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

110101010100100111000001001011011101010010100100100001010010010100© 2023 Adobe. All Rights Reserved. Objects and State DEFINITION: An object's state is the bit configuration of memory that is under that delete[] begin_; } };© 2023 Adobe. All Rights Reserved. Hash map using global seed inline const unsigned global_seed = []{ std::random_device rd; std::uniform_int_distribution std::size_t hash = global_seed ^ std::hash{}(key); //… } };© 2023 Adobe. All Rights Reserved. Hash map using global seed inline const unsigned global_seed = []{ std::random_device

[1,300] for y ● You observe however, the window size is actually 640x480 stored in two separate global variables ○ So the range should be much larger for the initial circles to spawn in the screen again, because you have to maintain the value in two different places ○ Well--the point of having a global variable is to use it after all! ○ How about we just move it to a header file, and define some again, because you have to maintain the value in two different places ○ Well--the point of having a global variable is to use it after all! ○ How about we just move it to a header file, and define some

that are not predetermined or predefined in an environment that may have a variety of obstacles, objects, or events occurringAbout PickNik Robotics ● The Unstructured Robotics company ○ Unstructured: that are not predetermined or predefined in an environment that may have a variety of obstacles, objects, or events occurring ● Main maintainers of MoveIt ○ MoveIt is an open source robotics manipulation that are not predetermined or predefined in an environment that may have a variety of obstacles, objects, or events occurring ● Main maintainers of MoveIt ○ MoveIt is an open source robotics manipulation

Process 0 Process 1 Process 2 Process 3 - Partitioned - each process has its own shared segment - Global address space - each proc’s shared segment can be referenced by other processesPGAS Model Process Process 0 Process 1 Process 2 Process 3 - Partitioned - each process has its own shared segment - Global address space - each proc’s shared segment can be referenced by other processesPGAS Model Process Process 0 Process 1 Process 2 Process 3 - Partitioned - each process has its own shared segment - Global address space - each proc’s shared segment can be referenced by other processesAdvantages of PGAS

compatibility.py Conan 2 features a new extension mechanism to define binary compatibility at a global level. A compatibility.py file in the Conan cache will be used to define which fallbacks of binaries c/b/googletest/src/gtest_ ˓→main.cc [==========] Running 1 test from 1 test suite. [----------] Global test environment set-up. [----------] 1 test from HelloTest [ RUN ] HelloTest.ComposeMessages [ ] HelloTest.ComposeMessages (0 ms) [----------] 1 test from HelloTest (0 ms total) [----------] Global test environment tear-down [==========] 1 test from 1 test suite ran. (0 ms total) [ PASSED ] 1 test

compatibility.py Conan 2 features a new extension mechanism to define binary compatibility at a global level. A compatibility.py file in the Conan cache will be used to define which fallbacks of binaries c/b/googletest/src/gtest_ ˓→main.cc [==========] Running 1 test from 1 test suite. [----------] Global test environment set-up. [----------] 1 test from HelloTest [ RUN ] HelloTest.ComposeMessages [ ] HelloTest.ComposeMessages (0 ms) [----------] 1 test from HelloTest (0 ms total) [----------] Global test environment tear-down [==========] 1 test from 1 test suite ran. (0 ms total) [ PASSED ] 1 test

compatibility.py Conan 2 features a new extension mechanism to define binary compatibility at a global level. A compatibility.py file in the Conan cache will be used to define which fallbacks of binaries c/b/googletest/src/gtest_ ˓→main.cc [==========] Running 1 test from 1 test suite. [----------] Global test environment set-up. [----------] 1 test from HelloTest [ RUN ] HelloTest.ComposeMessages [ ] HelloTest.ComposeMessages (0 ms) [----------] 1 test from HelloTest (0 ms total) [----------] Global test environment tear-down [==========] 1 test from 1 test suite ran. (0 ms total) [ PASSED ] 1 test