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return ERRNO_AGAIN from fd_{read,write} when appropriate #13111

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Merged
alexcrichton merged 4 commits into from
Apr 16, 2026
Merged

return ERRNO_AGAIN from fd_{read,write} when appropriate #13111

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10a9b0b
return `ERRNO_AGAIN` from `fd_{read,write}` when appropriate
dicej Apr 15, 2026
f7bdd8e
make `BlockingMode::read` mirror `BlockingMode::write`
dicej Apr 16, 2026
5268f05
update p1 file I/O tests to cover blocking and non-blocking cases
dicej Apr 16, 2026
7bec0f1
fix `wasi-common`'s `path_open` with `APPEND | NONBLOCK`
dicej Apr 16, 2026
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16 changes: 9 additions & 7 deletions crates/test-programs/src/bin/p1_cli_hostcall_fuel.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,9 +1,11 @@
use std::ptr;
use test_programs::preview1::BlockingMode;

fn main() {
big_poll();
big_string();
big_iovecs();
big_iovecs(BlockingMode::Blocking);
big_iovecs(BlockingMode::NonBlocking);
}

fn big_string() {
Expand All @@ -18,7 +20,7 @@ fn big_string() {
);
}

fn big_iovecs() {
fn big_iovecs(blocking_mode: BlockingMode) {
let mut iovs = Vec::new();
let mut ciovs = Vec::new();
for _ in 0..10_000 {
Expand All @@ -40,14 +42,14 @@ fn big_iovecs() {
wasip1::OFLAGS_CREAT,
wasip1::RIGHTS_FD_WRITE | wasip1::RIGHTS_FD_READ,
0,
0,
blocking_mode.fd_flags(),
)
.unwrap()
};

unsafe {
assert_eq!(wasip1::fd_write(fd, &ciovs), Err(wasip1::ERRNO_NOMEM));
assert_eq!(wasip1::fd_read(fd, &iovs), Err(wasip1::ERRNO_NOMEM));
assert_eq!(blocking_mode.write(fd, &ciovs), Err(wasip1::ERRNO_NOMEM));
assert_eq!(blocking_mode.read(fd, &iovs), Err(wasip1::ERRNO_NOMEM));
assert_eq!(wasip1::fd_pwrite(fd, &ciovs, 0), Err(wasip1::ERRNO_NOMEM));
assert_eq!(wasip1::fd_pread(fd, &iovs, 0), Err(wasip1::ERRNO_NOMEM));
}
Expand All @@ -63,8 +65,8 @@ fn big_iovecs() {
buf_len: 10_000,
});
unsafe {
assert_eq!(wasip1::fd_write(fd, &ciovs), Err(wasip1::ERRNO_NOMEM));
assert_eq!(wasip1::fd_read(fd, &iovs), Err(wasip1::ERRNO_NOMEM));
assert_eq!(blocking_mode.write(fd, &ciovs), Err(wasip1::ERRNO_NOMEM));
assert_eq!(blocking_mode.read(fd, &iovs), Err(wasip1::ERRNO_NOMEM));
assert_eq!(wasip1::fd_pwrite(fd, &ciovs, 0), Err(wasip1::ERRNO_NOMEM));
assert_eq!(wasip1::fd_pread(fd, &iovs, 0), Err(wasip1::ERRNO_NOMEM));
}
Expand Down
113 changes: 60 additions & 53 deletions crates/test-programs/src/bin/p1_fd_flags_set.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,9 +1,9 @@
#![expect(unsafe_op_in_unsafe_fn, reason = "old code, not worth updating yet")]

use std::{env, process};
use test_programs::preview1::open_scratch_directory;
use test_programs::preview1::{BlockingMode, open_scratch_directory};

unsafe fn test_fd_fdstat_set_flags(dir_fd: wasip1::Fd) {
unsafe fn test_fd_fdstat_set_flags(dir_fd: wasip1::Fd, blocking_mode: BlockingMode) {
const FILE_NAME: &str = "file";
let data = &[0u8; 100];

