Merge "binderThroughputTest: compute percentiles exactly" into main
diff --git a/libs/binder/tests/binderThroughputTest.cpp b/libs/binder/tests/binderThroughputTest.cpp
index 8f99295..d7f6318 100644
--- a/libs/binder/tests/binderThroughputTest.cpp
+++ b/libs/binder/tests/binderThroughputTest.cpp
@@ -49,6 +49,63 @@
     }
 };
 
+static uint64_t warn_latency = std::numeric_limits<uint64_t>::max();
+
+struct ProcResults {
+    vector<uint64_t> data;
+
+    ProcResults(size_t capacity) { data.reserve(capacity); }
+
+    void add_time(uint64_t time) { data.push_back(time); }
+    void combine_with(const ProcResults& append) {
+        data.insert(data.end(), append.data.begin(), append.data.end());
+    }
+    uint64_t worst() {
+        return *max_element(data.begin(), data.end());
+    }
+    void dump() {
+        if (data.size() == 0) {
+            // This avoids index-out-of-bounds below.
+            cout << "error: no data\n" << endl;
+            return;
+        }
+
+        size_t num_long_transactions = 0;
+        for (uint64_t elem : data) {
+            if (elem > warn_latency) {
+                num_long_transactions += 1;
+            }
+        }
+
+        if (num_long_transactions > 0) {
+            cout << (double)num_long_transactions / data.size() << "% of transactions took longer "
+                "than estimated max latency. Consider setting -m to be higher than "
+                << worst() / 1000 << " microseconds" << endl;
+        }
+
+        sort(data.begin(), data.end());
+
+        uint64_t total_time = 0;
+        for (uint64_t elem : data) {
+            total_time += elem;
+        }
+
+        double best = (double)data[0] / 1.0E6;
+        double worst = (double)data.back() / 1.0E6;
+        double average = (double)total_time / data.size() / 1.0E6;
+        cout << "average:" << average << "ms worst:" << worst << "ms best:" << best << "ms" << endl;
+
+        double percentile_50 = data[(50 * data.size()) / 100] / 1.0E6;
+        double percentile_90 = data[(90 * data.size()) / 100] / 1.0E6;
+        double percentile_95 = data[(95 * data.size()) / 100] / 1.0E6;
+        double percentile_99 = data[(99 * data.size()) / 100] / 1.0E6;
+        cout << "50%: " << percentile_50 << " ";
+        cout << "90%: " << percentile_90 << " ";
+        cout << "95%: " << percentile_95 << " ";
+        cout << "99%: " << percentile_99 << endl;
+    }
+};
+
 class Pipe {
     int m_readFd;
     int m_writeFd;
@@ -79,13 +136,37 @@
         int error = read(m_readFd, &val, sizeof(val));
         ASSERT_TRUE(error >= 0);
     }
-    template <typename T> void send(const T& v) {
-        int error = write(m_writeFd, &v, sizeof(T));
+    void send(const ProcResults& v) {
+        size_t num_elems = v.data.size();
+
+        int error = write(m_writeFd, &num_elems, sizeof(size_t));
         ASSERT_TRUE(error >= 0);
+
+        char* to_write = (char*)v.data.data();
+        size_t num_bytes = sizeof(uint64_t) * num_elems;
+
+        while (num_bytes > 0) {
+            int ret = write(m_writeFd, to_write, num_bytes);
+            ASSERT_TRUE(ret >= 0);
+            num_bytes -= ret;
+            to_write += ret;
+        }
     }
-    template <typename T> void recv(T& v) {
-        int error = read(m_readFd, &v, sizeof(T));
+    void recv(ProcResults& v) {
+        size_t num_elems = 0;
+        int error = read(m_readFd, &num_elems, sizeof(size_t));
         ASSERT_TRUE(error >= 0);
+
+        v.data.resize(num_elems);
+        char* read_to = (char*)v.data.data();
+        size_t num_bytes = sizeof(uint64_t) * num_elems;
+
+        while (num_bytes > 0) {
+            int ret = read(m_readFd, read_to, num_bytes);
+            ASSERT_TRUE(ret >= 0);
+            num_bytes -= ret;
+            read_to += ret;
+        }
     }
     static tuple<Pipe, Pipe> createPipePair() {
         int a[2];
@@ -100,74 +181,6 @@
     }
 };
 
