Implementation of the GreenWeb language extensions.

third_party/WebKit/Source/core/events/EventDispatcher.cpp

Index: third_party/WebKit/Source/core/events/EventDispatcher.cpp
diff --git a/third_party/WebKit/Source/core/events/EventDispatcher.cpp b/third_party/WebKit/Source/core/events/EventDispatcher.cpp
index d069a1c9915fdbd64d5f4580fc562e9c1d86c480..d591daba67ead31ad67e418a438e24971c1fe545 100644
--- a/third_party/WebKit/Source/core/events/EventDispatcher.cpp
+++ b/third_party/WebKit/Source/core/events/EventDispatcher.cpp
@@ -26,9 +26,14 @@
 #include "config.h"
 #include "core/events/EventDispatcher.h"
 
+#include <iostream>
+#include <string>
+
+#include "content/renderer/greenweb_latency_tracking.h"
 #include "core/dom/ContainerNode.h"
 #include "core/dom/Document.h"
 #include "core/dom/Element.h"
+#include "core/dom/NodeComputedStyle.h"
 #include "core/events/EventDispatchMediator.h"
 #include "core/events/MouseEvent.h"
 #include "core/events/ScopedEventQueue.h"
@@ -36,10 +41,15 @@
 #include "core/frame/FrameView.h"
 #include "core/frame/LocalDOMWindow.h"
 #include "core/inspector/InspectorTraceEvents.h"
+#include "core/style/ComputedStyle.h"
 #include "platform/EventDispatchForbiddenScope.h"
 #include "platform/TraceEvent.h"
 #include "wtf/RefPtr.h"
 
+char g_qos_type = 'u';
+int g_qos_target = 0;
+bool g_ebs_enabled = false;
+
 namespace blink {
 
 bool EventDispatcher::dispatchEvent(Node& node, PassRefPtrWillBeRawPtr<EventDispatchMediator> mediator)
@@ -102,6 +112,320 @@ void EventDispatcher::dispatchSimulatedClick(Node& node, Event* underlyingEvent,
     nodesDispatchingSimulatedClicks->remove(&node);
 }
 
+bool init_ebs(bool *mode)
+{
+    FILE* arg_file;
+    arg_file = fopen("/data/local/tmp/chrome-shell-command-line", "r");
+    if (!arg_file) {
+        dbg_sched_fprintf(stdout, "[EBS] arg file open failed\n");
+        return false;
+    }
+    dbg_sched_fprintf(stdout, "[EBS] arg file opened\n");
+
+    char arg_list[100];
+    fgets(arg_list, 100, arg_file);
+    fclose(arg_file);
+
+    if (arg_list[13] == '-'
+        && arg_list[14] == '-'
+        && arg_list[15] == 'e'
+        && arg_list[16] == 'b'
+        && arg_list[17] == 's'
+        && arg_list[18] == '-'
+        && arg_list[19] == 'p')
+    {
+        if (arg_list[20] == 'i') {
+            *mode = true;
+            dbg_sched_fprintf(stdout, "[EBS] ebs enabled. Using Pi\n");
+            return true;
+        }
+        if (arg_list[20] == 'u') {
+            *mode = false;
+            dbg_sched_fprintf(stdout, "[EBS] ebs enabled. Using Pu\n");
+            return true;
+        }
+    }
+
+    return false;
+}
+
+void set_freq(uint32 freq)
+{
+    FILE* cpufreq = NULL;
+
+    if (!cpufreq) {
+        cpufreq = fopen("/sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed", "w");
+        if (!cpufreq)
+            dbg_sched_fprintf(stdout, "[EBS] file open failed\n");
+        else
+            dbg_sched_fprintf(stdout, "[EBS] freq file open succeeded\n");
+    }
+
+    if (cpufreq) {
+        int bytes = fprintf(cpufreq, "%u", freq);
+        if ((bytes != 6) && (bytes != 7)) {
+            dbg_sched_fprintf(stdout, "[EBS] cpufreq not set\n");
+        } else {
+            dbg_sched_fprintf(stdout, "[EBS] freq set to %d\n", freq);
+#ifdef EBS_DEBUG_TRACE_EVENT
+            TRACE_EVENT2("devtools.timeline", "EBS:Schedule",
+                         "log", "freq set",
+                         "freq", freq);
+#endif
+        }
+        fclose(cpufreq);
+    }
+}
+
+void schedule(uint32 last_state, int64 last_latency, uint32 *next_state, uint32 *next_freq, int qos_target, FreqLatencyMap *freq_map, int64 dom_node_id)
+{
+    // FSM state explanation:
+    // 0xFF - Calibrating on big core, 1.6G
+    // 0x00 - Calibrating on big core, 0.8G
+    // 0x01 - Calibrating on little core, 0.6G
+    // 0x02 - Calibrating on little core, 0.4G
+    // 0xN  - Running on core with frequency N/10 GHz (N = 3~16)
+
+    // First time we run an event on this node. Run with 1.6G.
