epoll() interface works great

This commit is contained in:
Neale Pickett 2008-03-10 23:57:07 -06:00
parent cd6a35240a
commit b032eef23a
7 changed files with 542 additions and 351 deletions

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@ -2,16 +2,14 @@ OCAMLPACKS[] =
equeue
pcre
str
OCAML_CLIBS = ocamlepoll
OCAMLCFLAGS += -g
.DEFAULT: ircd
OCamlProgram(ircd, ircd irc command iobuf client channel)
StaticCLibrary(ocamlepoll, epoll_wrapper)
section
OCAML_CLIBS = ocamlpoll
StaticCLibrary(ocamlpoll, poll_wrapper)
OCamlProgram(polltest, polltest)
OCamlProgram(ircd, ircd irc command iobuf client channel)
section
OCAMLPACKS[] +=

33
epoll.mli Normal file
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@ -0,0 +1,33 @@
(*
* OCaml epoll() interface
* Author: Neale Pickett <neale@woozle.org>
* Time-stamp: <2008-03-10 23:19:20 neale>
*)
(**
* This module provides an interface to epoll() on Linux, or poll() on
* everything else.
*)
type t
type event = In | Priority | Out | Error | Hangup
(** Event types, mirroring poll() and epoll() event constants. *)
type op = Add | Modify | Delete
(** Operations for ctl *)
external create : int -> t = "ocaml_epoll_create"
(** Create a new poll structure *)
external destroy : t -> unit = "ocaml_epoll_destroy"
(** Destroy a poll structure *)
external ctl : t -> op -> (Unix.file_descr * event list) -> unit = "ocaml_epoll_ctl"
(** Add, Modify, or Delete an event list *)
external wait : t -> int -> int -> (Unix.file_descr * event list) list = "ocaml_epoll_wait"
(** Block on events
*
* Returns a list of file descriptors and a list of the events that happened.
*)

410
epoll_wrapper.c Normal file
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@ -0,0 +1,410 @@
/** OCaml poll() interface
*
* Time-stamp: <2008-03-10 23:56:36 neale>
*
* Copyright (C) 2008 Neale Pickett
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or (at
* your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <caml/mlvalues.h>
#include <caml/fail.h>
#include <caml/custom.h>
#include <caml/memory.h>
#include <caml/alloc.h>
#ifdef __linux
# include <sys/epoll.h>
# define EPOLL
#else
# include <poll.h>
# undef EPOLL
# define EPOLLIN POLLIN
# define EPOLLPRI POLLPRI
# define EPOLLOUT POLLOUT
# define EPOLLERR POLLERR
# define EPOLLHUP POLLHUP
#endif
#include <stdio.h>
#include <errno.h>
#include <stdlib.h>
#define puke() \
{ \
char errstr[512]; \
snprintf(errstr, sizeof(errstr), "%s: %s", __FUNCTION__, strerror(errno)); \
caml_failwith(errstr); \
}
enum {
caml_POLLIN,
caml_POLLPRI,
caml_POLLOUT,
caml_POLLERR,
caml_POLLHUP
};
enum {
caml_POLL_ADD,
caml_POLL_MOD,
caml_POLL_DEL
};
static int
list_length(value list)
{
CAMLparam1(list);
CAMLlocal1(l);
int len = 0;
for (l = list; l != Val_int(0); l = Field(l, 1)) {
len += 1;
}
CAMLreturn(len);
}
static int
int_of_event_list(value list)
{
CAMLparam1(list);
CAMLlocal1(l);
int acc = 0;
for (l = list; l != Val_int(0); l = Field(l, 1)) {
switch (Int_val(Field(l, 0))) {
case caml_POLLIN:
acc |= EPOLLIN;
break;
case caml_POLLPRI:
acc |= EPOLLPRI;
break;
case caml_POLLOUT:
acc |= EPOLLOUT;
break;
case caml_POLLERR:
acc |= EPOLLERR;
break;
case caml_POLLHUP:
acc |= EPOLLHUP;
break;
}
}
CAMLreturn(acc);
}
static value
cons(value item, value list)
{
CAMLparam2(item, list);
CAMLlocal1(new);
new = alloc_small(2, 0);
Field(new, 0) = item;
Field(new, 1) = list;
CAMLreturn(new);
}
static value
event_list_of_int(int events)
{
CAMLparam0();
CAMLlocal1(result);
result = Val_int(0);
if (events & EPOLLIN) {
result = cons(Val_int(caml_POLLIN), result);
} else if (events & EPOLLPRI) {
result = cons(Val_int(caml_POLLPRI), result);
} else if (events & EPOLLOUT) {
