module Netsys_posix:POSIX-specific system calls missing in thesig
..end
Unix
module, and
further API's from POSIX-style operating systems.val int_of_file_descr : Unix.file_descr -> int
Netsys.int64_of_file_descr
which works for all OS.val file_descr_of_int : int -> Unix.file_descr
val sysconf_open_max : unit -> int
fd
:
fd < sysconf_open_max()
val get_nonblock : Unix.file_descr -> bool
val fchdir : Unix.file_descr -> unit
val fdopendir : Unix.file_descr -> Unix.dir_handle
Unix.closedir
.
This function is useful in conjunction with Netsys_posix.openat
to read directories relative to a parent directory.
This is a recent addition to the POSIX standard; be prepared to
get Invalid_argument
because it is unavailable.
val realpath : string -> string
val getpgid : int -> int
val getpgrp : unit -> int
getpgid 0
, i.e. returns the process group ID of the
current process.val setpgid : int -> int -> unit
setpgid pid pgid
: Set the process group ID of the process pid
to pgid
. If pid = 0
, the process group ID of the current process
is changed. If pgid = 0
, as process group ID the process ID of the
process referenced by pid
is used.
It is only possible for a process to join a process group if both
belong to the same session.
val setpgrp : unit -> unit
setpgid 0 0
: A new process group ID is created, and the
current process becomes its sole member.val tcgetpgrp : Unix.file_descr -> int
val tcsetpgrp : Unix.file_descr -> int -> unit
val ctermid : unit -> string
val ttyname : Unix.file_descr -> string
val getsid : int -> int
val with_tty : (Unix.file_descr -> unit) -> unit
with_tty f
: Runs f fd
where fd
is the terminal of the process.
If the process does not have a terminal (because it is a daemon)
with_tty
will fail.val tty_read_password : ?tty:Unix.file_descr -> string -> string
tty_read_password prompt
: If tty
is a terminal, the prompt
is printed, and a password is read from the terminal (echo off).
If tty
is not a terminal, no prompt
is printed, and just a
line is read from the tty
descriptor (non-interactive case).
tty
defaults to Unix.stdin
. If this function is used in a
program where stdin is not redirected, and the program is started
in a terminal, it will read the password with prompt and
echo disabled. If stdin is redirected, it is assumed that the program is
used in a script, and the password is piped into it.
Use in conjunction with with_tty
to ensure that tty
is
the terminal even if a redirection is in effect, e.g.
with_tty (fun tty -> tty_read_password ~tty prompt)
Raises Sys.Break
if the user triggers SIGINT (i.e. presses
CTRL-C) to abort the input of a password.
val posix_openpt : bool -> Unix.file_descr
posix_openpt noctty
: Opens an unused PTY master.
noctty
: If true, the descriptor will not become the controlling
terminal.
If this function is not provided by the OS, an emulation is used.
On some OS, System V style PTY's are unavailable (but they get
rare).
val grantpt : Unix.file_descr -> unit
val unlockpt : Unix.file_descr -> unit
val ptsname : Unix.file_descr -> string
type
node_type =
| |
S_IFREG |
| |
S_IFCHR of |
| |
S_IFBLK of |
| |
S_IFIFO |
| |
S_IFSOCK |
val mknod : string -> int -> node_type -> unit
val setreuid : int -> int -> unit
val setregid : int -> int -> unit
val initgroups : string -> int -> unit
openat
and then by using a function that references the file
by descriptor. An example for this is fstatat
: After the
openat
call one can use fstat
to get the stat record of the
file.val have_at : unit -> bool
*at
functions are available (they were only recently
standardized and cannot be expected on all OS yet)val at_fdcwd : Unix.file_descr
*at
functionstype
at_flag =
| |
AT_EACCESS |
|||
| |
AT_SYMLINK_NOFOLLOW |
|||
| |
AT_REMOVEDIR |
(* | Flags one can pass to "at" functions. Not all functions support all flags | *) |
val openat : Unix.file_descr ->
string -> Unix.open_flag list -> Unix.file_perm -> Unix.file_descr
Unix.openfile
but open relative to the directory given
by first argumentval faccessat : Unix.file_descr ->
string -> Unix.access_permission list -> at_flag list -> unit
Unix.access
but the file is taken relative to the directory
given by first argumentval mkdirat : Unix.file_descr -> string -> int -> unit
Unix.mkdir
but the file is taken relative to the directory
given by first argumentval renameat : Unix.file_descr -> string -> Unix.file_descr -> string -> unit
renameat olddirfd oldpath newdirfd newpath
val linkat : Unix.file_descr ->
string -> Unix.file_descr -> string -> at_flag list -> unit
