Ruby Return Value From Thread

Threads are the ruby implementation for a concurrent programming model.

Ruby return value from thread.

Then we are able to pause the execution of the main thread and allow our new. New puts what s the big deal. When you create a ruby proc it captures the current execution scope with it. Ruby threads are a lightweight and efficient way to achieve concurrency in your code.

You seem to be confusing two very different things here. 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. Threads are the ruby implementation for a concurrent programming model.

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. How to use fork exec to run external commands on a separate process. The only requirement of call is the value is returned at the end of the call. 6 updated with jörg s sept 2011 comment.

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. Then we are able to pause the execution of the main thread and allow our new. Threads ruby thread return value. Retrieving the value of a future is done through the value alias.

Does ruby have real multithreading. Notice that you still have to wait for the command to finish unless you run it inside a thread. Obtaining the value of a future is a potentially blocking operation. These two examples will return a string with the output of the ls command.

When a future is rejected a call to value will return nil immediately. New puts whats the big deal. To start a new thread just associate a block with a call to thread new. 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.

Ruby procs lambdas also have another special attribute. 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. For example we can create a new thread separate from the main thread s execution using new. Programs that require multiple threads of execution are a perfect candidate for ruby s thread class.