Consider a system with two processes, P$1$ and P$2,$ that need to access a shared resource.

They use the Test$-$and$-$Set mechanism for synchronization. The Test$-$and$-$Set mechanism is

implemented as follows:

c

boolean test$\_$and$\_$set$($boolean $*$lock$)\{$

boolean old $=*$lock;

$*$lock $=$ true;

return old;

$\}$

void P$1()\{$

while $($true$)\{$

while $($test$\_$and$\_$set$($&lock$))\{$

$//$ Busy$-$wait

$\}$

$//$ Critical Section

$//$ Exit Section

lock $=$ false;

$//$ Remainder Section

$\}$

$\}$

void P$2()\{$

while $($true$)\{$

while $($test$\_$and$\_$set$($&lock$))\{$

$//$ Busy$-$wait

$\}$

$//$ Critical Section

$//$ Exit Section

lock $=$ false;

$//$ Remainder Section

$\}$

$\}$

$1.$ Explain how the Test$-$and$-$Set mechanism works to ensure mutual exclusion.

$2.$ Identify and discuss the potential drawbacks of using the Test$-$and$-$Set mechanism for process synchronization. How can these drawbacks impact system performance?