10- Confinement

Jul 03, 2026 15:08 · 3:40 · English · Whisper Turbo · 2 Hátalar

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S… Speaker 1 (10- Confinement)

Let's see how we can use confinement to prevent race conditions.

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So instead of showing a single status object across multiple

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threads, we're going to have each thread work with its own status object.

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So let's remove this global status object and

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remove it from here as well.

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Now we go into constructor of this class and remove this parameter

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and then set the status field to a new download status

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object.

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Now back to our demo class.

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So we start 10 threads.

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We wait for them to finish.

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At the end,

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we have to ask each thread for its status object.

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Then we'll combine the total bytes across all these status objects.

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But there's a problem here.

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We're creating our download tasks over here.

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So later on,

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we won't have access to them.

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Now,

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to solve this,

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we're going to create a list of download file task objects.

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And every time we create a new download file task,

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we're going to add it to that list.

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So,

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Let's create a list of download file task We

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call it tasks and set it to a new array list now

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in our for loop First we create a task object new download

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file task Then we add it to our list so

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tasks that add task and now we can

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pass that object over here That's better now

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after all these threads are finished We need to

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combine the total bytes across these tasks.

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We go back to our download file task class and create a

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getter for this field so we can read it later on.

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We put the caret on the field name and bring up the generate palette to

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create a getter for this field.

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So here's our getter,

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getStatus,

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which returns the status field.

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Now,

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As a best practice,

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move these getters and setters down the bottom.

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This makes our code cleaner and easier to read.

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So first we list our fields,

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then we have our constructors,

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then we have our public methods,

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and finally we have our getters and setters.

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So,

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let's move this down.

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There you go.

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So, after the run method,

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we have our getter.

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Now,

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back to our demo class.

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Here we can use the streams API to combine the total bytes across

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these tasks.

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So,

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we go to our tasks list,

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get a stream,

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then map each task to the total bytes it

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has downloaded.

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So,

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map,

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we pass lambda,

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t goes to,

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t dot get status,

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and then we get the total bytes.

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With this we get a stream of integers.

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Now we can reduce this integer.

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So we call it reduce.

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We can pass an initial value and then a binary operator.

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For example,

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a and b goes to a plus b.

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Or we can rewrite this as integer

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sum.

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So we use a method reference here.

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With this we get the total bytes.

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So let's store it over here and then print

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it on a terminal.

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As simple as that.

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Take a look.

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we have 100 ,000 bytes.

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If we run this program again,

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we get the exact same result.

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So we no longer have a race condition because these threads are not

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modifying a shared object.

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