}
/* ****************************** Functions related to the SMPI_SAMPLE_ macros ************************************/
-typedef struct {
+namespace {
+class SampleLocation : public std::string {
+public:
+ SampleLocation(bool global, const char* file, int line) : std::string(std::string(file) + ":" + std::to_string(line))
+ {
+ if (not global)
+ this->append(":" + std::to_string(smpi_process()->index()));
+ }
+};
+
+class LocalData {
+public:
double threshold; /* maximal stderr requested (if positive) */
double relstderr; /* observed stderr so far */
double mean; /* mean of benched times, to be used if the block is disabled */
double sum_pow2; /* sum of the square of the benched times (to compute the stderr) */
int iters; /* amount of requested iterations */
int count; /* amount of iterations done so far */
- int benching; /* 1: we are benchmarking; 0: we have enough data, no bench anymore */
-} local_data_t;
-
-std::unordered_map<std::string, local_data_t*> samples; /* Allocated on first use */
+ bool benching; /* true: we are benchmarking; false: we have enough data, no bench anymore */
-static std::string sample_location(int global, const char* file, int line)
-{
- if (global) {
- return std::string(file) + ":" + std::to_string(line);
- } else {
- return std::string(file) + ":" + std::to_string(line) + ":" + std::to_string(smpi_process()->index());
- }
+ bool need_more_benchs() const;
+};
}
-static int sample_enough_benchs(local_data_t *data) {
- int res = data->count >= data->iters;
- if (data->threshold>0.0) {
- if (data->count <2)
- res = 0; // not enough data
- if (data->relstderr > data->threshold)
- res = 0; // stderr too high yet
- }
+std::unordered_map<SampleLocation, LocalData, std::hash<std::string>> samples;
+
+bool LocalData::need_more_benchs() const
+{
+ bool res = (count < iters) || (threshold > 0.0 && (count < 2 || // not enough data
+ relstderr > threshold // stderr too high yet
+ ));
XBT_DEBUG("%s (count:%d iter:%d stderr:%f thres:%f mean:%fs)",
- (res?"enough benchs":"need more data"), data->count, data->iters, data->relstderr, data->threshold, data->mean);
+ (res ? "need more data" : "enough benchs"), count, iters, relstderr, threshold, mean);
return res;
}
void smpi_sample_1(int global, const char *file, int line, int iters, double threshold)
{
- std::string loc = sample_location(global, file, line);
+ SampleLocation loc(global, file, line);
smpi_bench_end(); /* Take time from previous, unrelated computation into account */
smpi_process()->set_sampling(1);
- auto ld = samples.find(loc);
- local_data_t* data;
- if (ld == samples.end()) {
- xbt_assert(threshold>0 || iters>0,
- "You should provide either a positive amount of iterations to bench, or a positive maximal stderr (or both)");
- data = static_cast<local_data_t*>(xbt_new(local_data_t, 1));
- data->count = 0;
- data->sum = 0.0;
- data->sum_pow2 = 0.0;
- data->iters = iters;
- data->threshold = threshold;
- data->benching = 1; // If we have no data, we need at least one
- data->mean = 0;
- samples[loc] = data;
+ auto insert = samples.emplace(loc, LocalData{
+ threshold, // threshold
+ 0.0, // relstderr
+ 0.0, // mean
+ 0.0, // sum
+ 0.0, // sum_pow2
+ iters, // iters
+ 0, // count
+ true // benching (if we have no data, we need at least one)
+ });
+ LocalData& data = insert.first->second;
+ if (insert.second) {
XBT_DEBUG("XXXXX First time ever on benched nest %s.", loc.c_str());
+ xbt_assert(threshold > 0 || iters > 0,
+ "You should provide either a positive amount of iterations to bench, or a positive maximal stderr (or both)");
} else {
- data = ld->second;
- if (data->iters != iters || data->threshold != threshold) {
+ if (data.iters != iters || data.threshold != threshold) {
XBT_ERROR("Asked to bench block %s with different settings %d, %f is not %d, %f. "
"How did you manage to give two numbers at the same line??",
- loc.c_str(), data->iters, data->threshold, iters, threshold);
+ loc.c_str(), data.iters, data.threshold, iters, threshold);
THROW_IMPOSSIBLE;
}
// if we already have some data, check whether sample_2 should get one more bench or whether it should emulate
// the computation instead
