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uNetworkingABuNetworkingAB
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Add experimental fast timers
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‎src/FastTimers.h

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#include <stdio.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <limits.h>
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/* Free timers is a stack of available timer offsets */
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unsigned int freeTimersHead = 0;
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unsigned int freeTimers[1000000];
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/* Every timer is a bunch of components */
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unsigned int componentMultiplierMs[5] = {10, 50, 100, 500, 1000};
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struct Timer {
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/* Offsets in timers array */
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unsigned int next, prev;
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/* The components remaining for this untriggered run */
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unsigned int components[5];
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/* We need to track the original Ms in case of repeat timers */
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unsigned int nextOriginalMs;
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/* Overshoot Ms is used to track accumulated overshoot and to remove smallest 10ms when overshot more than 10ms */
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unsigned int overshootMs;
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/* What list the timer is in */
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unsigned int componentOffset;
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};
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/* Timers are strides over an integer array */
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struct Timer timers[1000000];
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/* Timer to registered callback */
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void (*timerCallbacks[1000000])();
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/* Per component timer doubly linked list (head) */
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unsigned int timerListHead[5] = {UINT_MAX, UINT_MAX, UINT_MAX, UINT_MAX, UINT_MAX};
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void cb() {
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printf("A timer triggered!\n");
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}
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void init() {
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freeTimersHead = 0;
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for (int i = 0; i < 1000000; i++) {
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freeTimers[i] = i;
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}
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for (int i = 0; i < 5; i++) {
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timerListHead[i] = UINT_MAX;
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}
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}
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unsigned int allocateTimer() {
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freeTimersHead++;
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//printf("Allocating timer: %d\n", freeTimers[freeTimersHead - 1]);
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return freeTimers[freeTimersHead - 1];
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}
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void freeTimer(unsigned int timer) {
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//printf("Freeing timer: %d\n", timer);
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freeTimersHead--;
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freeTimers[freeTimersHead] = timer;
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}
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unsigned int divideComponents(unsigned int components[5], unsigned int *biggestSetComponent, unsigned int ms) {
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/* Start on fifth component */
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int biggestComponent = 4;
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while (ms > 0 && biggestComponent >= 0) {
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/* Can we divide by this component? */
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if (ms >= componentMultiplierMs[biggestComponent]) {
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components[biggestComponent] = ms / componentMultiplierMs[biggestComponent];
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ms -= components[biggestComponent] * componentMultiplierMs[biggestComponent];
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if (*biggestSetComponent < biggestComponent) {
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*biggestSetComponent = biggestComponent;
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}
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}
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biggestComponent--;
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}
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unsigned int overshoot = 0;
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if (ms) {
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components[0]++;
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overshoot = 10 - ms;
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}
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/* Return the overshoot */
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return overshoot;
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}
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void addTimerToList(unsigned int timer, unsigned int componentOffset) {
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unsigned int head = timerListHead[componentOffset];
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timers[timer].next = head;
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timers[timer].prev = UINT_MAX;
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if (head != UINT_MAX) {
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timers[head].prev = timer;
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}
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timerListHead[componentOffset] = timer;
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/* Track what list the timer is in */
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timers[timer].componentOffset = componentOffset;
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}
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/* Returns the next timer in the list or UINT_MAX */
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unsigned int removeTimerFromList(unsigned int timer, unsigned int componentOffset) {
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unsigned int prev = timers[timer].prev;
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unsigned int next = timers[timer].next;
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if (prev != UINT_MAX) {
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timers[prev].next = next;
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} else {
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timerListHead[componentOffset] = next;
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}
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if (next != UINT_MAX) {
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timers[next].prev = prev;
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}
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return next;
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}
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unsigned int moveTimerToList(unsigned int timer, unsigned int newComponentOffset) {
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unsigned int currentComponentOffset = timers[timer].componentOffset;
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unsigned int nextTimer = removeTimerFromList(timer, currentComponentOffset);
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addTimerToList(timer, newComponentOffset);
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return nextTimer;
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}
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/* Trigger a tick of the given component offset, to be called from system timers */
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void tick(unsigned int componentOffset) {
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//printf("Tick for %d\n", componentOffset);
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/* Iterate this list, decrementing the timer components */
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unsigned int timerIterator = timerListHead[componentOffset];
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while (timerIterator != UINT_MAX) {
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//printf("Iterating timer %d\n", timerIterator);
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/* This timer needs to move to a higher precision list, or trigger */
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if (!--timers[timerIterator].components[componentOffset]) {
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/* Seek to next non-null component or the 0th component */
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unsigned int nextComponentOffsetForTimer = componentOffset;
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while (nextComponentOffsetForTimer && timers[timerIterator].components[nextComponentOffsetForTimer] == 0) {
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nextComponentOffsetForTimer--;
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}
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/* Here we either have a new list to join or we trigger the timer here and now */
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if (timers[timerIterator].components[nextComponentOffsetForTimer]) {
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/* This should return the next timerIterator */
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timerIterator = moveTimerToList(timerIterator, nextComponentOffsetForTimer);
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} else {
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/* This callback must not modify the list (but we can handle that later!) */
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timerCallbacks[timerIterator]();
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/* If the timer itself is removed in the above callback, below removal will fail */
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/* And remove the timer (this should return the next timerIterator) */
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timerIterator = removeTimerFromList(timerIterator, componentOffset);
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}
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} else {
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timerIterator = timers[timerIterator].next;
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}
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}
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}
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unsigned int setTimeout_(void (*cb)(), unsigned int ms) {
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/* Allocate free timer */
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unsigned int timer = allocateTimer();
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/* Divide given ms in components */
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unsigned int biggestSetComponent = 0;
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timers[timer].overshootMs = divideComponents(timers[timer].components, &biggestSetComponent, ms);
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//printf("Overshoot by %u ms\n", timers[timer].overshootMs);
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//printf("Biggest set component is %u\n", biggestSetComponent);
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/* Add the timer to the list of the highest component */
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addTimerToList(timer, biggestSetComponent);
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/* Set the callback */
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timerCallbacks[timer] = cb;
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return timer;
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}
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void clearTimeout_(unsigned int timer) {
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/* Unlink the timer from its list */
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removeTimerFromList(timer, timers[timer].componentOffset);
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/* Put the timer into free timer circle buffer */
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freeTimer(timer);
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}

