Unlock コマンドは識別子 mutexId をもつミューテックスのロックを解除します。 Unlock を使うスレッドは Lock コマンドでロックされている必要がありま。

ミューテックスについてより詳しくは Mutex を参照ください。

p := proc( m )
    global count;
    print( count );
    count := count+1;
end proc;

      p := proc(m) global count; print(count); count := count + 1 end proc

count := 1;

                                   count := 1

Threads:-Wait( seq( Threads:-Create( p(m) ), i=1..10 ) );

                                       1

                                       2

                                       3

                                       4

                                       5

                                       6

                                       6

                                       8

                                       8

                                       10

p := proc( m )
    global count;
    Threads:-Mutex:-Lock( m );
    print( count );
    count := count+1;
   
    Threads:-Mutex:-Unlock( m );
end proc;

p := proc(m)
global count;
    Threads:-Mutex:-Lock(m);
    print(count);
    count := count + 1;
    Threads:-Mutex:-Unlock(m)
end proc

count := 1;

                                   count := 1

m := Threads:-Mutex:-Create();

                                     m := 1

Threads:-Wait( seq( Threads:-Create( p(m) ), i=1..10 ) ):

                                       1

                                       2

                                       3

                                       4

                                       5

                                       6

                                       7

                                       8

                                       9

                                       10

Threads:-Mutex:-Destroy( m );