From: "Jérémie Dimino" <jeremie@dimino.org>
To: Yaron Minsky <yminsky@gmail.com>
Cc: caml-list@inria.fr
Subject: Re: [Caml-list] Asynchronous IO programming in OCaml
Date: Mon, 25 Oct 2010 19:26:33 +0200 [thread overview]
Message-ID: <20101025172633.GC32282@aurora> (raw)
In-Reply-To: <AANLkTikZvCMQaOFknx4TBKUESpYcc2riRUexpU4QnFht@mail.gmail.com>
On Mon, Oct 25, 2010 at 11:34:41AM -0400, Yaron Minsky wrote:
> I don't quite understand how this whole benchmark holds together. Could
> you post the C code? I don't understand the differences between (1), (2)
> and (3) well enough to explain where the factor of 100 comes in.
Yes. Here is the code of the first program:
,----
| #include <sys/types.h>
| #include <sys/stat.h>
| #include <fcntl.h>
| #include <unistd.h>
|
| int main()
| {
| int fd = open("data", O_RDONLY);
| char buffer[4096];
|
| while (read(fd, buffer, 4096) > 0);
|
| close(fd);
|
| return 0;
| }
`----
the code of the second:
,----
| #include <sys/types.h>
| #include <sys/stat.h>
| #include <fcntl.h>
| #include <unistd.h>
| #include <pthread.h>
|
| int fd;
| char buffer[4096];
| int done = 0;
|
| void *callback(void* data)
| {
| int count = read(fd, buffer, 4096);
| if (count == 0) done = 1;
| return NULL;
| }
|
| int main()
| {
| fd = open("data", O_RDONLY);
|
| while (!done) {
| pthread_t thread;
| pthread_create(&thread, NULL, callback, NULL);
| pthread_join(thread, NULL);
| }
|
| close(fd);
|
| return 0;
| }
`----
and the third:
,----
| #include <sys/types.h>
| #include <sys/stat.h>
| #include <fcntl.h>
| #include <unistd.h>
| #include <pthread.h>
|
| int fd;
| char buffer[4096];
| int done = 0;
| pthread_cond_t start = PTHREAD_COND_INITIALIZER;
| pthread_cond_t stop = PTHREAD_COND_INITIALIZER;
| pthread_mutex_t start_mutex = PTHREAD_MUTEX_INITIALIZER;
| pthread_mutex_t stop_mutex = PTHREAD_MUTEX_INITIALIZER;
|
| void *callback(void* data)
| {
| while (!done) {
| pthread_cond_wait(&start, &start_mutex);
|
| int count = read(fd, buffer, 4096);
| if (count == 0) done = 1;
|
| pthread_mutex_lock(&stop_mutex);
| pthread_cond_signal(&stop);
| pthread_mutex_unlock(&stop_mutex);
| }
| return NULL;
| }
|
| int main()
| {
| fd = open("data", O_RDONLY);
|
| pthread_cond_init(&start, NULL);
| pthread_cond_init(&stop, NULL);
|
| pthread_mutex_lock(&start_mutex);
| pthread_mutex_lock(&stop_mutex);
|
| pthread_t thread;
| pthread_create(&thread, NULL, callback, NULL);
|
| while (!done) {
| pthread_mutex_lock(&start_mutex);
| pthread_cond_signal(&start);
| pthread_mutex_unlock(&start_mutex);
|
| pthread_cond_wait(&stop, &stop_mutex);
| }
|
| pthread_join(thread, NULL);
| close(fd);
|
| return 0;
| }
`----
Jérémie
next prev parent reply other threads:[~2010-10-25 17:26 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-10-24 10:34 Jon Harrop
2010-10-24 12:51 ` [Caml-list] " philippe
2010-10-24 12:52 ` Dario Teixeira
2010-10-24 16:33 ` oliver
2010-10-24 18:50 ` Dario Teixeira
2010-10-24 19:04 ` bluestorm
2010-10-24 20:02 ` oliver
2010-10-24 21:51 ` Michael Ekstrand
2010-10-24 16:17 ` Jake Donham
2010-10-24 20:54 ` Anil Madhavapeddy
2010-10-24 22:50 ` Jérémie Dimino
2010-10-25 3:42 ` Markus Mottl
2010-10-25 7:49 ` Richard Jones
2010-10-25 8:42 ` Goswin von Brederlow
2010-10-25 11:10 ` Jérémie Dimino
[not found] ` <AANLkTimP77PDEChW3Yt6uUy_qxYpj6EOZWQ_==id-LBC@mail.gmail.com>
[not found] ` <20101025143317.GB32282@aurora>
2010-10-25 15:34 ` Yaron Minsky
2010-10-25 17:26 ` Jérémie Dimino [this message]
2010-10-27 9:33 ` Goswin von Brederlow
2010-10-27 11:18 ` Jérémie Dimino
2010-10-27 13:43 ` Goswin von Brederlow
2010-10-27 15:30 ` Jérémie Dimino
2010-10-28 9:00 ` Goswin von Brederlow
2010-10-28 9:28 ` Jérémie Dimino
2010-10-28 10:11 ` Goswin von Brederlow
2010-10-25 15:58 ` DS
2010-10-24 20:42 ` Goswin von Brederlow
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