code review 12413043: net: reduce number of memory allocations during IO oper...

src/pkg/runtime/netpoll_windows.c

 // Copyright 2013 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
 #include "runtime.h"
 #include "defs_GOOS_GOARCH.h"
 #include "os_GOOS.h"
 
 #define DWORD_MAX 0xffffffff
 
 #pragma dynimport runtime·CreateIoCompletionPort CreateIoCompletionPort "kernel32.dll"
 #pragma dynimport runtime·GetQueuedCompletionStatus GetQueuedCompletionStatus "kernel32.dll"
 
 extern void *runtime·CreateIoCompletionPort;
 extern void *runtime·GetQueuedCompletionStatus;
 
 #define INVALID_HANDLE_VALUE ((uintptr)-1)
 
-// net_anOp must be the same as beginning of net.anOp. Keep these in sync.
-typedef struct net_anOp net_anOp;
-struct net_anOp
+// net_op must be the same as beginning of net.operation. Keep these in sync.
+typedef struct net_op net_op;
+struct net_op
 {
         // used by windows
         Overlapped      o;
         // used by netpoll
         uintptr runtimeCtx;
         int32   mode;
         int32   errno;
         uint32  qty;
 };
 
@@ skipping 27 matching lines @@
         return 0;
 }
 
 // Polls for completed network IO.
 // Returns list of goroutines that become runnable.
 G*
 runtime·netpoll(bool block)
 {
         uint32 wait, qty, key;
         int32 mode, errno;
-        net_anOp *o;
+        net_op *o;
         G *gp;
 
         if(iocphandle == INVALID_HANDLE_VALUE)
                 return nil;
         gp = nil;
 retry:
         o = nil;
         errno = 0;
         qty = 0;
         wait = INFINITE;
@@ skipping 23 matching lines @@
                 runtime·printf("netpoll: GetQueuedCompletionStatus returned invalid mode=%d\n", mode);
                 runtime·throw("netpoll: GetQueuedCompletionStatus returned invalid mode");
         }
         o->errno = errno;
         o->qty = qty;
         runtime·netpollready(&gp, (void*)o->runtimeCtx, mode);
         if(block && gp == nil)
                 goto retry;
         return gp;
 }