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 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286
// vim: tw=80 //! POSIX Asynchronous I/O //! //! The POSIX AIO interface is used for asynchronous I/O on files and disk-like //! devices. It supports [`read`](struct.AioCb.html#method.read), //! [`write`](struct.AioCb.html#method.write), and //! [`fsync`](struct.AioCb.html#method.fsync) operations. Completion //! notifications can optionally be delivered via //! [signals](../signal/enum.SigevNotify.html#variant.SigevSignal), via the //! [`aio_suspend`](fn.aio_suspend.html) function, or via polling. Some //! platforms support other completion //! notifications, such as //! [kevent](../signal/enum.SigevNotify.html#variant.SigevKevent). //! //! Multiple operations may be submitted in a batch with //! [`lio_listio`](fn.lio_listio.html), though the standard does not guarantee //! that they will be executed atomically. //! //! Outstanding operations may be cancelled with //! [`cancel`](struct.AioCb.html#method.cancel) or //! [`aio_cancel_all`](fn.aio_cancel_all.html), though the operating system may //! not support this for all filesystems and devices. use {Error, Result}; use errno::Errno; use std::os::unix::io::RawFd; use libc::{c_void, off_t, size_t}; use libc; use std::borrow::{Borrow, BorrowMut}; use std::fmt; use std::fmt::Debug; use std::marker::PhantomData; use std::mem; use std::ptr::{null, null_mut}; use sys::signal::*; use std::thread; use sys::time::TimeSpec; libc_enum! { /// Mode for `AioCb::fsync`. Controls whether only data or both data and /// metadata are synced. #[repr(i32)] pub enum AioFsyncMode { /// do it like `fsync` O_SYNC, /// on supported operating systems only, do it like `fdatasync` #[cfg(any(target_os = "ios", target_os = "linux", target_os = "macos", target_os = "netbsd", target_os = "openbsd"))] O_DSYNC } } libc_enum! { /// When used with [`lio_listio`](fn.lio_listio.html), determines whether a /// given `aiocb` should be used for a read operation, a write operation, or /// ignored. Has no effect for any other aio functions. #[repr(i32)] pub enum LioOpcode { LIO_NOP, LIO_WRITE, LIO_READ, } } libc_enum! { /// Mode for [`lio_listio`](fn.lio_listio.html) #[repr(i32)] pub enum LioMode { /// Requests that [`lio_listio`](fn.lio_listio.html) block until all /// requested operations have been completed LIO_WAIT, /// Requests that [`lio_listio`](fn.lio_listio.html) return immediately LIO_NOWAIT, } } /// Return values for [`AioCb::cancel`](struct.AioCb.html#method.cancel) and /// [`aio_cancel_all`](fn.aio_cancel_all.html) #[repr(i32)] #[derive(Clone, Copy, Debug, PartialEq)] pub enum AioCancelStat { /// All outstanding requests were canceled AioCanceled = libc::AIO_CANCELED, /// Some requests were not canceled. Their status should be checked with /// `AioCb::error` AioNotCanceled = libc::AIO_NOTCANCELED, /// All of the requests have already finished AioAllDone = libc::AIO_ALLDONE, } /// Owns (uniquely or shared) a memory buffer to keep it from `Drop`ing while /// the kernel has a pointer to it. pub enum Buffer<'a> { /// No buffer to own. /// /// Used for operations like `aio_fsync` that have no data, or for unsafe /// operations that work with raw pointers. None, /// Keeps a reference to a slice Phantom(PhantomData<&'a mut [u8]>), /// Generic thing that keeps a buffer from dropping BoxedSlice(Box<Borrow<[u8]>>), /// Generic thing that keeps a mutable buffer from dropping BoxedMutSlice(Box<BorrowMut<[u8]>>), } impl<'a> Debug for Buffer<'a> { // Note: someday it may be possible to Derive Debug for a trait object, but // not today. // https://github.com/rust-lang/rust/issues/1563 fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result { match *self { Buffer::None => write!(fmt, "None"), Buffer::Phantom(p) => p.fmt(fmt), Buffer::BoxedSlice(ref bs) => { let borrowed : &Borrow<[u8]> = bs.borrow(); write!(fmt, "BoxedSlice({:?})", borrowed as *const Borrow<[u8]>) }, Buffer::BoxedMutSlice(ref bms) => { let borrowed : &BorrowMut<[u8]> = bms.borrow(); write!(fmt, "BoxedMutSlice({:?})", borrowed as *const BorrowMut<[u8]>) } } } } /// AIO Control Block. /// /// The basic structure used by all aio functions. Each `AioCb` represents one /// I/O request. pub struct AioCb<'a> { aiocb: libc::aiocb, /// Tracks whether the buffer pointed to by `libc::aiocb.aio_buf` is mutable mutable: bool, /// Could this `AioCb` potentially have any in-kernel state? in_progress: bool, /// Optionally keeps a reference to the data. /// /// Used to keep buffers from `Drop`'ing, and may be returned once the /// `AioCb` is completed by [`buffer`](#method.buffer). buffer: Buffer<'a> } impl<'a> AioCb<'a> { /// Remove the inner `Buffer` and return it /// /// It is an error to call this method while the `AioCb` is still in /// progress. pub fn buffer(&mut self) -> Buffer<'a> { assert!