From c1ae024da5b72abab95bd211ca2cfbded43a5a5f Mon Sep 17 00:00:00 2001
From: YuQing <384681@qq.com>
Date: Sun, 12 Feb 2023 10:38:46 +0800
Subject: [PATCH] enable epoll edge trigger by global variable
 epoll_edge_trigger

---
 src/sf_global.h  |  3 +++
 src/sf_nio.c     | 59 ++++++++++++++++++++++++++++++++++++++++--------
 src/sf_service.c | 17 ++++++++++++--
 3 files changed, 68 insertions(+), 11 deletions(-)

diff --git a/src/sf_global.h b/src/sf_global.h
index f017404..e6cb1e4 100644
--- a/src/sf_global.h
+++ b/src/sf_global.h
@@ -40,6 +40,7 @@ typedef struct sf_global_variables {
 
     volatile bool continue_flag;
     bool tcp_quick_ack;
+    bool epoll_edge_trigger;
     int max_connections;
     int max_pkg_size;
     int min_buff_size;
@@ -98,6 +99,8 @@ extern SFContext                 g_sf_context;
 #define SF_G_ERROR_HANDLER       g_sf_global_vars.error_handler
 #define SF_G_EMPTY_STRING        g_sf_global_vars.empty
 
+#define SF_G_EPOLL_EDGE_TRIGGER  g_sf_global_vars.epoll_edge_trigger
+
 #define SF_WORK_THREADS(sf_context)        sf_context.work_threads
 #define SF_ALIVE_THREAD_COUNT(sf_context)  sf_context.thread_count
 #define SF_THREAD_INDEX(sf_context, tdata) (int)(tdata - sf_context.thread_data)
diff --git a/src/sf_nio.c b/src/sf_nio.c
index 0883802..659d4c7 100644
--- a/src/sf_nio.c
+++ b/src/sf_nio.c
@@ -37,6 +37,7 @@
 #include "fastcommon/sockopt.h"
 #include "fastcommon/fast_task_queue.h"
 #include "fastcommon/ioevent_loop.h"
+#include "fastcommon/fc_atomic.h"
 #include "sf_global.h"
 #include "sf_service.h"
 #include "sf_nio.h"
@@ -143,7 +144,7 @@ static inline int set_write_event(struct fast_task_info *task)
     return 0;
 }
 
-int sf_set_read_event(struct fast_task_info *task)
+static int setup_read_event(struct fast_task_info *task)
 {
     int result;
 
@@ -169,6 +170,27 @@ int sf_set_read_event(struct fast_task_info *task)
     return 0;
 }
 
+int sf_set_read_event(struct fast_task_info *task)
+{
+    int result;
+
+    if ((result=setup_read_event(task)) != 0) {
+        return result;
+    }
+
+    if (SF_G_EPOLL_EDGE_TRIGGER) {
+        if (FC_ATOMIC_GET(task->nio_stages.notify) == SF_NIO_STAGE_SEND) {
+            __sync_bool_compare_and_swap(&task->nio_stages.next,
+                    SF_NIO_STAGE_NONE, SF_NIO_STAGE_RECV);
+            return 0;
+        } else {
+            return sf_nio_notify(task, SF_NIO_STAGE_RECV);
+        }
+    } else {
+        return 0;
+    }
+}
+
 static inline int sf_ioevent_add(struct fast_task_info *task,
         IOEventCallback callback, const int timeout)
 {
@@ -276,8 +298,7 @@ static int sf_nio_deal_task(struct fast_task_info *task, const int stage)
             result = sf_connect_server(task);
             break;
         case SF_NIO_STAGE_RECV:
-            if ((result=sf_set_read_event(task)) == 0)
-            {
+            if ((result=setup_read_event(task)) == 0) {
                 sf_client_sock_read(task->event.fd,
                         IOEVENT_READ, task);
             }
@@ -321,7 +342,7 @@ int sf_nio_notify(struct fast_task_info *task, const int stage)
     int old_stage;
     bool notify;
 
