Lock access to resource by threads

Question

I have an app in which records audio files. User can specify length of recorded audio, number of samples and time between recordings. For example:

length   = 3 sec
samples  = 2
interval = 5 sec

When app starts it creates a thread, waits 5 seconds and creates second thread.

First thread records 3 seconds sample to a specified directory.

After 2 seconds, next thread starts recording second sample. It works and creates two files: sample1.3gp, sample2.3gp.

But when user specify:

length   = 3 sec
samples  = 2
interval = 1 sec

recording cannot be done because of 2nd thread try to access to media recorder when 1st thread still uses it.

I want to be able to set some lock for that resource. What I mean ?

When 1st thread starts 3 seconds recording, after 1 second 2nd thread tries to record too.

But it should wait next two seconds until 1st thread finishes its job.

What is the best way to solve that problem ?

Answer 1

I suggest you read up on threading and mutex in general. Read this SO question first and maybe refine what you're asking.

This isn't really an Android specific problem but more about threading with Java in general.