Refactored PerfSampler into a more general Perf class for re-use.
Review: https://reviews.apache.org/r/37423
diff --git a/src/linux/perf.cpp b/src/linux/perf.cpp
index cb1a13d..cab6271 100644
--- a/src/linux/perf.cpp
+++ b/src/linux/perf.cpp
@@ -73,7 +73,7 @@
const Duration& duration)
{
vector<string> argv = {
- "perf", "stat",
+ "stat",
// System-wide collection from all CPUs.
"--all-cpus",
@@ -123,7 +123,7 @@
const Duration& duration)
{
vector<string> argv = {
- "perf", "stat",
+ "stat",
// System-wide collection from all CPUs.
"--all-cpus",
@@ -155,15 +155,28 @@
}
-class PerfSampler : public Process<PerfSampler>
+// Executes the 'perf' command using the supplied arguments, and
+// returns stdout as the value of the future or a failure if calling
+// the command fails or the command returns a non-zero exit code.
+//
+// TODO(bmahler): Add a process::os::shell to generalize this.
+class Perf : public Process<Perf>
{
public:
- PerfSampler(const vector<string>& _argv, const Duration& _duration)
- : argv(_argv), duration(_duration) {}
+ Perf(const vector<string>& _argv) : argv(_argv)
+ {
+ // The first argument should be 'perf'. Note that this is
+ // a bit hacky because this class is specialized to only
+ // execute the 'perf' binary. Ultimately, this should be
+ // generalized to something like process::os::shell.
+ if (argv.empty() || argv.front() != "perf") {
+ argv.insert(argv.begin(), "perf");
+ }
+ }
- virtual ~PerfSampler() {}
+ virtual ~Perf() {}
- Future<hashmap<string, mesos::PerfStatistics>> future()
+ Future<string> future()
{
return promise.future();
}
@@ -173,18 +186,9 @@
{
// Stop when no one cares.
promise.future().onDiscard(lambda::bind(
- static_cast<void(*)(const UPID&, bool)>(terminate), self(), true));
+ static_cast<void(*)(const UPID&, bool)>(terminate), self(), true));
- if (duration < Seconds(0)) {
- promise.fail("Perf sample duration cannot be negative: '" +
- stringify(duration.secs()) + "'");
- terminate(self());
- return;
- }
-
- start = Clock::now();
-
- sample();
+ execute();
}
virtual void finalize()
@@ -273,7 +277,7 @@
}
}
- void sample()
+ void execute()
{
Try<Subprocess> _perf = subprocess(
"perf",
@@ -311,7 +315,7 @@
} else if (status.get().isNone()) {
error = Error("Failed to execute perf: failed to reap");
} else if (status.get().get() != 0) {
- error = Error("Failed to collect perf statistics: " +
+ error = Error("Failed to execute perf: " +
WSTRINGIFY(status.get().get()));
} else if (!output.isReady()) {
error = Error("Failed to read perf output: " +
@@ -324,35 +328,15 @@
return;
}
- // Parse output from stdout.
- Try<hashmap<string, mesos::PerfStatistics>> parse =
- perf::parse(output.get());
-
- if (parse.isError()) {
- promise.fail("Failed to parse perf output: " + parse.error());
- terminate(self());
- return;
- }
-
- // Create a non-const copy from the Try<> so we can set the
- // timestamp and duration.
- hashmap<string, mesos::PerfStatistics> statistics = parse.get();
- foreachvalue (mesos::PerfStatistics& s, statistics) {
- s.set_timestamp(start.secs());
- s.set_duration(duration.secs());
- }
-
- promise.set(statistics);
+ promise.set(output.get());
terminate(self());
return;
}));
-}
+ }
- const vector<string> argv;
- const Duration duration;
- Time start;
+ vector<string> argv;
+ Promise<string> promise;
Option<Subprocess> perf;
- Promise<hashmap<string, mesos::PerfStatistics>> promise;
};
@@ -364,6 +348,36 @@
return statistics.get(key).get();
}
+
+Future<hashmap<string, mesos::PerfStatistics>> sample(
+ const vector<string>& argv,
+ const Duration& duration)
+{
+ Time start = Clock::now();
+
+ Perf* perf = new Perf(argv);
+ Future<string> future = perf->future();
+ spawn(perf, true);
+
+ auto parse = [start, duration](const string& output) ->
+ Future<hashmap<string, mesos::PerfStatistics>> {
+ Try<hashmap<string, mesos::PerfStatistics>> parse = perf::parse(output);
+
+ if (parse.isError()) {
+ return Failure("Failed to parse perf sample: " + parse.error());
+ }
+
+ foreachvalue (mesos::PerfStatistics& statistics, parse.get()) {
+ statistics.set_timestamp(start.secs());
+ statistics.set_duration(duration.secs());
+ }
+
+ return parse.get();
+ };
+
+ return future.then(parse);
+}
+
} // namespace internal {
@@ -387,11 +401,7 @@
return Failure("Perf is not supported");
}
- const vector<string> argv = internal::argv(events, pids, duration);
- internal::PerfSampler* sampler = new internal::PerfSampler(argv, duration);
- Future<hashmap<string, mesos::PerfStatistics>> future = sampler->future();
- spawn(sampler, true);
- return future
+ return internal::sample(internal::argv(events, pids, duration), duration)
.then(lambda::bind(&internal::select, PIDS_KEY, lambda::_1));
}
@@ -417,11 +427,7 @@
return Failure("Perf is not supported");
}
- const vector<string> argv = internal::argv(events, cgroups, duration);
- internal::PerfSampler* sampler = new internal::PerfSampler(argv, duration);
- Future<hashmap<string, mesos::PerfStatistics>> future = sampler->future();
- spawn(sampler, true);
- return future;
+ return internal::sample(internal::argv(events, cgroups, duration), duration);
}
