I/O Objects T H E N E T W O R K I N G T S F R O M S C R A T C H Robert Leahy - rleahy@rleahy.caNetworking TS & Asio ISO C++ Networking is blocked on Executors (P0443) Target for Networking is composed asynchronous operations depend on those guarantees being honored transitively 6I/O Objects “I/O objects” provide a handle to low level asynchronous functionality within the framework of the Networking one or more I/O objects) is a useful pattern 19Service Named Type Requirement Service objects own completion handlers thereby breaking the potential ownership cycle Service objects are owned by an

std::string Bar std::stringObject Introspection (OI) Goals • Byte level memory footprint analysis for objects • Complete object type hierarchies • Dynamic allocations and containers • Optimised, production void doit(Foo&, Foo&) ‘this’ pointer entry:_ZN3FooD1Ev:this // Foo::~Foo() Global data global:myGlobalState Probe examples1. Inject OI into the target process 2. Wait for a thread to (Cumulative) Feature folly::small_vector 414132 8 2.359 10 0 88 25315061 • 2800 nested objects of type ‘FooBar’ were analysed. Top of the list: • UnusedSz (cumulative) = (10 - 2.359) * 8 * 4141321

pointers protect access to objects that may be removed concurrently. SAFE RECLAMATION Concurrency TS2 Essential Hazard Pointer Interface Base class for protectable objects template class time) Asynchronous Reclamation • Asynchronous reclamation is invoked when the number of retired objects reaches some threshold: • In the Folly library: • The threshold is the max of 1000 and twice the Extract retired objects from lists in the (global) domain structure. • Read hazard pointer values • Match addresses of retired objects with values read from hazard pointers. • Push matched objects back into

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 859 4 Global search . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . item level, it is possible to define global and proxy timeouts for various item types. Timeouts configured on the item level have the highest priority. By default, global timeouts are applied to all items; items; however, if proxy timeouts are set, they will override the global ones. Manual user input for scripts Manual user input for frontend scripts allows to supply a custom parameter on each execution

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 849 4 Global search . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . server runtime commands • Zabbix proxy runtime commands Date removed from export When exporting objects (hosts, templates, etc.), note that the element date is removed from the export format. Host and incremental configuration sync, full configuration is no longer sent if there are no changes to host or global regular expressions, thus default sync interval has been reduced to 5 seconds. ’RefreshActiveChecks’

Perforce A Custom Importer Summary Git Internals Plumbing and Porcelain Git Objects Tree Objects Commit Objects Object Storage Git References The HEAD Tags Remotes Packfiles The Refspec Protocols Summary Maintenance and Data Recovery Maintenance Data Recovery Removing Objects Environment Variables Global Behavior Repository Locations Pathspecs Committing Networking Diffing and Merging about Git and can wield it with power and grace, you can move on to discuss how Git stores its objects, what the object model is, details of packfiles, server protocols, and more. Throughout the book

Perforce A Custom Importer Summary Git Internals Plumbing and Porcelain Git Objects Tree Objects Commit Objects Object Storage Git References The HEAD Tags Remotes Packfiles The Refspec Protocols Summary Maintenance and Data Recovery Maintenance Data Recovery Removing Objects Environment Variables Global Behavior Repository Locations Pathspecs Committing Networking Diffing and Merging about Git and can wield it with power and grace, you can move on to discuss how Git stores its objects, what the object model is, details of packfiles, server protocols, and more. Throughout the book

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104 10 Scope of Variables 105 10.1 Global Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106 10.2 Local Optional and keyword Arguments . . . . . . . . . . . . . . . . . . . . . . . 164 12.9 Function-like objects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165 12.10 Empty generic functions 3 Data Movement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 315 25.4 Global variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 315 25.5 Parallel

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104 10 Scope of Variables 105 10.1 Global Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106 10.2 Local Optional and keyword Arguments . . . . . . . . . . . . . . . . . . . . . . . 164 12.9 Function-like objects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165 12.10 Empty generic functions 3 Data Movement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 315 25.4 Global variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 315 25.5 Parallel

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 414 Git Objects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . about Git and can wield it with power and grace, you can move on to discuss how Git stores its objects, what the object model is, details of packfiles, server protocols, and more. Throughout the book personally to you, the user. You can make Git read and write to this file specifically by passing the --global option, and this affects all of the repositories you work with on your system. 3. config file in