ccan/io: benchmarks.

[ccan] / ccan / io / benchmarks / run-loop.c

diff --git a/ccan/io/benchmarks/run-loop.c b/ccan/io/benchmarks/run-loop.c
new file mode 100644 (file)
index 0000000..9af564c
--- /dev/null
+++ b/ccan/io/benchmarks/run-loop.c
@@ -0,0 +1,130 @@
+#include <ccan/io/io.h>
+#include <ccan/time/time.h>
+#include <sys/wait.h>
+#include <stdio.h>
+#include <string.h>
+#include <assert.h>
+#include <err.h>
+#include <signal.h>
+
+#define NUM 500
+#define NUM_ITERS 10000
+
+struct buffer {
+       int iters;
+       struct io_conn *reader, *writer;
+       char buf[32];
+};
+
+static struct io_op *poke_writer(struct io_conn *conn, struct buffer *buf);
+static struct io_op *poke_reader(struct io_conn *conn, struct buffer *buf);
+
+static struct io_op *do_read(struct io_conn *conn, struct buffer *buf)
+{
+       assert(conn == buf->reader);
+
+       return io_read(&buf->buf, sizeof(buf->buf),
+                      io_next(conn, poke_writer, buf));
+}
+
+static struct io_op *do_write(struct io_conn *conn, struct buffer *buf)
+{
+       assert(conn == buf->writer);
+
+       return io_write(&buf->buf, sizeof(buf->buf),
+                       io_next(conn, poke_reader, buf));
+}
+
+static struct io_op *poke_writer(struct io_conn *conn, struct buffer *buf)
+{
+       assert(conn == buf->reader);
+
+       if (buf->iters == NUM_ITERS)
+               return io_close(conn, NULL);
+
+       /* You write. */
+       io_wake(buf->writer, do_write, buf);
+
+       /* I'll wait until you wake me. */
+       return io_idle(conn);
+}
+
+static struct io_op *poke_reader(struct io_conn *conn, struct buffer *buf)
+{
+       assert(conn == buf->writer);
+       /* You read. */
+       io_wake(buf->reader, do_read, buf);
+
+       if (++buf->iters == NUM_ITERS)
+               return io_close(conn, NULL);
+
+       /* I'll wait until you tell me to write. */
+       return io_idle(conn);
+}
+
+static struct io_op *reader(struct io_conn *conn, struct buffer *buf)
+{
+       assert(conn == buf->reader);
+
+       /* Wait for writer to tell us to read. */
+       return io_idle(conn);
+}
+
+int main(void)
+{
+       unsigned int i;
+       int fds[2], last_read, last_write;
+       struct timespec start, end;
+       struct buffer buf[NUM];
+
+       if (pipe(fds) != 0)
+               err(1, "pipe");
+       last_read = fds[0];
+       last_write = fds[1];
+
+       for (i = 1; i < NUM; i++) {
+               buf[i].iters = 0;
+               if (pipe(fds) < 0)
+                       err(1, "pipe");
+               memset(buf[i].buf, i, sizeof(buf[i].buf));
+               sprintf(buf[i].buf, "%i-%i", i, i);
+
+               buf[i].reader = io_new_conn(last_read, reader, NULL, &buf[i]);
+               if (!buf[i].reader)
+                       err(1, "Creating reader %i", i);
+               buf[i].writer = io_new_conn(fds[1], do_write, NULL, &buf[i]);
+               if (!buf[i].writer)
+                       err(1, "Creating writer %i", i);
+               last_read = fds[0];
+       }
+
+       /* Last one completes the cirle. */
+       i = 0;
+       buf[i].iters = 0;
+       sprintf(buf[i].buf, "%i-%i", i, i);
+       buf[i].reader = io_new_conn(last_read, reader, NULL, &buf[i]);
+       if (!buf[i].reader)
+               err(1, "Creating reader %i", i);
+       buf[i].writer = io_new_conn(last_write, do_write, NULL, &buf[i]);
+       if (!buf[i].writer)
+               err(1, "Creating writer %i", i);
+
+       /* They should eventually exit */
+       start = time_now();
+       if (io_loop() != NULL)
+               errx(1, "io_loop?");
+       end = time_now();
+
+       for (i = 0; i < NUM; i++) {
+               char b[sizeof(buf[0].buf)];
+               memset(b, i, sizeof(b));
+               sprintf(b, "%i-%i", i, i);
+               if (memcmp(b, buf[(i + NUM_ITERS) % NUM].buf, sizeof(b)) != 0)
+                       errx(1, "Buffer for %i was '%s' not '%s'",
+                            i, buf[(i + NUM_ITERS) % NUM].buf, b);
+       }
+
+       printf("run-many: %u %u iterations: %llu usec\n",
+              NUM, NUM_ITERS, (long long)time_to_usec(time_sub(end, start)));
+       return 0;
+}