$1.$ Explain why this solution for mutual exclusion does not work:

$```$

boolean blocked $[2]$;

int turn;

void P $($int id$)$

$\{$

while $($true$)\{$

blocked$[$id$]=$ true;

while $($turn $!=$ id$)\{$

while $($blocked$[1-$id$])$

$/*$ do nothing $*/$;

turn $=$ id;

$\}$

$/*$ critical section $*/$

blocked$[$id$]=$ false;

$/*$ remainder $*/$

$\}$

$\}$

void main$()$

$\{$

blocked$[0]=$ false;

blocked$[1]=$ false;

turn $=0$;

parbegin $($P$(0),$ P$(1))$;

$\}$

$```$