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
//! `hermit-abi` is small interface to call functions from the
//! [Hermit unikernel](https://github.com/hermit-os/kernel).

#![no_std]
#![allow(nonstandard_style)]
#![allow(clippy::missing_safety_doc)]
#![allow(clippy::result_unit_err)]

pub mod errno;

use core::ffi::c_char;
pub use core::ffi::{c_int, c_short, c_void};

pub use self::errno::*;

/// A thread handle type
pub type Tid = u32;

/// Maximum number of priorities
pub const NO_PRIORITIES: usize = 31;

/// Priority of a thread
#[derive(PartialEq, Eq, PartialOrd, Ord, Debug, Clone, Copy)]
pub struct Priority(u8);

impl Priority {
	pub const fn into(self) -> u8 {
		self.0
	}

	pub const fn from(x: u8) -> Self {
		Priority(x)
	}
}

pub const HIGH_PRIO: Priority = Priority::from(3);
pub const NORMAL_PRIO: Priority = Priority::from(2);
pub const LOW_PRIO: Priority = Priority::from(1);

pub const FUTEX_RELATIVE_TIMEOUT: u32 = 1;
pub const CLOCK_REALTIME: clockid_t = 1;
pub const CLOCK_MONOTONIC: clockid_t = 4;
pub const STDIN_FILENO: c_int = 0;
pub const STDOUT_FILENO: c_int = 1;
pub const STDERR_FILENO: c_int = 2;
pub const O_RDONLY: i32 = 0o0;
pub const O_WRONLY: i32 = 0o1;
pub const O_RDWR: i32 = 0o2;
pub const O_CREAT: i32 = 0o100;
pub const O_EXCL: i32 = 0o200;
pub const O_TRUNC: i32 = 0o1000;
pub const O_APPEND: i32 = 0o2000;
pub const O_NONBLOCK: i32 = 0o4000;
pub const O_DIRECTORY: i32 = 0o200000;
pub const F_DUPFD: i32 = 0;
pub const F_GETFD: i32 = 1;
pub const F_SETFD: i32 = 2;
pub const F_GETFL: i32 = 3;
pub const F_SETFL: i32 = 4;
pub const FD_CLOEXEC: i32 = 1;

/// returns true if file descriptor `fd` is a tty
pub fn isatty(_fd: c_int) -> bool {
	false
}

/// `timespec` is used by `clock_gettime` to retrieve the
/// current time
#[derive(Default, Copy, Clone, Debug)]
#[repr(C)]
pub struct timespec {
	/// seconds
	pub tv_sec: time_t,
	/// nanoseconds
	pub tv_nsec: i32,
}

#[repr(C)]
#[derive(Debug, Copy, Clone)]
pub struct timeval {
	pub tv_sec: time_t,
	pub tv_usec: suseconds_t,
}

/// The largest number `rand` will return
pub const RAND_MAX: i32 = 2_147_483_647;