(!self.in_progress); let mut x = Buffer::None; mem::swap(&mut self.buffer, &mut x); x } /// Remove the inner boxed slice, if any, and return it. /// /// The returned value will be the argument that was passed to /// `from_boxed_slice` when this `AioCb` was created. /// /// It is an error to call this method while the `AioCb` is still in /// progress. pub fn boxed_slice(&mut self) -> Option<Box<Borrow<[u8]>>> { assert!(!self.in_progress, "Can't remove the buffer from an AioCb that's still in-progress. Did you forget to call aio_return?"); if let Buffer::BoxedSlice(_) = self.buffer { let mut oldbuffer = Buffer::None; mem::swap(&mut self.buffer, &mut oldbuffer); if let Buffer::BoxedSlice(inner) = oldbuffer { Some(inner) } else { unreachable!(); } } else { None } } /// Remove the inner boxed mutable slice, if any, and return it. /// /// The returned value will be the argument that was passed to /// `from_boxed_mut_slice` when this `AioCb` was created. /// /// It is an error to call this method while the `AioCb` is still in /// progress. pub fn boxed_mut_slice(&mut self) -> Option<Box<BorrowMut<[u8]>>> { assert!(!self.in_progress, "Can't remove the buffer from an AioCb that's still in-progress. Did you forget to call aio_return?"); if let Buffer::BoxedMutSlice(_) = self.buffer { let mut oldbuffer = Buffer::None; mem::swap(&mut self.buffer, &mut oldbuffer); if let Buffer::BoxedMutSlice(inner) = oldbuffer { Some(inner) } else { unreachable!(); } } else { None } } /// Returns the underlying file descriptor associated with the `AioCb` pub fn fd(&self) -> RawFd { self.aiocb.aio_fildes } /// Constructs a new `AioCb` with no associated buffer. /// /// The resulting `AioCb` structure is suitable for use with `AioCb::fsync`. /// /// # Parameters /// /// * `fd`: File descriptor. Required for all aio functions. /// * `prio`: If POSIX Prioritized IO is supported, then the /// operation will be prioritized at the process's /// priority level minus `prio`. /// * `sigev_notify`: Determines how you will be notified of event /// completion. /// /// # Examples /// /// Create an `AioCb` from a raw file descriptor and use it for an /// [`fsync`](#method.fsync) operation. /// /// ``` /// # extern crate tempfile; /// # extern crate nix; /// # use nix::errno::Errno; /// # use nix::Error; /// # use nix::sys::aio::*; /// # use nix::sys::signal::SigevNotify::SigevNone; /// # use std::{thread, time}; /// # use std::os::unix::io::AsRawFd; /// # use tempfile::tempfile; /// # fn main() { /// let f = tempfile().unwrap(); /// let mut aiocb = AioCb::from_fd( f.as_raw_fd(), 0, SigevNone); /// aiocb.fsync(AioFsyncMode::O_SYNC).expect("aio_fsync failed early"); /// while (aiocb.error() == Err(Error::from(Errno::EINPROGRESS))) { /// thread::sleep(time::Duration::from_millis(10)); /// } /// aiocb.aio_return().expect("aio_fsync failed late"); /// # } /// ``` pub fn from_fd(fd: RawFd, prio: libc::c_int, sigev_notify: SigevNotify) -> AioCb<'a> { let mut a = AioCb::common_init(fd, prio, sigev_notify); a.aio_offset = 0; a.aio_nbytes = 0; a.aio_buf = null_mut(); AioCb { aiocb: a, mutable: false, in_progress: false, buffer: Buffer::None } } /// Constructs a new `AioCb` from a mutable slice. /// /// The resulting `AioCb` will be suitable for both read and write /// operations, but only if the borrow checker can guarantee that the slice /// will outlive the `AioCb`. That will usually be the case if the `AioCb` /// is stack-allocated. If the borrow checker gives you trouble, try using /// [`from_boxed_mut_slice`](#method.from_boxed_mut_slice) instead. /// /// # Parameters /// /// * `fd`: File descriptor. Required for all aio functions. /// * `offs`: File offset /// * `buf`: A memory buffer /// * `prio`: If POSIX Prioritized IO is supported, then the /// operation will be prioritized at the process's /// priority level minus `prio` /// * `sigev_notify`: Determines how you will be notified of event /// completion. /// * `opcode`: This field is only used for `lio_listio`. It /// determines which operation to use for this individual /// aiocb /// /// # Examples /// /// Create an `AioCb` from a mutable slice and read into it. /// /// ``` /// # extern crate tempfile; /// # extern crate nix; /// # use nix::errno::Errno; /// # use nix::Error; /// # use nix::sys::aio::*; /// # use nix::sys::signal::SigevNotify; /// # use std::{thread, time}; /// # use std::io::Write; /// # use std::os::unix::io::AsRawFd; /// # use tempfile::tempfile; /// # fn main() { /// const INITIAL: &[u8] = b"abcdef123456"; /// const LEN: usize = 4; /// let mut rbuf = vec![0; LEN]; /// let mut f = tempfile().unwrap(); /// f.write_all(INITIAL).unwrap(); /// { /// let mut aiocb = AioCb::from_mut_slice( f.as_raw_fd(), /// 2, //offset /// &mut rbuf, /// 0, //priority /// SigevNotify::SigevNone, /// LioOpcode::LIO_NOP); /// aiocb.read().unwrap(); /// while (aiocb.error() == Err(Error::from(Errno::EINPROGRESS))) { /// thread::sleep(time::Duration::from_millis(10)); /// } /// assert_eq!(aiocb.aio_return().unwrap() as usize, LEN); /// } /// assert_eq!