Improve lttng/commands/calibrate.c usage() printout.
Document and enforce the expected return values for the cmd_calibrate() chain
of functions.
This includes a couple of documentation lines in lib/lttng-ctl/lttng-ctl.c.
------------------------------
>From 4c9089ec185d72c9e457dc6656323ae0e2939ae3 Thu, 26 Jan 2012 16:05:04 -0500
From: Daniel U. Thibault <[email protected]>
Date: Thu, 26 Jan 2012 16:04:41 -0500
Subject: [PATCH] lttng-tools lttng commands calibrate.c : Return values of the
cmd_calibrate() chain of functions
diff --git a/src/bin/lttng/commands/calibrate.c
b/src/bin/lttng/commands/calibrate.c
index 81eadbf..1af1807 100644
--- a/src/bin/lttng/commands/calibrate.c
+++ b/src/bin/lttng/commands/calibrate.c
@@ -89,14 +89,14 @@
fprintf(ofp, "\n");
fprintf(ofp, " -h, --help Show this help\n");
fprintf(ofp, " --list-options Simple listing of options\n");
- fprintf(ofp, " -k, --kernel Apply for the kernel
tracer\n");
+ fprintf(ofp, " -k, --kernel Apply to the kernel tracer\n");
#if 0
- fprintf(ofp, " -u, --userspace [CMD] Apply for the user-space
tracer\n");
- fprintf(ofp, " If no CMD, the domain used is
UST global\n");
- fprintf(ofp, " or else the domain is UST
EXEC_NAME\n");
+ fprintf(ofp, " -u, --userspace [CMD] Apply to the user-space tracer
(domain: UST\n");
+ fprintf(ofp, " EXEC_NAME). If no CMD, the
domain is UST globa.\n");
+ fprintf(ofp, " (-k preempts -u)\n");
fprintf(ofp, " -p, --pid PID If -u, apply to specific PID
(domain: UST PID)\n");
#else
- fprintf(ofp, " -u, --userspace Apply for the user-space
tracer\n");
+ fprintf(ofp, " -u, --userspace Apply to the user-space
tracer\n");
#endif
fprintf(ofp, "\n");
fprintf(ofp, "Calibrate options:\n");
@@ -120,6 +120,7 @@
* calibrate_lttng
*
* Calibrate LTTng.
+ * Returns one of the CMD_* result constants.
*/
static int calibrate_lttng(void)
{
@@ -140,7 +141,7 @@
handle = lttng_create_handle(NULL, &dom);
if (handle == NULL) {
- ret = -1;
+ ret = CMD_ERROR;
goto error;
}
@@ -154,9 +155,17 @@
case LTTNG_EVENT_FUNCTION:
DBG("Calibrating kernel functions");
calibrate.type = LTTNG_CALIBRATE_FUNCTION;
+ /*
+ * lttng_calibrate() returns the size of
+ * the returned session payload data
+ * or a negative error code.
+ */
ret = lttng_calibrate(handle, &calibrate);
if (ret < 0) {
+ ret = CMD_ERROR;
goto error;
+ } else {
+ ret = CMD_SUCCESS;
}
MSG("%s calibration done", opt_kernel ? "Kernel" : "UST");
break;
@@ -181,6 +190,7 @@
* cmd_calibrate
*
* Calibrate LTTng tracer.
+ * Returns one of the CMD_* result constants.
*/
int cmd_calibrate(int argc, const char **argv)
{
@@ -196,7 +206,7 @@
while ((opt = poptGetNextOpt(pc)) != -1) {
switch (opt) {
case OPT_HELP:
- usage(stderr);
+ usage(stdout);
ret = CMD_SUCCESS;
goto end;
case OPT_TRACEPOINT:
diff --git a/src/lib/lttng-ctl/lttng-ctl.c b/src/lib/lttng-ctl/lttng-ctl.c
index b7fc781..e7ebab5 100644
--- a/src/lib/lttng-ctl/lttng-ctl.c
+++ b/src/lib/lttng-ctl/lttng-ctl.c
@@ -302,7 +302,7 @@
/*
* Ask the session daemon a specific command and put the data into buf.
*
- * Return size of data (only payload, not header).
+ * Return size of data (only payload, not header) or a negative error code.
*/
static int ask_sessiond(struct lttcomm_session_msg *lsm, void **buf)
{
@@ -808,6 +808,7 @@
/*
* lttng_calibrate
+ * Returns size of returned session payload data or a negative error code.
*/
int lttng_calibrate(struct lttng_handle *handle,
struct lttng_calibrate *calibrate)
------------------------------
Daniel U. Thibault
R & D pour la défense Canada - Valcartier (RDDC Valcartier) / Defence R&D
Canada - Valcartier (DRDC Valcartier)
Système de systèmes (SdS) / System of Systems (SoS)
Solutions informatiques et expérimentations (SIE) / Computing Solutions and
Experimentations (CSE)
2459 Boul. Pie XI Nord
Québec, QC G3J 1X5
CANADA
Vox : (418) 844-4000 x4245
Fax : (418) 844-4538
NAC: 918V QSDJ
Gouvernement du Canada / Government of Canada
<http://www.valcartier.drdc-rddc.gc.ca/>
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