+    // ODroid doesn't allow setting all 4 cores to 1.8G.
+    if (last_latency == 0) {
+        *next_state = 0xFF;
+        *next_freq = 1600000;
+        dbg_sched_fprintf(stdout, "[EBS] state %d --> %d: Now calibrate on 1.6G\n", last_state, *next_state);
+        return;
+    }
+
+    // Second time we run an event on this node. Run with 0.8G.
+    if (last_state == 0xFF) {
+        *next_state = 0;
+        *next_freq = 800000;
+        dbg_sched_fprintf(stdout, "[EBS] state %d --> %d: Now calibrate on 0.8G\n", last_state, *next_state);
+    } else if (last_state == 0) {
+        // Finished the two profiling runs on the big core.
+        int64 time_8 = (*freq_map)[800000];
+        int64 time_16 = (*freq_map)[1600000];
+
+        if (qos_target <= time_16) {
+            // Have to provision the highest conf.
+            *next_state = 16;
+            *next_freq = 1600000;
+            dbg_sched_fprintf(stdout, "[EBS] state %d --> %d: T16 > Target. Have to use the highest big\n", last_state, *next_state);
+        } else if (qos_target >= time_8) {
+            // Try the little core
+            *next_state = 1;
+            *next_freq = 600000;
+            dbg_sched_fprintf(stdout, "[EBS] state %d --> %d: T8 < Target. Now calibrate on 0.6G\n", last_state, *next_state);
+        } else {
+            if (time_8 <= time_16) {
+                // Recalibrate on the big core
+                *next_state = 0xFF;
+                *next_freq = 1600000;
+                dbg_sched_fprintf(stdout, "[EBS] state %d --> %d: T8 < T16. Recalibrate on big\n", last_state, *next_state);
+            } else {
+                double beta = (time_8 - time_16) * 1.6 * 1000000;
+                double alpha = time_8 - beta / 800000;
+                *next_freq = (int)(beta / (qos_target - alpha) + 1) / 100000 * 100000;
+                *next_state = *next_freq / 100000;
+                dbg_sched_fprintf(stdout, "[EBS] state %d --> %d: On big, predicted by model\n", last_state, *next_state);
+            }
+        }
+    } else if (last_state == 1) {
+        // First profiling run on the little core.
+        *next_state = 2;
+        // Never uses 300 MHz, beucase it leads to more energy than 400 MHz
+        *next_freq = 400000;
+        dbg_sched_fprintf(stdout, "[EBS] state %d --> %d: Now calibrate on 0.4G\n", last_state, *next_state);
+    } else if (last_state == 2) {
+        // Finished the two profiling runs on the little core.