- data->benching = (sample_enough_benchs(data) == 0);
+ data.benching = data.need_more_benchs();
XBT_DEBUG("XXXX Re-entering the benched nest %s. %s", loc.c_str(),
- (data->benching ? "more benching needed" : "we have enough data, skip computes"));
+ (data.benching ? "more benching needed" : "we have enough data, skip computes"));
}
}
int smpi_sample_2(int global, const char *file, int line)
{
- std::string loc = sample_location(global, file, line);
+ SampleLocation loc(global, file, line);
int res;
- xbt_assert(not samples.empty(),
- "Y U NO use SMPI_SAMPLE_* macros? Stop messing directly with smpi_sample_* functions!");
- local_data_t* data = samples.at(loc);
XBT_DEBUG("sample2 %s", loc.c_str());
+ auto sample = samples.find(loc);
+ if (sample == samples.end())
+ xbt_die("Y U NO use SMPI_SAMPLE_* macros? Stop messing directly with smpi_sample_* functions!");
+ LocalData& data = sample->second;
- if (data->benching==1) {
+ if (data.benching) {
// we need to run a new bench
XBT_DEBUG("benchmarking: count:%d iter:%d stderr:%f thres:%f; mean:%f",
- data->count, data->iters, data->relstderr, data->threshold, data->mean);
+ data.count, data.iters, data.relstderr, data.threshold, data.mean);
res = 1;
} else {
// Enough data, no more bench (either we got enough data from previous visits to this benched nest, or we just
//ran one bench and need to bail out now that our job is done). Just sleep instead
XBT_DEBUG("No benchmark (either no need, or just ran one): count >= iter (%d >= %d) or stderr<thres (%f<=%f)."
" apply the %fs delay instead",
- data->count, data->iters, data->relstderr, data->threshold, data->mean);
- smpi_execute(data->mean);
+ data.count, data.iters, data.relstderr, data.threshold, data.mean);
+ smpi_execute(data.mean);
smpi_process()->set_sampling(0);
res = 0; // prepare to capture future, unrelated computations
}
void smpi_sample_3(int global, const char *file, int line)
{
- std::string loc = sample_location(global, file, line);
+ SampleLocation loc(global, file, line);
- xbt_assert(not samples.empty(),
- "Y U NO use SMPI_SAMPLE_* macros? Stop messing directly with smpi_sample_* functions!");
- local_data_t* data = samples.at(loc);
XBT_DEBUG("sample3 %s", loc.c_str());
+ auto sample = samples.find(loc);
+ if (sample == samples.end())
+ xbt_die("Y U NO use SMPI_SAMPLE_* macros? Stop messing directly with smpi_sample_* functions!");
+ LocalData& data = sample->second;
- if (data->benching==0)
+ if (not data.benching)
THROW_IMPOSSIBLE;
// ok, benchmarking this loop is over
xbt_os_threadtimer_stop(smpi_process()->timer());
// update the stats
- data->count++;
- double sample = xbt_os_timer_elapsed(smpi_process()->timer());
- data->sum += sample;
- data->sum_pow2 += sample * sample;
- double n = static_cast<double>(data->count);
- data->mean = data->sum / n;
- data->relstderr = sqrt((data->sum_pow2 / n - data->mean * data->mean) / n) / data->mean;
- if (sample_enough_benchs(data)==0) {
- data->mean = sample; // Still in benching process; We want sample_2 to simulate the exact time of this loop
+ data.count++;
+ double period = xbt_os_timer_elapsed(smpi_process()->timer());
+ data.sum += period;
+ data.sum_pow2 += period * period;
+ double n = static_cast<double>(data.count);
+ data.mean = data.sum / n;
+ data.relstderr = sqrt((data.sum_pow2 / n - data.mean * data.mean) / n) / data.mean;
+ if (data.need_more_benchs()) {
+ data.mean = period; // Still in benching process; We want sample_2 to simulate the exact time of this loop
// occurrence before leaving, not the mean over the history
}
- XBT_DEBUG("Average mean after %d steps is %f, relative standard error is %f (sample was %f)", data->count,
- data->mean, data->relstderr, sample);
+ XBT_DEBUG("Average mean after %d steps is %f, relative standard error is %f (sample was %f)",
+ data.count, data.mean, data.relstderr, period);
// That's enough for now, prevent sample_2 to run the same code over and over
- data->benching = 0;
+ data.benching = false;
}
extern "C" { /** These functions will be called from the user code **/
void smpi_bench_destroy()
{
- for (auto const& elm : samples)
- xbt_free(elm.second);
+ samples.clear();
}
