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Module Linux_ext

module Linux_ext: Linux_ext

Interface to Linux-specific system calls

sysinfo


module Sysinfo: sig .. end

Filesystem functions


val sendfile : (?pos:int ->
        ?len:int -> fd:Unix.File_descr.t -> Unix.File_descr.t -> int)
       Or_error.t
sendfile ?pos ?len ~fd sock sends mmap-able data from file descriptor fd to socket sock using offset pos and length len.
Raises Unix_error on Unix-errors.
Returns the number of characters actually written.

NOTE: if the returned value is unequal to what was requested (= the initial size of the data by default), the system call may have been interrupted by a signal, the source file may have been truncated during operation, or a timeout occurred on the socket during sending. It is currently impossible to find out which of the events above happened. Calling Linux_ext.sendfile several times on the same descriptor that only partially accepted data due to a timeout will eventually lead to the unix error EAGAIN.


Non-portable TCP-functionality


type tcp_bool_option =
| TCP_CORK 
val gettcpopt_bool : (Unix.File_descr.t -> tcp_bool_option -> bool) Or_error.t
gettcpopt_bool sock opt
Returns the current value of the boolean TCP socket option opt for socket sock.
val settcpopt_bool : (Unix.File_descr.t -> tcp_bool_option -> bool -> unit)
       Or_error.t
settcpopt_bool sock opt v sets the current value of the boolean TCP socket option opt for socket sock to value v.
val send_nonblocking_no_sigpipe : (Unix.File_descr.t -> ?pos:int -> ?len:int -> string -> int option)
       Or_error.t
send_nonblocking_no_sigpipe sock ?pos ?len buf tries to do a nonblocking send on socket sock given buffer buf, offset pos and length len. Prevents SIGPIPE, i.e. raise a Unix-error in that case immediately.
Raises Returns Some bytes_written or None if the operation would have blocked.
val send_no_sigpipe : (Unix.File_descr.t -> ?pos:int -> ?len:int -> string -> int) Or_error.t
send_no_sigpipe sock ?pos ?len buf tries to do a blocking send on socket sock given buffer buf, offset pos and length len. Prevents SIGPIPE, i.e. raise a Unix-error in that case immediately.
Raises Returns the number of bytes written.
val sendmsg_nonblocking_no_sigpipe : (Unix.File_descr.t ->
        ?count:int -> string Unix.IOVec.t array -> int option)
       Or_error.t
sendmsg_nonblocking_no_sigpipe sock ?count iovecs tries to do a nonblocking send on socket sock using count I/O-vectors iovecs. Prevents SIGPIPE, i.e. raises a Unix-error in that case immediately.
Raises Returns Some bytes_written or None if the operation would have blocked.

Clock functions


module Clock: sig .. end

Parent death notifications


val pr_set_pdeathsig : (Signal.t -> unit) Or_error.t
pr_set_pdeathsig s sets the signal s to be sent to the executing process when its parent dies. NOTE: the parent may have died before or while executing this system call. To make sure that you do not miss this event, you should call getppid to get the parent process id after this system call. If the parent has died, the returned parent PID will be 1, i.e. the init process will have adopted the child. You should then either send the signal to yourself using Unix.kill, or execute an appropriate handler.
val pr_get_pdeathsig : (unit -> Signal.t) Or_error.t
pr_get_pdeathsig () get the signal that will be sent to the currently executing process when its parent dies.

Task name


val pr_set_name_first16 : (string -> unit) Or_error.t
pr_set_name_first16 name sets the name of the executing thread to name. Only the first 16 bytes in name will be used, the rest is ignored.
val pr_get_name : (unit -> string) Or_error.t
pr_get_name () gets the name of the executing thread. The name is at most 16 bytes long.

Pathname resolution


val file_descr_realpath : (Unix.File_descr.t -> string) Or_error.t
file_descr_realpath fd
Raises Unix_error on errors.
Returns the canonicalized absolute pathname of the file associated with file descriptor fd.
val out_channel_realpath : (Pervasives.out_channel -> string) Or_error.t
out_channel_realpath oc
Raises Unix_error on errors.
Returns the canonicalized absolute pathname of the file associated with output channel oc.
val in_channel_realpath : (Pervasives.in_channel -> string) Or_error.t
in_channel_realpath ic
Raises Unix_error on errors.
Returns the canonicalized absolute pathname of the file associated with input channel ic.

