From c42a4ca372b8476c78c026cab856694830735490 Mon Sep 17 00:00:00 2001
From: Jameson Nash <vtjnash@gmail.com>
Date: Thu, 16 Jul 2015 01:54:28 -0400
Subject: [PATCH] win,pipe: race condition canceling readfile thread
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Fixes a race condition where if uv_read_stop was called shortly
after uv_read_start or a successful read and before the
uv_pipe_zero_readfile_thread_proc thread started,
that thread would call the blocking ReadFile call after the
HANDLE_READING flag had already been cleared.

Also ignores EINTR to be more consistent with unix
(although we generally don't expect to see this condition on windows).

PR-URL: https://github.com/libuv/libuv/pull/1322
Reviewed-By: Saúl Ibarra Corretgé <saghul@gmail.com>
Reviewed-By: Bartosz Sosnowski <bartosz@janeasystems.com>
---
 src/win/pipe.c | 47 +++++++++++++++++++++++++++--------------------
 1 file changed, 27 insertions(+), 20 deletions(-)

diff --git a/src/win/pipe.c b/src/win/pipe.c
index edf30021..9b10cc9f 100644
--- a/src/win/pipe.c
+++ b/src/win/pipe.c
@@ -968,27 +968,31 @@ static DWORD WINAPI uv_pipe_zero_readfile_thread_proc(void* parameter) {
     uv_mutex_unlock(m);
   }
 restart_readfile:
-  result = ReadFile(handle->handle,
-                    &uv_zero_,
-                    0,
-                    &bytes,
-                    NULL);
-  if (!result) {
-    err = GetLastError();
-    if (err == ERROR_OPERATION_ABORTED &&
-        handle->flags & UV_HANDLE_PIPE_READ_CANCELABLE) {
-      if (handle->flags & UV_HANDLE_READING) {
-        /* just a brief break to do something else */
-        handle->pipe.conn.readfile_thread = NULL;
-        /* resume after it is finished */
-        uv_mutex_lock(m);
-        handle->pipe.conn.readfile_thread = hThread;
-        uv_mutex_unlock(m);
-        goto restart_readfile;
-      } else {
-        result = 1; /* successfully stopped reading */
+  if (handle->flags & UV_HANDLE_READING) {
+    result = ReadFile(handle->handle,
+                      &uv_zero_,
+                      0,
+                      &bytes,
+                      NULL);
+    if (!result) {
+      err = GetLastError();
+      if (err == ERROR_OPERATION_ABORTED &&
+          handle->flags & UV_HANDLE_PIPE_READ_CANCELABLE) {
+        if (handle->flags & UV_HANDLE_READING) {
+          /* just a brief break to do something else */
+          handle->pipe.conn.readfile_thread = NULL;
+          /* resume after it is finished */
+          uv_mutex_lock(m);
+          handle->pipe.conn.readfile_thread = hThread;
+          uv_mutex_unlock(m);
+          goto restart_readfile;
+        } else {
+          result = 1; /* successfully stopped reading */
+        }
       }
     }
+  } else {
+    result = 1; /* successfully aborted read before it even started */
   }
   if (hThread) {
     assert(hThread == handle->pipe.conn.readfile_thread);
@@ -1515,7 +1519,10 @@ static void uv_pipe_read_error(uv_loop_t* loop, uv_pipe_t* handle, int error,
 
 static void uv_pipe_read_error_or_eof(uv_loop_t* loop, uv_pipe_t* handle,
     int error, uv_buf_t buf) {
-  if (error == ERROR_BROKEN_PIPE) {
+  if (error == ERROR_OPERATION_ABORTED) {
+    /* do nothing (equivalent to EINTR) */
+  }
+  else if (error == ERROR_BROKEN_PIPE) {
     uv_pipe_read_eof(loop, handle, buf);
   } else {
     uv_pipe_read_error(loop, handle, error, buf);