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fixes for A2

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mostly include some things that should and remove some things that shouldn't have been included in the handout (yes this does hint at some places that need to be touched for A2)
This commit is contained in:
Niklas Gollenstede
2025-11-24 15:04:26 +01:00
parent 174fe17e89
commit 4245798955
18 changed files with 186 additions and 3300 deletions
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24
libsys/iostream.h
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@@ -1,24 +0,0 @@
#pragma once
#include "outputstream.h"
#include "stub.h"
class IOStream : public OutputStream {
private:
IOStream(IOStream &copy); // no copy
int fd;
public:
explicit IOStream(int sysfd = 0) : fd(sysfd) {}
~IOStream() {
if (pos > 0) {
sys_write(fd, buffer, pos);
}
}
void flush() override {
sys_write(fd, buffer, pos);
pos = 0;
}
};

68
libsys/rand.cc
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@@ -1,68 +0,0 @@
#include "rand.h"
// Mersenne Twister (32 bit pseudorandom number generator)
// https://en.wikipedia.org/wiki/Mersenne_Twister
static const uint32_t N = 624;
static const uint32_t M = 397;
static const uint32_t R = 31;
static const uint32_t A = 0x9908B0DF;
// initialization multiplier
static const uint32_t F = 1812433253;
static const uint32_t U = 11;
static const uint32_t S = 7;
static const uint32_t B = 0x9D2C5680;
static const uint32_t T = 15;
static const uint32_t C = 0xEFC60000;
static const uint32_t L = 18;
static const uint32_t MASK_LOWER = (1ULL << R) - 1;
static const uint32_t MASK_UPPER = (1ULL << R);
static uint32_t mt[N];
static uint16_t index;
void srand(const uint32_t seed) {
mt[0] = seed;
for (uint32_t i = 1; i < N; i++) {
mt[i] = (F * (mt[i - 1] ^ (mt[i - 1] >> 30)) + i);
}
index = N;
}
uint32_t rand() {
uint16_t v = index;
if (index >= N) {
// Twist
for (uint32_t i = 0; i < N; i++) {
uint32_t x = (mt[i] & MASK_UPPER) + (mt[(i + 1) % N] & MASK_LOWER);
uint32_t xA = x >> 1;
if ((x & 0x1) != 0) {
xA ^= A;
}
mt[i] = mt[(i + M) % N] ^ xA;
}
v = index = 0;
}
uint32_t y = mt[v];
index = v + 1;
y ^= (y >> U);
y ^= (y << S) & B;
y ^= (y << T) & C;
y ^= (y >> L);
return y;
}

9
libsys/rand.h
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@@ -1,9 +0,0 @@
#pragma once
#include "types.h"
const uint32_t RAND_MAX = UINT32_MAX;
void srand(uint32_t seed);
uint32_t rand();