Signal thread names in instrumented binaries, even when a debugger is not attached.

base/debug/profiler.cc

 // Copyright (c) 2012 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/debug/profiler.h"
 
 #include <string>
 
 #include "base/process_util.h"
 #include "base/string_util.h"
@@ skipping 70 matching lines @@
 ReturnAddressLocationResolver GetProfilerReturnAddrResolutionFunc() {
   return NULL;
 }
 
 #else  // defined(OS_WIN)
 
 // http://blogs.msdn.com/oldnewthing/archive/2004/10/25/247180.aspx
 extern "C" IMAGE_DOS_HEADER __ImageBase;
 
 bool IsBinaryInstrumented() {
-  HMODULE this_module = reinterpret_cast<HMODULE>(&__ImageBase);
-  base::win::PEImage image(this_module);
+  enum InstrumentationCheckState {
+    UNINITIALIZED,
+    INSTRUMENTED_IMAGE,
+    NON_INSTRUMENTED_IMAGE,
+  };
 
-  // This should be self-evident, soon as we're executing.
-  DCHECK(image.VerifyMagic());
+  static InstrumentationCheckState state = UNINITIALIZED;
 
-  // Syzygy-instrumented binaries contain a PE image section named ".thunks",
-  // and all Syzygy-modified binaries contain the ".syzygy" image section.
-  // This is a very fast check, as it only looks at the image header.
-  return (image.GetImageSectionHeaderByName(".thunks") != NULL) &&
-      (image.GetImageSectionHeaderByName(".syzygy") != NULL);
+  if (state == UNINITIALIZED) {
+    HMODULE this_module = reinterpret_cast<HMODULE>(&__ImageBase);
+    base::win::PEImage image(this_module);
+
+    // This should be self-evident, soon as we're executing.

[jar (doing other things), 2012/05/30 19:41:23]

nit: This was a strange comment.
Are you saying in the comment that: "This comment is not necessary."

If the comment is true, it should not be here ;-).

I wasn't familiar with VerifyMagic(), so IF you wanted to comment, it might be
something more like:
// Check to be sure or image is structured as we'd expect.

[Sigurður Ásgeirsson, 2012/05/30 20:52:12]

Done.

+    DCHECK(image.VerifyMagic());
+
+    // Syzygy-instrumented binaries contain a PE image section named ".thunks",
+    // and all Syzygy-modified binaries contain the ".syzygy" image section.
+    // This is a very fast check, as it only looks at the image header.
+    if ((image.GetImageSectionHeaderByName(".thunks") != NULL) &&
+        (image.GetImageSectionHeaderByName(".syzygy") != NULL)) {
+      state = INSTRUMENTED_IMAGE;
+    } else {
+      state = NON_INSTRUMENTED_IMAGE;
+    }
+  }
+  DCHECK(state != UNINITIALIZED);
+
+  return state == INSTRUMENTED_IMAGE;
 }
 
 // Callback function to PEImage::EnumImportChunks.
 static bool FindResolutionFunctionInImports(
     const base::win::PEImage &image, const char* module_name,
     PIMAGE_THUNK_DATA unused_name_table, PIMAGE_THUNK_DATA import_address_table,
     PVOID cookie) {
   // Our import address table contains pointers to the functions we import
   // at this point. Let's retrieve the first such function and use it to
   // find the module this import was resolved to by the loader.
@@ skipping 39 matching lines @@
   ReturnAddressLocationResolver resolver_func = NULL;
   image.EnumImportChunks(FindResolutionFunctionInImports, &resolver_func);
 
   return resolver_func;
 }
 
 #endif  // defined(OS_WIN)
 
 }  // namespace debug
 }  // namespace base