Merge pull request #2525 from daurnimator/uring

std: linux uring kernel interfaces

std/math.zig

@@ -686,6 +686,11 @@ pub fn alignCast(comptime alignment: u29, ptr: var) AlignCastError!@typeOf(@alig
     return @alignCast(alignment, ptr);
 }
 
+pub fn isPowerOfTwo(v: var) bool {
+    assert(v != 0);
+    return (v & (v - 1)) == 0;
+}
+
 pub fn floorPowerOfTwo(comptime T: type, value: T) T {
     var x = value;
 

std/os/bits/linux.zig

@@ -119,6 +119,23 @@ pub const O_RDONLY = 0o0;
 pub const O_WRONLY = 0o1;
 pub const O_RDWR = 0o2;
 
+pub const kernel_rwf = u32;
+
+/// high priority request, poll if possible
+pub const RWF_HIPRI = kernel_rwf(0x00000001);
+
+/// per-IO O_DSYNC
+pub const RWF_DSYNC = kernel_rwf(0x00000002);
+
+/// per-IO O_SYNC
+pub const RWF_SYNC = kernel_rwf(0x00000004);
+
+/// per-IO, return -EAGAIN if operation would block
+pub const RWF_NOWAIT = kernel_rwf(0x00000008);
+
+/// per-IO O_APPEND
+pub const RWF_APPEND = kernel_rwf(0x00000010);
+
 pub const SEEK_SET = 0;
 pub const SEEK_CUR = 1;
 pub const SEEK_END = 2;
@@ -950,3 +967,129 @@ pub const stack_t = extern struct {
     ss_flags: i32,
     ss_size: isize,
 };
+
+pub const io_uring_params = extern struct {
+    sq_entries: u32,
+    cq_entries: u32,
+    flags: u32,
+    sq_thread_cpu: u32,
+    sq_thread_idle: u32,
+    resv: [5]u32,
+    sq_off: io_sqring_offsets,
+    cq_off: io_cqring_offsets,
+};
+
+// io_uring_params.flags
+
+/// io_context is polled
+pub const IORING_SETUP_IOPOLL = (1 << 0);
+
+/// SQ poll thread
+pub const IORING_SETUP_SQPOLL = (1 << 1);
+
+/// sq_thread_cpu is valid
+pub const IORING_SETUP_SQ_AFF = (1 << 2);
+
+pub const io_sqring_offsets = extern struct {
+    /// offset of ring head
+    head: u32,
+
+    /// offset of ring tail
+    tail: u32,
+
+    /// ring mask value
+    ring_mask: u32,
+
+    /// entries in ring
+    ring_entries: u32,
+
+    /// ring flags
+    flags: u32,
+
+    /// number of sqes not submitted
+    dropped: u32,
+
+    /// sqe index array
+    array: u32,
+
+    resv1: u32,
+    resv2: u64,
+};
+
+// io_sqring_offsets.flags
+
+/// needs io_uring_enter wakeup
+pub const IORING_SQ_NEED_WAKEUP = 1 << 0;
+
+pub const io_cqring_offsets = extern struct {
+    head: u32,
+    tail: u32,
+    ring_mask: u32,
+    ring_entries: u32,
+    overflow: u32,
+    cqes: u32,
+    resv: [2]u64,
+};
+
+pub const io_uring_sqe = extern struct {
+    opcode: u8,
+    flags: u8,
+    ioprio: u16,
+    fd: i32,
+    off: u64,
+    addr: u64,
+    len: u32,
+    pub const union1 = extern union {
+        rw_flags: kernel_rwf,
+        fsync_flags: u32,
+        poll_event: u16,
+    };
+    union1: union1,
+    user_data: u64,
+    pub const union2 = extern union {
+        buf_index: u16,
+        __pad2: [3]u64,
+    };
+    union2: union2,
+};
+
+// io_uring_sqe.flags
+
+/// use fixed fileset
+pub const IOSQE_FIXED_FILE = (1 << 0);
+
+pub const IORING_OP_NOP = 0;
+pub const IORING_OP_READV = 1;
+pub const IORING_OP_WRITEV = 2;
+pub const IORING_OP_FSYNC = 3;
+pub const IORING_OP_READ_FIXED = 4;
+pub const IORING_OP_WRITE_FIXED = 5;
+pub const IORING_OP_POLL_ADD = 6;
+pub const IORING_OP_POLL_REMOVE = 7;
+
+// io_uring_sqe.fsync_flags
+pub const IORING_FSYNC_DATASYNC = (1 << 0);
+
+// IO completion data structure (Completion Queue Entry)
+pub const io_uring_cqe = extern struct {
+    /// io_uring_sqe.data submission passed back
+    user_data: u64,
+
+    /// result code for this event
+    res: i32,
+    flags: u32,
+};
+
+pub const IORING_OFF_SQ_RING = 0;
+pub const IORING_OFF_CQ_RING = 0x8000000;
+pub const IORING_OFF_SQES = 0x10000000;
+
+// io_uring_enter flags
+pub const IORING_ENTER_GETEVENTS = (1 << 0);
+pub const IORING_ENTER_SQ_WAKEUP = (1 << 1);
+
+// io_uring_register opcodes and arguments
+pub const IORING_REGISTER_BUFFERS = 0;
+pub const IORING_UNREGISTER_BUFFERS = 1;
+pub const IORING_REGISTER_FILES = 2;
+pub const IORING_UNREGISTER_FILES = 3;

