diff options
| -rw-r--r-- | Documentation/technical/api-trace2.txt | 40 | ||||
| -rw-r--r-- | trace2.c | 31 | ||||
| -rw-r--r-- | trace2.h | 25 | ||||
| -rw-r--r-- | trace2/tr2_tgt.h | 5 | ||||
| -rw-r--r-- | trace2/tr2_tgt_event.c | 22 | ||||
| -rw-r--r-- | trace2/tr2_tgt_normal.c | 14 | ||||
| -rw-r--r-- | trace2/tr2_tgt_perf.c | 15 |
7 files changed, 152 insertions, 0 deletions
diff --git a/Documentation/technical/api-trace2.txt b/Documentation/technical/api-trace2.txt index b9f3198fbe..ef7fe02a8f 100644 --- a/Documentation/technical/api-trace2.txt +++ b/Documentation/technical/api-trace2.txt @@ -613,6 +613,46 @@ stopping after the waitpid() and includes OS process creation overhead). So this time will be slightly larger than the atexit time reported by the child process itself. +`"child_ready"`:: + This event is generated after the current process has started + a background process and released all handles to it. ++ +------------ +{ + "event":"child_ready", + ... + "child_id":2, + "pid":14708, # child PID + "ready":"ready", # child ready state + "t_rel":0.110605 # observed run-time of child process +} +------------ ++ +Note that the session-id of the child process is not available to +the current/spawning process, so the child's PID is reported here as +a hint for post-processing. (But it is only a hint because the child +process may be a shell script which doesn't have a session-id.) ++ +This event is generated after the child is started in the background +and given a little time to boot up and start working. If the child +startups normally and while the parent is still waiting, the "ready" +field will have the value "ready". +If the child is too slow to start and the parent times out, the field +will have the value "timeout". +If the child starts but the parent is unable to probe it, the field +will have the value "error". ++ +After the parent process emits this event, it will release all of its +handles to the child process and treat the child as a background +daemon. So even if the child does eventually finish booting up, +the parent will not emit an updated event. ++ +Note that the `t_rel` field contains the observed run time in seconds +when the parent released the child process into the background. +The child is assumed to be a long-running daemon process and may +outlive the parent process. So the parent's child event times should +not be compared to the child's atexit times. + `"exec"`:: This event is generated before git attempts to `exec()` another command rather than starting a child process. @@ -394,6 +394,37 @@ void trace2_child_exit_fl(const char *file, int line, struct child_process *cmd, us_elapsed_child); } +void trace2_child_ready_fl(const char *file, int line, + struct child_process *cmd, + const char *ready) +{ + struct tr2_tgt *tgt_j; + int j; + uint64_t us_now; + uint64_t us_elapsed_absolute; + uint64_t us_elapsed_child; + + if (!trace2_enabled) + return; + + us_now = getnanotime() / 1000; + us_elapsed_absolute = tr2tls_absolute_elapsed(us_now); + + if (cmd->trace2_child_us_start) + us_elapsed_child = us_now - cmd->trace2_child_us_start; + else + us_elapsed_child = 0; + + for_each_wanted_builtin (j, tgt_j) + if (tgt_j->pfn_child_ready_fl) + tgt_j->pfn_child_ready_fl(file, line, + us_elapsed_absolute, + cmd->trace2_child_id, + cmd->pid, + ready, + us_elapsed_child); +} + int trace2_exec_fl(const char *file, int line, const char *exe, const char **argv) { @@ -254,6 +254,31 @@ void trace2_child_exit_fl(const char *file, int line, struct child_process *cmd, trace2_child_exit_fl(__FILE__, __LINE__, (cmd), (code)) /** + * Emits a "child_ready" message containing the "child-id" and a flag + * indicating whether the child was considered "ready" when we + * released it. + * + * This function should be called after starting a daemon process in + * the background (and after giving it sufficient time to boot + * up) to indicate that we no longer control or own it. + * + * The "ready" argument should contain one of { "ready", "timeout", + * "error" } to indicate the state of the running daemon when we + * released it. + * + * If the daemon process fails to start or it exits or is terminated + * while we are still waiting for it, the caller should emit a + * regular "child_exit" to report the normal process exit information. + * + */ +void trace2_child_ready_fl(const char *file, int line, + struct child_process *cmd, + const char *ready); + +#define