE SOCKETS CLASS CATEGORY (ACE_SOCK) ......................................................................................................7 Using Streams in ACE ............................................................................................................................................8 Using Datagrams in ACE............................12 Using Multicast with ACE ....................................................................................................................................15 MEMORY MANAGEMENT ...................................................................................................................................19 ALLOCATORS .............................................................................................................................................................20 Using the Cached Allocator .................................................................................................................................20 ACE_MALLOC23 How ACE_Malloc works...........................24 Using ACE_Malloc...............................................................................................................................................25 USING THE MALLOC CLASSES WITH THE ALLOCATOR INTERFACE..........................................................................28 THREAD MANAGEMENT .....................................................................................................................................29 CREATING AND CANCELING THREADS ......................................................................................................................29 SYNCHRONIZATION PRIMITIVES IN ACE...................................................................................................................32 The ACE Locks Category .....................................................................................................................................32 Using the Mutex classes....................................................................................................................................................... 33 Using the Lock and Lock Adapter for dynamic binding.................................................................................................... 35 Using Tokens..................................................... 37 The ACE Guards Category...................................................................................................................................38 E Conditions Category.............................................................................................................................40 Miscellaneous Synchronization Classes ..............................................................................................................43 Barriers in ACE .................................................................................................................................................................... 43 Atomic Op............................................................................................................................................................................. 44 THREAD MANAGEMENT WITH THE ACE_THREAD_MANAGER.................................................................................46 THREAD SPECIFIC STORAGE......................................................................................................................................49 TASKS AND ACTIVE OBJECTS...........................................................................................................................52 ACTIVE OBJECTS.........................52 ACE_TASK.................................53 Structure of a Task ................................................................................................................................................53 Creating and using a Task....................................................................................................................................54 Communication between tasks .............................................................................................................................55 THE ACTIVE OBJECT PATTERN..................................................................................................................................58 How the Active Object Pattern Works .................................................................................................................58 I  THE REACTOR ........................................................................................................................................................66 REACTOR COMPONENTS............................................................................................................................................66 EVENT HANDLERS......................67 Registration of Event Handlers ............................................................................................................................70 Removal and lifetime management of Event Handlers .......................................................................................70 Implicit Removal of Event Handlers from the Reactors Internal dispatch tables.............................................................. 71 Explicit removal of Event Handlers from thrs Internal Dispatch Tables........... 71 EVENT HANDLING WITH THE REACTOR....................................................................................................................72 I/O Event De-multiplexing....................................................................................................................................72 TIMERS........................................76 ACE_Time_Value..................................................................................................................................................76 Setting and Removing Timers...............................................................................................................................77 Using different Timer Queues ...................................................................................................78 HANDLING SIGNALS...................................................................................................................................................79 USING NOTIFICATIONS................79 THE ACCEPTOR AND CONNECTOR ................................................................................................................83 THE ACCEPTOR PATTERN.................................................................................................................................84 COMPONENTS ....................................................................................................................................................85 USAGE ..................................................................................................................................................................86 THE CONNECTOR ..................................................................................................................90 USING THE ACCEPTOR AND CONNECTOR TOGETHER ..........................................................................91 ADVANCED SECTIONS................................................................................................................................................93 THE ACE_SVC_HANDLER CLASS ...................................................................................................................94 ACE_Task........................................................................................................................