std/os/linux.zig

@@ -189,6 +189,10 @@ pub fn preadv(fd: i32, iov: [*]const iovec, count: usize, offset: u64) usize {
     return syscall4(SYS_preadv, @bitCast(usize, isize(fd)), @ptrToInt(iov), count, offset);
 }
 
+pub fn preadv2(fd: i32, iov: [*]const iovec, count: usize, offset: u64, flags: kernel_rwf) usize {
+    return syscall5(SYS_preadv2, @bitCast(usize, isize(fd)), @ptrToInt(iov), count, offset, flags);
+}
+
 pub fn readv(fd: i32, iov: [*]const iovec, count: usize) usize {
     return syscall3(SYS_readv, @bitCast(usize, isize(fd)), @ptrToInt(iov), count);
 }
@@ -201,6 +205,10 @@ pub fn pwritev(fd: i32, iov: [*]const iovec_const, count: usize, offset: u64) us
     return syscall4(SYS_pwritev, @bitCast(usize, isize(fd)), @ptrToInt(iov), count, offset);
 }
 
+pub fn pwritev2(fd: i32, iov: [*]const iovec_const, count: usize, offset: u64, flags: kernel_rwf) usize {
+    return syscall5(SYS_pwritev2, @bitCast(usize, isize(fd)), @ptrToInt(iov), count, offset, flags);
+}
+
 // TODO https://github.com/ziglang/zig/issues/265
 pub fn rmdir(path: [*]const u8) usize {
     if (@hasDecl(@This(), "SYS_rmdir")) {
@@ -887,6 +895,18 @@ pub fn dl_iterate_phdr(comptime T: type, callback: extern fn (info: *dl_phdr_inf
     return last_r;
 }
 
+pub fn io_uring_setup(entries: u32, p: *io_uring_params) usize {
+    return syscall2(SYS_io_uring_setup, entries, @ptrToInt(p));
+}
+
+pub fn io_uring_enter(fd: i32, to_submit: u32, min_complete: u32, flags: u32, sig: ?*sigset_t) usize {
+    return syscall6(SYS_io_uring_enter, @bitCast(usize, isize(fd)), to_submit, min_complete, flags, @ptrToInt(sig), NSIG / 8);
+}
+
+pub fn io_uring_register(fd: i32, opcode: u32, arg: ?*const c_void, nr_args: u32) usize {
+    return syscall4(SYS_io_uring_register, @bitCast(usize, isize(fd)), opcode, @ptrToInt(arg), nr_args);
+}
+
 test "" {
     if (is_the_target) {
         _ = @import("linux/test.zig");

std/testing.zig

@@ -78,8 +78,10 @@ pub fn expectEqual(expected: var, actual: @typeOf(expected)) void {
 
         TypeId.Array => |array| expectEqualSlices(array.child, &expected, &actual),
 
-        TypeId.Struct => {
-            @compileError("TODO implement testing.expectEqual for structs");
+        TypeId.Struct => |structType| {
+            inline for (structType.fields) |field| {
+                expectEqual(@field(expected, field.name), @field(actual, field.name));
+            }
         },
 
         TypeId.Union => |union_info| {