Writing. raudone.info Code. Ben Watson [PDF]), in particular how it applies to sequential programs and picking which parts of a program. NET code to have the absolute best performance it can This book demystifies the CLR, teaching you how and why to write code with optimum. Take performance to the next level! This book does not just teach you how the CLR worksit teaches you exactly what you need to do now to obtain the best.
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For more information about this book, please visit raudone.info or [PDF]), in particular how it applies to sequential programs and picking which. Writing raudone.info Code. Ben Watson .. Disable Security Checks for Trusted Code. .. New typesetting system for print and PDF editions. Description. NOTE: This is the PDF edition of the book. If you want the look of the print edition electronically, this is it. Take performance to the.
NET Core 1. NET Core as the development framework and learn about industry-wide best practices and guidelines, then this book is for you. The book starts with a brief introduction to enterprise Manning Publications, Functional languages help developers support concurrency by encouraging immutable data structures that can be passed between threads without having to worry about a shared state, all while avoiding side effects.
Concurrency in. NET teaches readers how to build concurrent and scalable programs in. NET using the functional paradigm. This essential classic title provides a comprehensive foundation in the C programming language and the frameworks it lives in. NET 4. NET Core, up to and including. NET Core 2. Learn the secrets of excellent. NET performance with insightful, detailed, and clear explanations.
Synchronized ] void foo int a, b;. These vary from fewer features very fast to many features very slow. It is important to use this correctly to get optimal performance. Synchoronization primitives can be defined as: a. Monitor or lock: Provides a mechanism that synchronizes access to objects b. Interlocked: Provides atomic access to variables that are shared by multiple threads. Mutex: Synchronization primitives that can be used for inter process synchronization.
They are considerably slower; use it when you absolutely need it. ReaderWriterLock: Lock that supports single writer and multiple readers. If you have a scenario where you read your data frequently but update only once in a while, consider using this as it supports multiple readers.
It also avoids many cases of potential deadlock and has improved performance. Using this is recommended. Semaphore: Limits of threads that can access a resource or pool of resources concurrently. Use it only when you need to control pool of resources. Suspend and Thread. Resume to synchronize activities. The suspend and resume operation doesn t happen immediately as CLR has to make sure the execution control is in safe point.
This can lead to race conditions or deadlock 1 f Never use Thread. Abort to abort another thread: 1 g Don t lock this and type of an object: Locking this pointer is a bad idea as this can have correctness issue as it is visible.
Similarly, locking type of an object is a bad idea as these objects are the same across application domains and so thus we lock all instances of objects across app domains in a process.
Consider using this to reduce lock contention. Some collection classes ex: ArrayList allow multiple readers concurrently. If another thread modifies the underlying collection then an exception will be thrown.
GC manages the allocation and reclaiming of memory in your application.
When ever you call new to create a new object, GC will allocate memory from managed heap as long as space is available and once it runs out of memory it triggers collection, reclaim memory so that it can start allocating again. We will go into some detail about GC algorithms, how they work, different GC flavors, and how you can write a GC friendly code.. We have 3 generations Gen0, 1 and NET GC assumes that most of the objects you create die young, so only a part of your entire manage help can be collected which is much faster than collecting the entire manage heap.
Writing High-Performance .NET Code, 2nd Edition
GC first marks the root objects to find out those who are alive and then compacts the heap moving all live objects to a part of the heap which forms older generation s. Always, allocations happen in Gen0 heap. The initial gen0 heap is some fraction of the last level cache. The idea is to have gen0 fit in the cache to avoid cache misses..
Concurrent GC on which is the default and can be turned off. Concurrent GC on will have less pause time, increasing the UI responsiveness. GC stops the application threads for a shorter duration when absolutely necessary. If you have a throughput kind of application console app non UI then turning off concurrent GC might get you better performance. In your application configuration file ex: foo. NET application. For example, if you are on a 4 processor system, you will have 4 heaps and 4 GC threads operating on each of those heaps.