linkat olddirfd oldpath newdirfd newpath flags
val unlinkat : Unix.file_descr -> string -> at_flag list -> unit
Unix.unlink
but unlink the file relative to the directory
given by first argumentval symlinkat : string -> Unix.file_descr -> string -> unit
symlinkat oldpath newdirfd newpath flags
val mkfifoat : Unix.file_descr -> string -> int -> unit
mkfifoat dirfd path mode
val readlinkat : Unix.file_descr -> string -> string
readlinkat dirfd path
type
poll_array
poll_cell
entriestype
poll_req_events
type
poll_act_events
poll_req_events
is used to request that certain
event types are observed. poll_act_event
shows which
event types are actually possibletype
poll_cell = {
|
mutable poll_fd : |
|
mutable poll_req_events : |
|
mutable poll_act_events : |
poll_fd
. The poll_req_events
are the events the descriptor is polled for. The poll_act_events
are the actually reported events.val have_poll : unit -> bool
poll
implementation on this OSval poll_req_events : bool -> bool -> bool -> poll_req_events
poll_req_events rd wr pri
: Create a set of in events consisting
of the bits rd
, wr
, and pri
. rd
means to poll for
input data, wr
to poll for output data, and pri
to poll for urgent
input data.val poll_req_triple : poll_req_events -> bool * bool * bool
poll_req_events
value, and returns the triple
(rd,wr,pri)
.val poll_null_events : unit -> poll_act_events
poll_act_events
, for initilization
of poll cells.val poll_result : poll_act_events -> bool
poll_out_events
val poll_rd_result : poll_act_events -> bool
val poll_wr_result : poll_act_events -> bool
val poll_pri_result : poll_act_events -> bool
val poll_err_result : poll_act_events -> bool
val poll_hup_result : poll_act_events -> bool
val poll_nval_result : poll_act_events -> bool
poll_act_events
and return the statusval create_poll_array : int -> poll_array
poll_fd
member is
initialized with Unix.stdin
, and the two event members are empty.val set_poll_cell : poll_array -> int -> poll_cell -> unit
set_poll_cell a k c
: Sets the poll cell k
to c
.
The index k
must be in the range from 0
to N-1
when N
is the
length of the poll array.val get_poll_cell : poll_array -> int -> poll_cell
get_poll_cell a k
: Returns the poll cell k
.
The index k
must be in the range from 0
to N-1
when N
is the
length of the poll array.val blit_poll_array : poll_array ->
int -> poll_array -> int -> int -> unit
blit_poll_array a1 p1 a2 p2 len
: Copies the len
cells at index p1
from a1
to a2
at index p2
.val poll_array_length : poll_array -> int
val poll : poll_array -> int -> float -> int
poll a n tmo
: Poll for the events of the cells 0 to n-1
of
poll array a
, and set the poll_act_events
member of all cells.
Wait for at most tmo
seconds (a negative value means there is
no timeout). Returns the number of ready file descriptors.
On platforms without native support for poll
the function is
emulated using Unix.select
. Note, however, that there is a
performance penalty for the emulation, and that the output
flags poll_error_result
, poll_hangup_result
, and
poll_invalid_result
are not emulated.
val restarting_poll : poll_array -> int -> float -> int
poll
that handles the EINTR
conditionval poll_single : Unix.file_descr -> bool -> bool -> bool -> float -> bool
poll_single fd rd wr pri tmo
: Polls a single descriptor for the
events given by rd
, wr
, and pri
. In tmo
the timeout can be
passed. Returns true
if one of the requested events is indicated
for the descriptor. The EINTR
case is not handled.poll_req_events
and poll_act_events
are integers that
are bitmasks of some constants. The following functions allow access to
this detail.val int_of_req_events : poll_req_events -> int
val int_of_act_events : poll_act_events -> int
val req_events_of_int : int -> poll_req_events
val act_events_of_int : int -> poll_act_events
val const_rd_event : int
val const_wr_event : int
val const_pri_event : int
val const_err_event : int
val const_hup_event : int
val const_nval_event : int
epoll
for Linux is supported.
The model exhibited in this API is the smallest common denominator
of Linux epoll, BSD kqueue, and Solaris ports. The event_aggregator
represents the set of monitored event sources. There is, so far,
only one source, namely file descriptors, i.e. one can check whether
a descriptor is readable or writable (like poll
). The source can
be added to the event_aggregator
to monitor the source.
By calling poll_event_sources
one can determine sources that
are currently active (i.e. in signalling state).