pub const AF_INET: i32 = 0;
pub const AF_INET6: i32 = 1;
pub const IPPROTO_IP: i32 = 0;
pub const IPPROTO_IPV6: i32 = 41;
pub const IPPROTO_UDP: i32 = 17;
pub const IPPROTO_TCP: i32 = 6;
pub const IPV6_ADD_MEMBERSHIP: i32 = 12;
pub const IPV6_DROP_MEMBERSHIP: i32 = 13;
pub const IPV6_MULTICAST_LOOP: i32 = 19;
pub const IPV6_V6ONLY: i32 = 27;
pub const IP_TOS: i32 = 1;
pub const IP_TTL: i32 = 2;
pub const IP_MULTICAST_TTL: i32 = 5;
pub const IP_MULTICAST_LOOP: i32 = 7;
pub const IP_ADD_MEMBERSHIP: i32 = 3;
pub const IP_DROP_MEMBERSHIP: i32 = 4;
pub const SHUT_RD: i32 = 0;
pub const SHUT_WR: i32 = 1;
pub const SHUT_RDWR: i32 = 2;
pub const SOCK_DGRAM: i32 = 2;
pub const SOCK_STREAM: i32 = 1;
pub const SOCK_NONBLOCK: i32 = 0o4000;
pub const SOCK_CLOEXEC: i32 = 0o40000;
pub const SOL_SOCKET: i32 = 4095;
pub const SO_REUSEADDR: i32 = 0x0004;
pub const SO_KEEPALIVE: i32 = 0x0008;
pub const SO_BROADCAST: i32 = 0x0020;
pub const SO_LINGER: i32 = 0x0080;
pub const SO_SNDBUF: i32 = 0x1001;
pub const SO_RCVBUF: i32 = 0x1002;
pub const SO_SNDTIMEO: i32 = 0x1005;
pub const SO_RCVTIMEO: i32 = 0x1006;
pub const SO_ERROR: i32 = 0x1007;
pub const TCP_NODELAY: i32 = 1;
pub const MSG_PEEK: i32 = 1;
pub const FIONBIO: i32 = 0x8008667eu32 as i32;
pub const EAI_AGAIN: i32 = 2;
pub const EAI_BADFLAGS: i32 = 3;
pub const EAI_FAIL: i32 = 4;
pub const EAI_FAMILY: i32 = 5;
pub const EAI_MEMORY: i32 = 6;
pub const EAI_NODATA: i32 = 7;
pub const EAI_NONAME: i32 = 8;
pub const EAI_SERVICE: i32 = 9;
pub const EAI_SOCKTYPE: i32 = 10;
pub const EAI_SYSTEM: i32 = 11;
pub const EAI_OVERFLOW: i32 = 14;
pub const POLLIN: i16 = 0x1;
pub const POLLPRI: i16 = 0x2;
pub const POLLOUT: i16 = 0x4;
pub const POLLERR: i16 = 0x8;
pub const POLLHUP: i16 = 0x10;
pub const POLLNVAL: i16 = 0x20;
pub const POLLRDNORM: i16 = 0x040;
pub const POLLRDBAND: i16 = 0x080;
pub const POLLWRNORM: i16 = 0x0100;
pub const POLLWRBAND: i16 = 0x0200;
pub const POLLRDHUP: i16 = 0x2000;
pub const EFD_SEMAPHORE: i16 = 0o1;
pub const EFD_NONBLOCK: i16 = 0o4000;
pub const EFD_CLOEXEC: i16 = 0o40000;
pub const IOV_MAX: usize = 1024;
pub type sa_family_t = u8;
pub type socklen_t = u32;
pub type in_addr_t = u32;
pub type in_port_t = u16;
pub type time_t = i64;
pub type useconds_t = u32;
pub type suseconds_t = i32;
pub type nfds_t = usize;
pub type sem_t = *const c_void;
pub type pid_t = i32;
pub type clockid_t = i32;

#[repr(C)]
#[derive(Debug, Copy, Clone, Default)]
pub struct in_addr {
	pub s_addr: in_addr_t,
}

#[repr(C, align(4))]
#[derive(Debug, Copy, Clone, Default)]
pub struct in6_addr {
	pub s6_addr: [u8; 16],
}

#[repr(C)]
#[derive(Debug, Copy, Clone)]
pub struct sockaddr {
	pub sa_len: u8,
	pub sa_family: sa_family_t,
	pub sa_data: [c_char; 14],
}

#[repr(C)]
#[derive(Debug, Copy, Clone)]
pub struct sockaddr_in {
	pub sin_len: u8,
	pub sin_family: sa_family_t,
	pub sin_port: in_port_t,
	pub sin_addr: in_addr,
	pub sin_zero: [c_char; 8],
}

#[repr(C)]
#[derive(Debug, Copy, Clone)]
pub struct sockaddr_in6 {
	pub sin6_len: u8,
	pub sin6_family: sa_family_t,
	pub sin6_port: in_port_t,
	pub sin6_flowinfo: u32,
	pub sin6_addr: in6_addr,
	pub sin6_scope_id: u32,
}

