Chris Bohn

Good morning

#GoodMorning #alpacas

A rooster and six hens perch on a branch in their run.

Good morning

#GoodMorning #chickens 🪶

What I'm wondering is why FIFA is awarding a thingamajob that has hands touching a round object.

Two hens in their run. One stands near a window, and the other perches on an old ladder that has been converted into, well, perches.

Good morning

#GoodMorning #chickens 🪶

Many years ago I went into the clinic for a wound check (just below the elbow) after I'd popped some stitches. After removing the bandaging, the med tech turned several shades of green. A few minutes later, I learned from the flight surgeon that it was because she was not prepared to see the bone.

Rebound library copies of Kernighan and Plauger's "The Elements of Programming Style" and "The Elements of Programming Style, 2nd edition".

I've got my reading material for the winter break.

#AcademicSky #CompSky #ComputerScienceEducation

Six alpacas wearing orange coats, outside their barn. The sky is darkening, and some stars in the Big Dipper are visible. The corral is snow-covered.

Good morning

#GoodMorning #alpacas

Nothing has gone rwong yet.

Two roosters and four hens sitting on a perch in their coop.

Good morning

#GoodMorning #chickens 🪶

Good morning

#GoodMorning #alpacas

Alpacas staring at a hen who is nesting in a hay feeder.

She s̶t̶a̶n̶d̶s̶ sits accused of wanton nesting in someone else's lunch.

Good morning

#GoodMorning #chickens 🪶

I named my fists Masters and Johnson because...

um, never mind.

There was a bill in our state's legislature a couple of years ago that would have required schools to hold a student back if the parent/guardian requested it. It didn't make it to a floor vote.

Good morning

#GoodMorning #alpacas

A kiln

CupFactory

There's nothing quite like an imminent deadline (ahem) to focus your attention on the problem at hand.

Many years ago (and I don't recall what precipitated this question) someone asked me what I'd do if I fell out of an airplane without a parachute.

"I'd enjoy the ride down." That earned me a funny look. "I really enjoy solving problems. I'll probably try to solve the problem of generating lift."

Good morning

#GoodMorning #chickens 🪶

Five alpacas in their pasture. Three are kushed, and two are grazing. A maple tree devoid of leaves fills the foreground.

Good morning

#GoodMorning #alpacas

a man and a girl are standing next to each other and the girl is crying and the man is saying mostly . Alt: Scene from "Aliens", in which Newt tells Ripley that the monsters mostly come out at night. "Mostly."

The special ingredients mostly run out at night.

Good morning

#GoodMorning #chickens 🪶

How interestifying

Good morning

#GoodMorning #alpacas

Therac 25 has entered the chat

Post a famous bathroom scene

Returning the favor...

bsky.app/profile/docb...

I discovered a couple of interesting things while preparing this demo -- `timspec_get()` provides microsecond-precision timing on my Mac (my department's Linux server provides nanosecond-precision timing), and my Mac doesn't have 4KB pages (the Linux server, unsurprisingly, does have 4KB pages).

constexpr size_t SIZE_OF_PAGE = 16 * 1024; static uint8_t volatile array[128 * SIZE_OF_PAGE]; static inline long long get_nanoseconds(struct timespec timestamp) { return 1000000000LL * timestamp.tv_sec + timestamp.tv_nsec; } void load_page(void) { printf("Enter a character: "); unsigned char c = (unsigned char) getchar(); uint8_t foo = array[c * SIZE_OF_PAGE]; } void deduce_character(void) { struct timespec start, stop; unsigned char fastest_character = UCHAR_MAX; long long fastest_access_time = LLONG_MAX; for (unsigned char c = '\0'; c <= CHAR_MAX; c++) { timespec_get(&start, TIME_UTC); uint8_t foo = array[c * SIZE_OF_PAGE]; timespec_get(&stop, TIME_UTC); long long access_time = get_nanoseconds(stop) - get_nanoseconds(start); printf(isgraph(c) ? "%4c" : "\\x%02x", c); printf(" :%12lld" "ns\n", access_time); if (access_time < fastest_access_time) { fastest_access_time = access_time; fastest_character = c; } fflush(stdout); } printf("\n\nYou entered: %c\n\n", fastest_character); } int main(void) { load_page(); deduce_character(); return 0; }

I just threw together a bit of code to demonstrate to my students the timing benefits of locality with respect to virtual memory pages.

godbolt.org/z/PP7PEzT9M

(I may or may not have been influenced by meltdownattack.com)