ilo-pona/xv6-65oo2
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Activity

cow moved to xv6-riscv-fall19

Browse source
This commit is contained in:
Frans Kaashoek 2019-08-26 21:16:33 -04:00
parent 92c3c02098
commit a3f6d9fd1e
2 changed files with 0 additions and 197 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

1
Makefile
View file

@ -129,7 +129,6 @@ UPROGS=\
$U/_usertests\ $U/_usertests\
$U/_wc\ $U/_wc\
$U/_zombie\ $U/_zombie\
$U/_cow\
fs.img: mkfs/mkfs README $(UPROGS) fs.img: mkfs/mkfs README $(UPROGS)
mkfs/mkfs fs.img README $(UPROGS) mkfs/mkfs fs.img README $(UPROGS)

196
user/cow.c
View file

@ -1,196 +0,0 @@
//
// tests for copy-on-write fork() assignment.
//
#include "kernel/types.h"
#include "kernel/memlayout.h"
#include "user/user.h"
// allocate more than half of physical memory,
// then fork. this will fail in the default
// kernel, which does not support copy-on-write.
void
simpletest()
{
uint64 phys_size = PHYSTOP - KERNBASE;
int sz = (phys_size / 3) * 2;
printf(1, "simple: ");
char *p = sbrk(sz);
if(p == (char*)0xffffffffffffffffL){
printf(1, "sbrk(%d) failed\n", sz);
exit();
}
for(char *q = p; q < p + sz; q += 4096){
*(int*)q = getpid();
}
int pid = fork();
if(pid < 0){
printf(1, "fork() failed\n");
exit();
}
if(pid == 0)
exit();
wait();
if(sbrk(-sz) == (char*)0xffffffffffffffffL){
printf(1, "sbrk(-%d) failed\n", sz);
exit();
}
printf(1, "ok\n");
}
// three processes all write COW memory.
// this causes more than half of physical memory
// to be allocated, so it also checks whether
// copied pages are freed.
void
threetest()
{
uint64 phys_size = PHYSTOP - KERNBASE;
int sz = phys_size / 4;
int pid1, pid2;
printf(1, "three: ");
char *p = sbrk(sz);
if(p == (char*)0xffffffffffffffffL){
printf(1, "sbrk(%d) failed\n", sz);
exit();
}
pid1 = fork();
if(pid1 < 0){
printf(1, "fork failed\n");
exit();
}
if(pid1 == 0){
pid2 = fork();
if(pid2 < 0){
printf(1, "fork failed");
exit();
}
if(pid2 == 0){
for(char *q = p; q < p + (sz/5)*4; q += 4096){
*(int*)q = getpid();
}
for(char *q = p; q < p + (sz/5)*4; q += 4096){
if(*(int*)q != getpid()){
printf(1, "wrong content\n");
exit();
}
}
exit();
}
for(char *q = p; q < p + (sz/2); q += 4096){
*(int*)q = 9999;
}
exit();
}
for(char *q = p; q < p + sz; q += 4096){
*(int*)q = getpid();
}
wait();
sleep(1);
for(char *q = p; q < p + sz; q += 4096){
if(*(int*)q != getpid()){
printf(1, "wrong content\n");
exit();
}
}
if(sbrk(-sz) == (char*)0xffffffffffffffffL){
printf(1, "sbrk(-%d) failed\n", sz);
exit();
}
printf(1, "ok\n");
}
char junk1[4096];
int fds[2];
char junk2[4096];
char buf[4096];
char junk3[4096];
// test whether copyout() simulates COW faults.
void
filetest()
{
int parent = getpid();
printf(1, "file: ");
buf[0] = 99;
for(int i = 0; i < 4; i++){
if(pipe(fds) != 0){
printf(1, "pipe() failed\n");
exit();
}
int pid = fork();
if(pid < 0){
printf(1, "fork failed\n");
exit();
}
if(pid == 0){
sleep(1);
if(read(fds[0], buf, sizeof(i)) != sizeof(i)){
printf(1, "read failed\n");
kill(parent);
exit();
}
sleep(1);
int j = *(int*)buf;
if(j != i){
printf(1, "read the wrong value\n");
kill(parent);
exit();
}
exit();
}
if(write(fds[1], &i, sizeof(i)) != sizeof(i)){
printf(1, "write failed\n");
exit();
}
}
for(int i = 0; i < 4; i++)
wait();
if(buf[0] != 99){
printf(1, "child overwrote parent\n");
exit();
}
printf(1, "ok\n");
}
int
main(int argc, char *argv[])
{
simpletest();
// check that the first simpletest() freed the physical memory.
simpletest();
threetest();
threetest();
threetest();
filetest();
printf(1, "ALL COW TESTS PASSED\n");
exit();
}