result = cons(Val_int(caml_POLLOUT), result);
} else if (events & EPOLLERR) {
result = cons(Val_int(caml_POLLERR), result);
} else if (events & EPOLLHUP) {
result = cons(Val_int(caml_POLLHUP), result);
}
CAMLreturn(result);
}
#ifdef EPOLL
/********************************************************************************
*
* epoll()
*
********************************************************************************/
CAMLprim value
ocaml_epoll_create(value size)
{
CAMLparam1(size);
CAMLlocal1(result);
int ret;
ret = epoll_create(Int_val(size));
if (-1 == ret) {
puke();
}
result = Val_int(ret);
CAMLreturn(result);
}
CAMLprim value
ocaml_epoll_destroy(value t)
{
CAMLparam1(t);
int ret;
ret = close(Int_val(t));
if (-1 == ret) {
puke();
}
CAMLreturn(Val_unit);
}
/* There are three reasons why I can't store a continuation or any other
* complex type in evt.data:
*
* 1. GC might blow them away
* 2. Heap compaction might move them
* 3. The kernel can remove events from its internal table without
* telling us (this is why there's no EPOLLNVAL)
*
* 1 and 2 can be solved by calling caml_register_global_root for each
* continuation, but this does not solve 3. So you get file
* descriptors. You can make a nice record type and wrap a Set around
* it. */
CAMLprim value
ocaml_epoll_ctl(value t, value op, value what)
{
CAMLparam3(t, op, what);
int op_;
int fd;
struct epoll_event evt;
int ret;
switch (Int_val(op)) {
case caml_POLL_ADD:
op_ = EPOLL_CTL_ADD;
break;
case caml_POLL_MOD:
op_ = EPOLL_CTL_MOD;
break;
case caml_POLL_DEL:
op_ = EPOLL_CTL_DEL;
break;
}
fd = Int_val(Field(what, 0));
evt.events = int_of_event_list(Field(what, 1));
evt.data.fd = fd;
ret = epoll_ctl(Int_val(t), op_, fd, &evt);
if (-1 == ret) {
puke();
}
CAMLreturn(Val_unit);
}
CAMLprim value
ocaml_epoll_wait(value t, value maxevents, value timeout)
{
CAMLparam2(t, timeout);
CAMLlocal2(result, item);
int maxevents_ = Int_val(maxevents);
struct epoll_event events[maxevents_];
int i;
int ret;
caml_enter_blocking_section();
ret = epoll_wait(Int_val(t), events, maxevents_, Int_val(timeout));
caml_leave_blocking_section();
if (-1 == ret) {
puke();
}
result = Val_int(0);
for (i = 0; i < ret; i += 1) {
item = alloc_small(2,0);
Field(item, 0) = Val_int(events[i].data.fd);
Field(item, 1) = event_list_of_int(events[i].events);
result = cons(item, result);
}
CAMLreturn(result);
}
#else
/********************************************************************************
*
* poll() compatibility
*
********************************************************************************/
#warn "The poll() compatibility routines have not been tested, nay compiled."
/* I just coded up how it more or less ought to go. I haven't debugged
* it at all. I haven't even tried to compile it. */
struct t {
int nfds;
int size;
struct pollfd *fds;
}
CAMLprim value
ocaml_epoll_create(value size)
{
CAMLparam1(size);
CAMLlocal1(result);
struct t *t_;
t_ = (struct t *)malloc(sizeof(struct t));
t_->nfds = 0;
t_->size = size;
t_->fds = (struct pollfd *)calloc(size, sizeof(struct pollfd));
result = caml_alloc(1, Abstract_tag);
Field(result, 0) = (value)t_;
CAMLreturn(result);
}
CAMLprim value
ocaml_epoll_destroy(value t)
{
CAMLparam1(t);
struct t *t_ = Field(t, 0);
free(t_->fds);
free(t_);
CAMLreturn(Val_unit);
}
CAMLprim value
ocaml_epoll_ctl(value t, value op, value what)
{
CAMLparam3(t, op, what);
struct t *t_ = Field(t, 0);
int op_ = Int_val(op);
struct pollfd pfd;
int i;
pfd.fd = Int_val(Field(what, 0));
pfd.events = int_of_event_list(Field(what, 1));
/* Find this fd in our list */
for (i == 0; i < t_->nfds; i += 1) {
struct pollfd *p = &(t_->fds[i]);
