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Why is thread-safety important?
Thread safety simply ensures that when a thread is modifying or reading shared data, no other thread can access it in a way that changes the data. If your code depends on a certain order for execution for correctness, then you need other synchronization mechanisms beyond those required for thread safety to ensure this.
What does it mean to say that a class is thread-safe?
A class is thread‐safe if it behaves correctly when accessed from multiple threads, regardless of the scheduling or interleaving of the execution of those threads by the runtime environment, and with no additional synchronization or other coordination on the part of the calling code.
What makes an object thread-safe?
“Thread safe” is a bit of an unfortunate term because it doesn’t really have a solid definition. Basically it means that certain operations on the object are guaranteed to behave sensibly when the object is being operated on via multiple threads. Consider the simplest example: a counter.
What makes code not to be thread safe?
An easier way to understand it, is what make code not thread-safe. There’s two main issue that will make a threaded application to have unwanted behavior. This variable could be modified by another thread while executing the function.
Why is a race not thread-safe in Java?
The fourth and final condition that must occur for a race to happen (and for the code to therefore NOT be “thread-safe”) is that another thread must be able to access the shared memory while the invariant is broken, thereby causing inconsistent or incorrect behavior.
What is the meaning of the term ” thread safe “?
Unpredictable results when multiple threads are running is not a required condition of thread-safe code, but it is often a by-product. For example, you could have a producer-consumer scheme set up with a shared queue, one producer thread, and few consumer threads, and the data flow might be perfectly predictable.
Can a class be used on more than one thread?
If a class can be safely used on only one thread, it may be better to do so. For example, Java has two classes that are almost equivalent, StringBuffer and StringBuilder. The difference is that StringBuffer is thread-safe, so a single instance of a StringBuffer may be used by multiple threads at once.