(rbuf, b"cdef"); /// # } /// ``` pub fn from_mut_slice(fd: RawFd, offs: off_t, buf: &'a mut [u8], prio: libc::c_int, sigev_notify: SigevNotify, opcode: LioOpcode) -> AioCb<'a> { let mut a = AioCb::common_init(fd, prio, sigev_notify); a.aio_offset = offs; a.aio_nbytes = buf.len() as size_t; a.aio_buf = buf.as_ptr() as *mut c_void; a.aio_lio_opcode = opcode as libc::c_int; AioCb { aiocb: a, mutable: true, in_progress: false, buffer: Buffer::Phantom(PhantomData), } } /// The safest and most flexible way to create an `AioCb`. /// /// Unlike [`from_slice`], this method returns a structure suitable for /// placement on the heap. It may be used for write operations, but not /// read operations. Unlike `from_ptr`, this method will ensure that the /// buffer doesn't `drop` while the kernel is still processing it. Any /// object that can be borrowed as a boxed slice will work. /// /// # Parameters /// /// * `fd`: File descriptor. Required for all aio functions. /// * `offs`: File offset /// * `buf`: A boxed slice-like object /// * `prio`: If POSIX Prioritized IO is supported, then the /// operation will be prioritized at the process's /// priority level minus `prio` /// * `sigev_notify`: Determines how you will be notified of event /// completion. /// * `opcode`: This field is only used for `lio_listio`. It /// determines which operation to use for this individual /// aiocb /// /// # Examples /// /// Create an `AioCb` from a Vector and use it for writing /// /// ``` /// # extern crate tempfile; /// # extern crate nix; /// # use nix::errno::Errno; /// # use nix::Error; /// # use nix::sys::aio::*; /// # use nix::sys::signal::SigevNotify; /// # use std::{thread, time}; /// # use std::io::Write; /// # use std::os::unix::io::AsRawFd; /// # use tempfile::tempfile; /// # fn main() { /// let wbuf = Box::new(Vec::from("CDEF")); /// let expected_len = wbuf.len(); /// let mut f = tempfile().unwrap(); /// let mut aiocb = AioCb::from_boxed_slice( f.as_raw_fd(), /// 2, //offset /// wbuf, /// 0, //priority /// SigevNotify::SigevNone, /// LioOpcode::LIO_NOP); /// aiocb.write().unwrap(); /// while (aiocb.error() == Err(Error::from(Errno::EINPROGRESS))) { /// thread::sleep(time::Duration::from_millis(10)); /// } /// assert_eq!(aiocb.aio_return().unwrap() as usize, expected_len); /// # } /// ``` /// /// Create an `AioCb` from a `Bytes` object /// /// ``` /// # extern crate bytes; /// # extern crate tempfile; /// # extern crate nix; /// # use bytes::Bytes; /// # use nix::sys::aio::*; /// # use nix::sys::signal::SigevNotify; /// # use std::os::unix::io::AsRawFd; /// # use tempfile::tempfile; /// # fn main() { /// let wbuf = Box::new(Bytes::from(&b"CDEF"[..])); /// let mut f = tempfile().unwrap(); /// let mut aiocb = AioCb::from_boxed_slice( f.as_raw_fd(), /// 2, //offset /// wbuf, /// 0, //priority /// SigevNotify::SigevNone, /// LioOpcode::LIO_NOP); /// # } /// ``` /// /// If a library needs to work with buffers that aren't `Box`ed, it can /// create a `Box`ed container for use with this method. Here's an example /// using an un`Box`ed `Bytes` object. /// /// ``` /// # extern crate bytes; /// # extern crate tempfile; /// # extern crate nix; /// # use bytes::Bytes; /// # use nix::sys::aio::*; /// # use nix::sys::signal::SigevNotify; /// # use std::borrow::Borrow; /// # use std::os::unix::io::AsRawFd; /// # use tempfile::tempfile; /// struct BytesContainer(Bytes); /// impl Borrow<[u8]> for BytesContainer { /// fn borrow(&self) -> &[u8] { /// self.0.as_ref() /// } /// } /// fn main() { /// let wbuf = Bytes::from(&b"CDEF"[..]); /// let boxed_wbuf = Box::new(BytesContainer(wbuf)); /// let mut f = tempfile().unwrap(); /// let mut aiocb = AioCb::from_boxed_slice( f.as_raw_fd(), /// 2, //offset /// boxed_wbuf, /// 0, //priority /// SigevNotify::SigevNone, /// LioOpcode::LIO_NOP); /// } /// ``` /// /// [`from_slice`]: #method.from_slice pub fn from_boxed_slice(fd: RawFd, offs: off_t, buf: Box<Borrow<[u8]>>, prio: libc::c_int, sigev_notify: SigevNotify, opcode: LioOpcode) -> AioCb<'a> { let mut a = AioCb::common_init(fd, prio, sigev_notify); { let borrowed : &Borrow<[u8]> = buf.borrow(); let slice : &[u8] = borrowed.borrow(); a.aio_nbytes = slice.len() as size_t; a.aio_buf = slice.as_ptr() as *mut c_void; } a.aio_offset = offs; a.aio_lio_opcode = opcode as libc::c_int; AioCb { aiocb: a, mutable: false, in_progress: false, buffer: Buffer::BoxedSlice(buf), } } /// The safest and most flexible way to create an `AioCb` for reading. /// /// Like [`from_boxed_slice`], but the slice is a mutable one. More /// flexible than [`from_mut_slice`], because a wide range of objects can be /// used. /// /// # Examples /// /// Create an `AioCb` from a Vector and use it for reading /// /// ``` /// # extern crate tempfile; /// # extern crate nix; /// # use nix::errno::Errno; /// # use nix::Error; /// # use nix::sys::aio::*; /// # use nix::sys::signal::SigevNotify; /// # use std::{thread, time}; /// # use std::io::Write; /// # use std::os::unix::io::AsRawFd; /// # use tempfile::tempfile; /// # fn main() { /// const INITIAL: &[u8] = b"abcdef123456"; /// const LEN: usize = 4; /// let rbuf = Box::new(vec![0; LEN]); /// let mut f = tempfile().unwrap(); /// f.write_all(INITIAL).unwrap(); /// let mut aiocb = AioCb::from_boxed_mut_slice( f.as_raw_fd(), /// 2, //offset /// rbuf, /// 0, //priority /// SigevNotify::SigevNone, /// LioOpcode::LIO_NOP); /// aiocb.read().unwrap(); /// while (aiocb.error() == Err(Error::from(Errno::EINPROGRESS))) { /// thread::sleep(time::Duration::from_millis(10)); /// } /// assert_eq!