--- /dev/null
+# eloop-bench
+
+eloop is a portable event loop designed to be dropped into the code of a
+program. It is not in any library to date.
+The basic requirement of eloop is a descriptor polling mechanism which
+allows the safe delivery of signals.
+As such, select(2) and poll(2) are not suitable.
+
+This is an eloop benchmark to test the performance of the various
+polling functions. It's inspired by libevent/bench.
+
+eloop needs to be compiled for a specific function, and these can be chosen
+by giving one of these CPPFLAGS to the Makefile:
+ * HAVE_KQUEUE
+ * HAVE_EPOLL
+ * HAVE_PSELECT
+ * HAVE_POLLTS
+ * HAVE_PPOLL
+
+kqueue(2) is found on modern BSD kernels.
+epoll(2) is found on modern Linux and Solaris kernels.
+These two *should* be the best performers.
+
+pselect(2) *should* be found on any POSIX libc.
+This *should* be the worst performer.
+
+pollts(2) and ppoll(2) are NetBSD and Linux specific variants on poll(2),
+but allow safe signal delivery like pselect(2).
+Aside from the function name, the arguments and functionality are identical.
+They are of little use as both platforms have kqueue(2) and epoll(2),
+but there is an edge case where system doesn't have epoll(2) compiled hence
+it's inclusion here.
+
+## using eloop-bench
+
+The benchmark runs by setting up npipes to read/write to and attaching
+an eloop callback for each pipe reader.
+Once setup, it will perform a run by writing to nactive pipes.
+For each successful pipe read, if nwrites >0 then the reader will reduce
+nwrites by one on successful write back to itself.
+Once nwrites is 0, the timed run will end once the last write has been read.
+At the end of run, the time taken in seconds and nanoseconds is printed.
+
+The following arguments can influence the benchmark:
+
+ * `-a active`
+ The number of active pipes.
+ (default 1)
+ * `-n pipes`
+ The number of pipes to create and attach an eloop callback to.
+ (default (100)
+ * `-r runs`
+ The number of timed runs to make.
+ (default 25)
+ * `-w writes`
+ The number of writes to make by the read callbacks.
+ (default 100)
--- /dev/null
+/*
+ * eloop benchmark
+ * Copyright (c) 2006-2017 Roy Marples <roy@marples.name>
+ * All rights reserved.
+
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/resource.h>
+
+#include <err.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <time.h>
+#include <unistd.h>
+
+#include "eloop.h"
+
+#ifndef timespecsub
+#define timespecsub(tsp, usp, vsp) \
+ do { \
+ (vsp)->tv_sec = (tsp)->tv_sec - (usp)->tv_sec; \
+ (vsp)->tv_nsec = (tsp)->tv_nsec - (usp)->tv_nsec; \
+ if ((vsp)->tv_nsec < 0) { \
+ (vsp)->tv_sec--; \
+ (vsp)->tv_nsec += 1000000000L; \
+ } \
+ } while (/* CONSTCOND */ 0)
+#endif
+
+struct pipe {
+ int fd[2];
+};
+
+static size_t good, bad, writes, fired;
+static size_t npipes = 100, nwrites = 100, nactive = 1;
+static struct pipe *pipes;
+static struct eloop *e;
+
+static void
+read_cb(void *arg)
+{
+ struct pipe *p = arg;
+ unsigned char c;
+ ssize_t l;
+
+ l = read(p->fd[0], &c, sizeof(c));
+ if (l == -1)
+ bad++;
+ else
+ good += (size_t)l;
+ if (writes) {
+ p = (struct pipe *)arg;
+ l = write(p->fd[1], "e", 1);
+ if (l != 1)
+ bad++;
+ else {
+ writes -= (size_t)l;
+ fired += (size_t)l;
+ }
+ }
+
+ if (writes == 0) {
+ if (good == fired)
+ eloop_exit(e, EXIT_SUCCESS);
+ }
+}
+
+static struct timespec *
+runone(void)
+{
+ size_t i;
+ struct pipe *p;
+ static struct timespec _ts;
+ struct timespec ts, te;
+
+ writes = nwrites;
+ fired = good = 0;
+
+ for (i = 0, p = pipes; i < nactive; i++, p++) {
+ if (write(p->fd[1], "e", 1) != 1)
+ err(EXIT_FAILURE, "send");
+ }
+
+ if (clock_gettime(CLOCK_MONOTONIC, &ts) == -1)
+ err(EXIT_FAILURE, "clock_gettime");
+ (void) eloop_start(e, NULL);
+ if (clock_gettime(CLOCK_MONOTONIC, &te) == -1)
+ err(EXIT_FAILURE, "clock_gettime");
+
+ timespecsub(&te, &ts, &_ts);
+ return &_ts;
+}
+
+int
+main(int argc, char **argv)
+{
+ int c;
+ size_t i, nruns = 25;
+ struct pipe *p;
+ struct timespec *ts;
+
+ if ((e = eloop_new()) == NULL)
+ err(EXIT_FAILURE, "eloop_init");
+
+ while ((c = getopt(argc, argv, "a:n:w:")) != -1) {
+ switch (c) {
+ case 'a':
+ nactive = (size_t)atoi(optarg);
+ break;
+ case 'n':
+ npipes = (size_t)atoi(optarg);
+ break;
+ case 'r':
+ nruns = (size_t)atoi(optarg);
+ break;
+ case 'w':
+ nwrites = (size_t)atoi(optarg);
+ break;
+ default:
+ errx(EXIT_FAILURE, "illegal argument `%c'", c);
+ }
+ }
+
+ if (nactive > npipes)
+ nactive = npipes;
+
+ pipes = malloc(sizeof(*p) * npipes);
+ if (pipes == NULL)
+ err(EXIT_FAILURE, "malloc");
+
+ for (i = 0, p = pipes; i < npipes; i++, p++) {
+ if (pipe(p->fd) == -1)
+ err(EXIT_FAILURE, "pipe");
+ if (eloop_event_add(e, p->fd[0], read_cb, p) == -1)
+ err(EXIT_FAILURE, "eloop_event_add");
+ }
+
+ for (i = 0; i < nruns; i++) {
+ if ((ts = runone()) == NULL)
+ err(EXIT_FAILURE, "runone");
+ printf("%lld.%.9ld\n", (long long)ts->tv_sec, ts->tv_nsec);
+ }
+
+ exit(0);
+}
projects / thirdparty / dhcpcd.git / commitdiff