Expand All @@ -14,20 +14,21 @@ unsafe fn test_fd_fdstat_set_flags(dir_fd: wasip1::Fd) {
wasip1::OFLAGS_CREAT,
wasip1::RIGHTS_FD_READ | wasip1::RIGHTS_FD_WRITE,
0,
wasip1::FDFLAGS_APPEND,
blocking_mode.fd_flags() | wasip1::FDFLAGS_APPEND,
)
.expect("opening a file");

// Write some data and then verify the written data
assert_eq!(
wasip1::fd_write(
file_fd,
&[wasip1::Ciovec {
buf: data.as_ptr(),
buf_len: data.len(),
}],
)
.expect("writing to a file"),
blocking_mode
.write(
file_fd,
&[wasip1::Ciovec {
buf: data.as_ptr(),
buf_len: data.len(),
}],
)
.expect("writing to a file"),
data.len(),
"should write {} bytes",
data.len(),
Expand All @@ -38,14 +39,15 @@ unsafe fn test_fd_fdstat_set_flags(dir_fd: wasip1::Fd) {
let buffer = &mut [0u8; 100];

assert_eq!(
wasip1::fd_read(
file_fd,
&[wasip1::Iovec {
buf: buffer.as_mut_ptr(),
buf_len: buffer.len(),
}]
)
.expect("reading file"),
blocking_mode
.read(
file_fd,
&[wasip1::Iovec {
buf: buffer.as_mut_ptr(),
buf_len: buffer.len(),
}]
)
.expect("reading file"),
buffer.len(),
"should read {} bytes",
buffer.len()
Expand All @@ -59,14 +61,15 @@ unsafe fn test_fd_fdstat_set_flags(dir_fd: wasip1::Fd) {
wasip1::fd_seek(file_fd, 0, wasip1::WHENCE_SET).expect("seeking file");

assert_eq!(
wasip1::fd_write(
file_fd,
&[wasip1::Ciovec {
buf: data.as_ptr(),
buf_len: data.len(),
}],
)
.expect("writing to a file"),
blocking_mode
.write(
file_fd,
&[wasip1::Ciovec {
buf: data.as_ptr(),
buf_len: data.len(),
}],
)
.expect("writing to a file"),
data.len(),
"should write {} bytes",
data.len(),
Expand All @@ -75,37 +78,39 @@ unsafe fn test_fd_fdstat_set_flags(dir_fd: wasip1::Fd) {
wasip1::fd_seek(file_fd, 100, wasip1::WHENCE_SET).expect("seeking file");

assert_eq!(
wasip1::fd_read(
file_fd,
&[wasip1::Iovec {
buf: buffer.as_mut_ptr(),
buf_len: buffer.len(),
}]
)
.expect("reading file"),
blocking_mode
.read(
file_fd,
&[wasip1::Iovec {
buf: buffer.as_mut_ptr(),
buf_len: buffer.len(),
}]
)
.expect("reading file"),
buffer.len(),
"should read {} bytes",
buffer.len()
);

assert_eq!(&data[..], &buffer[..]);

wasip1::fd_fdstat_set_flags(file_fd, 0).expect("disabling flags");
wasip1::fd_fdstat_set_flags(file_fd, blocking_mode.fd_flags()).expect("disabling flags");

// Overwrite some existing data to ensure the append mode is now off
wasip1::fd_seek(file_fd, 0, wasip1::WHENCE_SET).expect("seeking file");

let data = &[2u8; 100];

assert_eq!(
wasip1::fd_write(
file_fd,
&[wasip1::Ciovec {
buf: data.as_ptr(),
buf_len: data.len(),
}],
)
.expect("writing to a file"),
blocking_mode
.write(
file_fd,
&[wasip1::Ciovec {
buf: data.as_ptr(),
buf_len: data.len(),
}],
)
.expect("writing to a file"),
data.len(),
"should write {} bytes",
data.len(),
Expand All @@ -114,14 +119,15 @@ unsafe fn test_fd_fdstat_set_flags(dir_fd: wasip1::Fd) {
wasip1::fd_seek(file_fd, 0, wasip1::WHENCE_SET).expect("seeking file");