(aiocb.aio_return().unwrap() as usize, LEN); /// let mut buffer = aiocb.boxed_mut_slice().unwrap(); /// const EXPECT: &[u8] = b"cdef"; /// assert_eq!(buffer.borrow_mut(), EXPECT); /// # } /// ``` /// /// [`from_boxed_slice`]: #method.from_boxed_slice /// [`from_mut_slice`]: #method.from_mut_slice pub fn from_boxed_mut_slice(fd: RawFd, offs: off_t, mut buf: Box<BorrowMut<[u8]>>, prio: libc::c_int, sigev_notify: SigevNotify, opcode: LioOpcode) -> AioCb<'a> { let mut a = AioCb::common_init(fd, prio, sigev_notify); { let borrowed : &mut BorrowMut<[u8]> = buf.borrow_mut(); let slice : &mut [u8] = borrowed.borrow_mut(); a.aio_nbytes = slice.len() as size_t; a.aio_buf = slice.as_mut_ptr() as *mut c_void; } a.aio_offset = offs; a.aio_lio_opcode = opcode as libc::c_int; AioCb { aiocb: a, mutable: true, in_progress: false, buffer: Buffer::BoxedMutSlice(buf), } } /// Constructs a new `AioCb` from a mutable raw pointer /// /// Unlike `from_mut_slice`, this method returns a structure suitable for /// placement on the heap. It may be used for both reads and writes. Due /// to its unsafety, this method is not recommended. It is most useful when /// heap allocation is required but for some reason the data cannot be /// wrapped in a `struct` that implements `BorrowMut<[u8]>` /// /// # Parameters /// /// * `fd`: File descriptor. Required for all aio functions. /// * `offs`: File offset /// * `buf`: Pointer to the memory buffer /// * `len`: Length of the buffer pointed to by `buf` /// * `prio`: If POSIX Prioritized IO is supported, then the /// operation will be prioritized at the process's /// priority level minus `prio` /// * `sigev_notify`: Determines how you will be notified of event /// completion. /// * `opcode`: This field is only used for `lio_listio`. It /// determines which operation to use for this individual /// aiocb /// /// # Safety /// /// The caller must ensure that the storage pointed to by `buf` outlives the /// `AioCb`. The lifetime checker can't help here. pub unsafe fn from_mut_ptr(fd: RawFd, offs: off_t, buf: *mut c_void, len: usize, prio: libc::c_int, sigev_notify: SigevNotify, opcode: LioOpcode) -> AioCb<'a> { let mut a = AioCb::common_init(fd, prio, sigev_notify); a.aio_offset = offs; a.aio_nbytes = len; a.aio_buf = buf; a.aio_lio_opcode = opcode as libc::c_int; AioCb { aiocb: a, mutable: true, in_progress: false, buffer: Buffer::None } } /// Constructs a new `AioCb` from a raw pointer. /// /// Unlike `from_slice`, this method returns a structure suitable for /// placement on the heap. Due to its unsafety, this method is not /// recommended. It is most useful when heap allocation is required but for /// some reason the data cannot be wrapped in a `struct` that implements /// `Borrow<[u8]>` /// /// # Parameters /// /// * `fd`: File descriptor. Required for all aio functions. /// * `offs`: File offset /// * `buf`: Pointer to the memory buffer /// * `len`: Length of the buffer pointed to by `buf` /// * `prio`: If POSIX Prioritized IO is supported, then the /// operation will be prioritized at the process's /// priority level minus `prio` /// * `sigev_notify`: Determines how you will be notified of event /// completion. /// * `opcode`: This field is only used for `lio_listio`. It /// determines which operation to use for this individual /// aiocb /// /// # Safety /// /// The caller must ensure that the storage pointed to by `buf` outlives the /// `AioCb`. The lifetime checker can't help here. pub unsafe fn from_ptr(fd: RawFd, offs: off_t, buf: *const c_void, len: usize, prio: libc::c_int, sigev_notify: SigevNotify, opcode: LioOpcode) -> AioCb<'a> { let mut a = AioCb::common_init(fd, prio, sigev_notify); a.aio_offset = offs; a.aio_nbytes = len; // casting a const ptr to a mutable ptr here is ok, because we set the // AioCb's mutable field to false a.aio_buf = buf as *mut c_void; a.aio_lio_opcode = opcode as libc::c_int; AioCb { aiocb: a, mutable: false, in_progress: false, buffer: Buffer::None } } /// Like `from_mut_slice`, but works on constant slices rather than /// mutable slices. /// /// An `AioCb` created this way cannot be used with `read`, and its /// `LioOpcode` cannot be set to `LIO_READ`. This method is useful when /// writing a const buffer with `AioCb::write`, since `from_mut_slice` can't /// work with const buffers. /// /// # Examples /// /// Construct an `AioCb` from a slice and use it for writing. /// /// ``` /// # extern crate tempfile; /// # extern crate nix; /// # use nix::errno::Errno; /// # use nix::Error; /// # use nix::sys::aio::*; /// # use nix::sys::signal::SigevNotify; /// # use std::{thread, time}; /// # use std::os::unix::io::AsRawFd; /// # use tempfile::tempfile; /// # fn main() { /// const WBUF: &[u8] = b"abcdef123456"; /// let mut f = tempfile().unwrap(); /// let mut aiocb = AioCb::from_slice( f.as_raw_fd(), /// 2, //offset /// WBUF, /// 0, //priority /// SigevNotify::SigevNone, /// LioOpcode::LIO_NOP); /// aiocb.write().unwrap(); /// while (aiocb.error() == Err(Error::from(Errno::EINPROGRESS))) { /// thread::sleep(time::Duration::from_millis(10)); /// } /// assert_eq!