Hi Thomas,
On Mon, 2023-07-31 at 20:28 +0200, Thomas Weißschuh wrote:
On 2023-08-01 02:01:36+0800, Yuan Tan wrote:
Hi Thomas, On Mon, 2023-07-31 at 17:41 +0200, Thomas Weißschuh wrote:
On 2023-07-31 20:35:28+0800, Yuan Tan wrote:
On Mon, 2023-07-31 at 08:10 +0200, Thomas Weißschuh wrote:
On 2023-07-31 13:51:00+0800, Yuan Tan wrote:
Add a testcase of pipe that child process sends message to parent process.
Thinking about it some more:
What's the advantage of going via a child process? The pipe should work the same within the same process.
The pipe is commonly used for process communication, and I think as a test case it is supposed to cover the most common scenarios.
The testcase is supposed to cover the code of nolibc. It should be the *minimal* amount of code to be reasonable sure that the code in nolibc does the correct thing. If pipe() returns a value that behaves like a pipe I see no reason to doubt it will also survive fork().
Validating that would mean testing the kernel and not nolibc. For the kernel there are different testsuites.
Less code means less work for everyone involved, now and in the future.
It's a good point and I never thought about this aspect.
I wonder whether the code below is enough?
static int test_pipe(void) { int pipefd[2];
if (pipe(pipefd) == -1) return 1;
close(pipefd[0]); close(pipefd[1]);
return 0; }
That is very barebones.
If accidentally a wrong syscall number was used and the used syscall would not take any arguments this test would still succeed.
Keeping the write-read-cycle from the previous revision would test that nicely. Essentially the same code as before but without the fork().
And I forgot to add this line:
CASE_TEST(pipe); EXPECT_SYSZR(1, test_pipe()); break;
I will add it in next patch.
In the situation you described, that is indeed the case.
Would this be fine?
static int test_pipe(void) { const char *const msg = "hello, nolibc"; int pipefd[2]; char buf[32]; ssize_t len;
if (pipe(pipefd) == -1) return 1;
write(pipefd[1], msg, strlen(msg)); close(pipefd[1]); len = read(pipefd[0], buf, sizeof(buf)); close(pipefd[0]);
if (len != strlen(msg)) return 1;
return !!memcmp(buf, msg, len); }