+        int64 time_4 = (*freq_map)[400000];
+        int64 time_6 = (*freq_map)[600000];
+
+        if (qos_target <= time_6) {
+            // Recalibrate on the big core
+            *next_state = 0xFF;
+            *next_freq = 1600000;
+            dbg_sched_fprintf(stdout, "[EBS] state %d --> %d: T6 > Target. Recalibrate on big\n", last_state, *next_state);
+        } else if (qos_target >= time_4) {
+            // It's safe to provision the lowest on the little core
+            *next_state = 4;
+            *next_freq = 400000;
+            dbg_sched_fprintf(stdout, "[EBS] state %d --> %d: T4 < Target. Safe to use the lowest little\n", last_state, *next_state);
+        } else {
+            if (time_4 <= time_6) {
+                // Recalibrate on the little core
+                *next_state = 1;
+                *next_freq = 600000;
+                dbg_sched_fprintf(stdout, "[EBS] state %d --> %d: T4 < T6. Recalibrate on little\n", last_state, *next_state);
+            } else {
+                double beta = (time_4 - time_6) * 1.2 * 1000000;
+                double alpha = time_4 - beta / 400000;
+                *next_freq = (int)(beta / (qos_target - alpha) + 1) / 100000 * 100000;
+                *next_state = *next_freq / 100000;
+                dbg_sched_fprintf(stdout, "[EBS] state %d --> %d: On little, predicted by model\n", last_state, *next_state);
+            }
+        }
+    } else {
+        // Fine tune phase, depending on the last_latency.
+        static std::map<int64, int> underpred;
+        static std::map<int64, int> overpred;
+
+        if (last_latency < qos_target * 0.8) {
+            // Overpredicting
+            if (last_state == 4) {
+                // Already lowest. Nothing we can do.
+                *next_state = last_state;
+                *next_freq = (*next_state) * 100000;
+                dbg_sched_fprintf(stdout, "[EBS] state %d --> %d: Keep the last prediction\n", last_state, *next_state);
+                return;
+            }
+
+            underpred[dom_node_id] = 0;
+            overpred[dom_node_id]++;
+
+            if (overpred[dom_node_id] <= 2) {
+                if (last_state == 4)
+                    *next_state = 4;
+                else if (last_state == 8)
+                    *next_state = 6;
+                else
+                    *next_state = last_state - 1;
+                *next_freq = (*next_state) * 100000;
+                dbg_sched_fprintf(stdout, "[EBS] state %d --> %d: Overpredict\n", last_state, *next_state);
+            } else if (overpred[dom_node_id] <= 4) {
+                if (last_state <= 5)
+                    *next_state = 4;
+                else if (last_state == 9)
+                    *next_state = 6;
+                else
+                    *next_state = last_state - 2;
+                *next_freq = (*next_state) * 100000;
+                dbg_sched_fprintf(stdout, "[EBS] state %d --> %d: Too many overpredict\n", last_state, *next_state);
+            } else {
+                overpred[dom_node_id] = 0;
+                *next_state = 0xFF;
+                *next_freq = 1600000;
+                dbg_sched_fprintf(stdout, "[EBS] state %d --> %d: Way too many overpredict\n", last_state, *next_state);
+            }
+        } else if (last_latency > qos_target * 0.9) {
+            // Underpredicting
+            if (last_state == 16) {
+                // Already highest. Nothing we can do.
