[PATCH v5 07/13] perf stat: factor out event handling loop into dispatch_events()

[Alexey Budankov]

Consolidate event dispatching loops for launch, attach and system wide
monitoring use cases into common dispatch_events() function. If passed
pid contains valid pid i.e. doesn't equal to -1 then the function returns
pid process exit status in case the process terminates during monitoring.

Signed-off-by: Alexey Budankov <alexey.budan...@linux.intel.com>
---
 tools/perf/builtin-stat.c | 35 ++++++++++++++++++++++++-----------
 1 file changed, 24 insertions(+), 11 deletions(-)

diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index dc7506be8bbd..8eeaf92912d8 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -504,6 +504,27 @@ static bool is_target_alive(struct target *_target,
        return false;
 }
 
+static int dispatch_events(pid_t pid, bool timeout, int interval, int *times, 
struct timespec *ts)
+{
+       bool stop = false;
+       int child = 0, status = 0;
+
+       while (1) {
+               if (pid != -1)
+                       child = waitpid(pid, &status, WNOHANG);
+               else
+                       child = is_target_alive(&target, 
evsel_list->core.threads) == false ? 1 : 0;
+
+               if (done || stop || child)
+                       break;
+
+               nanosleep(ts, NULL);
+               stop = process_timeout(timeout, interval, times);
+       }
+
+       return status;
+}
+
 enum counter_recovery {
        COUNTER_SKIP,
        COUNTER_RETRY,
@@ -575,7 +596,6 @@ static int __run_perf_stat(int argc, const char **argv, int 
run_idx)
        struct affinity affinity;
        int i, cpu;
        bool second_pass = false;
-       bool stop = false;
 
        if (interval) {
                ts.tv_sec  = interval / USEC_PER_MSEC;
@@ -744,12 +764,8 @@ static int __run_perf_stat(int argc, const char **argv, 
int run_idx)
                perf_evlist__start_workload(evsel_list);
                enable_counters();
 
-               if (interval || timeout) {
-                       while (!stop && !waitpid(child_pid, &status, WNOHANG)) {
-                               nanosleep(&ts, NULL);
-                               stop = process_timeout(timeout, interval, 
&times);
-                       }
-               }
+               if (interval || timeout)
+                       status = dispatch_events(child_pid, timeout, interval, 
&times, &ts);
                if (child_pid != -1) {
                        if (timeout)
                                kill(child_pid, SIGTERM);
@@ -766,10 +782,7 @@ static int __run_perf_stat(int argc, const char **argv, 
int run_idx)
                        psignal(WTERMSIG(status), argv[0]);
        } else {
                enable_counters();
-               while (!done && !stop && is_target_alive(&target, 
evsel_list->core.threads)) {
-                       nanosleep(&ts, NULL);
-                       stop = process_timeout(timeout, interval, &times);
-               }
+               dispatch_events(-1, timeout, interval, &times, &ts);
        }
 
        disable_counters();
-- 
2.24.1