It is undefined what happens when a file descriptor is closed while
being member of the aggregator.
type
event_aggregator
type
event_source
val have_event_aggregation : unit -> bool
val create_event_aggregator : bool -> event_aggregator
create_event_aggregator is_interruptible
: Creates a new aggregator,
and allocates the required OS resources.
If is_interruptible
, the aggregator can be interrupted from a
different thread. See interrupt_event_aggregator
below.
val destroy_event_aggregator : event_aggregator -> unit
val fd_event_source : Unix.file_descr -> poll_req_events -> event_source
poll_req_events
.
The event_source
contains
state about the relation to the aggregator, and because of this,
the event_source
should only be used together with one aggregator
(at a time).
val modify_fd_event_source : event_source -> poll_req_events -> unit
val get_fd_of_event_source : event_source -> Unix.file_descr
val act_events_of_event_source : event_source -> poll_act_events
poll_event_sources
returns the source.val add_event_source : event_aggregator -> event_source -> unit
val del_event_source : event_aggregator -> event_source -> unit
val interrupt_event_aggregator : event_aggregator -> unit
create_event_aggregator
was called with true
as argument, the
aggregator is interruptible, and this function interrupts it. The
effect is that a currently running poll_event_sources
, or, if
it is not running, the next invocation of poll_event_sources
returns immediately.
If the aggregator is not interruptible, this function is a NOP.
val push_event_updates : event_aggregator -> unit
val poll_event_sources : event_aggregator -> float -> event_source list
poll_event_sources ea tmo
: First, all modifications are pushed
to the kernel, and polling is set up to get events. If no events
can currently be delivered, the function waits up to tmo
seconds
(or endlessly if negative) for events. The function returns only a
limited number of events at a time. It is allowed that the function
returns fewer events than are currently in signalled state, even
none.
Call the function with tmo=0.0
for non-blocking behavior.
Note that this is the "level-triggered" behavior: If a source
remains active it will be reported again by the next poll_event_sources
,
just as poll
would do.
val event_aggregator_fd : event_aggregator -> Unix.file_descr
push_event_updates
before polling from the descriptor.Unix.fork
at some places to create child processes
for doing real work. The following functions
allow it to register a handler that is run in the forked child
process. Note that this is done by the O'caml code calling fork
,
and not via the POSIX atfork()
facility.
The handler should release OS resources like file descriptors that are by default shared with the parent process.
The handler are not invoked when the only purpose of the fork
is
to exec
a different process.
class type post_fork_handler =object
..end
post_fork_handler
is a named function unit -> unit
val register_post_fork_handler : post_fork_handler -> unit
val remove_post_fork_handler : post_fork_handler -> unit
val run_post_fork_handlers : unit -> unit
type
wd_spec =
| |
Wd_keep |
(* | Keep the current working directory in the spawned process | *) |
| |
Wd_chdir of |
(* | Change to this directory in the spawned process | *) |
| |
Wd_fchdir of |
(* | Change to the directory which has been previously been opened | *) |
type
pg_spec =
| |
Pg_keep |
(* | The new process will be member of the same process group as this process | *) |
| |
Pg_new_bg_group |
(* | A new background process group is created, and the spawned process will be its single member | *) |
| |
Pg_new_fg_group |
(* | A new foreground process group is created, and the spawned process will be its single member | *) |
| |
Pg_join_group of |
(* | The spawned process will be member of this process group | *) |
type
fd_action =
| |
Fda_close of |
(* | Close the descriptor | *) |
| |
Fda_close_ignore of |
(* | Close the descriptor but ignore EBADF errors | *) |
| |
Fda_close_except of |
(* | Closes all descriptors except those for which
except.(k) is true where k = int_of_file_descr fd .
Descriptors outside the array index range are closed. | *) |
| |
Fda_dup2 of |
(* | Duplicate the first descriptor to the second as dup2 does | *) |
type
sig_action =
| |
Sig_default of |
(* | Resets this signal to default behavior in the spawned process | *) |
| |
Sig_ignore of |
(* | Ignores the signal in the spawned process | *) |
| |
Sig_mask of |
(* | Set the signal mask in the spawned process | *) |
val spawn : ?chdir:wd_spec ->
?pg:pg_spec ->
?fd_actions:fd_action list ->
?sig_actions:sig_action list ->
?env:string array -> ?no_posix_spawn:bool -> string -> string array -> int
spawn cmd args
: Fork the process and exec cmd
which gets the
arguments args
. On success, the PID of the new process is returned.
