Don't hang during DiskCacheEntryTest.CancelSparseIO on infinitely fast disks....

net/disk_cache/entry_unittest.cc

 // Copyright (c) 2006-2009 The Chromium 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 "base/basictypes.h"
 #include "base/platform_thread.h"
 #include "base/timer.h"
 #include "base/string_util.h"
 #include "net/base/io_buffer.h"
 #include "net/base/net_errors.h"
@@ skipping 1338 matching lines @@
   std::string key("the first key");
   disk_cache::Entry* entry;
   ASSERT_TRUE(cache_->CreateEntry(key, &entry));
 
   const int kSize = 40 * 1024;
   scoped_refptr<net::IOBuffer> buf = new net::IOBuffer(kSize);
   CacheTestFillBuffer(buf->data(), kSize, false);
 
   SimpleCallbackTest cb1, cb2, cb3, cb4;
   int64 offset = 0;
-  for (int ret = 0; ret != net::ERR_IO_PENDING; offset += kSize * 4)
+  int tries = 0;
+  const int maxtries = 1000;  // Avoid hang on infinitely fast disks

[rvargas (doing something else), 2009/10/27 23:04:58]

Are you sure you want to have a number that high? If this loop doesn't take more
than 10 secs I'm fine with it.

+  for (int ret = 0; ret != net::ERR_IO_PENDING; offset += kSize * 4) {
     ret = entry->WriteSparseData(offset, buf, kSize, &cb1);
+    if (++tries > maxtries) {
+       LOG(ERROR) << "Data writes never come back PENDING; skipping test";
+       entry->Close();
+       return;
+    }
+  }
 
   // Cannot use the entry at this point.
   offset = 0;
   EXPECT_EQ(net::ERR_CACHE_OPERATION_NOT_SUPPORTED,
             entry->GetAvailableRange(offset, kSize, &offset));
   EXPECT_EQ(net::OK, entry->ReadyForSparseIO(&cb2));
 
   // We cancel the pending operation, and register multiple notifications.
   entry->CancelSparseIO();
   EXPECT_EQ(net::ERR_IO_PENDING, entry->ReadyForSparseIO(&cb2));
@@ skipping 12 matching lines @@
   // Now see if we receive all notifications.
   EXPECT_EQ(kSize, cb1.GetResult(net::ERR_IO_PENDING));
   EXPECT_EQ(net::OK, cb2.GetResult(net::ERR_IO_PENDING));
   EXPECT_EQ(net::OK, cb3.GetResult(net::ERR_IO_PENDING));
   EXPECT_EQ(net::OK, cb4.GetResult(net::ERR_IO_PENDING));
 
   EXPECT_EQ(kSize, entry->GetAvailableRange(offset, kSize, &offset));
   EXPECT_EQ(net::OK, entry->ReadyForSparseIO(&cb2));
   entry->Close();
 }