(aiocb.aio_return().unwrap() as usize, WBUF.len()); /// # } /// ``` // Note: another solution to the problem of writing const buffers would be // to genericize AioCb for both &mut [u8] and &[u8] buffers. AioCb::read // could take the former and AioCb::write could take the latter. However, // then lio_listio wouldn't work, because that function needs a slice of // AioCb, and they must all be of the same type. pub fn from_slice(fd: RawFd, offs: off_t, buf: &'a [u8], prio: libc::c_int, sigev_notify: SigevNotify, opcode: LioOpcode) -> AioCb { let mut a = AioCb::common_init(fd, prio, sigev_notify); a.aio_offset = offs; a.aio_nbytes = buf.len() as size_t; // casting an immutable buffer to a mutable pointer looks unsafe, // but technically its only unsafe to dereference it, not to create // it. a.aio_buf = buf.as_ptr() as *mut c_void; assert!(opcode != LioOpcode::LIO_READ, "Can't read into an immutable buffer"); a.aio_lio_opcode = opcode as libc::c_int; AioCb { aiocb: a, mutable: false, in_progress: false, buffer: Buffer::None, } } fn common_init(fd: RawFd, prio: libc::c_int, sigev_notify: SigevNotify) -> libc::aiocb { // Use mem::zeroed instead of explicitly zeroing each field, because the // number and name of reserved fields is OS-dependent. On some OSes, // some reserved fields are used the kernel for state, and must be // explicitly zeroed when allocated. let mut a = unsafe { mem::zeroed::<libc::aiocb>()}; a.aio_fildes = fd; a.aio_reqprio = prio; a.aio_sigevent = SigEvent::new(sigev_notify).sigevent(); a } /// Update the notification settings for an existing `aiocb` pub fn set_sigev_notify(&mut self, sigev_notify: SigevNotify) { self.aiocb.aio_sigevent = SigEvent::new(sigev_notify).sigevent(); } /// Cancels an outstanding AIO request. /// /// The operating system is not required to implement cancellation for all /// file and device types. Even if it does, there is no guarantee that the /// operation has not already completed. So the caller must check the /// result and handle operations that were not canceled or that have already /// completed. /// /// # Examples /// /// Cancel an outstanding aio operation. Note that we must still call /// `aio_return` to free resources, even though we don't care about the /// result. /// /// ``` /// # extern crate tempfile; /// # extern crate nix; /// # use nix::errno::Errno; /// # use nix::Error; /// # use nix::sys::aio::*; /// # use nix::sys::signal::SigevNotify; /// # use std::{thread, time}; /// # use std::io::Write; /// # use std::os::unix::io::AsRawFd; /// # use tempfile::tempfile; /// # fn main() { /// let wbuf = b"CDEF"; /// let mut f = tempfile().unwrap(); /// let mut aiocb = AioCb::from_slice( f.as_raw_fd(), /// 2, //offset /// &wbuf[..], /// 0, //priority /// SigevNotify::SigevNone, /// LioOpcode::LIO_NOP); /// aiocb.write().unwrap(); /// let cs = aiocb.cancel().unwrap(); /// if cs == AioCancelStat::AioNotCanceled { /// while (aiocb.error() == Err(Error::from(Errno::EINPROGRESS))) { /// thread::sleep(time::Duration::from_millis(10)); /// } /// } /// // Must call `aio_return`, but ignore the result /// let _ = aiocb.aio_return(); /// # } /// ``` /// /// # References /// /// [aio_cancel](http://pubs.opengroup.org/onlinepubs/9699919799/functions/aio_cancel.html) pub fn cancel(&mut self) -> Result<AioCancelStat> { match unsafe { libc::aio_cancel(self.aiocb.aio_fildes, &mut self.aiocb) } { libc::AIO_CANCELED => Ok(AioCancelStat::AioCanceled), libc::AIO_NOTCANCELED => Ok(AioCancelStat::AioNotCanceled), libc::AIO_ALLDONE => Ok(AioCancelStat::AioAllDone), -1 => Err(Error::last()), _ => panic!("unknown aio_cancel return value") } } /// Retrieve error status of an asynchronous operation. /// /// If the request has not yet completed, returns `EINPROGRESS`. Otherwise, /// returns `Ok` or any other error. /// /// # Examples /// /// Issue an aio operation and use `error` to poll for completion. Polling /// is an alternative to `aio_suspend`, used by most of the other examples. /// /// ``` /// # extern crate tempfile; /// # extern crate nix; /// # use nix::errno::Errno; /// # use nix::Error; /// # use nix::sys::aio::*; /// # use nix::sys::signal::SigevNotify; /// # use std::{thread, time}; /// # use std::os::unix::io::AsRawFd; /// # use tempfile::tempfile; /// # fn main() { /// const WBUF: &[u8] = b"abcdef123456"; /// let mut f = tempfile().unwrap(); /// let mut aiocb = AioCb::from_slice( f.as_raw_fd(), /// 2, //offset /// WBUF, /// 0, //priority /// SigevNotify::SigevNone, /// LioOpcode::LIO_NOP); /// aiocb.write().unwrap(); /// while (aiocb.error() == Err(Error::from(Errno::EINPROGRESS))) { /// thread::sleep(time::Duration::from_millis(10)); /// } /// assert_eq!