assert_eq!(
wasip1::fd_read(
file_fd,
&[wasip1::Iovec {
buf: buffer.as_mut_ptr(),
buf_len: buffer.len(),
}]
)
.expect("reading file"),
blocking_mode
.read(
file_fd,
&[wasip1::Iovec {
buf: buffer.as_mut_ptr(),
buf_len: buffer.len(),
}]
)
.expect("reading file"),
buffer.len(),
"should read {} bytes",
buffer.len()
Expand Down Expand Up @@ -157,6 +163,7 @@ fn main() {
};

unsafe {
test_fd_fdstat_set_flags(dir_fd);
test_fd_fdstat_set_flags(dir_fd, BlockingMode::Blocking);
test_fd_fdstat_set_flags(dir_fd, BlockingMode::NonBlocking);
}
}
51 changes: 35 additions & 16 deletions crates/test-programs/src/bin/p1_file_read_write.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,9 +1,9 @@
#![expect(unsafe_op_in_unsafe_fn, reason = "old code, not worth updating yet")]

use std::{env, process};
use test_programs::preview1::open_scratch_directory;
use test_programs::preview1::{BlockingMode, open_scratch_directory};

unsafe fn test_file_read_write(dir_fd: wasip1::Fd) {
unsafe fn test_file_read_write(dir_fd: wasip1::Fd, blocking_mode: BlockingMode) {
// Create a file in the scratch directory.
let file_fd = wasip1::path_open(
dir_fd,
Expand All @@ -12,7 +12,7 @@ unsafe fn test_file_read_write(dir_fd: wasip1::Fd) {
wasip1::OFLAGS_CREAT,
wasip1::RIGHTS_FD_READ | wasip1::RIGHTS_FD_WRITE,
0,
0,
blocking_mode.fd_flags(),
)
.expect("opening a file");
assert!(
Expand All @@ -25,7 +25,9 @@ unsafe fn test_file_read_write(dir_fd: wasip1::Fd) {
buf: contents.as_ptr() as *const _,
buf_len: contents.len(),
};
let mut nwritten = wasip1::fd_write(file_fd, &[ciovec]).expect("writing bytes at offset 0");
let mut nwritten = blocking_mode
.write(file_fd, &[ciovec])
.expect("writing bytes at offset 0");
assert_eq!(nwritten, 4, "nwritten bytes check");

let contents = &mut [0u8; 4];
Expand All @@ -34,7 +36,9 @@ unsafe fn test_file_read_write(dir_fd: wasip1::Fd) {
buf_len: contents.len(),
};
wasip1::fd_seek(file_fd, 0, wasip1::WHENCE_SET).expect("seeking to offset 0");
let mut nread = wasip1::fd_read(file_fd, &[iovec]).expect("reading bytes at offset 0");
let mut nread = blocking_mode
.read(file_fd, &[iovec])
.expect("reading bytes at offset 0");
assert_eq!(nread, 4, "nread bytes check");
assert_eq!(contents, &[0u8, 1, 2, 3], "written bytes equal read bytes");

Expand All @@ -61,8 +65,9 @@ unsafe fn test_file_read_write(dir_fd: wasip1::Fd) {
buf_len: remaining,
});

nwritten =
wasip1::fd_write(file_fd, ciovecs.as_slice()).expect("writing bytes at offset 0");
nwritten = blocking_mode
.write(file_fd, ciovecs.as_slice())
.expect("writing bytes at offset 0");

offset += nwritten;
if offset == contents.len() {
Expand Down Expand Up @@ -91,7 +96,9 @@ unsafe fn test_file_read_write(dir_fd: wasip1::Fd) {
buf_len: 2,
},
];
nread = wasip1::fd_read(file_fd, iovecs).expect("reading bytes at offset 0");
nread = blocking_mode
.read(file_fd, iovecs)
.expect("reading bytes at offset 0");
if nread == 0 {
break;
}
Expand All @@ -107,7 +114,9 @@ unsafe fn test_file_read_write(dir_fd: wasip1::Fd) {
buf_len: contents.len(),
};
wasip1::fd_seek(file_fd, 2, wasip1::WHENCE_SET).expect("seeking to offset 2");
nread = wasip1::fd_read(file_fd, &[iovec]).expect("reading bytes at offset 2");
nread = blocking_mode
.read(file_fd, &[iovec])
.expect("reading bytes at offset 2");
assert_eq!(nread, 2, "nread bytes check");
assert_eq!(contents, &[2u8, 3, 0, 0], "file cursor was overwritten");