#[repr(C)]
#[derive(Debug, Copy, Clone)]
pub struct addrinfo {
	pub ai_flags: i32,
	pub ai_family: i32,
	pub ai_socktype: i32,
	pub ai_protocol: i32,
	pub ai_addrlen: socklen_t,
	pub ai_canonname: *mut c_char,
	pub ai_addr: *mut sockaddr,
	pub ai_next: *mut addrinfo,
}

#[repr(C)]
#[derive(Debug, Copy, Clone)]
pub struct sockaddr_storage {
	pub s2_len: u8,
	pub ss_family: sa_family_t,
	__ss_pad1: [u8; 6],
	__ss_align: i64,
	__ss_pad2: [u8; 112],
}

#[repr(C)]
#[derive(Debug, Copy, Clone)]
pub struct ip_mreq {
	pub imr_multiaddr: in_addr,
	pub imr_interface: in_addr,
}

#[repr(C)]
#[derive(Debug, Copy, Clone)]
pub struct ipv6_mreq {
	pub ipv6mr_multiaddr: in6_addr,
	pub ipv6mr_interface: u32,
}

#[repr(C)]
#[derive(Debug, Copy, Clone)]
pub struct linger {
	pub l_onoff: i32,
	pub l_linger: i32,
}

#[repr(C)]
#[derive(Debug, Copy, Clone)]
pub struct pollfd {
	/// file descriptor
	pub fd: i32,
	/// events to look for
	pub events: i16,
	/// events returned
	pub revents: i16,
}

#[repr(C)]
#[derive(Debug, Default, Copy, Clone)]
pub struct stat {
	pub st_dev: u64,
	pub st_ino: u64,
	pub st_nlink: u64,
	/// access permissions
	pub st_mode: u32,
	/// user id
	pub st_uid: u32,
	/// group id
	pub st_gid: u32,
	/// device id
	pub st_rdev: u64,
	/// size in bytes
	pub st_size: u64,
	/// block size
	pub st_blksize: i64,
	/// size in blocks
	pub st_blocks: i64,
	/// time of last access
	pub st_atim: timespec,
	/// time of last modification
	pub st_mtim: timespec,
	/// time of last status change
	pub st_ctim: timespec,
}

#[repr(C)]
#[derive(Debug, Clone, Copy)]
pub struct dirent64 {
	/// 64-bit inode number
	pub d_ino: u64,
	/// 64-bit offset to next structure
	pub d_off: i64,
	/// Size of this dirent
	pub d_reclen: u16,
	/// File type
	pub d_type: u8,
	/// Filename (null-terminated)
	pub d_name: [c_char; 256],
}

#[repr(C)]
#[derive(Debug, Clone, Copy)]
/// Describes  a  region  of  memory, beginning at `iov_base` address and with the size of `iov_len` bytes.
pub struct iovec {
	/// Starting address
	pub iov_base: *mut c_void,
	/// Size of the memory pointed to by iov_base.
	pub iov_len: usize,
}

pub const DT_UNKNOWN: u8 = 0;
pub const DT_FIFO: u8 = 1;
pub const DT_CHR: u8 = 2;
pub const DT_DIR: u8 = 4;
pub const DT_BLK: u8 = 6;
pub const DT_REG: u8 = 8;
pub const DT_LNK: u8 = 10;
pub const DT_SOCK: u8 = 12;
pub const DT_WHT: u8 = 14;

pub const S_IFIFO: u32 = 0o1_0000;
pub const S_IFCHR: u32 = 0o2_0000;
pub const S_IFBLK: u32 = 0o6_0000;
pub const S_IFDIR: u32 = 0o4_0000;
pub const S_IFREG: u32 = 0o10_0000;
pub const S_IFLNK: u32 = 0o12_0000;
pub const S_IFSOCK: u32 = 0o14_0000;
pub const S_IFMT: u32 = 0o17_0000;

