heap(1) BSD General Commands Manual heap(1)NAMEheap — List all the malloc-allocated buffers in the process's heapSYNOPSISheap [-guessNonObjects] [-sumObjectFields] [-showSizes]
[-addresses all | <classes-pattern>] [-noContent] pid |
partial-executable-name
DESCRIPTIONheap lists the objects currently allocated on the heap of the specified
process, as well as summary data. Objects are categorized by class name,
type (Objective-C, C++, or CFType), and binary image. C++ objects are
identified by the vtable referenced from the start of the object, so with
multiple inheritance this may not give the precise class of the object.
The binary image identified for a class is the image which implements the
class, not necessarily the binary image which caused the objects to be
allocated at runtime, or which "owns" those objects.
heap requires one parameter -- either a process ID or a full or partial
executable name.
The following options are available:
-guessNonObjects
Look through the memory contents of each Objective-C object to
find pointers to malloc'ed blocks (non-objects), such as the
variable array hanging from an NSArray. These referenced blocks
of memory are identified as their offset from the start of the
object (say "__NSCFArray[12]"). The count, number of bytes, and
average size of memory blocks referenced from each different
object offset location are listed in the output.
-sumObjectFields
Do the same analysis as with the -guessNonObjects option, but add
the sizes of those referenced non-object fields into the entries
for the corresponding objects.
-showSizes
Show the distribution of each malloc size for each object,
instead of summing and averaging the sizes in a single entry.
-addresses all | <classes-pattern>
Print the addresses of all malloc blocks found on the heap in
ascending address order, or the addresses of those objects whose
full class name is matched by the regular expression <classes-
pattern>. The string "all" indicates that the addresses of all
blocks (both objects and non-objects) should be printed. The
<classes-pattern> regular expression is interpreted as an
extended (modern) regular expression as described by the re_for‐
mat(7) manual page. Note that toll-freed-bridged CoreFoundation
and Foundation classes have the "__NSCF" prefix rather than just
"NS" or "CF". Examples of valid classes-patterns include:
__NSCFString
'NS.*'
'__NSCFString|__NSCFArray'
'.*(String|Array)'
non-object
-noContent
Do not show object content in -addresses mode.
SEE ALSOmalloc(3), leaks(1), malloc_history(1), stringdups(1), vmmap(1),
DevToolsSecurity(1)
The Xcode developer tools also include Instruments, a graphical applica‐
tion that can give information similar to that provided by heap. The
Allocations instrument graphically displays dynamic, real-time informa‐
tion about the object and memory use in an application, including back‐
traces of where the allocations occurred. The Leaks instrument performs
memory leak analysis.
BSD Mar. 16, 2013 BSD
