Add trace code to track all posted tasks in message_loop.

base/tracked.h

Index: base/tracked.h
diff --git a/base/tracked.h b/base/tracked.h
index 3c73519c6c650d051423918a59892763bcdf7fba..9b99b3e8485628e8f596db6ec545d2a558949a17 100644
--- a/base/tracked.h
+++ b/base/tracked.h
@@ -22,6 +22,8 @@
 #include <string>
 
 #include "base/base_export.h"
+#include "base/string_piece.h"
+#include "base/stringize_macros.h"
 #include "base/time.h"
 
 #ifndef NDEBUG
@@ -38,15 +40,15 @@ namespace tracked_objects {
 
 class BASE_EXPORT Location {
  public:
-  // Constructor should be called with a long-lived char*, such as __FILE__.
-  // It assumes the provided value will persist as a global constant, and it
-  // will not make a copy of it.
-  Location(const char* function_name,
-           const char* file_name,
-           int line_number,
+  // Constructor should be called with a long-lived char*. It assumes the
+  // provided value will persist as a global constant, and it will not make a
+  // copy of it.
+  // |file_line| is formatted as "FILE:LINE".
+  Location(const char* file_line,
+           const char* function_name,
            const void* program_counter);
 
-  // Provide a default constructor for easy of debugging.
+  // Default constructor initializes to "Unknown:-1", "Unknown", NULL.
   Location();
 
   // Comparison operator for insertion into a std::map<> hash tables.
@@ -56,16 +58,16 @@ class BASE_EXPORT Location {
   // a difference), and then pointers as secondary keys (just to get some
   // distinctions).
   bool operator < (const Location& other) const {
-    if (line_number_ != other.line_number_)
-      return line_number_ < other.line_number_;
-    if (file_name_ != other.file_name_)
-      return file_name_ < other.file_name_;
+    if (file_line_ != other.file_line_)
+      return file_line_ < other.file_line_;
     return function_name_ < other.function_name_;
   }
 
-  const char* function_name()   const { return function_name_; }
-  const char* file_name()       const { return file_name_; }
-  int line_number()             const { return line_number_; }
+  // Get long-lived file_line string "FILE:LINE".
+  const char* file_line() const { return file_line_; }
+  const base::StringPiece file_name() const;
+  int line_number() const;
+  const base::StringPiece function_name() const;
   const void* program_counter() const { return program_counter_; }
 
   void Write(bool display_filename, bool display_function_name,
@@ -75,10 +77,9 @@ class BASE_EXPORT Location {
   void WriteFunctionName(std::string* output) const;
 
  private:
-  const char* const function_name_;
-  const char* const file_name_;
-  const int line_number_;
-  const void* const program_counter_;
+  const char* file_line_;
+  const char* function_name_;
+  const void* program_counter_;
 };
 
 BASE_EXPORT const void* GetProgramCounter();
@@ -86,11 +87,9 @@ BASE_EXPORT const void* GetProgramCounter();
 //------------------------------------------------------------------------------
 // Define a macro to record the current source location.
 
-#define FROM_HERE tracked_objects::Location(                                   \
-    __FUNCTION__,                                                              \
-    __FILE__,                                                                  \
-    __LINE__,                                                                  \
-    tracked_objects::GetProgramCounter())                                      \
+#define FROM_HERE tracked_objects::Location( \
+    __FILE__ ":" STRINGIZE(__LINE__), __FUNCTION__, \

[joth, 2011/09/15 10:38:09]

random musing:
if we passed in (sizeof(__FILE__) + sizeof( STRINGIZE(__LINE__) - 1) as an
additional param here, we'll get it as a compile time constant, and then we
could store file_line_ as a string piece with a compile-time generated length,
meaning we never need to run it searching for the null-term in the file_name()
and line_number() methods. 
which in turn brings them nearer to the hacker_style() requirement of being mere
getters; at the moment they feel rather like they should be FileName() style
methods.

[jar (doing other things), 2011/09/15 16:26:39]

I think that sizeof(__FILE__) == sizeof(char*)

I don't think you get what you're hoping for.  You may perchance be thinking
about:

static array[] = __FILE__;
then sizeof(array) == strlen(array) I think.

On 2011/09/15 10:38:09, joth wrote:

[jbates, 2011/09/15 16:48:33]

I think it's best to just change to FileName style - there are no performance
critical usecases for file_name.

+    tracked_objects::GetProgramCounter())
 
 
 //------------------------------------------------------------------------------