-    if (__sync_add_and_fetch(&task->canceled, 0)) {
+    if (FC_ATOMIC_GET(task->canceled)) {
         if (stage == SF_NIO_STAGE_CONTINUE) {
             if (task->continue_callback != NULL) {
                 return task->continue_callback(task);
@@ -342,12 +363,22 @@ int sf_nio_notify(struct fast_task_info *task, const int stage)
     while (!__sync_bool_compare_and_swap(&task->nio_stages.notify,
                 SF_NIO_STAGE_NONE, stage))
     {
-        old_stage = __sync_fetch_and_add(&task->nio_stages.notify, 0);
+        old_stage = FC_ATOMIC_GET(task->nio_stages.notify);
         if (old_stage == stage) {
             logDebug("file: "__FILE__", line: %d, "
                     "current stage: %d equals to the target, skip set",
                     __LINE__, stage);
             return 0;
+
+        } else if (SF_G_EPOLL_EDGE_TRIGGER && (
+                    (old_stage == SF_NIO_STAGE_RECV &&
+                     stage == SF_NIO_STAGE_SEND) ||
+                    (old_stage == SF_NIO_STAGE_SEND &&
+                     stage == SF_NIO_STAGE_RECV)))
+        {
+            __sync_bool_compare_and_swap(&task->nio_stages.
+                    next, SF_NIO_STAGE_NONE, stage);
+            return 0;
         } else if (old_stage != SF_NIO_STAGE_NONE) {
             logWarning("file: "__FILE__", line: %d, "
                     "current stage: %d != %d, skip set stage to %d",
@@ -390,6 +421,7 @@ void sf_recv_notify_read(int sock, short event, void *arg)
 {
     int64_t n;
     int stage;
+    int next;
     struct nio_thread_data *thread_data;
     struct fast_task_info *task;
     struct fast_task_info *current;
@@ -410,7 +442,7 @@ void sf_recv_notify_read(int sock, short event, void *arg)
         task = current;
         current = current->next;
 
-        stage = __sync_add_and_fetch(&task->nio_stages.notify, 0);
+        stage = FC_ATOMIC_GET(task->nio_stages.notify);
         if (!task->canceled) {
             if (stage == SF_NIO_STAGE_CONTINUE) {
                 /* MUST set to SF_NIO_STAGE_NONE first for re-entry */
@@ -422,6 +454,15 @@ void sf_recv_notify_read(int sock, short event, void *arg)
                 __sync_bool_compare_and_swap(&task->nio_stages.notify,
                         stage, SF_NIO_STAGE_NONE);
             }
+
+            if (SF_G_EPOLL_EDGE_TRIGGER) {
+                next = FC_ATOMIC_GET(task->nio_stages.next);
+                if (next != SF_NIO_STAGE_NONE) {
+                    sf_nio_notify(task, next);
+                    __sync_bool_compare_and_swap(&task->nio_stages.next,
+                            next, SF_NIO_STAGE_NONE);
+                }
+            }
         } else {
             if (stage != SF_NIO_STAGE_NONE) {
                 if (stage == SF_NIO_STAGE_CONTINUE) {
@@ -749,9 +790,9 @@ int sf_client_sock_write(int sock, short event, void *arg)
             }
         } else if (bytes == 0) {
             logWarning("file: "__FILE__", line: %d, "
-                "client ip: %s, sock: %d, send failed, "
-                "connection disconnected",
-                __LINE__, task->client_ip, sock);
+                "client ip: %s, sock: %d, task length: %d, offset: %d, "
+                "send failed, connection disconnected", __LINE__,
+                task->client_ip, sock, task->length, task->offset);
 
             ioevent_add_to_deleted_list(task);
             return -1;
diff --git a/src/sf_service.c b/src/sf_service.c
index 819b817..d74ebf6 100644
--- a/src/sf_service.c
+++ b/src/sf_service.c
@@ -131,6 +131,7 @@ int sf_service_init_ex2(SFContext *sf_context, const char *name,
 {
     int result;
     int bytes;
+    int extra_events;
     struct worker_thread_context *thread_contexts;
     struct worker_thread_context *thread_ctx;
     struct nio_thread_data *thread_data;
@@ -172,6 +173,18 @@ int sf_service_init_ex2(SFContext *sf_context, const char *name,
         return ENOMEM;
     }
 
+    if (SF_G_EPOLL_EDGE_TRIGGER) {
+#ifdef OS_LINUX
+        extra_events = EPOLLET;
+#elif defined(OS_FREEBSD)
+        extra_events = EV_CLEAR;
+#else
+        extra_events = 0;
+#endif
+    } else {
+        extra_events = 0;
+    }
+
     g_current_time = time(NULL);
     sf_context->thread_count = 0;
     data_end = sf_context->thread_data + sf_context->work_threads;
@@ -187,8 +200,8 @@ int sf_service_init_ex2(SFContext *sf_context, const char *name,
             thread_data->arg = NULL;
         }
 
-        if (ioevent_init(&thread_data->ev_puller,
-            g_sf_global_vars.max_connections + 2, net_timeout_ms, 0) != 0)
+        if (ioevent_init(&thread_data->ev_puller, 2 + g_sf_global_vars.
+                    max_connections, net_timeout_ms, extra_events) != 0)
         {
             result  = errno != 0 ? errno : ENOMEM;
             logError("file: "__FILE__", line: %d, "