[DTrace-devel] [PATCH v2] Implementation of the exit() action
Kris Van Hees
kris.van.hees at oracle.com
Thu Apr 9 00:20:05 PDT 2020
The exit() action is quite instrumental to the use of DTrace because it
allows a tracing script to terminate the tracing session.
Because exit() must be able to signal that trace data processing is
done, dt_consume_one(), dt_consume_cpu(), and dt_consume() have been
updated to return a dtrace_workstatus_t value to indicate whether
processing of trace data is to continue (DTRACE_WORKSTATUS_OKAY),
is done (DTRACE_WORKSTATUS_DONE), or whether an error occurred
(DTRACE_WORKSTATUS_ERROR).
Signed-off-by: Kris Van Hees <kris.van.hees at oracle.com>
---
libdtrace/dt_cg.c | 5 +++--
libdtrace/dt_consume.c | 37 ++++++++++++++++++++++++-------------
libdtrace/dt_work.c | 9 +--------
3 files changed, 28 insertions(+), 23 deletions(-)
diff --git a/libdtrace/dt_cg.c b/libdtrace/dt_cg.c
index f71fc62c..492a5b61 100644
--- a/libdtrace/dt_cg.c
+++ b/libdtrace/dt_cg.c
@@ -362,11 +362,12 @@ dt_cg_act_exit(dt_pcb_t *pcb, dt_node_t *dnp, dtrace_actkind_t kind)
dt_cg_node(dnp->dn_args, &pcb->pcb_ir, pcb->pcb_regs);
off = dt_rec_add(pcb->pcb_hdl, dt_cg_fill_gap, DTRACEACT_EXIT,
- sizeof(uint64_t), sizeof(uint64_t), NULL,
+ sizeof(uint32_t), sizeof(uint32_t), NULL,
DT_ACT_EXIT);
- instr = BPF_STORE(BPF_DW, BPF_REG_9, off, BPF_REG_0); /* FIXME */
+ instr = BPF_STORE(BPF_W, BPF_REG_9, off, dnp->dn_args->dn_reg);
dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
+ dt_regset_free(pcb->pcb_regs, dnp->dn_args->dn_reg);
}
static void
diff --git a/libdtrace/dt_consume.c b/libdtrace/dt_consume.c
index 46e1efaf..ae8a7ea8 100644
--- a/libdtrace/dt_consume.c
+++ b/libdtrace/dt_consume.c
@@ -2254,10 +2254,10 @@ nextepid:
return (dt_handle_cpudrop(dtp, cpu, DTRACEDROP_PRINCIPAL, drops));
}
#else
-int
+dtrace_workstatus_t
dt_consume_one(dtrace_hdl_t *dtp, FILE *fp, int cpu, char *buf,
dtrace_consume_probe_f *efunc, dtrace_consume_rec_f *rfunc,
- int flow, int quiet, dtrace_epid_t last, void *arg)
+ int flow, int quiet, dtrace_epid_t *last, void *arg)
{
char *data = buf;
struct perf_event_header *hdr;
@@ -2270,6 +2270,7 @@ dt_consume_one(dtrace_hdl_t *dtp, FILE *fp, int cpu, char *buf,
char *ptr = data;
uint32_t size, epid, tag;
int i;
+ int done = 0;
dtrace_probedata_t pdat;
/*
@@ -2319,7 +2320,7 @@ dt_consume_one(dtrace_hdl_t *dtp, FILE *fp, int cpu, char *buf,
return rval;
if (flow)
- dt_flowindent(dtp, &pdat, last, DTRACE_EPIDNONE);
+ dt_flowindent(dtp, &pdat, *last, DTRACE_EPIDNONE);
rval = (*efunc)(&pdat, arg);
@@ -2345,6 +2346,8 @@ dt_consume_one(dtrace_hdl_t *dtp, FILE *fp, int cpu, char *buf,
dtrace_recdesc_t *rec;
rec = &pdat.dtpda_ddesc->dtdd_recs[i];
+ if (rec->dtrd_action == DTRACEACT_EXIT)
+ done = 1;
pdat.dtpda_data = data + rec->dtrd_offset;
