1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
|
#define TEST_MACROS
#include <init/stdlib.h>
#include <init/tests/main.h>
#include <shared/flags.h>
#include <shared/syscalls.h>
static const char *pipe_msgs[2] = {"hello", "world"};
void test_pipe(void) {
handle_t ends[2];
char buf[16];
int ret;
/* test regular reads / writes */
assert(_syscall_pipe(ends, 0) >= 0);
if (!_syscall_fork(0, NULL)) {
/* those repeated asserts ensure that you can't read/write to the wrong ends */
assert(_syscall_read(ends[1], buf, 16, 0) < 0);
assert(_syscall_write(ends[0], buf, 16, 0) < 0);
ret = _syscall_write(ends[1], pipe_msgs[0], 5, -1);
assert(ret == 5);
assert(_syscall_read(ends[1], buf, 16, 0) < 0);
assert(_syscall_write(ends[0], buf, 16, 0) < 0);
ret = _syscall_write(ends[1], pipe_msgs[1], 5, -1);
assert(ret == 5);
_syscall_exit(0);
} else {
assert(_syscall_read(ends[1], buf, 16, 0) < 0);
assert(_syscall_write(ends[0], buf, 16, 0) < 0);
ret = _syscall_read(ends[0], buf, 16, 0);
assert(ret == 5);
assert(!memcmp(buf, pipe_msgs[0], 5));
assert(_syscall_read(ends[1], buf, 16, 0) < 0);
assert(_syscall_write(ends[0], buf, 16, 0) < 0);
_syscall_read(ends[0], buf, 16, 0);
assert(ret == 5);
assert(!memcmp(buf, pipe_msgs[1], 5));
_syscall_await();
}
_syscall_close(ends[0]);
_syscall_close(ends[1]);
/* writing to pipes with one end closed */
assert(_syscall_pipe(ends, 0) >= 0);
if (!_syscall_fork(0, NULL)) {
_syscall_close(ends[1]);
assert(_syscall_read(ends[0], buf, 16, 0) < 0);
_syscall_exit(0);
} else {
_syscall_close(ends[1]);
_syscall_await();
}
assert(_syscall_pipe(ends, 0) >= 0);
if (!_syscall_fork(0, NULL)) {
_syscall_close(ends[0]);
assert(_syscall_write(ends[1], buf, 16, 0) < 0);
_syscall_exit(0);
} else {
_syscall_close(ends[0]);
_syscall_await();
}
// not a to.do detect when all processes that can read are stuck on writing to the pipe and vice versa
// it seems like linux just lets the process hang endlessly.
// TODO kill process that's waiting on a pipe
// TODO queue
}
|