if (p->fd == pfd.fd) {
break;
}
}
switch (op_) {
case caml_POLL_ADD:
if (i < t_->nfds) {
caml_failwith("file descriptor already present");
}
if (i >= t->size) {
struct pollfd *newfds;
int newsize;
newsize = t_->size + 20;
new = (struct pollfd *)realloc(t_, (sizeof struct pollfd) * newsize);
if (! new) {
caml_failwith("out of memory");
}
t_->size = newsize;
t_->fds = newfds;
}
t_->nfds += 1;
t_->fds[i] = pfd;
break;
case caml_POLL_MOD:
t_->fds[i] = pdf;
break;
case caml_POLL_DEL:
if (i == t_->nfds) {
caml_failwith("file descriptor not present");
}
t_->nfds -= 1;
for(; i < t_->nfds; i += 1) {
t_->fds[i] = t_->fds[i+1];
}
break;
}
}
CAMLprim value
ocaml_epoll_wait(value t, value maxevents, value timeout)
{
CAMLparam3(t, maxevents, caml_timeout);
CAMLlocal2(result, l, v);
struct t *t_ = Field(t, 0);
int maxevents_ = Int_val(maxevents);
int i;
int j;
int ret;
/* Call poll */
caml_enter_blocking_section();
ret = poll(t_->fds, t_->nfds, Int_val(timeout));
caml_leave_blocking_section();
if (-1 == ret) {
puke();
}
result = Val_int(0);
j = 0;
for (i=0; ((i < t_->nfds) && (i < maxevents_)); i += 1) {
struct pollfd *p = &(t_->fds[i]);
if (p->revents & POLLNVAL) {
/* Don't let j increment: remove this item */
continue;
} else if (p->revents) {
v = alloc_small(2, 0);
Field(v, 0) = Val_int(p->fd);
Field(v, 1) = event_list_of_int(p->revents);
result = cons(v, result);
}
if (i != j) {
t_->fds[i] = t_->fds[j];
}
j += i;
}
t_->nfds = j;
CAMLreturn(result);
}
#endif

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@ -1,37 +0,0 @@
(*
* OCaml poll() / epoll() interface
* Author: Neale Pickett <neale@woozle.org>
* Time-stamp: <2008-03-10 16:38:38 neale>
*)
(**
* This module provides an interface to epoll() on Linux, or poll() on
* everything else. The provided interface is pretty raw, and if you're
* not careful you can really booger things up.
*)
type t
type event = In | Out | Pri | Err | Hup | Nval
(** Event types, mirroring poll() and epoll() event constants.
* Apparently Linux has some way to deal with Nval so that you never
* see it.
*)
type op = Add | Modify | Delete
(** Operations for ctl *)
type data
(** User data type *)
external create : int -> t = "ocaml_poll_create"
(* Create a new poll structure *)
external destroy : t -> unit = "ocaml_poll_destroy"
(* Destroy a poll structure *)
external ctl : t -> op -> (Unix.file_descr * event list) -> unit = "ocaml_poll_ctl"
(* Add, Modify, or Delete an event list and associated user data *)
external wait : t -> int -> (Unix.file_descr * event list) list = "ocaml_poll_wait"
(* Block on events *)

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@ -1,300 +0,0 @@
/** OCaml poll() interface
*
* Time-stamp: <2008-03-10 17:19:26 neale>
*
* Copyright (C) 2008 Neale Pickett
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or (at
* your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <caml/mlvalues.h>
#include <caml/fail.h>
#include <caml/custom.h>
#include <caml/memory.h>
#include <caml/alloc.h>
#ifdef __linux
# include <sys/epoll.h>
# define EPOLL
# define POLL_IN EPOLLIN
# define POLL_PRI EPOLLPRI
# define POLL_OUT EPOLLOUT
# define POLL_ERR EPOLLERR
# define POLL_HUP EPOLLHUP
# define POLL_NVAL 0
#else
# include <poll.h>
# undef EPOLL
# define POLL_IN POLLIN
# define POLL_PRI POLLPRI
# define POLL_OUT POLLOUT
# define POLL_ERR POLLERR
# define POLL_HUP POLLHUP
# define POLL_NVAL POLLNVAL
#endif
#include <string.h>
#include <errno.h>
#include <stdlib.h>
#define puke() \
{ \
char errstr[512]; \
snprintf(errstr, sizeof(errstr), __FUNCTION__ ": %s", strerror(errno)); \
caml_failwith(errstr); \
}
enum {
caml_POLLIN,
caml_POLLPRI,
caml_POLLOUT,
