Sensible TIMEOUT_USEC

[Tijs Michels]

Function cmd_getc in command.c contains this line (2.7.3):
#define TIMEOUT_USEC 5000

TIMEOUT_USEC is used only once, in:
    value.tv_usec = TIMEOUT_USEC;

cmd_getc defines:
    struct timeval  value;

<bits/time.h> defines timeval:
struct timeval
  {
    __time_t tv_sec;       /* Seconds. */
    __time_t tv_usec;      /* Microseconds. */
  };

<bits/types.h> defines:
typedef long int __time_t;

So TIMEOUT_USEC is a long integer specifying microseconds.
I was wondering whether
#define TIMEOUT_USEC 5000
means that cmd_getc probes for input almost 200 times a
second. And if so, could this not slow down processes in
the background?

I tested a value of 50000 and noticed no effect on the
performance of rxvt.
Far larger values do slow down rxvt significantly;
delaying the rendering of the last character typed.

So I wondered why a value of 5000 was chosen, and
if this really means that cmd_getc probes for input
200 times a second?

Cheers,

Tijs