## Designing an ultra low-overhead multithreading runtime for Nim Mamy Ratsimbazafy mamy@numforge.co ## Hello! ## I am Mamy Ratsimbazafy During the day blockchain/Ethereum 2 developer (in Nim) During refactoring of the internals ## Agenda ## Understanding the design space Hardware and software multithreading: definitions and use-cases Parallel APIs Sources of overhead and runtime design Minimum viable threads -> N hardware threads The same distinctions can be done at a multithreaded language or multithreading runtime level. ## The problem ## How to schedule M tasks on N hardware threads? ## Latency vs

information about hardware and the operating system. source Base.Threads - Module. Experimental multithreading support. source Base.GC - Module. Base.GC Module with garbage collection utilities. source

471 35.27 @code_warntype ..... 472 35.28 Performance of captured variable ..... 474 35.29 Multithreading and linear algebra ..... 475 35.30 Alternative linear algebra backends ..... 476 35.31 Execution packages like FastClosures automate the insertion of let statements as in abmult3. ### 35.29 Multithreading and linear algebra This section applies to multithreaded Julia code which, in each thread, performs case, one must ensure that cores aren't oversubscribed due to the two different types of multithreading. Julia compiles and uses its own copy of OpenBLAS for linear algebra, whose number of threads

categories) Modern C++ Data Types (move semantics) CsString library (unicode) Multithreading in C++ Multithreading using libGuarded Signals and Slots Templates in the Real World What's in CsString Library ☐ standalone Unicode aware string library ## • CsLibGuarded ☐ standalone multithreading library for shared data ## Applications ## • KitchenSink contains 30 demos and links with almost

synchronize access to its count field in multithreading environment * fixed DebugInterceptor to properly synchronize access to its count field in multithreading environment * abstractBeanFactory based getCount()" accessor * fixed DebugInterceptor to properly synchronize access to its count field in multithreading environment * BeanWrapperImpl supports PropertyEditors (typically from BeanInfo classes) * fixed ResponseTimeMonitorImpl to properly synchronize access to its instance variables in a multithreading environment Package org.springframework.validatio * added further accessors to Errors interface:

v=jIa17JCaNvo What is the C++ Standard Library ☐ CsString library - Intro to Unicode char8_t Multithreading in C++ Modern C++ Threads ☐ C++ Memory Model #### Presentations - www.youtube.com/copperspice CsString Library ☐ standalone Unicode aware string library ## • CsLibGuarded ☐ standalone multithreading library for shared data ## Libraries ## • CsCrypto ☐ C++ interface to the Botan and OpenSSL

Stellaris 2.7 starts in 54s Stellaris 2.8 beta starts in 21s Same amount of work Both rely on multithreading  2.7 (Old) Startup music tracks from zips Can we optimize unzip() further? PhysFS still has a lock per archive, so multithreading might be tricky ## Loading audio How many music tracks do we need to display loading screen

AbstractMonitoringInterceptor * fixed DebugInterceptor to properly synchronize access to its count field in a multithreading environment Package org.springframework.beans * BeanWrapperImpl keeps registered editors in * fixed ResponseTimeMonitorImpl to properly synchronize access to its instance variables in a multithreading environment Package org.springframework.web * used NestedServletException wherever a root cause root Changes in version 1.0 M4 (4.1.2004) Package org.springframework.aop * fixed potential multithreading issue on nested prototype resolution in * added "registerCustomEditor(Class, PropertyEditor)"

rceptor * fixed DebugInterceptor to properly synchronize access to its count field in a multithreading environment Package org.springframework.beans * BeanWrapperImpl keeps registered editors * fixed ResponseTimeMonitorImpl to properly synchronize access to its instance variables in a multithreading environment Package org.springframework.web * used NestedServletException wherever a root ManagedList and ManagedMap resolution for prototypes in AbstractBeanFactory $ ^{*} $ fixed potential multithreading issue on nested prototype resolution in * dependent beans (with corresponding "depends-on")

accessor * fixed DebugInterceptor to properly synchronize access to its count field in a multithreading environment Package org.springframework.beans * factored out extended PropertyController and fixed ResponseTimeMonitorImpl to properly synchronize access to its instance variables in a multithreading environment Package org.springframework.validation * added further accessors to Errors interface: