[DTrace-devel] [PATCH 4/6] test: Add a USDT "deferred" test trigger
Kris Van Hees
kris.van.hees at oracle.com
Mon Oct 28 20:32:14 UTC 2024
On Fri, Sep 27, 2024 at 10:21:56PM -0400, eugene.loh at oracle.com wrote:
> From: Eugene Loh <eugene.loh at oracle.com>
>
> After a dtrace session has started, it is possible for new USDT
> processes to start and for there to be a delay before dtprobed
> and then dtrace becomes aware of the new process.
>
> Add a test trigger with USDT probes that waits for dtrace to
> discover it and send it USR1. Once the USR1 is received, a
> short workload is run to completion.
>
> Signed-off-by: Eugene Loh <eugene.loh at oracle.com>
Reviewed-by: Kris Van Hees <kris.van.hees at oracle.com>
> ---
> test/triggers/Build | 5 +-
> test/triggers/usdt-tst-defer-prov.d | 11 ++++
> test/triggers/usdt-tst-defer.c | 79 ++++++++++++++++++++++++
> test/unittest/usdt/tst.defer-nodtrace.r | 1 +
> test/unittest/usdt/tst.defer-nodtrace.sh | 49 +++++++++++++++
> 5 files changed, 144 insertions(+), 1 deletion(-)
> create mode 100644 test/triggers/usdt-tst-defer-prov.d
> create mode 100644 test/triggers/usdt-tst-defer.c
> create mode 100644 test/unittest/usdt/tst.defer-nodtrace.r
> create mode 100755 test/unittest/usdt/tst.defer-nodtrace.sh
>
> diff --git a/test/triggers/Build b/test/triggers/Build
> index db80b30ed..107b3b4d1 100644
> --- a/test/triggers/Build
> +++ b/test/triggers/Build
> @@ -13,7 +13,7 @@ EXTERNAL_64BIT_TRIGGERS = testprobe readwholedir mmap bogus-ioctl open delaydie
> ustack-tst-spin ustack-tst-mtspin \
> visible-constructor visible-constructor-static visible-constructor-static-unstripped
>
> -EXTERNAL_64BIT_SDT_TRIGGERS = usdt-tst-argmap usdt-tst-args usdt-tst-forker usdt-tst-special
> +EXTERNAL_64BIT_SDT_TRIGGERS = usdt-tst-argmap usdt-tst-args usdt-tst-forker usdt-tst-defer usdt-tst-special
> EXTERNAL_64BIT_TRIGGERS += $(EXTERNAL_64BIT_SDT_TRIGGERS)
>
> EXTERNAL_32BIT_TRIGGERS := visible-constructor-32
> @@ -203,6 +203,9 @@ usdt-tst-args_PROV := usdt-tst-args-prov.d
> # usdt-tst-forker calls USDT probes based on dtrace -h
> usdt-tst-forker_PROV := usdt-tst-forker-prov.d
>
> +# usdt-tst-defer calls USDT probes based on dtrace -h
> +usdt-tst-defer_PROV := usdt-tst-defer-prov.d
> +
> # usdt-tst-special calls USDT probes based on dtrace -h
> usdt-tst-special_CFLAGS := -fno-inline -O2
> usdt-tst-special_PROV := usdt-tst-special-prov.d
> diff --git a/test/triggers/usdt-tst-defer-prov.d b/test/triggers/usdt-tst-defer-prov.d
> new file mode 100644
> index 000000000..a4ef8323d
> --- /dev/null
> +++ b/test/triggers/usdt-tst-defer-prov.d
> @@ -0,0 +1,11 @@
> +/*
> + * Oracle Linux DTrace.
> + * Copyright (c) 2024, Oracle and/or its affiliates. All rights reserved.
> + * Licensed under the Universal Permissive License v 1.0 as shown at
> + * http://oss.oracle.com/licenses/upl.
> + */
> +
> +provider testprov {
> + probe foo();
> + probe bar(int, int, int);
> +};
> diff --git a/test/triggers/usdt-tst-defer.c b/test/triggers/usdt-tst-defer.c
> new file mode 100644
> index 000000000..2df5401b2
> --- /dev/null
> +++ b/test/triggers/usdt-tst-defer.c
> @@ -0,0 +1,79 @@
> +/*
> + * Oracle Linux DTrace.
> + * Copyright (c) 2024, Oracle and/or its affiliates. All rights reserved.
> + * Licensed under the Universal Permissive License v 1.0 as shown at
> + * http://oss.oracle.com/licenses/upl.