// symbols, which are part of the library operating system
extern "C" {
	/// Get the last error number from the thread local storage
	#[link_name = "sys_get_errno"]
	pub fn get_errno() -> i32;

	/// Get the last error number from the thread local storage
	#[link_name = "sys_errno"]
	pub fn errno() -> i32;

	/// If the value at address matches the expected value, park the current thread until it is either
	/// woken up with [`futex_wake`] (returns 0) or an optional timeout elapses (returns -ETIMEDOUT).
	///
	/// Setting `timeout` to null means the function will only return if [`futex_wake`] is called.
	/// Otherwise, `timeout` is interpreted as an absolute time measured with [`CLOCK_MONOTONIC`].
	/// If [`FUTEX_RELATIVE_TIMEOUT`] is set in `flags` the timeout is understood to be relative
	/// to the current time.
	///
	/// Returns -EINVAL if `address` is null, the timeout is negative or `flags` contains unknown values.
	#[link_name = "sys_futex_wait"]
	pub fn futex_wait(
		address: *mut u32,
		expected: u32,
		timeout: *const timespec,
		flags: u32,
	) -> i32;

	/// Wake `count` threads waiting on the futex at `address`. Returns the number of threads
	/// woken up (saturates to `i32::MAX`). If `count` is `i32::MAX`, wake up all matching
	/// waiting threads. If `count` is negative or `address` is null, returns -EINVAL.
	#[link_name = "sys_futex_wake"]
	pub fn futex_wake(address: *mut u32, count: i32) -> i32;

	/// sem_init() initializes the unnamed semaphore at the address
	/// pointed to by `sem`.  The `value` argument specifies the
	/// initial value for the semaphore. If `pshared` is nonzero,
	/// then the semaphore is shared between processes (currently
	/// not supported).
	#[link_name = "sys_sem_init"]
	pub fn sem_init(sem: *mut sem_t, pshared: i32, value: u32) -> i32;

	/// sem_destroy() frees the unnamed semaphore at the address
	/// pointed to by `sem`.
	#[link_name = "sys_sem_destroy"]
	pub fn sem_destroy(sem: *mut sem_t) -> i32;

	/// sem_post() increments the semaphore pointed to by `sem`.
	/// If the semaphore's value consequently becomes greater
	/// than zero, then another thread blocked in a sem_wait call
	/// will be woken up and proceed to lock the semaphore.
	#[link_name = "sys_sem_post"]
	pub fn sem_post(sem: *mut sem_t) -> i32;

	/// try to decrement a semaphore
	///
	/// sem_trywait() is the same as sem_timedwait(), except that
	/// if the  decrement cannot be immediately performed, then  call
	/// returns a negative value instead of blocking.
	#[link_name = "sys_sem_trywait"]
	pub fn sem_trywait(sem: *mut sem_t) -> i32;

	/// decrement a semaphore
	///
	/// sem_timedwait() decrements the semaphore pointed to by `sem`.
	/// If the semaphore's value is greater than zero, then the
	/// the function returns immediately. If the semaphore currently
	/// has the value zero, then the call blocks until either
	/// it becomes possible to perform the decrement of the time limit
	/// to wait for the semaphore is expired. A time limit `ms` of
	/// means infinity waiting time.
	#[link_name = "sys_sem_timedwait"]
	pub fn sem_timedwait(sem: *mut sem_t, abs_timeout: *const timespec) -> i32;

	/// Determines the id of the current thread
	#[link_name = "sys_getpid"]
	pub fn getpid() -> pid_t;

	/// cause normal termination and return `status`
	/// to the host system
	#[link_name = "sys_exit"]
	pub fn exit(status: i32) -> !;

	/// cause abnormal termination
	#[link_name = "sys_abort"]
	pub fn abort() -> !;

	/// suspend execution for microsecond intervals
	///
	/// The usleep() function suspends execution of the calling
	/// thread for (at least) `usecs` microseconds.
	#[link_name = "sys_usleep"]
	pub fn usleep(usecs: u64);