caml_POLLERR,
caml_POLLHUP,
caml_POLLNVAL
};
enum {
caml_POLL_ADD,
caml_POLL_MOD,
caml_POLL_DEL
};
static int
list_length(value list)
{
int len = 0;
value l;
for (l = list; l != caml_Val_int(0); l = caml_Field(l, 1)) {
len += 1;
}
return len;
}
static int
int_of_event_list(value list)
{
int acc = 0;
value l;
for (l = list; l != caml_Val_int(0); l = caml_Field(l, 1)) {
switch (caml_Int_val(caml_Field(l, 0))) {
case caml_POLLIN:
acc |= POLL_IN;
break;
case caml_POLLPRI:
acc |= POLL_PRI;
break;
case caml_POLLOUT:
acc |= POLL_OUT;
break;
case caml_POLLERR:
acc |= POLL_ERR;
break;
case caml_POLLHUP:
acc |= POLL_HUP;
break;
case caml_POLLNVAL:
acc |= POLL_NVAL;
break;
}
}
return acc;
}
static value
append(value list, value item)
{
value new = alloc_small(2, 0);
caml_Field(new, 0) = item;
caml_Field(new, 1) = list;
return new;
}
static value
event_list_of_int(int events)
{
value result = caml_Val_int(0);
if (events & POLL_IN) {
result = append(result, caml_Val_int(caml_POLLIN));
} else if (events & POLL_PRI) {
result = append(result, caml_Val_int(caml_POLLPRI));
} else if (events & POLL_OUT) {
result = append(result, caml_Val_int(caml_POLLOUT));
} else if (events & POLL_ERR) {
result = append(result, caml_Val_int(caml_POLLERR));
} else if (events & POLL_HUP) {
result = append(result, caml_Val_int(caml_POLLHUP));
} else if (events & POLL_NVAL) {
result = append(result, caml_Val_int(caml_POLLNVAL));
}
inspect_block(result);
return result;
}
#ifdef EPOLL
/********************************************************************************
*
* epoll()
*
********************************************************************************/
CAMLprim value
ocaml_poll_create(value size)
{
CAMLparam1(size);
CAMLlocal1(result);
int ret;
ret = epoll_create(caml_Int_val(size));
if (-1 == ret) {
puke();
}
result = caml_Val_int(ret);
CAMLreturn(result);
}
CAMLprim value
ocaml_poll_destroy(value caml_t)
{
CAMLparam1(caml_t);
int ret;
ret = close(caml_Int_val(caml_t));
if (-1 == ret) {
puke();
}
CAMLreturn(caml_Val_unit);
}
/* I'm sad that I can't do anything more interesting with evt.data than
* put the file descriptor in it. Like, say, storing a continuation.
* Unfortunately doing so would require caml_register_global_root for
* each one to prevent the GC from blowing them away or heap compaction
* from moving them, and I don't want to do that for so many objects
* (plus I'd (maybe) have to keep track of them). Anyway this isn't so
* bad, you can make a record type with the fd in it and search through
* that pretty quickly with the balanced binary tree provided by Set, or
* use a hash table if you like those better. */
CAMLprim value
ocaml_poll_ctl(value caml_t, value caml_op, value caml_what)
{
CAMLparam3(caml_t, caml_op, caml_what);
int op;
int fd;
int ret;
struct epoll_event evt;
switch (caml_Int_val(caml_op)) {
case caml_POLL_ADD:
op = EPOLL_CTL_ADD;
break;
case caml_POLL_MOD:
op = EPOLL_CTL_MOD;
break;
case caml_POLL_DEL:
op = EPOLL_CTL_DEL;
break;
}
fd = caml_Int_val(Field(caml_what, 0));
evt.events = int_of_event_list(caml_Field(f, 1));
evt.data.fd = fd;
ret = epoll_ctl(caml_Int_val(caml_t), op, fd, *evt);
if (-1 == ret) {
puke();
}
CAMLreturn(caml_Val_unit);
}
CAMLprim value
ocaml_poll_wait(value caml_t, value caml_timeout)
{
CAMLparam2(caml_t, caml_timeout);
CAMLlocal1(result);
/* XXX: complete me */
caml_enter_blocking_section();
/* XXX: fix me */
ret = epoll_wait(caml_Int_val(caml_t), fds, nfds, timeout);
caml_leave_blocking_section();
CAMLreturn(result);
}
#else
/********************************************************************************
*
* epoll()
*