trace2_child_ready(cmd, ready) \ + trace2_child_ready_fl(__FILE__, __LINE__, (cmd), (ready)) + +/** * Emit an 'exec' event prior to calling one of exec(), execv(), * execvp(), and etc. On Unix-derived systems, this will be the * last event emitted for the current process, unless the exec diff --git a/trace2/tr2_tgt.h b/trace2/tr2_tgt.h index 1f66fd6573..65f94e1574 100644 --- a/trace2/tr2_tgt.h +++ b/trace2/tr2_tgt.h @@ -45,6 +45,10 @@ typedef void(tr2_tgt_evt_child_exit_fl_t)(const char *file, int line, uint64_t us_elapsed_absolute, int cid, int pid, int code, uint64_t us_elapsed_child); +typedef void(tr2_tgt_evt_child_ready_fl_t)(const char *file, int line, + uint64_t us_elapsed_absolute, + int cid, int pid, const char *ready, + uint64_t us_elapsed_child); typedef void(tr2_tgt_evt_thread_start_fl_t)(const char *file, int line, uint64_t us_elapsed_absolute); @@ -116,6 +120,7 @@ struct tr2_tgt { tr2_tgt_evt_alias_fl_t *pfn_alias_fl; tr2_tgt_evt_child_start_fl_t *pfn_child_start_fl; tr2_tgt_evt_child_exit_fl_t *pfn_child_exit_fl; + tr2_tgt_evt_child_ready_fl_t *pfn_child_ready_fl; tr2_tgt_evt_thread_start_fl_t *pfn_thread_start_fl; tr2_tgt_evt_thread_exit_fl_t *pfn_thread_exit_fl; tr2_tgt_evt_exec_fl_t *pfn_exec_fl; diff --git a/trace2/tr2_tgt_event.c b/trace2/tr2_tgt_event.c index 578a9a5287..70cfc2f77c 100644 --- a/trace2/tr2_tgt_event.c +++ b/trace2/tr2_tgt_event.c @@ -383,6 +383,27 @@ static void fn_child_exit_fl(const char *file, int line, jw_release(&jw); } +static void fn_child_ready_fl(const char *file, int line, + uint64_t us_elapsed_absolute, int cid, int pid, + const char *ready, uint64_t us_elapsed_child) +{ + const char *event_name = "child_ready"; + struct json_writer jw = JSON_WRITER_INIT; + double t_rel = (double)us_elapsed_child / 1000000.0; + + jw_object_begin(&jw, 0); + event_fmt_prepare(event_name, file, line, NULL, &jw); + jw_object_intmax(&jw, "child_id", cid); + jw_object_intmax(&jw, "pid", pid); + jw_object_string(&jw, "ready", ready); + jw_object_double(&jw, "t_rel", 6, t_rel); + jw_end(&jw); + + tr2_dst_write_line(&tr2dst_event, &jw.json); + + jw_release(&jw); +} + static void fn_thread_start_fl(const char *file, int line, uint64_t us_elapsed_absolute) { @@ -610,6 +631,7 @@ struct tr2_tgt tr2_tgt_event = { fn_alias_fl, fn_child_start_fl, fn_child_exit_fl, + fn_child_ready_fl, fn_thread_start_fl, fn_thread_exit_fl, fn_exec_fl, diff --git a/trace2/tr2_tgt_normal.c b/trace2/tr2_tgt_normal.c index a5751c8864..58d9e430f0 100644 --- a/trace2/tr2_tgt_normal.c +++ b/trace2/tr2_tgt_normal.c @@ -251,6 +251,19 @@ static void fn_child_exit_fl(const char *file, int line, strbuf_release(&buf_payload); } +static void fn_child_ready_fl(const char *file, int line, + uint64_t us_elapsed_absolute, int cid, int pid, + const char *ready, uint64_t us_elapsed_child) +{ + struct strbuf buf_payload = STRBUF_INIT; + double elapsed = (double)us_elapsed_child / 1000000.0; + + strbuf_addf(&buf_payload, "child_ready[%d] pid:%d ready:%s elapsed:%.6f", + cid, pid, ready, elapsed); + normal_io_write_fl(file, line, &buf_payload); + strbuf_release(&buf_payload); +} + static void fn_exec_fl(const char *file, int line, uint64_t us_elapsed_absolute, int exec_id, const char *exe, const char **argv) { @@ -330,6 +343,7 @@ struct tr2_tgt tr2_tgt_normal = { fn_alias_fl, fn_child_start_fl, fn_child_exit_fl, + fn_child_ready_fl, NULL, /* thread_start */ NULL, /* thread_exit */ fn_exec_fl, diff --git a/trace2/tr2_tgt_perf.c b/trace2/tr2_tgt_perf.c index af4d65a0a5..e4acca13d6 100644 --- a/trace2/tr2_tgt_perf.c +++ b/trace2/tr2_tgt_perf.c @@ -360,6 +360,20 @@ static void fn_child_exit_fl(const char *file, int line, strbuf_release(&buf_payload); } +static void fn_child_ready_fl(const char *file, int line, + uint64_t us_elapsed_absolute, int cid, int pid, + const char *ready, uint64_t us_elapsed_child) +{ + const char *event_name = "child_ready"; + struct strbuf buf_payload = STRBUF_INIT; + + strbuf_addf(&buf_payload, "[ch%d] pid:%d ready:%s", cid, pid, ready); + + perf_io_write_fl(file, line, event_name, NULL, &us_elapsed_absolute, + &us_elapsed_child, NULL, &buf_payload); + strbuf_release(&buf_payload); +} + static void fn_thread_start_fl(const char *file, int line, uint64_t us_elapsed_absolute) { @@ -553,6 +567,7 @@ struct tr2_tgt tr2_tgt_perf = { fn_alias_fl, fn_child_start_fl, fn_child_exit_fl, + fn_child_ready_fl, fn_thread_start_fl, fn_thread_exit_fl, fn_exec_fl, |