	/// suspend thread execution for an interval measured in nanoseconds
	#[link_name = "sys_nanosleep"]
	pub fn nanosleep(req: *const timespec) -> i32;

	/// spawn a new thread
	///
	/// spawn() starts a new thread. The new thread starts execution
	/// by invoking `func(usize)`; `arg` is passed as the argument
	/// to `func`. `prio` defines the priority of the new thread,
	/// which can be between `LOW_PRIO` and `HIGH_PRIO`.
	/// `core_id` defines the core, where the thread is located.
	/// A negative value give the operating system the possibility
	/// to select the core by its own.
	#[link_name = "sys_spawn"]
	pub fn spawn(
		id: *mut Tid,
		func: extern "C" fn(usize),
		arg: usize,
		prio: u8,
		core_id: isize,
	) -> i32;

	/// spawn a new thread with user-specified stack size
	///
	/// spawn2() starts a new thread. The new thread starts execution
	/// by invoking `func(usize)`; `arg` is passed as the argument
	/// to `func`. `prio` defines the priority of the new thread,
	/// which can be between `LOW_PRIO` and `HIGH_PRIO`.
	/// `core_id` defines the core, where the thread is located.
	/// A negative value give the operating system the possibility
	/// to select the core by its own.
	/// In contrast to spawn(), spawn2() is able to define the
	/// stack size.
	#[link_name = "sys_spawn2"]
	pub fn spawn2(
		func: extern "C" fn(usize),
		arg: usize,
		prio: u8,
		stack_size: usize,
		core_id: isize,
	) -> Tid;

	/// join with a terminated thread
	///
	/// The join() function waits for the thread specified by `id`
	/// to terminate.
	#[link_name = "sys_join"]
	pub fn join(id: Tid) -> i32;

	/// yield the processor
	///
	/// causes the calling thread to relinquish the CPU. The thread
	/// is moved to the end of the queue for its static priority.
	#[link_name = "sys_yield"]
	pub fn yield_now();

	/// get current time
	///
	/// The clock_gettime() functions allow the calling thread
	/// to retrieve the value used by a clock which is specified
	/// by `clockid`.
	///
	/// `CLOCK_REALTIME`: the system's real time clock,
	/// expressed as the amount of time since the Epoch.
	///
	/// `CLOCK_MONOTONIC`: clock that increments monotonically,
	/// tracking the time since an arbitrary point
	#[link_name = "sys_clock_gettime"]
	pub fn clock_gettime(clockid: clockid_t, tp: *mut timespec) -> i32;

	/// open and possibly create a file
	///
	/// The open() system call opens the file specified by `name`.
	/// If the specified file does not exist, it may optionally
	/// be created by open().
	#[link_name = "sys_open"]
	pub fn open(name: *const c_char, flags: i32, mode: i32) -> i32;

	/// open a directory
	///
	/// The opendir() system call opens the directory specified by `name`.
	#[deprecated(since = "0.4.0", note = "please use `open`")]
	#[link_name = "sys_opendir"]
	pub fn opendir(name: *const c_char) -> i32;

	/// delete the file it refers to `name`
	#[link_name = "sys_unlink"]
	pub fn unlink(name: *const c_char) -> i32;

	/// remove directory it refers to `name`
	#[link_name = "sys_rmdir"]
	pub fn rmdir(name: *const c_char) -> i32;

	/// stat
	#[link_name = "sys_stat"]
	pub fn stat(name: *const c_char, stat: *mut stat) -> i32;

	/// lstat
	#[link_name = "sys_lstat"]
	pub fn lstat(name: *const c_char, stat: *mut stat) -> i32;

	/// fstat
	#[link_name = "sys_fstat"]
	pub fn fstat(fd: i32, stat: *mut stat) -> i32;

	/// Returns an estimate of the default amount of parallelism
	/// a program should use. This number often corresponds to the
	/// amount of CPUs a computer has, but it may diverge in
	/// various cases.
	#[link_name = "sys_available_parallelism"]
	pub fn available_parallelism() -> usize;

