From 83d199acbac98152925d004292229fe40efaed8f Mon Sep 17 00:00:00 2001
From: Nodir Temirkhodjaev <nodir.temir@gmail.com>
Date: Tue, 21 Nov 2017 16:00:24 +0500
Subject: [PATCH] Driver: Micro-optimize pending buffer handling.

---
 src/driver/fortbuf.c |  7 +++++--
 src/driver/forttmr.c | 13 +++++++------
 2 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/src/driver/fortbuf.c b/src/driver/fortbuf.c
index f488e49f..fc41955c 100644
--- a/src/driver/fortbuf.c
+++ b/src/driver/fortbuf.c
@@ -54,12 +54,14 @@ fort_buffer_blocked_write (PFORT_BUFFER buf, UINT32 remote_ip, UINT32 pid,
   KeAcquireSpinLock(&buf->lock, &irq);
 
   /* Try to directly write to pending client */
-  if (buf->irp != NULL) {
+  if (buf->out_len) {
     const UINT32 out_top = buf->out_top;
     UINT32 new_top = out_top + len;
 
     /* Is it time to flush logs? */
     if (buf->out_len - new_top < FORT_LOG_BLOCKED_SIZE_MAX) {
+      buf->out_len = 0;
+
       *irp = buf->irp;
       buf->irp = NULL;
 
@@ -105,7 +107,7 @@ fort_buffer_xmove (PFORT_BUFFER buf, PIRP irp, PVOID out, ULONG out_len,
   *info = buf_top = buf->top;
 
   if (!buf_top) {
-    if (buf->irp != NULL) {
+    if (buf->out_len) {
       status = STATUS_INSUFFICIENT_RESOURCES;
     } else if (out_len < FORT_LOG_BLOCKED_SIZE_MAX) {
       status = STATUS_BUFFER_TOO_SMALL;
@@ -143,6 +145,7 @@ fort_buffer_cancel_pending (PFORT_BUFFER buf, PIRP irp, ULONG_PTR *info)
   KeAcquireSpinLock(&buf->lock, &irq);
   if (irp == buf->irp) {
     buf->irp = NULL;
+    buf->out_len = 0;
 
     if (buf->out_top) {
       *info = buf->out_top;
diff --git a/src/driver/forttmr.c b/src/driver/forttmr.c
index 6e68a76a..6d5282ea 100644
--- a/src/driver/forttmr.c
+++ b/src/driver/forttmr.c
@@ -12,23 +12,24 @@ static void
 fort_timer_callback (PKDPC dpc, PFORT_BUFFER buf, PVOID arg1, PVOID arg2)
 {
   PIRP irp = NULL;
-  ULONG info = 0;
+  ULONG info;
 
   UNUSED(dpc);
   UNUSED(arg1);
   UNUSED(arg2);
 
   KeAcquireSpinLockAtDpcLevel(&buf->lock);
-  if (buf->irp != NULL && buf->out_top) {
+  info = buf->out_top;
+  if (info) {
+    buf->out_top = 0;
+    buf->out_len = 0;
+
     irp = buf->irp;
     buf->irp = NULL;
-
-    info = buf->out_top;
-    buf->out_top = 0;
   }
   KeReleaseSpinLockFromDpcLevel(&buf->lock);
 
-  if (irp != NULL) {
+  if (info) {
     fort_request_complete_info(irp, STATUS_SUCCESS, info);
   }
 }