This function does not wait for the completion of the process; use
Unix.waitpid
for this purpose.
chdir
: If set, the new process starts with this working directory
(this is done before anything else)pg
: If set, the new process will be a member of this process groupfd_actions
: If set, these descriptor actions are executed
sequentiallysig_actions
: If set, these signal actions are executed sequentiallyenv
: If set, the process gets this environment instead of the
current oneno_posix_spawn
: If set, the posix_spawn
family of library
functions is not used to spawn even if possible, and always a
fork/exec
approach is taken. This may be slower, but there is
normally better error reporting.Fda_close_ignore
leads to EBADF
for a descriptor, this error is
ignored.
If pg=Pg_new_fg_group
, one should include Sig_ignore Sys.sigttou
in sig_actions
.
There are two implementations for spawn
: One calls fork
and exec
directly, and one uses the posix_spawn
family of library functions.
The latter is faster on certain conditions, but this is very OS-specific.
A number of features are not supported by posix_spawn
and will force
that fork/exec
is used: Wd_chdir
, Wd_fchdir
, Pg_new_fg_group
,
and Sig_ignore
. However, note some implementations of posix_spawn
also fall back to fork/exec
internally for some combinations of flags,
and it is hard to predict which spawn calls can actually be accelerated.
The tendency, though, is that recent OS have sped up posix_spawn
so far possible (e.g. by using vfork
internally, or even by making
posix_spawn
a system call).
eventfd
system call. On other platforms, pipes are used for emulation.
A not_event
can have two states: off and on. Initially, the
not_event
is off. By signalling it, the state changes to on,
and the underlying real file descriptor becomes readable.
By consuming the event, the state is switched back to off.
Note that a similar API exists for Win32: See Netsys_win32.w32_event
.
type
not_event
val create_event : unit -> not_event
val set_nonblock_event : not_event -> unit
val get_event_fd : not_event -> Unix.file_descr
val set_event : not_event -> unit
val wait_event : not_event -> unit
val consume_event : not_event -> unit
EAGAIN
or EWOULDBLOCK
(in non-blocking mode).
This is effectively an atomic "wait-and-reset" operation.
val destroy_event : not_event -> unit
get_event_fd
is not sufficient.val report_signal_as_event : not_event -> int -> unit
report_signal_as_event ev sig
Installs a new signal handler for
signal sig
so that ev
is signalled when a signal arrives.install_subprocess_handler
type
watched_subprocess
val watch_subprocess : int -> int -> bool -> Unix.file_descr * watched_subprocess
let fd, ws = watch_subprocess pid pgid kill_flag
:
Enters the subprocess pid
into the watch list. If pgid > 0
, the process group ID is
pgid
(for killpg_subprocess
and killpg_all_subprocesses
).
The kill_flag
controls the process selection of
kill_all_subprocesses
and killpg_all_subprocesses
.
The returned descriptor fd
is open for reading and
will indicate EOF when the subprocess is terminated. Via ws
it is possible to query information about the subprocess. The
installed signal handler will wait
for the subprocess and
put the process status into ws
.
The caller has to close fd
after the termination is signaled.
val ignore_subprocess : watched_subprocess -> unit
wait
s for the subprocess
to avoid zombies.
Any further access to ws
will fail.
val forget_subprocess : watched_subprocess -> unit
ws
will fail.val get_subprocess_status : watched_subprocess -> Unix.process_status option
None
is returnedval kill_subprocess : int -> watched_subprocess -> unit
val killpg_subprocess : int -> watched_subprocess -> unit
val kill_all_subprocesses : int -> bool -> bool -> unit
kill_all_subprocess signal override nogroup
:
Sends a signal to potentially
all subprocesses. The signal is sent to a watched process if the process
still exists, and these two conditions hold both:not nogroup || pgid = 0
: Processes with pgid > 0
are excluded
if nogroup
is setkill_flag || override
: A process needs to have
kill_flag
set, or override
is specifiedval killpg_all_subprocesses : int -> bool -> unit
killpg_all_subprocess signal override
: Sends a signal to potentially
all subprocesses belonging to a process group (i.e. pgid>0
).
. The signal is sent to a process group if there are still watched
subprocesses
belonging to the group, and if either the kill_flag
of any of the
subprocesses process was set to true
, or override
is true
.
Never throws an exception if the signal handler is installed.
val install_subprocess_handler : unit -> unit
wait
ed for that are registered with
watch_subprocess
.
The handler works both in the single-threaded and the multi-threaded
case. install_subprocess_handler
can safely called several times.
The handler is installed every time the function is called, but the
required data structures are only initialized at the first call.
val register_subprocess_handler : unit -> unit
Netsys_signal
framework to manage the installation of
the SIGCHLD handler.
