From: Nir Soffer <nsoffer@redhat.com>
Date: Wed, 29 Sep 2021 19:31:13 +0000 (-0400)
Subject: testsuite traceaio.c
X-Git-Tag: release-4.6~55
X-Git-Url: https://sourceware.org/git/?a=commitdiff_plain;h=cbb34b7244ba60cb0904d61dc9167290855106aa;p=systemtap.git

testsuite traceaio.c

Add simple test program calling io_submit() with several iocbs, testing
handling or PWRITE, PREAD, PWRITEV, and PREADV.

The test can be run manually by compiling the program, running it with
"stap -c", and inspecting the generated trace.

With more work, this can be used in "make installcheck", and verified
using expected output file.

Signed-off-by: Nir Soffer <nsoffer@redhat.com>
---

diff --git a/testsuite/systemtap.examples/io/traceaio.c b/testsuite/systemtap.examples/io/traceaio.c
new file mode 100644
index 000000000..54168af10
--- /dev/null
+++ b/testsuite/systemtap.examples/io/traceaio.c
@@ -0,0 +1,94 @@
+// Test program for traceaio.stp example.
+// Copyright (C) 2001 Red Hat Inc.
+//
+// This file is part of systemtap, and is free software.  You can
+// redistribute it and/or modify it under the terms of the GNU General
+// Public License (GPL); either version 2, or (at your option) any
+// later version.
+//
+// Example usage:
+//
+//     $ gcc -D_GNU_SOURCE -o traceaio traceaio.c -laio
+//
+//     $ sudo stap traceaio.stp -c "./traceaio /var/tmp/traceaio.data"
+//     Tracing started
+//     [     0 traceaio(756217):] io_submit(140589416931328, 4, 0x7ffc6d6bb8a0)
+//         iocb[   0]=0x7ffc6d6bb8c0, fd=3, opcode=1, offset=0, nbytes=4096, buf=0x1764000
+//         iocb[   1]=0x7ffc6d6bb900, fd=3, opcode=0, offset=4096, nbytes=4096, buf=0x1765000
+//         iocb[   2]=0x7ffc6d6bb940, fd=3, opcode=8, offset=8192, nbytes=1, buf=0x7ffc6d6bb880
+//             iovec[   0]=0x7ffc6d6bb880, base=0x1766000, len=4096
+//         iocb[   3]=0x7ffc6d6bb980, fd=3, opcode=7, offset=12288, nbytes=1, buf=0x7ffc6d6bb890
+//             iovec[   0]=0x7ffc6d6bb890, base=0x1767000, len=4096
+//     Tracing stopped
+//
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <assert.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <string.h>
+#include <unistd.h>
+#include <libaio.h>
+
+#define IO_SIZE 4096
+
+int main(int argc, char *argv[])
+{
+    int fd;
+    void *buffer;
+    io_context_t ioctx = {0};
+    struct iocb iocbs[4];
+    struct iocb *iocbp[] = {&iocbs[0], &iocbs[1], &iocbs[2], &iocbs[3]};
+    struct iovec iovs[2];
+    int err;
+
+    if (argc != 2) {
+        fprintf(stderr, "Usage: traceaio-test FILENAME\n");
+        exit(1);
+    }
+
+    fd = open(argv[1], O_RDWR | O_CREAT | O_DIRECT, 0644);
+    assert(fd != -1);
+
+    err = fallocate(fd, 0, 0, 4 * IO_SIZE);
+    assert(err == 0);
+
+    err = posix_memalign(&buffer, IO_SIZE, 4 * IO_SIZE);
+    assert(err == 0);
+
+    memset(buffer, 0, 4 * IO_SIZE);
+
+    err = io_setup(128, &ioctx);
+    assert(err == 0);
+
+    /* PWRITE */
+
+    io_prep_pwrite(&iocbs[0], fd, buffer + 0 * IO_SIZE, IO_SIZE, 0 * IO_SIZE);
+
+    /* PREAD */
+
+    io_prep_pread(&iocbs[1], fd, buffer + 1 * IO_SIZE, IO_SIZE, 1 * IO_SIZE);
+
+    /* PWRITEV */
+
+    iovs[0].iov_base = buffer + 2 * IO_SIZE;
+    iovs[0].iov_len = IO_SIZE;
+    io_prep_pwritev(&iocbs[2], fd, &iovs[0], 1, 2 * IO_SIZE);
+
+    /* PREADV */
+
+    iovs[1].iov_base = buffer + 3 * IO_SIZE;
+    iovs[1].iov_len = IO_SIZE;
+    io_prep_preadv(&iocbs[3], fd, &iovs[1], 1, 3 * IO_SIZE);
+
+    io_submit(ioctx, 4, iocbp);
+
+    io_getevents(ioctx, 4, 4, NULL, NULL);
+    io_destroy(ioctx);
+    free(buffer);
+    close(fd);
+
+    return 0;
+}