heap(1) | General Commands Manual | heap(1) |
heap
— List all
the malloc-allocated buffers in the process's heap
heap |
[-s | -sortBySize ]
[-z | -zones ]
[-guessNonObjects ]
[-sumObjectFields ]
[-showSizes ] [-addresses
all | <classes-pattern>]
[-noContent ] pid |
partial-executable-name |
memory-graph-file |
heap
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.
If the target process is running with MallocStackLogging, then
heap
attempts to identify the types of
"non-object" allocations, using the form
"<allocation-call> in <caller>". The <caller> is
determined by walking up the allocation stack backtrace (if available) to
find the symbol name of the function that called an "allocation
function", such as malloc, calloc, realloc, C++ "operator
new", strndup, various internal functions of libc++.1.dylib, etc. If
<caller> is a C++ function, the type name is created by simplifying
the demangled symbol name by removing the return type, the "__1::"
substrings from use of llvm's libc++abi.dylib, and standard arguments such
as "std::__1::allocator<T>"."
For example, this type information:
malloc in std::basic_string<char>::basic_string<std::nullptr_t>(char const*) C++ Metal
is determined from the backtrace:
The binary image identified for a class is the image which implements the class. For types derived from allocation backtraces, the binary image is that of <caller>.
heap
requires one argument -- either the
process ID or the full or partial executable name of the process to examine,
or the pathname of a memory graph file generated by
leaks
or the Xcode Memory Graph Debugger.
The following options are available:
-s
|
-sortBySize
-z
|
-zones
-guessNonObjects
-sumObjectFields
-guessNonObjects
option, but add the sizes of those referenced non-object fields into the
entries for the corresponding objects.-showSizes
-diffFrom=<memgraph>
-addresses
all |
<classes-pattern>The <classes-pattern> regular expression is interpreted as an extended (modern) regular expression as described by the re_format(7) manual page. "malloc" or "non-object" can be used to refer to blocks that are not of any specific type. Examples of valid classes-patterns include:
The <classes-pattern> pattern can be followed by an optional allocation size specifier, which can be one of the following forms. The square brackets are required. The size can include a 'k' suffix for kilobytes, or an 'm' suffix for megabytes:
Examples of <classes-pattern> with size specifications include:
-noContent
malloc(3), leaks(1), malloc_history(1), stringdups(1), vmmap(1), DevToolsSecurity(1)
The Xcode developer tools also include Instruments, a graphical
application that can give information similar to that provided by
heap.
The Allocations instrument graphically
displays dynamic, real-time information about the object and memory use in
an application, including backtraces of where the allocations occurred. The
Leaks instrument performs memory leak analysis.
Feb. 8, 2022 | macOS 14.6 |