From cfb2d37eb6044d8b9019202be26f7d19f352e8bb Mon Sep 17 00:00:00 2001
From: Junghoon Park <jh9216.park@samsung.com>
Date: Thu, 28 Jun 2018 14:20:43 +0900
Subject: [PATCH] Sleep and retry to write

- If EAGAIN or EWOULDBLOCK happen, sleep some time and retry to write

Change-Id: I40e57426d6d961b0b583cfd06388b8f6afcf1295
Signed-off-by: Junghoon Park <jh9216.park@samsung.com>
---
 src/port-internal.cc | 24 +++++++++++++++++-------
 1 file changed, 17 insertions(+), 7 deletions(-)

diff --git a/src/port-internal.cc b/src/port-internal.cc
index 52e9128..4287675 100644
--- a/src/port-internal.cc
+++ b/src/port-internal.cc
@@ -35,8 +35,10 @@
 
 #define LOG_TAG "RPC_PORT"
 
-#define MAX_RETRY_CNT 18
+#define MAX_RETRY_CNT 100
 #define SEND_TIMEOUT 500
+#define MAX_SLEEP 100 * 1000 * 1000
+#define MIN_SLEEP 5 * 1000 * 1000
 
 namespace rpc_port {
 namespace internal {
@@ -61,7 +63,7 @@ int Port::Read(void* buf, unsigned int size) {
   unsigned int left = size;
   ssize_t nb;
   int retry_cnt = 0;
-  struct timespec TRY_SLEEP_TIME = { 0, 5 * 1000 * 1000 };
+  struct timespec TRY_SLEEP_TIME = { 0, MIN_SLEEP };
   int bytes_read = 0;
   char* buffer = static_cast<char*>(buf);
   std::lock_guard<std::recursive_mutex> lock(mutex_);
@@ -77,18 +79,20 @@ int Port::Read(void* buf, unsigned int size) {
         retry_cnt++;
         nanosleep(&TRY_SLEEP_TIME, 0);
         TRY_SLEEP_TIME.tv_nsec *= 2;
-        if (TRY_SLEEP_TIME.tv_nsec > 999999999)
-          TRY_SLEEP_TIME.tv_nsec = 999999999;
+        if (TRY_SLEEP_TIME.tv_nsec > MAX_SLEEP)
+          TRY_SLEEP_TIME.tv_nsec = MAX_SLEEP;
         continue;
       }
+
       LOGE("read_socket: ...error fd %d: errno %d\n", fd_, errno);
-    return RPC_PORT_ERROR_IO_ERROR;
+      return RPC_PORT_ERROR_IO_ERROR;
     }
 
     left -= nb;
     buffer += nb;
     bytes_read += nb;
     retry_cnt = 0;
+    TRY_SLEEP_TIME.tv_nsec = MIN_SLEEP;
   }
 
   if (left != 0) {
@@ -103,6 +107,7 @@ int Port::Write(const void* buf, unsigned int size) {
   unsigned int left = size;
   ssize_t nb;
   int retry_cnt = 0;
+  struct timespec TRY_SLEEP_TIME = { 0, MIN_SLEEP };
   struct pollfd fds[1];
   int ret;
   int bytes_write = 0;
@@ -122,9 +127,13 @@ int Port::Write(const void* buf, unsigned int size) {
   while (left && (retry_cnt < MAX_RETRY_CNT)) {
     nb = write(fd_, buffer, left);
     if (nb == -1) {
-      if (errno == EINTR) {
-        LOGE("write_socket: EINTR error continue ...");
+      if (errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK) {
+        LOGE("write_socket: %d errno, sleep and retry ...", errno);
         retry_cnt++;
+        nanosleep(&TRY_SLEEP_TIME, 0);
+        TRY_SLEEP_TIME.tv_nsec *= 2;
+        if (TRY_SLEEP_TIME.tv_nsec > MAX_SLEEP)
+          TRY_SLEEP_TIME.tv_nsec = MAX_SLEEP;
         continue;
       }
 
@@ -136,6 +145,7 @@ int Port::Write(const void* buf, unsigned int size) {
     buffer += nb;
     bytes_write += nb;
     retry_cnt = 0;
+    TRY_SLEEP_TIME.tv_nsec = MIN_SLEEP;
   }
 
   if (left != 0) {
-- 
2.7.4