From b7d65ee96221e63c865b1bf8cda79b3021cba412 Mon Sep 17 00:00:00 2001
From: Determinant <ted.sybil@gmail.com>
Date: Fri, 5 Oct 2018 10:20:11 -0400
Subject: add burst_size; consumer can proceed to its normal event loop

---
 include/salticidae/event.h | 36 ++++++++++++++++++++++++++----------
 1 file changed, 26 insertions(+), 10 deletions(-)

diff --git a/include/salticidae/event.h b/include/salticidae/event.h
index 99fff2f..857518b 100644
--- a/include/salticidae/event.h
+++ b/include/salticidae/event.h
@@ -28,9 +28,7 @@
 #include <unistd.h>
 #include <event2/event.h>
 #include <sys/eventfd.h>
-#ifdef SALTICIDAE_DEBUG_LOG
-#include <thread>
-#endif
+//#include <thread>
 
 #include "salticidae/queue.h"
 #include "salticidae/util.h"
@@ -126,24 +124,34 @@ class Event {
 template<typename T>
 class MPSCQueueEventDriven: public MPMCQueue<T> {
     private:
+    const uint64_t dummy = 1;
     std::atomic<bool> wait_sig;
     int fd;
     Event ev;
 
     public:
     template<typename Func>
-    MPSCQueueEventDriven(const EventContext &ec, Func &&func, size_t capacity = 65536):
+    MPSCQueueEventDriven(const EventContext &ec, Func &&func,
+                        size_t burst_size = 128, size_t capacity = 65536):
         MPMCQueue<T>(capacity),
         wait_sig(true),
         fd(eventfd(0, EFD_NONBLOCK)),
         ev(Event(ec, fd, EV_READ | EV_PERSIST,
-            [this, func=std::forward<Func>(func)](int, short) {
+            [this, func=std::forward<Func>(func), burst_size](int, short) {
             uint64_t t;
             read(fd, &t, 8);
-            SALTICIDAE_LOG_DEBUG("%x\n", std::this_thread::get_id());
+            //fprintf(stderr, "%x\n", std::this_thread::get_id());
             T elem;
+            size_t cnt = burst_size;
             while (MPMCQueue<T>::try_dequeue(elem))
+            {
                 func(std::move(elem));
+                if (!--cnt)
+                {
+                    write(fd, &dummy, 8);
+                    return;
+                }
+            }
             wait_sig.store(true, std::memory_order_relaxed);
         })) { ev.add(); }
 
@@ -165,6 +173,7 @@ class MPSCQueueEventDriven: public MPMCQueue<T> {
 template<typename T>
 class MPMCQueueEventDriven: public MPMCQueue<T> {
     private:
+    const uint64_t dummy = 1;
     std::atomic<bool> wait_sig;
     std::vector<std::pair<BoxObj<Event>, int>> evs;
 
@@ -174,16 +183,24 @@ class MPMCQueueEventDriven: public MPMCQueue<T> {
         wait_sig(true) {}
 
     template<typename Func>
-    void listen(const EventContext &ec, Func &&func) {
+    void listen(const EventContext &ec, Func &&func, size_t burst_size=128) {
         int fd = eventfd(0, EFD_NONBLOCK);
         evs.emplace(evs.end(), std::make_pair(new Event(ec, fd, EV_READ | EV_PERSIST,
-            [this, func=std::forward<Func>(func)](int fd, short) {
+            [this, func=std::forward<Func>(func), burst_size](int fd, short) {
             uint64_t t;
             read(fd, &t, 8);
-            SALTICIDAE_LOG_DEBUG("%x\n", std::this_thread::get_id());
+            //fprintf(stderr, "%x\n", std::this_thread::get_id());
             T elem;
+            size_t cnt = burst_size;
             while (MPMCQueue<T>::try_dequeue(elem))
+            {
                 func(std::move(elem));
+                if (!--cnt)
+                {
+                    write(fd, &dummy, 8);
+                    return;
+                }
+            }
             wait_sig.store(true, std::memory_order_relaxed);
         }), fd));
         evs.rbegin()->first->add();
@@ -196,7 +213,6 @@ class MPMCQueueEventDriven: public MPMCQueue<T> {
 
     template<typename U>
     bool enqueue(U &&e) {
-        static const uint64_t dummy = 1;
         bool ret = MPMCQueue<T>::enqueue(std::forward<U>(e));
         if (wait_sig.exchange(false, std::memory_order_relaxed))
         {
-- 
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