Format Of The Overview Of Allocated Memory

Collaboration diagram for Format Of The Overview Of Allocated Memory:

Classes
class	libcwd::alloc_filter_ct
	An allocated-memory filter class.An object of this type can be passed to list_allocations_on containing formatting information for the Overview Of Allocated Memory . It can also be passed as argument to the constructor of a marker_ct object in order to specify which allocations should not be capatured by the marker (and optionally made invisible). More...

Typedefs
typedef unsigned short int	libcwd::alloc_format_t
	The type used for the formatting flags of an alloc_filter_ct object.

Variables
alloc_format_t const	libcwd::show_path
	Show the full path of the locations where the allocation was made.
alloc_format_t const	libcwd::show_objectfile
	Show the name of the shared library that is responsible for the allocation.
alloc_format_t const	libcwd::show_function
	Show the mangled name of the function that allocated the memory.
alloc_format_t const	libcwd::show_time
	Show the time at which the allocation was made.
alloc_format_t const	libcwd::show_allthreads
	Show the allocations of all threads, not just the current thread.

Detailed Description

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Detailed Description

The format of the Overview Of Allocated Memory can be altered and/or the content can be filtered by passing an object of type libcwd::alloc_filter_ct to the function list_allocations_on. This object is constructed out of alloc_format_t constants which act as bits in a bit-mask.It is possible to include the time at which each allocation was made by passing the bit show_time. This will prepend "hours:minutes:seconds.microseconds" to the output:

04:07:16.712874 malloc    0x8078648          alloctag.cc:65   void*; (sz = 220)

It is also possible to show the full path of the location file by passing the bit show_path. This makes the output look like:

malloc    0x8078648 /home/carlo/c++/libcwd/testsuite/libcwd.tst/alloctag.cc:65   void*; (sz = 220)

It is also possible to show the name of the object file (shared library or executable name) to which the allocation belongs by using the bit show_objectfile. The name of the corresponding object file is prepended to the location:

malloc    0x8078648 tst_alloctag_shared:         alloctag.cc:65   void*; (sz = 220)

Finally, it is possible to show the mangled function name where the allocation was done by using the bit show_function. The mangled name of the corresponding function is prepended to the location:

new[]     0x8199158 _Z7new1000j           module.cc:47   char[1000]; (sz = 1000)

The flags can be combined with the bit-wise OR operator.Example:

#ifdef CWDEBUG
libcwd::alloc_filter_ct filter(libcwd::show_time | libcwd::show_path);
#endif

Debug( list_allocations_on(libcw_do, filter) );

FilteringThere are four criteria on which can be filtered: the time at which an allocation was made, the shared library that an allocation belongs too, the name of the source file from which an allocation was made and whether or not an AllocTag was used for the allocation.It is possible to give a time interval of the allocations that should be shown. For each of the limits (start and end) one can use the constant struct timeval libcwd::alloc_filter_ct::no_time_limit to indicate that there is no limit required.It is also possible to specify a list of wildcard masks (of the kind where a '*' matches anything) that will be matched against the names of the shared libraries, hiding the allocations that belong to the libraries whose name match.It is also possible to specify a list of wildcard masks (of the kind where a '*' matches anything) that will be matched against the names of the source file from which the allocation was done, only showing the allocations that whose name match.Finally, it is also possible to hide all allocations except when one of the AllocTag macros was used. Please note that using this option makes it hard to see whether or not your application has any memory leaks in the case the leak has no AllocTag added.Examples:In order to show all allocations that were done one hour or more ago, one could do:

#ifdef CWDEBUG
libcwd::alloc_filter_ct filter(libcwd::show_time);
struct timeval end;
gettimeofday(&end, 0);
end.tv_sec -= 3600;
filter.set_time_interval(libcwd::alloc_filter_ct::no_time_limit, end);
#endif

Debug( list_allocations_on(libcw_do, filter) );

In order to hide all allocations that belong to any shared library (only leaving the allocations that belong to the executable), one could do:

#ifdef CWDEBUG
libcwd::alloc_filter_ct filter(libcwd::show_objectfile);
std::vector<std::string> masks;
masks.push_back("lib*");
filter.hide_objectfiles_matching(masks);
#endif

Debug( list_allocations_on(libcw_do, filter) );

In order to hide allocations done from a specific function in a specific shared library, one could do:

#ifdef CWDEBUG
libcwd::alloc_filter_ct filter(libcwd::show_objectfile|libcwd::show_function);
std::vector<std::pair<std::string, std::string> > hide_list;
hide_list.push_back(std::pair<std::string, std::string>("libdl.so.2", "_dlerror_run"));
hide_list.push_back(std::pair<std::string, std::string>("libstdc++.so.6", "__cxa_get_globals"));
filter.hide_functions_matching(hide_list);
#endif

Debug( list_allocations_on(libcw_do, filter) );

Note that also here it is allowed to use masks, for both the object file as well as the mangled function name.In order to hide all allocations that are done from inside the header files of installed libraries (like the STL), one could do:

#ifdef CWDEBUG
libcwd::alloc_filter_ct filter(libcwd::show_path);
std::vector<std::string> masks;
masks.push_back("/usr/include/*.h");
filter.hide_sourcefiles_matching(masks);
#endif

Debug( list_allocations_on(libcw_do, filter) );

In order to hide everything except those allocations that one explicitely added an AllocTag for, one could do:

#ifdef CWDEBUG
libcwd::alloc_filter_ct filter;
filter.hide_untagged_allocations();
#endif

Debug( list_allocations_on(libcw_do, filter) );