From 33b782a96d0fb1c82985c8bd5192f7a144b8877d Mon Sep 17 00:00:00 2001
From: Jack Christensen <jack@jackchristensen.com>
Date: Thu, 11 Aug 2022 20:55:50 -0500
Subject: [PATCH] Potential fix for Windows

https://github.com/jackc/pgx/issues/1274
---
 internal/nbconn/nbconn.go                | 60 --------------------
 internal/nbconn/nbconn_fake_non_block.go | 13 +++++
 internal/nbconn/nbconn_real_non_block.go | 70 ++++++++++++++++++++++++
 3 files changed, 83 insertions(+), 60 deletions(-)
 create mode 100644 internal/nbconn/nbconn_fake_non_block.go
 create mode 100644 internal/nbconn/nbconn_real_non_block.go

diff --git a/internal/nbconn/nbconn.go b/internal/nbconn/nbconn.go
index 16c4b713..c091ea3f 100644
--- a/internal/nbconn/nbconn.go
+++ b/internal/nbconn/nbconn.go
@@ -13,7 +13,6 @@ package nbconn
 import (
 	"crypto/tls"
 	"errors"
-	"io"
 	"net"
 	"os"
 	"sync"
@@ -389,35 +388,6 @@ func (c *NetConn) fakeNonblockingWrite(b []byte) (n int, err error) {
 	return c.conn.Write(b)
 }
 
-// realNonblockingWrite does a non-blocking write. readFlushLock must already be held.
-func (c *NetConn) realNonblockingWrite(b []byte) (n int, err error) {
-	c.nonblockWriteBuf = b
-	c.nonblockWriteN = 0
-	c.nonblockWriteErr = nil
-	err = c.rawConn.Write(func(fd uintptr) (done bool) {
-		c.nonblockWriteN, c.nonblockWriteErr = syscall.Write(int(fd), c.nonblockWriteBuf)
-		return true
-	})
-	n = c.nonblockWriteN
-	if err == nil && c.nonblockWriteErr != nil {
-		if errors.Is(c.nonblockWriteErr, syscall.EWOULDBLOCK) {
-			err = ErrWouldBlock
-		} else {
-			err = c.nonblockWriteErr
-		}
-	}
-	if err != nil {
-		// n may be -1 when an error occurs.
-		if n < 0 {
-			n = 0
-		}
-
-		return n, err
-	}
-
-	return n, nil
-}
-
 func (c *NetConn) nonblockingRead(b []byte) (n int, err error) {
 	if c.rawConn == nil {
 		return c.fakeNonblockingRead(b)
@@ -451,36 +421,6 @@ func (c *NetConn) fakeNonblockingRead(b []byte) (n int, err error) {
 	return c.conn.Read(b)
 }
 
-func (c *NetConn) realNonblockingRead(b []byte) (n int, err error) {
-	var funcErr error
-	err = c.rawConn.Read(func(fd uintptr) (done bool) {
-		n, funcErr = syscall.Read(int(fd), b)
-		return true
-	})
-	if err == nil && funcErr != nil {
-		if errors.Is(funcErr, syscall.EWOULDBLOCK) {
-			err = ErrWouldBlock
-		} else {
-			err = funcErr
-		}
-	}
-	if err != nil {
-		// n may be -1 when an error occurs.
-		if n < 0 {
-			n = 0
-		}
-
-		return n, err
-	}
-
-	// syscall read did not return an error and 0 bytes were read means EOF.
-	if n == 0 {
-		return 0, io.EOF
-	}
-
-	return n, nil
-}
-
 // syscall.Conn is interface
 
 // TLSClient establishes a TLS connection as a client over conn using config.
diff --git a/internal/nbconn/nbconn_fake_non_block.go b/internal/nbconn/nbconn_fake_non_block.go
new file mode 100644
index 00000000..7e8b7634
--- /dev/null
+++ b/internal/nbconn/nbconn_fake_non_block.go
@@ -0,0 +1,13 @@
+//go:build !(aix || android || darwin || dragonfly || freebsd || hurd || illumos || ios || linux || netbsd || openbsd || solaris)
+
+package nbconn
+
+// Not using unix build tag for support on Go 1.18.
+
+func (c *NetConn) realNonblockingWrite(b []byte) (n int, err error) {
+	return fakeNonblockingWrite(b)
+}
+
+func (c *NetConn) realNonblockingRead(b []byte) (n int, err error) {
+	return c.fakeNonblockingRead(b)
+}
diff --git a/internal/nbconn/nbconn_real_non_block.go b/internal/nbconn/nbconn_real_non_block.go
new file mode 100644
index 00000000..ee48d129
--- /dev/null
+++ b/internal/nbconn/nbconn_real_non_block.go
@@ -0,0 +1,70 @@
+//go:build aix || android || darwin || dragonfly || freebsd || hurd || illumos || ios || linux || netbsd || openbsd || solaris
+
+package nbconn
+
+// Not using unix build tag for support on Go 1.18.
+
+import (
+	"errors"
+	"io"
+	"syscall"
+)
+
+// realNonblockingWrite does a non-blocking write. readFlushLock must already be held.
+func (c *NetConn) realNonblockingWrite(b []byte) (n int, err error) {
+	c.nonblockWriteBuf = b
+	c.nonblockWriteN = 0
+	c.nonblockWriteErr = nil
+	err = c.rawConn.Write(func(fd uintptr) (done bool) {
+		c.nonblockWriteN, c.nonblockWriteErr = syscall.Write(int(fd), c.nonblockWriteBuf)
+		return true
+	})
+	n = c.nonblockWriteN
+	if err == nil && c.nonblockWriteErr != nil {
+		if errors.Is(c.nonblockWriteErr, syscall.EWOULDBLOCK) {
+			err = ErrWouldBlock
+		} else {
+			err = c.nonblockWriteErr
+		}
+	}
+	if err != nil {
+		// n may be -1 when an error occurs.
+		if n < 0 {
+			n = 0
+		}
+
+		return n, err
+	}
+
+	return n, nil
+}
+
+func (c *NetConn) realNonblockingRead(b []byte) (n int, err error) {
+	var funcErr error
+	err = c.rawConn.Read(func(fd uintptr) (done bool) {
+		n, funcErr = syscall.Read(int(fd), b)
+		return true
+	})
+	if err == nil && funcErr != nil {
+		if errors.Is(funcErr, syscall.EWOULDBLOCK) {
+			err = ErrWouldBlock
+		} else {
+			err = funcErr
+		}
+	}
+	if err != nil {
+		// n may be -1 when an error occurs.
+		if n < 0 {
+			n = 0
+		}
+
+		return n, err
+	}
+
+	// syscall read did not return an error and 0 bytes were read means EOF.
+	if n == 0 {
+		return 0, io.EOF
+	}
+
+	return n, nil
+}