A process can create objects in multiple heaps for load balancing the allocation on heaps and as mentioned above it is not the default. To enable Server GC, add the following in application configuration files. However if you want to run web garden scenario, then consider using WKS GC as the memory foot print might be really high as a result of multiple w3wp processes. SVR GC assumes it is the king and so will try to grab as many resources as possible. So if you have multiple processes running SVR GC, there can be degradation in performance and also an increase usage of system resources.
In order to enable ASP.
Tips for writing GC Friendly code: a. Never Call GC. Collect from your code:. At every collection it collects information such as survivor rate, and tunes its internal GC tuning parameters so the next GC is more effective than its previous GC. Unlike Java,. NET GC doesn t expose many tuning parameters for the developer. So when you call GC.
Collect in your code, it collects those parameters. Since you induced GC the next GC will not be as productive. Also, if GC.
Collect is executing not just once but many times lets say before you start expensive time consuming work and so you need more memory then GC will not be productive at all.
But there is an exception.
If you know that you opened a custom form and made some configuration changes and you know that you are not going to need that form any time sooner, you can go ahead and call GC. Collect so all the long live objects in Gen2 are now dead. It is recommended to use the following code starting from Orcas build.
Here even though GC.
Collect is called on gen2, GC will decide if it is helpful if it collects 2 nd parameter Optimized. This is not available in VS and older versions. Collect 2, GCCollectionMode. Optimized ; 8 9 b.
Watson B. Writing High-Performance .NET Code
Create objects that die young:. Don t allocate too many objects: One little line of code could trigger a lot of allocations. Most of the time, it is an allocation that triggers a collection. Keep an eye on what you allocate particularly in loops 2 d. Don t allocate too many almost long-life objects: Objects that are neither temporary nor long lived end up in Gen2 and die.
This puts pressure on gen2 heap and you may end up doing full collections which is expensive. This could put pressure on large object heap, resulting in your doing full collections, also expensive. Dispose and Finalize: Implement these only when needed.
Make sure you call these when an exception occurs to avoid a memory leak. Also make sure you implement finalize only when you have an unmanaged resource and keep the code very simple. NET tips for writing better code a.
If we are doing this frequently, then we will create lot of objects affect GC and also the extra code we execute for boxing and unboxing. Type casting is required when retrieving objects your type from the collection classes. This requires an expensive run time type check by looking at method table of that object.
If your object is inherited then this may require traversing one level up which is again expensive. Throw fewer exceptions: Throwing exceptions can be expensive as stalk walk is required etc for managing the frames.
Use StringBuilder for complex string manipulation: Whenever you modify a string such as append etc , it will create a new string leaving the first one to be collected.
Thus parsing and searching this information is very expensive. Don t make functions unnecessarily virtual or synchronized: JIT might disable some optimizations and so the generated code might not be optimal g. Avoid calling small functions inside loop: Consider inlining yourself incase JIT has not done it. Any mistake in the loop is magnified. Prefer arrays to collections unless you need that additional functionality that collection classes provide  j.
Use jagged arrays instead of multi dimensional arrays since the former has some special MSIL optimizations for faster array access  k. Smaller working set produces better performance and so consider using ngen for shared pages l.
Don t make too many Pinvoke calls chatty calls and do less work in unmanaged code: The overhead of transitions managed to unmanaged and back can negate performance speedup or even hurt.
Once the native image is created, runtime uses this image automatically each times it runs the assembly. Using native image will eliminate compiling on the fly using JIT compiler at runtime thus reducing application startup time. Always measure with and without ngening of your application.
In some cases, you want to use unmanaged code for some performance related reasons as well such as calling 3rd party highly optimized libraries. CLR provides several ways to do this. Improving ASP.In short this is a PDF library which does everything you would ever want. Learn critical lessons from a person who helped design and build Unlimited Publisher: If another thread modifies the underlying collection then an exception will be thrown.
Dispose and Finalize: Implement these only when needed. I enjoyed reading this book because it unveiled, in easy to understand terms, some of the considerations to writing better performing code. Smaller working set produces better performance and so consider using ngen for shared pages l. Always, allocations happen in Gen0 heap. Similarly, locking type of an object is a bad idea as these objects are the same across application domains and so thus we lock all instances of objects across app domains in a process.
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