| #include <stdbool.h> | |
| #include <stddef.h> | |
| #include <stdint.h> | |
| #include <stdio.h> | |
| #include <time.h> | |
| #if defined(__x86_64__) | |
| // fakes a read+write to register | |
| // using 'r' means that the value will be placed into a _general_ register for | |
| // the read if it not already in one, then possible re-read into another |
| #define _GNU_SOURCE | |
| #include <stdio.h> | |
| #include <stdlib.h> | |
| #include <fcntl.h> | |
| #include <sys/stat.h> | |
| #include <time.h> | |
| #include <unistd.h> | |
| #include <stdint.h> | |
| #include <pthread.h> |
| N = 1000 | |
| # make two scripts to pass to clickhouse client to demonstrate sadness with | |
| # materialized columns | |
| with open('create.sql', 'w') as f: | |
| f.write("DROP DATABASE IF EXISTS test;") | |
| f.write("CREATE DATABASE test;") | |
| # --- fast table as a baseline |
| # simple error correcting code | |
| # assume that data is transmitted over a channel which | |
| # sometimes corrupts the data stream | |
| # | |
| # for example, if we sent the bits 10110011 | |
| # we might receive 10110010 on the other side | |
| # | |
| # Consider a channel which has a 1% chance of incorrectly transmitting each bit | |
| # that is sent. | |
| # Additionally, assume messages we send contain 100 bits. |
My initial impression of Pin was that it said “hey there’s something
sitting at this memory location. Feel free to use it, even though, in
this context, the compiler can’t lexically prove that it is actually
still there.” My understanding of Pin was roughly that it was a
backdoor through the lifetime system.
Opening up the documentation, the page starts with a discussion about
Unpin. Unpin is weird. Basically, Unpin says “yeah I know this
| #include <array> | |
| #include <iostream> | |
| #include <stdexcept> | |
| template <typename T, size_t N> | |
| struct ring_buffer { | |
| std::array<T, N+1> entries; | |
| T* head = entries.data(); // pop from here | |
| T* tail = head+1; // push to here, one past the end |
| #include <stdlib.h> | |
| int test() { | |
| int *x = NULL; | |
| int y = rand(); | |
| int z = rand(); | |
| int v = 4; | |
| if (z == 8) x = &v; |
| #include <assert.h> | |
| #include <stdbool.h> | |
| #include <stddef.h> | |
| #include <stdint.h> | |
| #include <stdio.h> | |
| #include <stdlib.h> | |
| #include <string.h> | |
| #include <x86intrin.h> | |
| /* |
| #include <cstddef> | |
| #include <iostream> | |
| #include <sstream> | |
| #include <type_traits> | |
| struct nil { }; | |
| template <typename H, class T> | |
| struct cons | |
| { |
| #include <cstddef> | |
| #include <iostream> | |
| #include <type_traits> | |
| struct nil { }; | |
| template <typename H, class T> | |
| struct cons | |
| { | |
| using head = H; |