> + */
> +
> +/*
> + * The main characteristic of this trigger code is that it allows deferred
> + * DTrace detection of the trigger. That is, the trigger spins in "phase 1",
> + * waiting for DTrace to detect it and send it USR1. Only then does "phase 2"
> + * run a short workload to completion.
> + */
> +
> +#include <stdio.h>
> +#include <sys/types.h>
> +#include <unistd.h>
> +#include <signal.h>
> +#include "usdt-tst-defer-prov.h"
> +
> +static int phase = 1;
> +
> +static void
> +interrupt(int sig)
> +{
> + phase = 2;
> +}
> +
> +int
> +main(int argc, char **argv)
> +{
> + struct sigaction act;
> + int i;
> + int nphase1 = 0, nphase1foo = 0, nphase1bar = 0;
> + int nphase2 = 0, nphase2foo = 0, nphase2bar = 0;
> +
> + /* set the handler to listen for SIGUSR1 */
> + act.sa_handler = interrupt;
> + act.sa_flags = 0;
> + if (sigaction(SIGUSR1, &act, NULL)) {
> + printf("set handler failed\n");
> + return 1;
> + }
> +
> + /* in phase 1, loop on probe "foo" to wait on USR1 */
> + while (phase == 1) {
> + nphase1++;
> + if (TESTPROV_FOO_ENABLED()) {
> + nphase1foo++;
> + phase = 2;
> + }
> + if (TESTPROV_BAR_ENABLED()) {
> + nphase1bar++;
> + phase = 2;
> + }
> + TESTPROV_FOO();
> + }
> +
> + /* wait for probes to get set up */
> + usleep(100000);
> +
> + /* in phase 2, just loop over probe "bar" a fixed number of times */
> + for (i = 0; i < 10; i++) {
> + nphase2++;
> + usleep(2000);
> + if (TESTPROV_FOO_ENABLED())
> + nphase2foo++;
> + usleep(2000);
> + if (TESTPROV_BAR_ENABLED())
> + nphase2bar++;
> + usleep(2000);
> + TESTPROV_BAR(i, i + 2, i * 2);
> + }
> +
> + printf("%d: %d %d %d %d %d %d\n", getpid(),
> + nphase1, nphase1foo, nphase1bar, nphase2, nphase2foo, nphase2bar);
> +
> + return 0;
> +}
> diff --git a/test/unittest/usdt/tst.defer-nodtrace.r b/test/unittest/usdt/tst.defer-nodtrace.r
> new file mode 100644
> index 000000000..2e9ba477f
> --- /dev/null
> +++ b/test/unittest/usdt/tst.defer-nodtrace.r
> @@ -0,0 +1 @@
> +success
> diff --git a/test/unittest/usdt/tst.defer-nodtrace.sh b/test/unittest/usdt/tst.defer-nodtrace.sh
> new file mode 100755
> index 000000000..e5fd2855c
> --- /dev/null
> +++ b/test/unittest/usdt/tst.defer-nodtrace.sh
> @@ -0,0 +1,49 @@
> +#!/bin/bash
> +#
> +# Oracle Linux DTrace.
> +# Copyright (c) 2024, Oracle and/or its affiliates. All rights reserved.
> +# Licensed under the Universal Permissive License v 1.0 as shown at
> +# http://oss.oracle.com/licenses/upl.
> +#
> +# There are various tests that use the usdt-tst-defer trigger. As a
> +# baseline, let us run the trigger without enabling any USDT probes
> +# and check that the counts are as expected.
> +
> +dtrace=$1
> +trigger=`pwd`/test/triggers/usdt-tst-defer
> +
> +# Set up test directory.
> +
> +DIRNAME=$tmpdir/defer-nodtrace.$$.$RANDOM
> +mkdir -p $DIRNAME
> +cd $DIRNAME
> +
> +# Make a private copy of the trigger executable so that we get our
> +# own DOF stash.
> +
> +cp $trigger main
> +
> +# Check that the is-enabled probes are false when the USDT probes are not enabled.
> +# That is, nphase1foo == nphase1bar == nphase2foo == nphase2bar == 0.
> +# Also, nphase2 == 10.
> +# Note that nphase1 will be undefined.
> +
> +./main > main.out &
> +pid=$!
> +sleep 1
> +kill -USR1 $pid
> +wait
> +
> +echo "$pid: undefined 0 0 10 0 0" > main.out.expected
> +if ! awk '{ $2 = "undefined"; print }' main.out | diff -q - main.out.expected; then
> + echo program output looks wrong for the no-DTrace case
> + echo === got ===
> + cat main.out
> + echo === expected ===
> + cat main.out.expected
> + exit 1
> +fi
> +
> +echo success
> +
> +exit 0
> --
> 2.43.5
>
More information about the DTrace-devel
mailing list