+                *next_state = last_state;
+                *next_freq = (*next_state) * 100000;
+                dbg_sched_fprintf(stdout, "[EBS] state %d --> %d: Keep the last prediction\n", last_state, *next_state);
+                return;
+            }
+
+            overpred[dom_node_id] = 0;
+            underpred[dom_node_id]++;
+
+            if (underpred[dom_node_id] <= 2) {
+                if (last_state == 16)
+                    *next_state = 16;
+                else if (last_state == 6)
+                    *next_state = 8;
+                else
+                    *next_state = last_state + 1;
+                *next_freq = (*next_state) * 100000;
+                dbg_sched_fprintf(stdout, "[EBS] state %d --> %d: Underpredict\n", last_state, *next_state);
+            } else if (underpred[dom_node_id] <= 4) {
+                if (last_state >= 15)
+                    *next_state = 16;
+                else if (last_state == 5)
+                    *next_state = 8;
+                else
+                    *next_state = last_state + 2;
+                *next_freq = (*next_state) * 100000;
+                dbg_sched_fprintf(stdout, "[EBS] state %d --> %d: Too many underpredict\n", last_state, *next_state);
+            } else {
+                underpred[dom_node_id] = 0;
+                *next_state = 0xFF;
+                *next_freq = 1600000;
+                dbg_sched_fprintf(stdout, "[EBS] state %d --> %d: Way too many underpredict\n", last_state, *next_state);
+            }
+        } else {
+            overpred[dom_node_id] = 0;
+            underpred[dom_node_id] = 0;
+            *next_state = last_state;
+            *next_freq = (*next_state) * 100000;
+            dbg_sched_fprintf(stdout, "[EBS] state %d --> %d: Keep the last prediction\n", last_state, *next_state);
+        }
+    }
+
+#ifdef EBS_DEBUG_TRACE_EVENT
+    TRACE_EVENT2("devtools.timeline", "EBS:Schedule",
+                 "last_state", last_state,
+                 "next_state", *next_state);
+#endif
+}
+
+int isEventSupported(String event_name)
+{
+    if (event_name == "click")
+        return 1;
+    else if(event_name == "touchstart")
+        return 2;
+    else if(event_name == "touchend")
+        return 3;
+    else if(event_name == "scroll")
+        return 4;
+    else if(event_name == "touchmove")
+        return 5;
+    return 0;
+}
+
+void EventDispatcher::retriveQoSInfo(bool mode, int event)
+{
+    int pi, pu, type;
+
+    // TODO: handle cases where multiple events register callbacks on one node
+    switch (event) {
+        case 1: // click
+            pi = m_node->computedStyle()->onclickVpi();
+            pu = m_node->computedStyle()->onclickVpu();
+            type = m_node->computedStyle()->onclickType();
+            break;
+        case 2: // touchstart
+            pi = m_node->computedStyle()->ontouchstartVpi();
+            pu = m_node->computedStyle()->ontouchstartVpu();
+            type = m_node->computedStyle()->ontouchstartType();
+            break;
+        case 3: // touchend
+            pi = m_node->computedStyle()->ontouchendVpi();
+            pu = m_node->computedStyle()->ontouchendVpu();
+            type = m_node->computedStyle()->ontouchendType();
+            break;
+        case 4: // scroll
+            pi = m_node->computedStyle()->onscrollVpi();
+            pu = m_node->computedStyle()->onscrollVpu();
+            type = m_node->computedStyle()->onscrollType();
+            break;
+        case 5: // touchmove
+            pi = m_node->computedStyle()->ontouchmoveVpi();
+            pu = m_node->computedStyle()->ontouchmoveVpu();
+            type = m_node->computedStyle()->ontouchmoveType();
+            break;
+        default: // Should never reach here
+            dbg_sched_fprintf(stdout, "[EBS] Wrong event id. Should never reach here!\n");
+            ASSERT_NOT_REACHED();
+            return;
+    }
+
+    g_qos_target = mode ? pi : pu;
+
+    std::string QoSType;
+    if (type == 0)
+        QoSType = "single";
+    else
+        QoSType = "continuous";
+    g_qos_type = QoSType[0];
+
+    dbg_sched_cout("Node " << m_node->nodeName().utf8().data() <<
+                   " on" << m_event->type().string().utf8().data() <<
+                   ": (" << QoSType << ")" <<
+                   " [" << pi << ", " << pu << "]");
+}
+
 bool EventDispatcher::dispatch()
 {
     TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("blink.debug"), "EventDispatcher::dispatch");
@@ -120,6 +444,97 @@ bool EventDispatcher::dispatch()
     ASSERT(!EventDispatchForbiddenScope::isEventDispatchForbidden());
     ASSERT(m_event->target());
     TRACE_EVENT1("devtools.timeline", "EventDispatch", "data", InspectorEventDispatchEvent::data(*m_event));
+
+    static bool init = false;
+    static bool mode = true; // true-Pi, false-Pu
+
+    if (!init) {
+        init = true;
+        g_ebs_enabled = init_ebs(&mode);
+    }
+
+    String event_name = m_event->type().string();
+    int event_id = isEventSupported(event_name);
+    if (event_id) {
+        int64 dom_node_id = reinterpret_cast<int64>(m_node.get());
+        InputLatencyMap[InputLatencyID].dom_node = dom_node_id;
+
+        if (g_ebs_enabled && m_node->computedStyle()) {
+            retriveQoSInfo(mode, event_id);
+
+            // Deal with the single QoS type here. The GPU process deals with the continuous case.