This is the preferred method of installing the SIGCHLD handler.
fork()
: The subprocess handler uses
pipes for notification, and because of this it is sensitive to
unpredicted duplicates of the pipe descriptors. fork()
duplicates
these pipe descriptors. If nothing is done about this issue, it
can happen that the notification does not work anymore as it relies
on detecting closed pipes.
If fork()
is immediately followed by exec()
(as it is done
to run subcommands), the problem does not occur, because the relevant
descriptors are closed at exec()
time.
If fork()
is used to start worker processes, however, we have
to be careful. The descriptors need to be closed, so that the
parent can continue to monitor subprocesses, and to allow the worker
processes to use this mechanism. This module defines post fork
handlers (see above), and a handler is automatically added that
cleans the descriptors up. All user code has to do is to call
run_post_fork_handlers
immediately after fork()
has spawned
the new child, from the new child. This completely resets
everything.
The subprocess handler and multi-threading: The handler has been
carefully designed, and works even in multi-threaded programs.
However, one should know that multi-threading and fork()
do not
interact well with each other. Again, the problems do not occur
if fork()
is followed by exec()
. There is no solution for the
case that worker processes are started with fork()
, though.
The (very generic) problem is that the state of mutexes and other
multi-threading primitives is not well-defined after a fork()
.
Syslog
typelevel =
Netlog.level
typesyslog_facility =
[ `Authpriv
| `Cron
| `Daemon
| `Default
| `Ftp
| `Kern
| `Local0
| `Local1
| `Local2
| `Local3
| `Local4
| `Local5
| `Local6
| `Local7
| `Lpr
| `News
| `Syslog
| `User
| `Uucp ]
`User
and `Local0
to `Local7
are
standard POSIX. If a facility is unavailable it is silently
substituted by `Local0
. The value `Default
leaves this unspecified.typesyslog_option =
[ `Cons | `Ndelay | `Nowait | `Odelay | `Pid ]
`Cons
: Fall back to console logging if syslog is unavailable`Ndelay
: Open the connection immediately`Odelay
: Open the connection at the first call syslog
(default)`Nowait
: Do not wait until it is ensured that the message is
sent`Pid
: Log the PID with every messageval openlog : string option ->
syslog_option list -> syslog_facility -> unit
openlog ident options facility
: Opens a log stream. ident
is
prepended to every message if given (usually the program name).
The facility
is the default facility for syslog
calls.val syslog : syslog_facility -> level -> string -> unit
syslog facility level message
: Logs message
at level
for
facility
val closelog : unit -> unit
Netlog.current_logger
to syslog facility
, e.g.
Netlog.current_logger := Netsys_posix.syslog `User
val fsync : Unix.file_descr -> unit
val fdatasync : Unix.file_descr -> unit
fsync
sock
must be a connected
Unix domain socket.
The functionality backing this is non-standard but widely available.
Not yet implemented, but spec exists.
Optional POSIX functions
val have_fadvise : unit -> bool
type
advice =
| |
POSIX_FADV_NORMAL |
|||
| |
POSIX_FADV_SEQUENTIAL |
|||
| |
POSIX_FADV_RANDOM |
|||
| |
POSIX_FADV_NOREUSE |
|||
| |
POSIX_FADV_WILLNEED |
|||
| |
POSIX_FADV_DONTNEED |
|||
| |
FADV_NORMAL |
|||
| |
FADV_SEQUENTIAL |
|||
| |
FADV_RANDOM |
|||
| |
FADV_NOREUSE |
|||
| |
FADV_WILLNEED |
|||
| |
FADV_DONTNEED |
(* | Possible advices for fadvise. The names starting with "POSIX_" and the ones lacking the prefix have the same meaning. In new code, the names starting with "POSIX_" should be preferred (for better compaibility with other libraries). | *) |
val fadvise : Unix.file_descr -> int64 -> int64 -> advice -> unit
val have_fallocate : unit -> bool
val fallocate : Unix.file_descr -> int64 -> int64 -> unit
val have_posix_shm : unit -> bool
type
shm_open_flag =
| |
SHM_O_RDONLY |
| |
SHM_O_RDWR |
| |
SHM_O_CREAT |
| |
SHM_O_EXCL |
| |
SHM_O_TRUNC |
val shm_open : string -> shm_open_flag list -> int -> Unix.file_descr
The open flags are interpreted as follows:
SHM_O_RDONLY
: Open the object for read accessSHM_O_RDWR
: Open the object for read-write accessSHM_O_CREAT
: Create the object if it does not existSHM_O_EXCL
: If SHM_O_CREAT
was also specified, and a an object
with the given name already exists, return an error
(Unix.EEXIST
).SHM_O_TRUNC
: If the object already exists, truncate it to
zero bytesSHM_O_RDONLY
or SHM_O_RDWR
must be given.