	/// determines the number of activated processors
	#[deprecated(since = "0.4.0", note = "please use `available_parallelism`")]
	#[link_name = "sys_get_processor_count"]
	pub fn get_processor_count() -> usize;

	#[link_name = "sys_malloc"]
	pub fn malloc(size: usize, align: usize) -> *mut u8;

	#[link_name = "sys_alloc"]
	pub fn alloc(size: usize, align: usize) -> *mut u8;

	#[link_name = "sys_alloc_zeroed"]
	pub fn alloc_zeroed(size: usize, align: usize) -> *mut u8;

	#[link_name = "sys_realloc"]
	pub fn realloc(ptr: *mut u8, size: usize, align: usize, new_size: usize) -> *mut u8;

	#[link_name = "sys_free"]
	pub fn free(ptr: *mut u8, size: usize, align: usize);

	#[link_name = "sys_dealloc"]
	pub fn dealloc(ptr: *mut u8, size: usize, align: usize);

	#[link_name = "sys_notify"]
	pub fn notify(id: usize, count: i32) -> i32;

	#[doc(hidden)]
	#[link_name = "sys_add_queue"]
	pub fn add_queue(id: usize, timeout_ns: i64) -> i32;

	#[doc(hidden)]
	#[link_name = "sys_wait"]
	pub fn wait(id: usize) -> i32;

	#[doc(hidden)]
	#[link_name = "sys_init_queue"]
	pub fn init_queue(id: usize) -> i32;

	#[doc(hidden)]
	#[link_name = "sys_destroy_queue"]
	pub fn destroy_queue(id: usize) -> i32;

	/// initialize the network stack
	#[link_name = "sys_network_init"]
	pub fn network_init() -> i32;

	/// Add current task to the queue of blocked tasks. After calling `block_current_task`,
	/// call `yield_now` to switch to another task.
	#[link_name = "sys_block_current_task"]
	pub fn block_current_task();

	/// Add current task to the queue of blocked tasks, but wake it when `timeout` milliseconds
	/// have elapsed.
	///
	/// After calling `block_current_task`, call `yield_now` to switch to another task.
	#[link_name = "sys_block_current_task_with_timeout"]
	pub fn block_current_task_with_timeout(timeout: u64);

	/// Wakeup task with the thread id `tid`
	#[link_name = "sys_wakeup_taskt"]
	pub fn wakeup_task(tid: Tid);

	/// The system call `getaddrbyname` determine the network host entry.
	/// It expects an array of u8 with a size of in_addr or of in6_addr.
	/// The result of the DNS request will be stored in this array.
	///
	/// # Example
	///
	/// ```
	/// use hermit_abi::in_addr;
	/// let c_string = std::ffi::CString::new("rust-lang.org").expect("CString::new failed");
	/// let name = c_string.into_raw();
	/// let mut inaddr: in_addr = Default::default();
	/// let _ = unsafe {
	///         hermit_abi::getaddrbyname(
	///                 name,
	///                 &mut inaddr as *mut _ as *mut u8,
	///                 std::mem::size_of::<in_addr>(),
	///         )
	/// };
	///
	/// // retake pointer to free memory
	/// let _ = CString::from_raw(name);
	/// ```
	#[link_name = "sys_getaddrbyname"]
	pub fn getaddrbyname(name: *const c_char, inaddr: *mut u8, len: usize) -> i32;

	#[link_name = "sys_accept"]
	pub fn accept(s: i32, addr: *mut sockaddr, addrlen: *mut socklen_t) -> i32;

	/// bind a name to a socket
	#[link_name = "sys_bind"]
	pub fn bind(s: i32, name: *const sockaddr, namelen: socklen_t) -> i32;

	#[link_name = "sys_connect"]
	pub fn connect(s: i32, name: *const sockaddr, namelen: socklen_t) -> i32;