+            if (g_qos_type == 's') {
+                // Memoize the freq to latency mapping for each DOM node.
+                // Used for constructing/calibrating the model and prediction.
+                // Data structure: std::map<int64, std::map<uint32, int64>>
+                static NodeFreqLatencyMap EBSCoreMap;
+                // Memoize the latency, state, and freq for each DOM node
+                //  when it was executed last time.
+                static std::map<int64, int64> last_latency;
+                static std::map<int64, uint32> last_state;
+                static std::map<int64, uint32> last_freq;
+
+                uint32 last_state_t = last_state[dom_node_id];
+                uint32 last_freq_t = last_freq[dom_node_id];
+
+                if (DOMLatencyMap.find(dom_node_id) != DOMLatencyMap.end()) {
+                    // Updating last_latency of this DOM node.
+                    // This could not be done eagerly before it's actually executed.
+                    last_latency[dom_node_id] = DOMLatencyMap[dom_node_id].latency;
+                    EBSCoreMap[dom_node_id][last_freq_t] = last_latency[dom_node_id];
+                }
+#ifdef EBS_DEBUG_TRACE_EVENT
+                TRACE_EVENT2("devtools.timeline", "GreenWeb:EventDispatch",
+                             "trace_id", InputLatencyID,
+                             "last_latency", DOMLatencyMap[dom_node_id].latency);
+#endif
+                dbg_sched_cout("[EBS] trace_id " << InputLatencyID <<
+                               " dom_node " << dom_node_id <<
+                               " last_freq " << last_freq_t <<
+                               " last_latency " << DOMLatencyMap[dom_node_id].latency);
+
+                uint32 next_state;
+                uint32 next_freq;
+                int64 last_latency_t = last_latency[dom_node_id];
+
+                schedule(last_state_t,
+                         last_latency_t,
+                         &next_state,
+                         &next_freq,
+                         g_qos_target,
+                         &EBSCoreMap[dom_node_id],
+                         dom_node_id);
+                set_freq(next_freq);
+
+                // Early updating last_state and last_freq of this DOM node.
+                // Next time we see this DOM node, its last_state and last_freq
+                //   is the next_state and next_freq set in the previous run.
+                // Note that the last_latency of a DOM node can only be set
+                //   when it's seen the next time -- it has to be executed before
+                //   we know it's latency!
+                last_state[dom_node_id] = next_state;
+                last_freq[dom_node_id] = next_freq;
+            }
+        } else { // EBS not enabled
+#ifdef EBS_DEBUG_OS
+            std::cout << "[OS] dom_node " << dom_node_id << " last_latency " << DOMLatencyMap[dom_node_id].latency << std::endl;
+            for (int i = 4; i <= 16; i++) {
+                if (i == 7)
+                    continue;
+                std::cout << i * 100000 << " " << DOMLatencyMap[dom_node_id].FreqStatMap[i * 100000] << std::endl;
+            }
+            fprintf(stdout, " \n");
+#endif
+        }
+    }
+
+    static int counter_s = 0;
+    if ((counter_s != 4) && !strcmp(m_event->type().string().utf8().data(), "readystatechange")) {
+        if (++counter_s == 4)
+            fprintf(stdout, "PageStart\n");
+    }
+    fflush(stdout);
+
     void* preDispatchEventHandlerResult;
     if (dispatchEventPreProcess(preDispatchEventHandlerResult) == ContinueDispatching) {
         if (dispatchEventAtCapturing() == ContinueDispatching) {