On success, the function returns a file descriptor representing the
object. To access the object, one has to memory-map this file
use one of the map_file
functions in the Bigarray
module, or in Netsys_mem
). Use Unix.ftruncate
to resize the object.
Note that it is unspecified whether this file pops up somewhere in the file system, and if so, where.
If a system error occurs, the function raises a Unix.Unix_error
exception.
val shm_unlink : string -> unit
val shm_create : string -> int -> Unix.file_descr * string
let (fd,name) = shm_create prefix size
: Creates an shm object
with a unique name. The name has the passed prefix
. The prefix
must start with "/" but must not contain any further "/". The object
has a length of size
bytes. The object has a permissions 0o600
(independent of umask).val have_posix_semaphores : unit -> bool
true
if POSIX semaphores are supported on this systemval sem_value_max : int
max_int
val sem_size : int
sizeof(sem_t)
)typesem_kind =
[ `Anonymous | `Named ]
type 'a
semaphore
typenamed_semaphore =
[ `Named ] semaphore
typeanon_sempahore =
[ `Anonymous ] semaphore
type
sem_open_flag =
| |
SEM_O_CREAT |
| |
SEM_O_EXCL |
val sem_open : string ->
sem_open_flag list -> int -> int -> named_semaphore
sem_open name flags mode init_value
: Opens a named semaphore
which is optionally created. Sempahore names usually begin with
a slash followed by a single name component (not containing a
further slash).
Interpretation of flags
:
SEM_O_CREAT
: The semaphore is created if not yet existing.
The mode
and init_value
are interpreted if the creation
actually occurs. mode
is the permission of the semaphore.
init_value
is the (non-negative) initial value, up to
sem_value_max
.SEM_O_EXCL
: The semaphore is only opened if the semaphore
does not exist yet. Othwerwise an EEXIST
error is returnedval sem_close : named_semaphore -> unit
val sem_unlink : string -> unit
val sem_create : string -> int -> named_semaphore * string
let (sem,name) = sem_create prefix init_value
: Creates
a new semaphore with a unique name. The name has the passed prefix
.
The prefix
must start with "/" but must not contain any further "/".
The semaphore is initialized with init_value
. The object has
permissions 0o600 (modulo umask).val sem_init : Netsys_types.memory -> int -> bool -> int -> anon_sempahore
sem_init mem pos pshared init_value
: Initializes the memory
at position pos
to pos + sem_size() - 1
as anonymous semaphore.
If pshared
the semaphore is shared between processes.
init_value
is the initial non-negative value (max is
sem_value_max
.val sem_destroy : anon_sempahore -> unit
val as_sem : Netsys_types.memory -> int -> anon_sempahore
as_sem mem pos
: Interprets the memory at position pos
to pos + sem_size() - 1
as anonymous semaphore.
The memory region must already have been initialized.val sem_getvalue : 'a semaphore -> int
int
, an EINVAL
error is returned.
The returned value is non-negative - if the underlying POSIX
function reports a negative value zero is returned instead.
val sem_post : 'a semaphore -> unit
type
sem_wait_behavior =
| |
SEM_WAIT_BLOCK |
| |
SEM_WAIT_NONBLOCK |
val sem_wait : 'a semaphore -> sem_wait_behavior -> unit
SEM_WAIT_BLOCK
is given, the function
waits until another process or thread posts. If SEM_WAIT_NONBLOCK
the error EAGAIN
is returned.
sem_wait
may be interrupted by signals.
