Any relaxation of the polling interval will effect user experience in the control view. I guess one alternative is to just "assume" monotonically increasing time (one second and a time) and poll every 5 or 10 seconds to make sure we're still accurate. This could cause the progress bar to jump a bit though (poor UX).

I figure since we're on wifi anyway while doing this (a requirement) actually using the wifi once a second probably isn't so bad? If thats not reasonable let me know and we can continue to think of ways to mitigate the polling.

While it does not particularly affect battery life, it does poll at second intervals.

(strace -

ioctl(4, FIONREAD, [0]) = 0 gettimeofday({1278018980, 282657}, NULL) = 0 clock_gettime(CLOCK_MONOTONIC, {109956, 97679048}) = 0 poll([{fd=4, events=POLLIN}, {fd=3, events=POLLIN}, {fd=8, events=POLLIN}, {fd=7, events=POLLIN}, {fd=9, events=POLLIN}, {fd=12, events=POLLIN}, {fd=13, events=POLLIN}, {fd=15, events=POLLIN}, {fd=14, events=POLLIN}], 9, 993) = 0 (Timeout) gettimeofday({1278018981, 283439}, NULL) = 0 clock_gettime(CLOCK_MONOTONIC, {109957, 99161697}) = 0 futex(0x12c418, FUTEX_WAKE, 1) = 0 read(9, 0xbe80bf2f, 1) = -1 EAGAIN (Resource temporarily unavailable) futex(0x12c418, FUTEX_WAKE, 1) = 0 futex(0x17f8e0, FUTEX_WAKE, 1) = 0 futex(0x12c418, FUTEX_WAKE, 1) = 0 futex(0x12c418, FUTEX_WAKE, 1) = 0 futex(0x17f8e0, FUTEX_WAKE, 1) = 0 ioctl(4, FIONREAD, [0]) = 0

)

Is once a second really needed, or could it be relaxed to say 10.

Works perfectly for me. And it's fast, too. +1