| package main | |
| import ( | |
| "bytes" | |
| "crypto" | |
| "crypto/ecdsa" | |
| "crypto/elliptic" | |
| "crypto/rand" | |
| "crypto/x509" | |
| "crypto/x509/pkix" |
| package main | |
| // Run this in root of https://github.com/vscode-kubernetes-tools/vscode-kubernetes-tools | |
| // `snippets` dir is used. | |
| // Somehow vscode can't show snippets by default. | |
| import ( | |
| "encoding/json" | |
| "fmt" | |
| "io/fs" |
| package main | |
| import ( | |
| "crypto/tls" | |
| "crypto/x509" | |
| "flag" | |
| "io" | |
| "io/ioutil" | |
| "log" | |
| "os" |
| export USERNAME=myadmin | |
| export GROUPNAME=myadmin | |
| export CERTIFICATE_NAME=myadmin | |
| openssl genrsa -out ${USERNAME}.key 2048 | |
| openssl req -new -key ${USERNAME}.key -out ${USERNAME}.csr -subj "/CN=${USERNAME}/O=${GROUPNAME}" | |
| cat <<EOF | kubectl apply -f - | |
| apiVersion: certificates.k8s.io/v1beta1 | |
| kind: CertificateSigningRequest |
Erlang honors cgroup CPU quota from Erlang 23. But when less than 1 CPU is used, schedulers_online will be cores number(see below k8s 0-5).
$ docker run --rm -it --cpu-period 100000 --cpu-quota 100000 erlang:23 bash
root@3f793576001a:/# erl
Erlang/OTP 23 [erts-11.0.2] [source] [64-bit] [smp:4:1] [ds:4:1:10] [async-threads:1] [hipe]
| def read_until_eof(): | |
| buffer = '' | |
| batch_size = 1024 | |
| while True: | |
| ready, _, _ = select.select([sys.stdin], [], [], 0.0) | |
| if sys.stdin not in ready: | |
| continue | |
| # Don't know why, but sys.stdin.read() and sys.stdin.readline() | |
| # will cause EPIPE when writting to stdout |
| #include <stdio.h> | |
| #include <string.h> | |
| #include <sys/mman.h> | |
| #include <unistd.h> | |
| int main(void) { | |
| size_t pagesize = getpagesize(); | |
| printf("System page size: %zu bytes\n", pagesize); |
| defmodule BinaryParseSlow do | |
| def parse(bin) do | |
| parse(bin, 0) | |
| end | |
| def parse(bin, acc) do | |
| case do_parse(bin) do | |
| {:nofin, x, rest} -> | |
| parse(rest, acc + x) | |
| {:fin, x} -> |
| # For binary 0000 0001 0100 0000 1000 1000 | |
| # The result is 0b1 + 0b100_0000 + 0b1000 = 73 | |
| defmodule BinaryParseFast do | |
| def parse(bin) do | |
| parse(bin, 0) | |
| end | |
| # A byte beginning with 0 means the end, but still need to add the last 7 bits | |
| def parse(<<0::1, x::7, _::bits>>, acc), do: acc + x | |
| # A byte beginning with 1 means there is more data needed to be processed. |
| for a1 <- 0..1, | |
| a2 <- 0..1, | |
| a3 <- 0..1, | |
| a4 <- 0..1, | |
| a5 <- 0..1, | |
| a6 <- 0..1, | |
| a7 <- 0..1, | |
| a8 <- 0..1, | |
| a9 <- 0..1, |