Affinity


val sched_setaffinity : (?pid:Pid.t -> cpuset:int list -> unit -> unit) Or_error.t
val sched_setaffinity_this_thread : (cpuset:int list -> unit) Or_error.t
val cores : (unit -> int) Or_error.t
cores ()
Returns the number of cores on the machine
val get_terminal_size : (unit -> int * int) Or_error.t
get_terminal_size ()
Returns (rows, cols), the number of rows and columns of the terminal.
val gettid : (unit -> int) Or_error.t
module Priority: sig .. end
val setpriority : (Priority.t -> unit) Or_error.t
Set the calling thread's priority in the linux scheduler
val getpriority : (unit -> Priority.t) Or_error.t
Get the calling thread's priority in the linux scheduler
val get_ipv4_address_for_interface : (string -> string) Or_error.t
module Epoll: sig .. end
epoll() - a linux I/O multiplexer of the same family as select() or poll(). 
val bin_tcp_bool_option : tcp_bool_option Bin_prot.Type_class.t
val bin_read_tcp_bool_option : tcp_bool_option Bin_prot.Read_ml.reader
val bin_read_tcp_bool_option_ : tcp_bool_option Bin_prot.Unsafe_read_c.reader
val bin_read_tcp_bool_option__ : (int -> tcp_bool_option) Bin_prot.Unsafe_read_c.reader
val bin_reader_tcp_bool_option : tcp_bool_option Bin_prot.Type_class.reader
val bin_size_tcp_bool_option : tcp_bool_option Bin_prot.Size.sizer
val bin_write_tcp_bool_option : tcp_bool_option Bin_prot.Write_ml.writer
val bin_write_tcp_bool_option_ : tcp_bool_option Bin_prot.Unsafe_write_c.writer
val bin_writer_tcp_bool_option : tcp_bool_option Bin_prot.Type_class.writer
val tcp_bool_option_of_sexp : Sexplib.Sexp.t -> tcp_bool_option
val sexp_of_tcp_bool_option : tcp_bool_option -> Sexplib.Sexp.t

gettcpopt_bool sock opt

settcpopt_bool sock opt v sets the current value of the boolean TCP socket option opt for socket sock to value v.

send_nonblocking_no_sigpipe sock ?pos ?len buf tries to do a nonblocking send on socket sock given buffer buf, offset pos and length len. Prevents SIGPIPE, i.e. raise a Unix-error in that case immediately.

send_no_sigpipe sock ?pos ?len buf tries to do a blocking send on socket sock given buffer buf, offset pos and length len. Prevents SIGPIPE, i.e. raise a Unix-error in that case immediately.

sendmsg_nonblocking_no_sigpipe sock ?count iovecs tries to do a nonblocking send on socket sock using count I/O-vectors iovecs. Prevents SIGPIPE, i.e. raises a Unix-error in that case immediately.

Clock functions



get_process_clock the clock measuring the CPU-time of a process.

get_thread_clock the clock measuring the CPU-time of the current thread.

Parent death notifications



pr_set_pdeathsig s sets the signal s to be sent to the executing process when its parent dies. NOTE: the parent may have died before or while executing this system call. To make sure that you do not miss this event, you should call getppid to get the parent process id after this system call. If the parent has died, the returned parent PID will be 1, i.e. the init process will have adopted the child. You should then either send the signal to yourself using Unix.kill, or execute an appropriate handler.

pr_get_pdeathsig () get the signal that will be sent to the currently executing process when its parent dies.

Task name



pr_set_name_first16 name sets the name of the executing thread to name. Only the first 16 bytes in name will be used, the rest is ignored.

pr_get_name () gets the name of the executing thread. The name is at most 16 bytes long.

Pathname resolution



file_descr_realpath fd

out_channel_realpath oc

in_channel_realpath ic

Affinity



cores ()

get_terminal_size ()

Set the calling thread's priority in the linux scheduler

Get the calling thread's priority in the linux scheduler

epoll() - a linux I/O multiplexer of the same family as select() or poll(). Its main differences are support for Edge or Level triggered notifications (We're using Level-triggered to emulate select) and much better scaling with the number of file descriptors.

See the man pages for a full description of the epoll facility.

An Epoll.Flags.t is an immutable set of flags for which one can register interest for a file descriptor. It is implemented as a bitmask, and so all operations (+, -, etc.) are constant time with no allocation.

sexp_of_t produces a human-readable list of bits, e.g. "(in out)".

An Epoll.t maintains a map from File_descr.t to Flags.t, where the domain is the set of file descriptors that one is interested in, and the flags associated with each file descriptor specify the types of events one is interested in being notified about for that file descriptor. Our implementation maintains a user-level table equivalent to the kernel epoll set, so that sexp_of_t produces useful human-readable information, and so that we can present our standard table interface.

An Epoll.t also has a buffer that is used to store the set of ready fds returned by calling wait.

create ~num_file_descrs creates a new epoll set able to watch file descriptors in [0, num_file_descrs). Additionally, the set allocates space for reading the ready events when wait returns, allowing for up to max_ready_events to be returned in a single call to wait.

map operations

wait t ~timeout blocks until at least one file descriptor in t is ready for one of the events it is being watched for, or timeout passes. wait side effects t by storing the ready set in it. One can subsequently access the ready set by calling iter_ready or fold_ready.

The timeout has a granularity of one millisecond. wait rounds up the timeout to the next millisecond. E.g. a timeout of one microsecond will be rounded up to one millisecond.

Note that this method should not be considered thread safe. There is mutable state in t that will be changed by invocations to wait that cannot be prevented by mutexes around wait.

iter_ready and fold_ready iterate over the ready set computed by the last call to wait.