(aiocb.aio_return().unwrap() as usize, WBUF.len()); /// # } /// ``` /// /// # References /// /// [aio_error](http://pubs.opengroup.org/onlinepubs/9699919799/functions/aio_error.html) pub fn error(&mut self) -> Result<()> { match unsafe { libc::aio_error(&mut self.aiocb as *mut libc::aiocb) } { 0 => Ok(()), num if num > 0 => Err(Error::from_errno(Errno::from_i32(num))), -1 => Err(Error::last()), num => panic!("unknown aio_error return value {:?}", num) } } /// An asynchronous version of `fsync(2)`. /// /// # References /// /// [aio_fsync](http://pubs.opengroup.org/onlinepubs/9699919799/functions/aio_fsync.html) pub fn fsync(&mut self, mode: AioFsyncMode) -> Result<()> { let p: *mut libc::aiocb = &mut self.aiocb; Errno::result(unsafe { libc::aio_fsync(mode as libc::c_int, p) }).map(|_| { self.in_progress = true; }) } /// Returns the `aiocb`'s `LioOpcode` field /// /// If the value cannot be represented as an `LioOpcode`, returns `None` /// instead. pub fn lio_opcode(&self) -> Option<LioOpcode> { match self.aiocb.aio_lio_opcode { libc::LIO_READ => Some(LioOpcode::LIO_READ), libc::LIO_WRITE => Some(LioOpcode::LIO_WRITE), libc::LIO_NOP => Some(LioOpcode::LIO_NOP), _ => None } } /// Returns the requested length of the aio operation in bytes /// /// This method returns the *requested* length of the operation. To get the /// number of bytes actually read or written by a completed operation, use /// `aio_return` instead. pub fn nbytes(&self) -> usize { self.aiocb.aio_nbytes } /// Returns the file offset stored in the `AioCb` pub fn offset(&self) -> off_t { self.aiocb.aio_offset } /// Returns the priority of the `AioCb` pub fn priority(&self) -> libc::c_int { self.aiocb.aio_reqprio } /// Asynchronously reads from a file descriptor into a buffer /// /// # References /// /// [aio_read](http://pubs.opengroup.org/onlinepubs/9699919799/functions/aio_read.html) pub fn read(&mut self) -> Result<()> { assert!(self.mutable, "Can't read into an immutable buffer"); let p: *mut libc::aiocb = &mut self.aiocb; Errno::result(unsafe { libc::aio_read(p) }).map(|_| { self.in_progress = true; }) } /// Returns the `SigEvent` stored in the `AioCb` pub fn sigevent(&self) -> SigEvent { SigEvent::from(&self.aiocb.aio_sigevent) } /// Retrieve return status of an asynchronous operation. /// /// Should only be called once for each `AioCb`, after `AioCb::error` /// indicates that it has completed. The result is the same as for the /// synchronous `read(2)`, `write(2)`, of `fsync(2)` functions. /// /// # References /// /// [aio_return](http://pubs.opengroup.org/onlinepubs/9699919799/functions/aio_return.html) // Note: this should be just `return`, but that's a reserved word pub fn aio_return(&mut self) -> Result<isize> { let p: *mut libc::aiocb = &mut self.aiocb; self.in_progress = false; Errno::result(unsafe { libc::aio_return(p) }) } /// Asynchronously writes from a buffer to a file descriptor /// /// # References /// /// [aio_write](http://pubs.opengroup.org/onlinepubs/9699919799/functions/aio_write.html) pub fn write(&mut self) -> Result<()> { let p: *mut libc::aiocb = &mut self.aiocb; Errno::result(unsafe { libc::aio_write(p) }).map(|_| { self.in_progress = true; }) } } /// Cancels outstanding AIO requests for a given file descriptor. /// /// # Examples /// /// Issue an aio operation, then cancel all outstanding operations on that file /// descriptor. /// /// ``` /// # extern crate tempfile; /// # extern crate nix; /// # use nix::errno::Errno; /// # use nix::Error; /// # use nix::sys::aio::*; /// # use nix::sys::signal::SigevNotify; /// # use std::{thread, time}; /// # use std::io::Write; /// # use std::os::unix::io::AsRawFd; /// # use tempfile::tempfile; /// # fn main() { /// let wbuf = b"CDEF"; /// let mut f = tempfile().unwrap(); /// let mut aiocb = AioCb::from_slice( f.as_raw_fd(), /// 2, //offset /// &wbuf[..], /// 0, //priority /// SigevNotify::SigevNone, /// LioOpcode::LIO_NOP); /// aiocb.write().unwrap(); /// let cs = aio_cancel_all(f.as_raw_fd()).unwrap(); /// if cs == AioCancelStat::AioNotCanceled { /// while (aiocb.error() == Err(Error::from(Errno::EINPROGRESS))) { /// thread::sleep(time::Duration::from_millis(10)); /// } /// } /// // Must call `aio_return`, but ignore the result /// let _ = aiocb.aio_return(); /// # } /// ``` /// /// # References /// /// [`aio_cancel`](http://pubs.opengroup.org/onlinepubs/9699919799/functions/aio_cancel.html) pub fn aio_cancel_all(fd: RawFd) -> Result<AioCancelStat> { match unsafe { libc::aio_cancel(fd, null_mut()) } { libc::AIO_CANCELED => Ok(AioCancelStat::AioCanceled), libc::AIO_NOTCANCELED => Ok(AioCancelStat::AioNotCanceled), libc::AIO_ALLDONE => Ok(AioCancelStat::AioAllDone), -1 => Err(Error::last()), _ => panic!