‎src/addon.cpp

Lines changed: 31 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -109,6 +109,34 @@ void uWS_getParts(const FunctionCallbackInfo<Value> &args) {
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/* We'll return undefined on error */
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}
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/* Faster setTimeout, clearTimeout */
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#include "FastTimers.h"
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UniquePersistent<Function> timerCallbacksJS[1000];
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void uWS_setTimeout(const FunctionCallbackInfo<Value> &args) {
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/* Function, integer */
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unsigned int timer = setTimeout_(nullptr, 1000);
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timerCallbacksJS[timer].Reset(args.GetIsolate(), Local<Function>::Cast(args[0]));
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args.GetReturnValue().Set(Integer::New(args.GetIsolate(), timer));
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}
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void uWS_clearTimeout(const FunctionCallbackInfo<Value> &args) {
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/* Integer */
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uint32_t timer = Local<Integer>::Cast(args[0])->Value();
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clearTimeout_(timer);
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timerCallbacksJS[timer].Reset();
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}
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/* Pass various undocumented configs */
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void uWS_cfg(const FunctionCallbackInfo<Value> &args) {
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NativeString key(args.GetIsolate(), args[0]);
@@ -372,6 +400,9 @@ PerContextData *Main(Local<Object> exports) {
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exports->Set(isolate->GetCurrentContext(), String::NewFromUtf8(isolate, "deleteStringCollection", NewStringType::kNormal).ToLocalChecked(), FunctionTemplate::New(isolate, uWS_deleteStringCollection)->GetFunction(isolate->GetCurrentContext()).ToLocalChecked()).ToChecked();
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exports->Set(isolate->GetCurrentContext(), String::NewFromUtf8(isolate, "deleteIntegerCollection", NewStringType::kNormal).ToLocalChecked(), FunctionTemplate::New(isolate, uWS_deleteIntegerCollection)->GetFunction(isolate->GetCurrentContext()).ToLocalChecked()).ToChecked();
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exports->Set(isolate->GetCurrentContext(), String::NewFromUtf8(isolate, "setTimeout", NewStringType::kNormal).ToLocalChecked(), FunctionTemplate::New(isolate, uWS_setTimeout)->GetFunction(isolate->GetCurrentContext()).ToLocalChecked()).ToChecked();
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exports->Set(isolate->GetCurrentContext(), String::NewFromUtf8(isolate, "clearTimeout", NewStringType::kNormal).ToLocalChecked(), FunctionTemplate::New(isolate, uWS_clearTimeout)->GetFunction(isolate->GetCurrentContext()).ToLocalChecked()).ToChecked();
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exports->Set(isolate->GetCurrentContext(), String::NewFromUtf8(isolate, "_cfg", NewStringType::kNormal).ToLocalChecked(), FunctionTemplate::New(isolate, uWS_cfg)->GetFunction(isolate->GetCurrentContext()).ToLocalChecked()).ToChecked();
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exports->Set(isolate->GetCurrentContext(), String::NewFromUtf8(isolate, "getParts", NewStringType::kNormal).ToLocalChecked(), FunctionTemplate::New(isolate, uWS_getParts)->GetFunction(isolate->GetCurrentContext()).ToLocalChecked()).ToChecked();
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