By design, Android View objects are not thread-safe. An app is expected to create, use, and destroy UI objects, all on the main thread. If you try to modify or even reference a UI object in a thread other than the main thread, the result can be exceptions, silent failures, crashes, and other undefined misbehavior.
What is the use of thread in Android?
The main thread is responsible for dispatching events to the appropriate user interface widgets as well as communicating with components from the Android UI toolkit. To keep your application responsive, it is essential to avoid using the main thread to perform any operation that may end up keeping it blocked.
What is thread safe with example?
A good example of thread safe class is java servlets which have no fields and references, no fields from other classes etc. They are stateless. The transient state for a particular computation exists solely in local variables that are stored on the thread’s stack and are accessible only to the executing thread.
What is a thread safe method?
4 Answers. 4. 149. If a method (instance or static) only references variables scoped within that method then it is thread safe because each thread has its own stack: In this instance, multiple threads could call ThreadSafeMethod concurrently without issue.
What is thread-safety how do you achieve it?
Unlike their synchronized counterparts, concurrent collections achieve thread-safety by dividing their data into segments. In a ConcurrentHashMap, for instance, several threads can acquire locks on different map segments, so multiple threads can access the Map at the same time.
What are the main two types of thread in Android?
Android has four basic types of threads. You’ll see other documentation talk about even more, but we’re going to focus on Thread , Handler , AsyncTask , and something called HandlerThread . You may have heard HandlerThread just called the “Handler/Looper combo”.
How many threads can Android handle?
There is no maximum that I know of. I can tell you, however, that you most likely don’t NEED that many threads. You can keep countdown listeners in a single thread using Android’s Handler , specifically the postDelayed() method.
What is thread-safe and non thread-safe?
Conditionally safe: Different threads can access different objects simultaneously, and access to shared data is protected from race conditions. Not thread safe: Data structures should not be accessed simultaneously by different threads.
What is difference between reentrant and thread-safe functions?
Thread safe code is one that can be performed from multiple threads safely, even if the calls happen simultaneously on multiple threads. … Reentrant code means that you can do all the things thread safe code can do but also gurantee safety even if you call the same function within the same thread.
Is HashMap thread-safe?
HashMap is non-synchronized. It is not thread-safe and can’t be shared between many threads without proper synchronization code whereas Hashtable is synchronized.
Is StringBuffer thread-safe?
StringBuffer is synchronized and therefore thread-safe.
Is SessionFactory a thread-safe object?
The SessionFactory is a thread safe object and used by all the threads of an application. … You would need one SessionFactory object per database using a separate configuration file. So, if you are using multiple databases, then you would have to create multiple SessionFactory objects.
Which of the following is a thread-safe?
2) Read-only or final variables in Java are also thread-safe in Java. 3) Locking is one way of achieving thread-safety in Java. 4) Static variables if not synchronized properly become a major cause of thread-safety issues. 5) Example of thread-safe class in Java: Vector, Hashtable, ConcurrentHashMap, String, etc.