type
langinfo = {
|
nl_CODESET : |
(* | from LC_CTYPE : codeset name | *) |
|
nl_D_T_FMT : |
(* | from LC_TIME : string for formatting date and time | *) |
|
nl_D_FMT : |
(* | from LC_TIME : date format string | *) |
|
nl_T_FMT : |
(* | from LC_TIME : time format string | *) |
|
nl_T_FMT_AMPM : |
(* | from LC_TIME : a.m. or p.m. time format string | *) |
|
nl_AM_STR : |
(* | from LC_TIME : Ante Meridian affix | *) |
|
nl_PM_STR : |
(* | from LC_TIME : Post Meridian affix | *) |
|
nl_DAY_1 : |
(* | from LC_TIME : name of the first day of the week (for example, Sunday) | *) |
|
nl_DAY_2 : |
(* | from LC_TIME : name of the second day of the week (for example, Monday) | *) |
|
nl_DAY_3 : |
(* | from LC_TIME : name of the third day of the week (for example, Tuesday) | *) |
|
nl_DAY_4 : |
(* | from LC_TIME : name of the fourth day of the week (for example, Wednesday) | *) |
|
nl_DAY_5 : |
(* | from LC_TIME : name of the fifth day of the week (for example, Thursday) | *) |
|
nl_DAY_6 : |
(* | from LC_TIME : name of the sixth day of the week (for example, Friday) | *) |
|
nl_DAY_7 : |
(* | from LC_TIME : name of the seventh day of the week (for example, Saturday) | *) |
|
nl_ABDAY_1 : |
(* | from LC_TIME : abbreviated name of the first day of the week | *) |
|
nl_ABDAY_2 : |
(* | from LC_TIME : abbreviated name of the second day of the week | *) |
|
nl_ABDAY_3 : |
(* | from LC_TIME : abbreviated name of the third day of the week | *) |
|
nl_ABDAY_4 : |
(* | from LC_TIME : abbreviated name of the fourth day of the week | *) |
|
nl_ABDAY_5 : |
(* | from LC_TIME : abbreviated name of the fifth day of the week | *) |
|
nl_ABDAY_6 : |
(* | from LC_TIME : abbreviated name of the sixth day of the week | *) |
|
nl_ABDAY_7 : |
(* | from LC_TIME : abbreviated name of the seventh day of the week | *) |
|
nl_MON_1 : |
(* | from LC_TIME : name of the first month of the year | *) |
|
nl_MON_2 : |
(* | from LC_TIME : name of the second month | *) |
|
nl_MON_3 : |
(* | from LC_TIME : name of the third month | *) |
|
nl_MON_4 : |
(* | from LC_TIME : name of the fourth month | *) |
|
nl_MON_5 : |
(* | from LC_TIME : name of the fifth month | *) |
|
nl_MON_6 : |
(* | from LC_TIME : name of the sixth month | *) |
|
nl_MON_7 : |
(* | from LC_TIME : name of the seventh month | *) |
|
nl_MON_8 : |
(* | from LC_TIME : name of the eighth month | *) |
|
nl_MON_9 : |
(* | from LC_TIME : name of the ninth month | *) |
|
nl_MON_10 : |
(* | from LC_TIME : name of the tenth month | *) |
|
nl_MON_11 : |
(* | from LC_TIME : name of the eleventh month | *) |
|
nl_MON_12 : |
(* | from LC_TIME : name of the twelfth month | *) |
|
nl_ABMON_1 : |
(* | from LC_TIME : abbreviated name of the first month | *) |
|
nl_ABMON_2 : |
(* | from LC_TIME : abbreviated name of the second month | *) |
|
nl_ABMON_3 : |
(* | from LC_TIME : abbreviated name of the third month | *) |
|
nl_ABMON_4 : |
(* | from LC_TIME : abbreviated name of the fourth month | *) |
|
nl_ABMON_5 : |
(* | from LC_TIME : abbreviated name of the fifth month | *) |
|
nl_ABMON_6 : |
(* | from LC_TIME : abbreviated name of the sixth month | *) |
|
nl_ABMON_7 : |
(* | from LC_TIME : abbreviated name of the seventh month | *) |
|
nl_ABMON_8 : |
(* | from LC_TIME : abbreviated name of the eighth month | *) |
|
nl_ABMON_9 : |
(* | from LC_TIME : abbreviated name of the ninth month | *) |
|
nl_ABMON_10 : |
(* | from LC_TIME : abbreviated name of the tenth month | *) |
|
nl_ABMON_11 : |
(* | from LC_TIME : abbreviated name of the eleventh month | *) |
|
nl_ABMON_12 : |
(* | from LC_TIME : abbreviated name of the twelfth month | *) |
|
nl_ERA : |
(* | from LC_TIME : era description segments | *) |
|
nl_ERA_D_FMT : |
(* | from LC_TIME : era date format string | *) |
|
nl_ERA_D_T_FMT : |
(* | from LC_TIME : era date and time format string | *) |
|
nl_ERA_T_FMT : |
(* | from LC_TIME : era time format string | *) |
|
nl_ALT_DIGITS : |
(* | from LC_TIME : alternative symbols for digits | *) |
|
nl_RADIXCHAR : |
(* | from LC_NUMERIC : radix character | *) |
|
nl_THOUSEP : |
(* | from LC_NUMERIC : separator for thousands | *) |
|
nl_YESEXPR : |
(* | from LC_MESSAGES : affirmative response expression | *) |
|
nl_NOEXPR : |
(* | from LC_MESSAGES : negative response expression | *) |
|
nl_CRNCYSTR : |
(* | from LC_MONETARY : currency | *) |
val query_langinfo : string -> langinfo
query_langinfo locale
: Temporarily sets the passed locale
and
determines the language attributes. After that the orignal locale is
restored. Pass "" as locale
to get the locale requested in the
environment.