rval = (*rfunc)(&pdat, rec, arg);
@@ -2371,7 +2374,9 @@ dt_consume_one(dtrace_hdl_t *dtp, FILE *fp, int cpu, char *buf,
*/
rval = (*rfunc)(&pdat, NULL, arg);
- return epid;
+ *last = epid;
+
+ return done ? DTRACE_WORKSTATUS_DONE : DTRACE_WORKSTATUS_OKAY;
} else if (hdr->type == PERF_RECORD_LOST) {
uint64_t lost;
@@ -2386,9 +2391,9 @@ dt_consume_one(dtrace_hdl_t *dtp, FILE *fp, int cpu, char *buf,
lost = *(uint64_t *)(data + sizeof(uint64_t));
/* FIXME: To be implemented */
- return -1;
+ return DTRACE_WORKSTATUS_ERROR;
} else
- return -1;
+ return DTRACE_WORKSTATUS_ERROR;
}
int
@@ -2406,6 +2411,7 @@ dt_consume_cpu(dtrace_hdl_t *dtp, FILE *fp, int cpu, dt_peb_t *peb,
dt_pebset_t *pebset = dtp->dt_pebset;
uint64_t data_size = pebset->data_size;
int flow, quiet;
+ dtrace_workstatus_t rval = DTRACE_WORKSTATUS_OKAY;
flow = (dtp->dt_options[DTRACEOPT_FLOWINDENT] != DTRACEOPT_UNSET);
quiet = (dtp->dt_options[DTRACEOPT_QUIET] != DTRACEOPT_UNSET);
@@ -2450,15 +2456,18 @@ dt_consume_cpu(dtrace_hdl_t *dtp, FILE *fp, int cpu, dt_peb_t *peb,
event = dst;
}
- last = dt_consume_one(dtp, fp, cpu, event, efunc, rfunc,
- flow, quiet, last, arg);
+ rval = dt_consume_one(dtp, fp, cpu, event, efunc, rfunc,
+ flow, quiet, &last, arg);
+ if (rval != DTRACE_WORKSTATUS_OKAY)
+ return rval;
+
tail += hdr->size;
} while (tail != head);
ring_buffer_write_tail(rb_page, tail);
}
- return 0;
+ return DTRACE_WORKSTATUS_OKAY;
}
#endif
@@ -2666,7 +2675,7 @@ dt_consume_begin(dtrace_hdl_t *dtp, FILE *fp, dtrace_bufdesc_t *buf,
return (rval);
}
-int
+dtrace_workstatus_t
dtrace_consume(dtrace_hdl_t *dtp, FILE *fp,
dtrace_consume_probe_f *pf, dtrace_consume_rec_f *rf, void *arg)
{
@@ -2779,8 +2788,10 @@ dtrace_consume(dtrace_hdl_t *dtp, FILE *fp,
timeout /= NANOSEC / MILLISEC;
cnt = epoll_wait(dtp->dt_poll_fd, events, dtp->dt_conf.numcpus,
timeout);
- if (cnt < 0)
- return dt_set_errno(dtp, errno);
+ if (cnt < 0) {
+ dt_set_errno(dtp, errno);
+ return DTRACE_WORKSTATUS_ERROR;
+ }
/*
* Loop over the buffers that have data available, and process them one
@@ -2795,6 +2806,6 @@ dtrace_consume(dtrace_hdl_t *dtp, FILE *fp,
return rval;
}
- return 0;
+ return DTRACE_WORKSTATUS_OKAY;
#endif
}
diff --git a/libdtrace/dt_work.c b/libdtrace/dt_work.c
index 7889ba78..df7f8f5c 100644
--- a/libdtrace/dt_work.c
+++ b/libdtrace/dt_work.c
@@ -337,13 +337,6 @@ dtrace_workstatus_t
dtrace_work(dtrace_hdl_t *dtp, FILE *fp, dtrace_consume_probe_f *pfunc,
dtrace_consume_rec_f *rfunc, void *arg)
{
- dtrace_workstatus_t rval;
-
- rval = DTRACE_WORKSTATUS_OKAY;
-
- if (dtrace_consume(dtp, fp, pfunc, rfunc, arg) == -1)
- return DTRACE_WORKSTATUS_ERROR;
-
- return rval;
+ return dtrace_consume(dtp, fp, pfunc, rfunc, arg);
}
#endif
--
2.26.0
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