("unknown aio_cancel return value") } } /// Suspends the calling process until at least one of the specified `AioCb`s /// has completed, a signal is delivered, or the timeout has passed. /// /// If `timeout` is `None`, `aio_suspend` will block indefinitely. /// /// # Examples /// /// Use `aio_suspend` to block until an aio operation completes. /// // Disable doctest due to a known bug in FreeBSD's 32-bit emulation. The fix // will be included in release 11.2. // FIXME reenable the doc test when the CI machine gets upgraded to that release. // https://svnweb.freebsd.org/base?view=revision&revision=325018 /// ```no_run /// # extern crate tempfile; /// # extern crate nix; /// # use nix::sys::aio::*; /// # use nix::sys::signal::SigevNotify; /// # use std::os::unix::io::AsRawFd; /// # use tempfile::tempfile; /// # fn main() { /// const WBUF: &[u8] = b"abcdef123456"; /// let mut f = tempfile().unwrap(); /// let mut aiocb = AioCb::from_slice( f.as_raw_fd(), /// 2, //offset /// WBUF, /// 0, //priority /// SigevNotify::SigevNone, /// LioOpcode::LIO_NOP); /// aiocb.write().unwrap(); /// aio_suspend(&[&aiocb], None).expect("aio_suspend failed"); /// assert_eq!(aiocb.aio_return().unwrap() as usize, WBUF.len()); /// # } /// ``` /// # References /// /// [`aio_suspend`](http://pubs.opengroup.org/onlinepubs/9699919799/functions/aio_suspend.html) pub fn aio_suspend(list: &[&AioCb], timeout: Option<TimeSpec>) -> Result<()> { let plist = list as *const [&AioCb] as *const [*const libc::aiocb]; let p = plist as *const *const libc::aiocb; let timep = match timeout { None => null::<libc::timespec>(), Some(x) => x.as_ref() as *const libc::timespec }; Errno::result(unsafe { libc::aio_suspend(p, list.len() as i32, timep) }).map(drop) } impl<'a> Debug for AioCb<'a> { fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result { fmt.debug_struct("AioCb") .field("aio_fildes", &self.aiocb.aio_fildes) .field("aio_offset", &self.aiocb.aio_offset) .field("aio_buf", &self.aiocb.aio_buf) .field("aio_nbytes", &self.aiocb.aio_nbytes) .field("aio_lio_opcode", &self.aiocb.aio_lio_opcode) .field("aio_reqprio", &self.aiocb.aio_reqprio) .field("aio_sigevent", &SigEvent::from(&self.aiocb.aio_sigevent)) .field("mutable", &self.mutable) .field("in_progress", &self.in_progress) .finish() } } impl<'a> Drop for AioCb<'a> { /// If the `AioCb` has no remaining state in the kernel, just drop it. /// Otherwise, dropping constitutes a resource leak, which is an error fn drop(&mut self) { assert!(thread::panicking() || !self.in_progress, "Dropped an in-progress AioCb"); } } /// LIO Control Block. /// /// The basic structure used to issue multiple AIO operations simultaneously. #[cfg(not(any(target_os = "ios", target_os = "macos")))] pub struct LioCb<'a> { /// A collection of [`AioCb`]s. All of these will be issued simultaneously /// by the [`listio`] method. /// /// [`AioCb`]: struct.AioCb.html /// [`listio`]: #method.listio pub aiocbs: Vec<AioCb<'a>>, /// The actual list passed to `libc::lio_listio`. /// /// It must live for as long as any of the operations are still being /// processesed, because the aio subsystem uses its address as a unique /// identifier. list: Vec<*mut libc::aiocb>, /// A partial set of results. This field will get populated by /// `listio_resubmit` when an `LioCb` is resubmitted after an error results: Vec<Option<Result<isize>>> } #[cfg(not(any(target_os = "ios", target_os = "macos")))] impl<'a> LioCb<'a> { /// Initialize an empty `LioCb` pub fn with_capacity(capacity: usize) -> LioCb<'a> { LioCb { aiocbs: Vec::with_capacity(capacity), list: Vec::with_capacity(capacity), results: Vec::with_capacity(capacity) } } /// Submits multiple asynchronous I/O requests with a single system call. /// /// They are not guaranteed to complete atomically, and the order in which /// the requests are carried out is not specified. Reads, writes, and /// fsyncs may be freely mixed. /// /// This function is useful for reducing the context-switch overhead of /// submitting many AIO operations. It can also be used with /// `LioMode::LIO_WAIT` to block on the result of several independent /// operations. Used that way, it is often useful in programs that /// otherwise make little use of AIO. /// /// # Examples /// /// Use `listio` to submit an aio operation and wait for its completion. In /// this case, there is no need to use [`aio_suspend`] to wait or /// [`AioCb::error`] to poll. /// /// ``` /// # extern crate tempfile; /// # extern crate nix; /// # use nix::sys::aio::*; /// # use nix::sys::signal::SigevNotify; /// # use std::os::unix::io::AsRawFd; /// # use tempfile::tempfile; /// # fn main() { /// const WBUF: &[u8] = b"abcdef123456"; /// let mut f = tempfile().unwrap(); /// let mut liocb = LioCb::with_capacity(1); /// liocb.aiocbs.push(AioCb::from_slice( f.as_raw_fd(), /// 2, //offset /// WBUF, /// 0, //priority /// SigevNotify::SigevNone, /// LioOpcode::LIO_WRITE)); /// liocb.listio(LioMode::LIO_WAIT, /// SigevNotify::SigevNone).unwrap(); /// assert_eq!