********************************************************************************/
CAMLprim value
ocaml_poll(value caml_fds, value caml_timeout)
{
CAMLparam2(caml_fds, caml_timeout);
CAMLlocal2(result, l);
int nfds;
int timeout = caml_Int_val(caml_timeout);
int i;
int ret;
result = caml_Val_int(0);
/* Count entries */
nfds = list_length(caml_fds);
{
struct pollfd fds[nfds];
/* Build fds */
for (i=0, l = caml_fds; l != caml_Val_int(0); i += 1, l = caml_Field(l, 1)) {
value f = caml_Field(l, 0);
struct pollfd *p = &(fds[i]);
p->fd = caml_Int_val(caml_Field(f, 0));
p->events = int_of_event_list(caml_Field(f, 1));
}
/* Call poll */
caml_enter_blocking_section();
ret = poll(fds, nfds, timeout);
caml_leave_blocking_section();
if (-1 == ret) {
puke();
}
for (i=0; i < nfds; i += 1) {
struct pollfd *p = &(fds[i]);
if (p->revents) {
value v = alloc_small(2,0);
caml_Field(v, 0) = caml_Val_int(p->fd);
caml_Field(v, 1) = event_list_of_int(p->revents);
result = append(result, v);
}
}
CAMLreturn(result);
}
}
#endif

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@ -1,9 +0,0 @@
external poll : 'a -> 'b -> 'c = "ocaml_poll"
type event = POLLIN | POLLPRI | POLLOUT | POLLERR | POLLHUP | POLLNVAL
let _ =
poll [
(10, [POLLIN; POLLOUT]);
(20, [POLLOUT])
] ()

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@ -5,9 +5,105 @@ open Irc
let ues = Unixqueue.create_unix_event_system ()
let int_of_file_descr fd = (Obj.magic fd) + 0
let rec epollevents_as_list events =
match events with
| [] ->
[]
| Epoll.In :: tl ->
"POLLIN" :: (epollevents_as_list tl)
| Epoll.Priority :: tl ->
"POLLPRI" :: (epollevents_as_list tl)
| Epoll.Out :: tl ->
"POLLOUT" :: (epollevents_as_list tl)
| Epoll.Error :: tl ->
"POLLERR" :: (epollevents_as_list tl)
| Epoll.Hangup :: tl ->
"POLLHUP" :: (epollevents_as_list tl)
let rec epollfds_as_list pfds =
match pfds with
| [] ->
[]
| (fd, events) :: tl ->
(Printf.sprintf "{fd=%d; events=%s}"
(int_of_file_descr fd)
(String.concat "|" (epollevents_as_list events))) ::
epollfds_as_list tl
let epollfds_as_string pfds =
"[" ^ (String.concat ", " (epollfds_as_list pfds)) ^ "]"
let unit_tests =
"Unit tests" >:::
[
"epoll" >::
(fun () ->
let a,b = Unix.socketpair Unix.PF_UNIX Unix.SOCK_STREAM 0 in
let e = Epoll.create 1 in
Epoll.ctl e Epoll.Add (a, [Epoll.Out; Epoll.In]);
assert_equal
~printer:epollfds_as_string
[(a, [Epoll.Out])]
(Epoll.wait e 1 0);
Epoll.ctl e Epoll.Modify (a, [Epoll.In; Epoll.Priority]);
assert_equal
~printer:epollfds_as_string
[]
(Epoll.wait e 1 0);
Epoll.ctl e Epoll.Add (b, [Epoll.Out; Epoll.In]);
assert_equal
~printer:epollfds_as_string
[(b, [Epoll.Out])]
(Epoll.wait e 2 0);
Epoll.ctl e Epoll.Modify (a, [Epoll.Out; Epoll.In]);
assert_equal
~printer:epollfds_as_string
[(a, [Epoll.Out]); (b, [Epoll.Out])]
(Epoll.wait e 2 0);
Epoll.ctl e Epoll.Modify (a, [Epoll.Out; Epoll.In]);
assert_equal
~printer:epollfds_as_string
[(b, [Epoll.Out])]
(Epoll.wait e 1 0);
Epoll.ctl e Epoll.Delete (a, []);
assert_equal
~printer:epollfds_as_string
[(b, [Epoll.Out])]
(Epoll.wait e 2 0);
assert_raises
(Failure "ocaml_epoll_ctl: No such file or directory")
(fun () ->
Epoll.ctl e Epoll.Modify (a, [Epoll.In; Epoll.Priority]));
assert_raises
(Failure "ocaml_epoll_ctl: File exists")
(fun () ->
Epoll.ctl e Epoll.Add (b, [Epoll.In; Epoll.Priority]));
assert_equal
~printer:epollfds_as_string
[(b, [Epoll.Out])]
(Epoll.wait e 2 0);
Unix.close b;
assert_equal
~printer:epollfds_as_string
[]
(Epoll.wait e 2 0);
assert_raises
(Failure "ocaml_epoll_ctl: Bad file descriptor")
(fun () ->
Epoll.ctl e Epoll.Modify (b, [Epoll.In; Epoll.Priority]));
Epoll.destroy e;
Unix.close a
);
"command_of_string" >::
(fun () ->
assert_equal