Expand All @@ -117,7 +126,9 @@ unsafe fn test_file_read_write(dir_fd: wasip1::Fd) {
buf_len: contents.len(),
};
wasip1::fd_seek(file_fd, 2, wasip1::WHENCE_SET).expect("seeking to offset 2");
nwritten = wasip1::fd_write(file_fd, &[ciovec]).expect("writing bytes at offset 2");
nwritten = blocking_mode
.write(file_fd, &[ciovec])
.expect("writing bytes at offset 2");
assert_eq!(nwritten, 2, "nwritten bytes check");

let contents = &mut [0u8; 4];
Expand All @@ -126,15 +137,17 @@ unsafe fn test_file_read_write(dir_fd: wasip1::Fd) {
buf_len: contents.len(),
};
wasip1::fd_seek(file_fd, 0, wasip1::WHENCE_SET).expect("seeking to offset 0");
nread = wasip1::fd_read(file_fd, &[iovec]).expect("reading bytes at offset 0");
nread = blocking_mode
.read(file_fd, &[iovec])
.expect("reading bytes at offset 0");
assert_eq!(nread, 4, "nread bytes check");
assert_eq!(contents, &[0u8, 1, 1, 0], "file cursor was overwritten");

wasip1::fd_close(file_fd).expect("closing a file");
wasip1::path_unlink_file(dir_fd, "file").expect("removing a file");
}

unsafe fn test_file_write_and_file_pos(dir_fd: wasip1::Fd) {
unsafe fn test_file_write_and_file_pos(dir_fd: wasip1::Fd, blocking_mode: BlockingMode) {
let path = "file2";
let file_fd = wasip1::path_open(
dir_fd,
Expand All @@ -160,7 +173,9 @@ unsafe fn test_file_write_and_file_pos(dir_fd: wasip1::Fd) {
buf_len: 0,
};
wasip1::fd_seek(file_fd, 2, wasip1::WHENCE_SET).expect("seeking to offset 2");
let n = wasip1::fd_write(file_fd, &[ciovec]).expect("writing bytes at offset 2");
let n = blocking_mode
.write(file_fd, &[ciovec])
.expect("writing bytes at offset 2");
assert_eq!(n, 0);

assert_eq!(wasip1::fd_tell(file_fd).unwrap(), 2);
Expand All @@ -174,7 +189,9 @@ unsafe fn test_file_write_and_file_pos(dir_fd: wasip1::Fd) {
buf_len: buf.len(),
};
wasip1::fd_seek(file_fd, 50, wasip1::WHENCE_SET).expect("seeking to offset 50");
let n = wasip1::fd_write(file_fd, &[ciovec]).expect("writing bytes at offset 50");
let n = blocking_mode
.write(file_fd, &[ciovec])
.expect("writing bytes at offset 50");
assert_eq!(n, 1);

assert_eq!(wasip1::fd_tell(file_fd).unwrap(), 51);
Expand Down Expand Up @@ -206,7 +223,9 @@ fn main() {

// Run the tests.
unsafe {
test_file_read_write(dir_fd);
test_file_write_and_file_pos(dir_fd);
test_file_read_write(dir_fd, BlockingMode::Blocking);
test_file_read_write(dir_fd, BlockingMode::NonBlocking);
test_file_write_and_file_pos(dir_fd, BlockingMode::Blocking);
test_file_write_and_file_pos(dir_fd, BlockingMode::NonBlocking);
}
}
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