Ruby Return Value From Thread

Multiple calls to get will not cause the task to be rerun in the thread.

Ruby return value from thread.

Obtaining the value of a future is a potentially blocking operation. Then we are able to pause the execution of the main thread and allow our new. To start a new thread just associate a block with a call to thread new. Ruby procs lambdas also have another special attribute.

When a future is rejected a call to value will return nil immediately. For example we can create a new thread separate from the main thread s execution using new. The only requirement of call is the value is returned at the end of the call. How to use fork exec to run external commands on a separate process.

These two examples will return a string with the output of the ls command. Threads ruby thread return value. When you create a ruby proc it captures the current execution scope with it. Threads are the ruby implementation for a concurrent programming model.

Programs that require multiple threads of execution are a perfect candidate for ruby s thread class. Programs that require multiple threads of execution are a perfect candidate for ruby s thread class. New puts what s the big deal. Does ruby have real multithreading.

Retrieving the value of a future is done through the value alias. Ruby threads are a lightweight and efficient way to achieve concurrency in your code. This concept which is sometimes called closure means that a proc will carry with it values like local variables and methods from the context where it was defined. 6 updated with jörg s sept 2011 comment.

You seem to be confusing two very different things here. A new thread will be created to execute the code in the block and the original thread will return from thread new immediately and resume execution with the next. When the get method of future is later called the future will either have the value immediately if the task runs quickly as in this case or will wait until the value is done generating. Usr bin ruby for i in 0 5 if i 2 then break end puts value of local variable is i end this will produce the following result value of local variable is 0 value of local variable is 1 value of local variable is 2 ruby next statement syntax next jumps to the next iteration of the most internal loop.

The ruby programming language and the specific threading model of. When a future is fulfilled a call to value will immediately return the current value. Then we are able to pause the execution of the main thread and allow our new. Notice that you still have to wait for the command to finish unless you run it inside a thread.