The value for "" is cached.
typetimespec =
float * int
(t,t_nanos)
: Specifies a time by a base time t
to which the
nanoseconds t_nanos
are added.
If this pair is returned by a function t
will always be integral.
If a pair is passed to a function, it does not matter whether this
is the case or not, but using integral values for t
ensure
maximum precision.
val nanosleep : timespec -> timespec Pervasives.ref -> unit
nanosleep t t_rem
: Sleeps for t
seconds. The sleep can either be
finished, or the sleep can be interrupted by a signal. In the
latter case, the function will raise EÃNTR
, and write to t_rem
the remaining seconds.type
clock_id
type
clock =
| |
CLOCK_REALTIME |
(* | A clock measuring wallclock time | *) |
| |
CLOCK_MONOTONIC |
(* | A clock measuring kernel time (non-settable). Optional, i.e. not supported by all OS | *) |
| |
CLOCK_ID of |
(* | A clock ID | *) |
val clock_gettime : clock -> timespec
val clock_settime : clock -> timespec -> unit
val clock_getres : clock -> timespec
val clock_getcpuclockid : int -> clock_id
This function is not supported on all OS.
type
posix_timer
type
timer_expiration =
| |
TEXP_NONE |
| |
TEXP_EVENT of |
| |
TEXP_EVENT_CREATE |
| |
TEXP_SIGNAL of |
val have_posix_timer : unit -> bool
val timer_create : clock ->
timer_expiration -> posix_timer
TEXP_NONE
: no notificationTEXP_EVENT e
: the not_event
e
is signalledTEXP_EVENT_CREATE
: a special not_event
is created for the timer.
(Get the event via timer_event
, see below.)TEXP_SIGNAL n
: the signal n
is sent to the processTEXP_EVENT_CREATE
is much faster on Linux than
TEXP_EVENT
, because it can be avoided to start a new thread
whenever the timer expires. Instead, the timerfd machinery is used.
TEXP_EVENT
and TEXP_EVENT_CREATE
are only supported on systems
with pthreads.
val timer_settime : posix_timer ->
bool -> timespec -> timespec -> unit
timer_settime tm abstime interval value
:
If value=(0.0,0)
, the timer is stopped.
If value
is a positive time, the timer is started (or the timeout
is changed if it is already started). If abstime
, value
is
interpreted as the absolute point in time of the expiration.
Otherwise value
sets the number of seconds until the expiration.
If interval
is positive, the started timer will repeat to expire
after this many seconds once it has expired for the first time.
If interval=(0.0,0)
, the timer is a one-shot timer.
val timer_gettime : posix_timer -> timespec
(0.0,0)
if the timer is offval timer_delete : posix_timer -> unit
val timer_event : posix_timer -> not_event
TEXP_EVENT
and
TEXP_EVENT_CREATE
.
Note that the latter type of event does not allow to call set_event
.
timer_getoverrun
.
Additional overruns can occur because of the further processing
of the notifications: The OCaml runtime can merge signals,
which would not be noticed by the kernel overrun counter,
and events can also be merged. The workaround is to use one-shot timers
with absolute expiration timestamps, and to check for overruns
manually. Once we have TEXP_NQ
the issue is solved.
Per-process I/O priorities are currently only supported by the
CFQ I/O scheduler.
val have_ioprio : unit -> bool
true
if the system call ioprio_get
is supportedtype
ioprio_target =
| |
Ioprio_process of |
(* | A single process | *) |
| |
Ioprio_pgrp of |
(* | A process group | *) |
| |
Ioprio_user of |
(* | All processes owned by this user | *) |
type
ioprio =
| |
Noprio |
(* | I/O prioritization is unsupported by block layer | *) |
| |
Real_time of |
(* | 0..7 (higest..lowest prio) | *) |
| |
Best_effort of |
(* | 0..7 (higest..lowest prio) | *) |
| |
Idle |
val ioprio_get : ioprio_target -> ioprio
ESRCH
will be raised.val ioprio_set : ioprio_target -> ioprio -> unit
module Debug:sig
..end