-static const uint32_t num_buckets = 128;
-static uint64_t max_time_bucket = 50ull * 1000000;
-static uint64_t time_per_bucket = max_time_bucket / num_buckets;
-
-struct ProcResults {
-    uint64_t m_worst = 0;
-    uint32_t m_buckets[num_buckets] = {0};
-    uint64_t m_transactions = 0;
-    uint64_t m_long_transactions = 0;
-    uint64_t m_total_time = 0;
-    uint64_t m_best = max_time_bucket;
-
-    void add_time(uint64_t time) {
-        if (time > max_time_bucket) {
-            m_long_transactions++;
-        }
-        m_buckets[min((uint32_t)(time / time_per_bucket), num_buckets - 1)] += 1;
-        m_best = min(time, m_best);
-        m_worst = max(time, m_worst);
-        m_transactions += 1;
-        m_total_time += time;
-    }
-    static ProcResults combine(const ProcResults& a, const ProcResults& b) {
-        ProcResults ret;
-        for (int i = 0; i < num_buckets; i++) {
-            ret.m_buckets[i] = a.m_buckets[i] + b.m_buckets[i];
-        }
-        ret.m_worst = max(a.m_worst, b.m_worst);
-        ret.m_best = min(a.m_best, b.m_best);
-        ret.m_transactions = a.m_transactions + b.m_transactions;
-        ret.m_long_transactions = a.m_long_transactions + b.m_long_transactions;
-        ret.m_total_time = a.m_total_time + b.m_total_time;
-        return ret;
-    }
-    void dump() {
-        if (m_long_transactions > 0) {
-            cout << (double)m_long_transactions / m_transactions << "% of transactions took longer "
-                "than estimated max latency. Consider setting -m to be higher than "
-                 << m_worst / 1000 << " microseconds" << endl;
-        }
-
-        double best = (double)m_best / 1.0E6;
-        double worst = (double)m_worst / 1.0E6;
-        double average = (double)m_total_time / m_transactions / 1.0E6;
-        cout << "average:" << average << "ms worst:" << worst << "ms best:" << best << "ms" << endl;
-
-        uint64_t cur_total = 0;
-        float time_per_bucket_ms = time_per_bucket / 1.0E6;
-        for (int i = 0; i < num_buckets; i++) {
-            float cur_time = time_per_bucket_ms * i + 0.5f * time_per_bucket_ms;
-            if ((cur_total < 0.5f * m_transactions) && (cur_total + m_buckets[i] >= 0.5f * m_transactions)) {
-                cout << "50%: " << cur_time << " ";
-            }
-            if ((cur_total < 0.9f * m_transactions) && (cur_total + m_buckets[i] >= 0.9f * m_transactions)) {
-                cout << "90%: " << cur_time << " ";
-            }
-            if ((cur_total < 0.95f * m_transactions) && (cur_total + m_buckets[i] >= 0.95f * m_transactions)) {
-                cout << "95%: " << cur_time << " ";
-            }
-            if ((cur_total < 0.99f * m_transactions) && (cur_total + m_buckets[i] >= 0.99f * m_transactions)) {
-                cout << "99%: " << cur_time << " ";
-            }
-            cur_total += m_buckets[i];
-        }
-        cout << endl;
-    }
-};
-
 String16 generateServiceName(int num)
 {
     char num_str[32];
@@ -208,7 +221,8 @@
     }
 
     // Run the benchmark if client
-    ProcResults results;
+    ProcResults results(iterations);
+
     chrono::time_point<chrono::high_resolution_clock> start, end;
     for (int i = 0; (!cs_pair || num >= server_count) && i < iterations; i++) {
         Parcel data, reply;
@@ -302,11 +316,10 @@
     // Collect all results from the workers.
     cout << "collecting results" << endl;
     signal_all(pipes);
-    ProcResults tot_results;
+    ProcResults tot_results(0), tmp_results(0);
     for (int i = 0; i < workers; i++) {
-        ProcResults tmp_results;
         pipes[i].recv(tmp_results);
-        tot_results = ProcResults::combine(tot_results, tmp_results);
+        tot_results.combine_with(tmp_results);
     }
 
     // Kill all the workers.
@@ -320,13 +333,11 @@
         }
     }
     if (training_round) {
-        // sets max_time_bucket to 2 * m_worst from the training round.
-        // Also needs to adjust time_per_bucket accordingly.
-        max_time_bucket = 2 * tot_results.m_worst;
-        time_per_bucket = max_time_bucket / num_buckets;
-        cout << "Max latency during training: " << tot_results.m_worst / 1.0E6 << "ms" << endl;
+        // Sets warn_latency to 2 * worst from the training round.
+        warn_latency = 2 * tot_results.worst();
+        cout << "Max latency during training: " << tot_results.worst() / 1.0E6 << "ms" << endl;
     } else {
-            tot_results.dump();
+        tot_results.dump();
     }
 }
 
@@ -403,8 +414,7 @@
                 cout << "Max latency -m must be positive." << endl;
                 exit(EXIT_FAILURE);
             }
-            max_time_bucket = max_time_us * 1000ull;
-            time_per_bucket = max_time_bucket / num_buckets;
+            warn_latency = max_time_us * 1000ull;
             i++;
             continue;
         }