Reports memory usage information for a single area of the software.
1.0
39
Introduced
Gecko 1.9
Inherits from:
nsISupports
Last changed in Gecko 8.0 (Firefox 8.0 / Thunderbird 8.0 / SeaMonkey 2.5)Any piece of code that wishes to allow its memory use to be monitored may create an nsIMemoryReporter
object and then register it by calling nsIMemoryReporterManager.registerReporter()
. Once that has been done, the reporter will be found by any client accessing the enumerator returned by nsIMemoryReporterManager.enumerateReporters()
. This includes the about:memory
page.
Note: This interface is undergoing heavy development, and is subject to rapid changes.
Attributes
Attribute | Type | Description |
amount |
PRInt64 |
The numeric value reported by the memory reporter, specified in the units indicated by the
Note: This attribute was called
memoryUsed prior to Gecko 7.0 (Firefox 7.0 / Thunderbird 7.0 / SeaMonkey 2.4), and its type was long long . |
description |
AUTF8String |
A human-readable description of this memory usage report. Read only. |
kind |
PRInt32 |
The memory kind, one of the Memory reporter kind constants below. Read only. |
path |
AUTF8String |
The path that this memory usage should be reported under. Paths are delimited with '/' characters to allow a hierarchy of memory to be displayed in about:memory. As of Gecko 6.0, the path should start with "explicit/ " if the memory report accounts for all memory reported under sub-paths. Read only. |
process |
ACString |
The name of the process containing this reporter. Each reporter starts with an empty string for this value, indicating that it applies to the current process; this is true even for reporters in a child process. When a reporter from a child process is copied into the main process, the copy's process field is set appropriately. Read only. |
units |
PRInt32 |
The units used by the amount attribute; this will be one of the Unit type constants. Read only. |
Constants
Memory reporter kind constants
These allocation kind constants describe the types of memory allocation described by memory use reporters.
Constant | Value | Description |
KIND_MAPPED |
0 |
This is deprecated synonym for KIND_NONHEAP . Deprecated since Gecko 8.0 |
KIND_NONHEAP |
0 |
Allocated directly by OS calls e.g. mmap, VirtualAlloc, vm_allocate etc. |
KIND_HEAP |
1 |
Allocated by the heap allocator, e.g. malloc, new etc. |
KIND_OTHER |
2 |
An allocation that does not fit into another KIND category. |
Unit type constants
(Firefox 7.0 / Thunderbird 7.0 / SeaMonkey 2.4)The amount reported by a memory reporter may use one of the following units.
Constant | Value | Description |
UNITS_BYTES |
0 |
The amount is specified as a number of bytes. |
UNITS_COUNT |
1 |
The amount is an instantaneous count of things currently in existence. For example, the number of tabs currently open. |
UNITS_COUNT_CUMULATIVE |
2 |
The amount contains the number of times some event has occurred since the application started up. For example, the number of times the user has opened a new tab. The amount returned must never decrease over the lifetime of the application. |
UNITS_PERCENTAGE |
3 |
The amount contains a fraction that should be expressed as a percentage.
Note: The
amount field should be given a value 100 times the actual percentage; this number will be divided by 100 when shown. This allows a fractional percentage to be shown even though amount is an integer. For example if the actual percentage is 12.34%, amount should be 1234. |