	/// read from a file descriptor
	///
	/// read() attempts to read `len` bytes of data from the object
	/// referenced by the descriptor `fd` into the buffer pointed
	/// to by `buf`.
	#[link_name = "sys_read"]
	pub fn read(fd: i32, buf: *mut u8, len: usize) -> isize;

	/// `read()` attempts to read `nbyte` of data to the object referenced by the
	/// descriptor `fd` from a buffer. `read()` performs the same
	/// action, but scatters the input data from the `iovcnt` buffers specified by the
	/// members of the iov array: `iov[0], iov[1], ..., iov[iovcnt-1]`.
	///
	/// ```
	/// struct iovec {
	///     char   *iov_base;  /* Base address. */
	///     size_t iov_len;    /* Length. */
	/// };
	/// ```
	///
	/// Each `iovec` entry specifies the base address and length of an area in memory from
	/// which data should be written.  `readv()` will always fill an completely
	/// before proceeding to the next.
	#[link_name = "sys_readv"]
	pub fn readv(fd: i32, iov: *const iovec, iovcnt: usize) -> isize;

	/// `getdents64` reads directory entries from the directory referenced
	/// by the file descriptor `fd` into the buffer pointed to by `buf`.
	#[link_name = "sys_getdents64"]
	pub fn getdents64(fd: i32, dirp: *mut dirent64, count: usize) -> i64;

	/// 'mkdir' attempts to create a directory,
	/// it returns 0 on success and -1 on error
	#[link_name = "sys_mkdir"]
	pub fn mkdir(name: *const i8, mode: u32) -> i32;

	/// Fill `len` bytes in `buf` with cryptographically secure random data.
	///
	/// Returns either the number of bytes written to buf (a positive value) or
	/// * `-EINVAL` if `flags` contains unknown flags.
	/// * `-ENOSYS` if the system does not support random data generation.
	#[link_name = "sys_read_entropy"]
	pub fn read_entropy(buf: *mut u8, len: usize, flags: u32) -> isize;

	/// receive() a message from a socket
	#[link_name = "sys_recv"]
	pub fn recv(socket: i32, buf: *mut u8, len: usize, flags: i32) -> isize;

	/// receive() a message from a socket
	#[link_name = "sys_recvfrom"]
	pub fn recvfrom(
		socket: i32,
		buf: *mut u8,
		len: usize,
		flags: i32,
		addr: *mut sockaddr,
		addrlen: *mut socklen_t,
	) -> isize;

	/// write to a file descriptor
	///
	/// write() attempts to write `len` of data to the object
	/// referenced by the descriptor `fd` from the
	/// buffer pointed to by `buf`.
	#[link_name = "sys_write"]
	pub fn write(fd: i32, buf: *const u8, len: usize) -> isize;

	/// `write()` attempts to write `nbyte` of data to the object referenced by the
	/// descriptor `fd` from a buffer. `writev()` performs the same
	/// action, but gathers the output data from the `iovcnt` buffers specified by the
	/// members of the iov array: `iov[0], iov[1], ..., iov[iovcnt-1]`.
	///
	/// ```
	/// struct iovec {
	///     char   *iov_base;  /* Base address. */
	///     size_t iov_len;    /* Length. */
	/// };
	/// ```
	///
	/// Each `iovec` entry specifies the base address and length of an area in memory from
	/// which data should be written.  `writev()` will always write a
	/// complete area before proceeding to the next.
	#[link_name = "sys_writev"]
	pub fn writev(fd: i32, iov: *const iovec, iovcnt: usize) -> isize;

	/// close a file descriptor
	///
	/// The close() call deletes a file descriptor `fd` from the object
	/// reference table.
	#[link_name = "sys_close"]
	pub fn close(fd: i32) -> i32;

	/// duplicate an existing file descriptor
	#[link_name = "sys_dup"]
	pub fn dup(fd: i32) -> i32;

	#[link_name = "sys_getpeername"]
	pub fn getpeername(s: i32, name: *mut sockaddr, namelen: *mut socklen_t) -> i32;