(liocb.aio_return(0).unwrap() as usize, WBUF.len()); /// # } /// ``` /// /// # References /// /// [`lio_listio`](http://pubs.opengroup.org/onlinepubs/9699919799/functions/lio_listio.html) /// /// [`aio_suspend`]: fn.aio_suspend.html /// [`AioCb::error`]: struct.AioCb.html#method.error pub fn listio(&mut self, mode: LioMode, sigev_notify: SigevNotify) -> Result<()> { let sigev = SigEvent::new(sigev_notify); let sigevp = &mut sigev.sigevent() as *mut libc::sigevent; self.list.clear(); for a in &mut self.aiocbs { a.in_progress = true; self.list.push(a as *mut AioCb<'a> as *mut libc::aiocb); } let p = self.list.as_ptr(); Errno::result(unsafe { libc::lio_listio(mode as i32, p, self.list.len() as i32, sigevp) }).map(drop) } /// Resubmits any incomplete operations with [`lio_listio`]. /// /// Sometimes, due to system resource limitations, an `lio_listio` call will /// return `EIO`, or `EAGAIN`. Or, if a signal is received, it may return /// `EINTR`. In any of these cases, only a subset of its constituent /// operations will actually have been initiated. `listio_resubmit` will /// resubmit any operations that are still uninitiated. /// /// After calling `listio_resubmit`, results should be collected by /// [`LioCb::aio_return`]. /// /// # Examples /// ```no_run /// # extern crate tempfile; /// # extern crate nix; /// # use nix::Error; /// # use nix::errno::Errno; /// # use nix::sys::aio::*; /// # use nix::sys::signal::SigevNotify; /// # use std::os::unix::io::AsRawFd; /// # use std::{thread, time}; /// # use tempfile::tempfile; /// # fn main() { /// const WBUF: &[u8] = b"abcdef123456"; /// let mut f = tempfile().unwrap(); /// let mut liocb = LioCb::with_capacity(1); /// liocb.aiocbs.push(AioCb::from_slice( f.as_raw_fd(), /// 2, //offset /// WBUF, /// 0, //priority /// SigevNotify::SigevNone, /// LioOpcode::LIO_WRITE)); /// let mut err = liocb.listio(LioMode::LIO_WAIT, SigevNotify::SigevNone); /// while err == Err(Error::Sys(Errno::EIO)) || /// err == Err(Error::Sys(Errno::EAGAIN)) { /// thread::sleep(time::Duration::from_millis(10)); /// err = liocb.listio_resubmit(LioMode::LIO_WAIT, SigevNotify::SigevNone); /// } /// assert_eq!(liocb.aio_return(0).unwrap() as usize, WBUF.len()); /// # } /// ``` /// /// # References /// /// [`lio_listio`](http://pubs.opengroup.org/onlinepubs/9699919799/functions/lio_listio.html) /// /// [`lio_listio`]: http://pubs.opengroup.org/onlinepubs/9699919799/functions/lio_listio.html /// [`LioCb::aio_return`]: struct.LioCb.html#method.aio_return // Note: the addresses of any EINPROGRESS or EOK aiocbs _must_ not be // changed by this method, because the kernel relies on their addresses // being stable. // Note: aiocbs that are Ok(()) must be finalized by aio_return, or else the // sigev_notify will immediately refire. pub fn listio_resubmit(&mut self, mode:LioMode, sigev_notify: SigevNotify) -> Result<()> { let sigev = SigEvent::new(sigev_notify); let sigevp = &mut sigev.sigevent() as *mut libc::sigevent; self.list.clear(); while self.results.len() < self.aiocbs.len() { self.results.push(None); } for (i, a) in self.aiocbs.iter_mut().enumerate() { if self.results[i].is_some() { // Already collected final status for this operation continue; } match a.error() { Ok(()) => { // aiocb is complete; collect its status and don't resubmit self.results[i] = Some(a.aio_return()); }, Err(Error::Sys(Errno::EAGAIN)) => { self.list.push(a as *mut AioCb<'a> as *mut libc::aiocb); }, Err(Error::Sys(Errno::EINPROGRESS)) => { // aiocb is was successfully queued; no need to do anything () }, Err(Error::Sys(Errno::EINVAL)) => panic!( "AioCb was never submitted, or already finalized"), _ => unreachable!() } } let p = self.list.as_ptr(); Errno::result(unsafe { libc::lio_listio(mode as i32, p, self.list.len() as i32, sigevp) }).map(drop) } /// Collect final status for an individual `AioCb` submitted as part of an /// `LioCb`. /// /// This is just like [`AioCb::aio_return`], except it takes into account /// operations that were restarted by [`LioCb::listio_resubmit`] /// /// [`AioCb::aio_return`]: struct.AioCb.html#method.aio_return /// [`LioCb::listio_resubmit`]: #method.listio_resubmit pub fn aio_return(&mut self, i: usize) -> Result<isize> { if i >= self.results.len() || self.results[i].is_none() { self.aiocbs[i].aio_return() } else { self.results[i].unwrap() } } /// Retrieve error status of an individual `AioCb` submitted as part of an /// `LioCb`. /// /// This is just like [`AioCb::error`], except it takes into account /// operations that were restarted by [`LioCb::listio_resubmit`] /// /// [`AioCb::error`]: struct.AioCb.html#method.error /// [`LioCb::listio_resubmit`]: #method.listio_resubmit pub fn error(&mut self, i: usize) -> Result<()> { if i >= self.results.len() || self.results[i].is_none() { self.aiocbs[i].error() } else { Ok(()) } } } #[cfg(not(any(target_os = "ios", target_os = "macos")))] impl<'a> Debug for LioCb<'a> { fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result { fmt.debug_struct("LioCb") .field("aiocbs", &self.aiocbs) .finish() } } #[cfg(not(any(target_os = "ios", target_os = "macos")))] impl<'a> From<Vec<AioCb<'a>>> for LioCb<'a> { fn from(src: Vec<AioCb<'a>>) -> LioCb<'a> { LioCb { list: Vec::with_capacity(src.capacity()), results: Vec::with_capacity(src.capacity()), aiocbs: src, } } }