diff options
| -rw-r--r-- | conf/lab.mk | 2 | ||||
| -rwxr-xr-x | grade-lab-cow | 55 | ||||
| -rw-r--r-- | user/cowtest.c | 197 |
3 files changed, 253 insertions, 1 deletions
diff --git a/conf/lab.mk b/conf/lab.mk index 2b9988d..629f978 100644 --- a/conf/lab.mk +++ b/conf/lab.mk @@ -1 +1 @@ -LAB=traps +LAB=cow diff --git a/grade-lab-cow b/grade-lab-cow new file mode 100755 index 0000000..08b6990 --- /dev/null +++ b/grade-lab-cow @@ -0,0 +1,55 @@ +#!/usr/bin/env python3 + +import re +from gradelib import * + +r = Runner(save("xv6.out")) + +@test(0, "running cowtest") +def test_cowtest(): + r.run_qemu(shell_script([ + 'cowtest' + ])) + +@test(30, "simple", parent=test_cowtest) +def test_simple(): + matches = re.findall("^simple: ok$", r.qemu.output, re.M) + assert_equal(len(matches), 2, "Number of appearances of 'simple: ok'") + +@test(30, "three", parent=test_cowtest) +def test_three(): + matches = re.findall("^three: ok$", r.qemu.output, re.M) + assert_equal(len(matches), 3, "Number of appearances of 'three: ok'") + +@test(20, "file", parent=test_cowtest) +def test_file(): + r.match('^file: ok$') + +@test(0, "usertests") +def test_usertests(): + r.run_qemu(shell_script([ + 'usertests -q' + ]), timeout=1000) + r.match('^ALL TESTS PASSED$') + +def usertest_check(testcase, nextcase, output): + if not re.search(r'\ntest {}: [\s\S]*OK\ntest {}'.format(testcase, nextcase), output): + raise AssertionError('Failed ' + testcase) + +@test(5, "usertests: copyin", parent=test_usertests) +def test_sbrkbugs(): + usertest_check("copyin", "copyout", r.qemu.output) + +@test(5, "usertests: copyout", parent=test_usertests) +def test_sbrkbugs(): + usertest_check("copyout", "copyinstr1", r.qemu.output) + +@test(19, "usertests: all tests", parent=test_usertests) +def test_usertests_all(): + r.match('^ALL TESTS PASSED$') + +@test(1, "time") +def test_time(): + check_time() + +run_tests() diff --git a/user/cowtest.c b/user/cowtest.c new file mode 100644 index 0000000..29b918f --- /dev/null +++ b/user/cowtest.c @@ -0,0 +1,197 @@ +// +// 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("simple: "); + + char *p = sbrk(sz); + if(p == (char*)0xffffffffffffffffL){ + printf("sbrk(%d) failed\n", sz); + exit(-1); + } + + for(char *q = p; q < p + sz; q += 4096){ + *(int*)q = getpid(); + } + + int pid = fork(); + if(pid < 0){ + printf("fork() failed\n"); + exit(-1); + } + + if(pid == 0) + exit(0); + + wait(0); + + if(sbrk(-sz) == (char*)0xffffffffffffffffL){ + printf("sbrk(-%d) failed\n", sz); + exit(-1); + } + + printf("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("three: "); + + char *p = sbrk(sz); + if(p == (char*)0xffffffffffffffffL){ + printf("sbrk(%d) failed\n", sz); + exit(-1); + } + + pid1 = fork(); + if(pid1 < 0){ + printf("fork failed\n"); + exit(-1); + } + if(pid1 == 0){ + pid2 = fork(); + if(pid2 < 0){ + printf("fork failed"); + exit(-1); + } + 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("wrong content\n"); + exit(-1); + } + } + exit(-1); + } + for(char *q = p; q < p + (sz/2); q += 4096){ + *(int*)q = 9999; + } + exit(0); + } + + for(char *q = p; q < p + sz; q += 4096){ + *(int*)q = getpid(); + } + + wait(0); + + sleep(1); + + for(char *q = p; q < p + sz; q += 4096){ + if(*(int*)q != getpid()){ + printf("wrong content\n"); + exit(-1); + } + } + + if(sbrk(-sz) == (char*)0xffffffffffffffffL){ + printf("sbrk(-%d) failed\n", sz); + exit(-1); + } + + printf("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() +{ + printf("file: "); + + buf[0] = 99; + + for(int i = 0; i < 4; i++){ + if(pipe(fds) != 0){ + printf("pipe() failed\n"); + exit(-1); + } + int pid = fork(); + if(pid < 0){ + printf("fork failed\n"); + exit(-1); + } + if(pid == 0){ + sleep(1); + if(read(fds[0], buf, sizeof(i)) != sizeof(i)){ + printf("error: read failed\n"); + exit(1); + } + sleep(1); + int j = *(int*)buf; + if(j != i){ + printf("error: read the wrong value\n"); + exit(1); + } + exit(0); + } + if(write(fds[1], &i, sizeof(i)) != sizeof(i)){ + printf("error: write failed\n"); + exit(-1); + } + } + + int xstatus = 0; + for(int i = 0; i < 4; i++) { + wait(&xstatus); + if(xstatus != 0) { + exit(1); + } + } + + if(buf[0] != 99){ + printf("error: child overwrote parent\n"); + exit(1); + } + + printf("ok\n"); +} + +int +main(int argc, char *argv[]) +{ + simpletest(); + + // check that the first simpletest() freed the physical memory. + simpletest(); + + threetest(); + threetest(); + threetest(); + + filetest(); + + printf("ALL COW TESTS PASSED\n"); + + exit(0); +} |