	#[link_name = "sys_getsockname"]
	pub fn getsockname(s: i32, name: *mut sockaddr, namelen: *mut socklen_t) -> i32;

	#[link_name = "sys_getsockopt"]
	pub fn getsockopt(
		s: i32,
		level: i32,
		optname: i32,
		optval: *mut c_void,
		optlen: *mut socklen_t,
	) -> i32;

	#[link_name = "sys_setsockopt"]
	pub fn setsockopt(
		s: i32,
		level: i32,
		optname: i32,
		optval: *const c_void,
		optlen: socklen_t,
	) -> i32;

	#[link_name = "sys_ioctl"]
	pub fn ioctl(s: i32, cmd: i32, argp: *mut c_void) -> i32;

	#[link_name = "sys_fcntl"]
	pub fn fcntl(fd: i32, cmd: i32, arg: i32) -> i32;

	/// `eventfd` creates an linux-like "eventfd object" that can be used
	/// as an event wait/notify mechanism by user-space applications, and by
	/// the kernel to notify user-space applications of events. The
	/// object contains an unsigned 64-bit integer counter
	/// that is maintained by the kernel. This counter is initialized
	/// with the value specified in the argument `initval`.
	///
	/// As its return value, `eventfd` returns a new file descriptor that
	/// can be used to refer to the eventfd object.
	///
	/// The following values may be bitwise set in flags to change the
	/// behavior of `eventfd`:
	///
	/// `EFD_NONBLOCK`: Set the file descriptor in non-blocking mode
	/// `EFD_SEMAPHORE`: Provide semaphore-like semantics for reads
	/// from the new file descriptor.
	#[link_name = "sys_eventfd"]
	pub fn eventfd(initval: u64, flags: i16) -> i32;

	/// The unix-like `poll` waits for one of a set of file descriptors
	/// to become ready to perform I/O. The set of file descriptors to be
	/// monitored is specified in the `fds` argument, which is an array
	/// of structures of `pollfd`.
	#[link_name = "sys_poll"]
	pub fn poll(fds: *mut pollfd, nfds: nfds_t, timeout: i32) -> i32;

	/// listen for connections on a socket
	///
	/// The `backlog` parameter defines the maximum length for the queue of pending
	/// connections. Currently, the `backlog` must be one.
	#[link_name = "sys_listen"]
	pub fn listen(s: i32, backlog: i32) -> i32;

	#[link_name = "sys_send"]
	pub fn send(s: i32, mem: *const c_void, len: usize, flags: i32) -> isize;

	#[link_name = "sys_sendto"]
	pub fn sendto(
		s: i32,
		mem: *const c_void,
		len: usize,
		flags: i32,
		to: *const sockaddr,
		tolen: socklen_t,
	) -> isize;

	/// shut down part of a full-duplex connection
	#[link_name = "sys_shutdown"]
	pub fn shutdown(sockfd: i32, how: i32) -> i32;

	#[deprecated(since = "0.4.0", note = "use `shutdown` instead")]
	#[link_name = "sys_shutdown_socket"]
	pub fn shutdown_socket(s: i32, how: i32) -> i32;

	#[link_name = "sys_socket"]
	pub fn socket(domain: i32, type_: i32, protocol: i32) -> i32;

	#[link_name = "sys_freeaddrinfo"]
	pub fn freeaddrinfo(ai: *mut addrinfo);

	#[link_name = "sys_getaddrinfo"]
	pub fn getaddrinfo(
		nodename: *const c_char,
		servname: *const c_char,
		hints: *const addrinfo,
		res: *mut *mut addrinfo,
	) -> i32;

	fn sys_get_priority() -> u8;
	fn sys_set_priority(tid: Tid, prio: u8);
}

/// Determine the priority of the current thread
#[inline(always)]
pub unsafe fn get_priority() -> Priority {
	Priority::from(sys_get_priority())
}

/// Determine the priority of the current thread
#[inline(always)]
pub unsafe fn set_priority(tid: Tid, prio: Priority) {
	sys_set_priority(tid, prio.into());
}