Why stepping over the SCrypt.generate() (Bouncy Castle Java API) line using breakpoint(Eclipse) blocks the debugging process?

Question

I keep pressing F6 in eclipse during debugging

public void method() {   
Line 54: --------My breakpoint is here------
Line 55: -------Some line of code----- 

Line 56: byte[] sCryptHash1  = SCrypt.generate(plaintextPassword.getBytes(),  salt.getBytes(), 16384, 8, 1, 16);    

--------Some more lines of code----- 
}

When debugger line reached line 56, debugging gets blocked, does not proceed/respond, I will have to terminate the debugging.

What is the reason for such behavior ? Is it because of the SCrypt.generate method ?

I am using Bouncy Castle Java API for hashing.

If I don't use breakpoint on that line everything executes successfully.

Answer 1

To find out if the process is really hanging or just be very slow you can connect a profiler to the process and check what the process is currently doing. If you don't have a profile you can dump the thread dump and check the corresponding stacktrace.

The latter can be done on Windows systems by pressing CTRL-Break in the console the process is running (in case of Eclipse that's the output console). On Linux or other Unix-like systems you can dump it by sending a kill -3 [PID of the Java process]. The dump then goes to STDOUT of the Java process.