fuchsia.memory.heapdump.client

PROTOCOLS

Collector

Defined in fuchsia.memory.heapdump.client/client.fidl

Protocol to request and retrieve memory profiles.

DownloadStoredSnapshot

Retrieves a stored snapshot.

Request

Name	Type
payload	CollectorDownloadStoredSnapshotRequest

ListStoredSnapshots

Retrieves the list of all the available stored snapshots.

Request

Name	Type
payload	CollectorListStoredSnapshotsRequest

TakeLiveSnapshot

Obtains a snapshot of the current live allocations in an instrumented process.

Request

Name	Type
payload	CollectorTakeLiveSnapshotRequest

SnapshotReceiver

Defined in fuchsia.memory.heapdump.client/client.fidl

Protocol to transmit a snapshot as a stream of elements.

Batch

Delivers a batch of snapshot elements.

It will be called repeatedly until no elements are left, and then one final time with an empty vector to signal the end of the stream.

Request

Name	Type
batch	vector<SnapshotElement>

Response

<EMPTY>

ReportError

Reports an error. No other batches or errors will follow.

Request

Name	Type
error	CollectorError

Response

<EMPTY>

StoredSnapshotIterator

Defined in fuchsia.memory.heapdump.client/client.fidl

Protocol to retrieve a list of StoredSnapshots.

GetNext

Retrieves the next batch of StoredSnapshots elements.

An empty response signals the end of the list.

Request

<EMPTY>

Response

Name	Type
payload	StoredSnapshotIterator_GetNext_Result

STRUCTS

BuildId

Defined in fuchsia.memory.heapdump.client/client.fidl

An ELF build ID.

Field	Type	Description	Default
value	vector<uint8>[32]		No default

StoredSnapshotIterator_GetNext_Response

Defined in fuchsia.memory.heapdump.client/client.fidl

Field	Type	Description	Default
batch	vector<StoredSnapshot>		No default

ENUMS

CollectorError flexible

Type: uint32

Defined in fuchsia.memory.heapdump.client/client.fidl

The reason why a method failed.

Name	Value	Description
PROCESS_SELECTOR_UNSUPPORTED	1	The given ProcessSelector value is not supported.
PROCESS_SELECTOR_NO_MATCH	2	The given ProcessSelector value does not match any process.
PROCESS_SELECTOR_AMBIGUOUS	3	The given ProcessSelector value matches more than one process but the requested operation needs a unique match.
LIVE_SNAPSHOT_FAILED	4	Failed to take a live snapshot.
STORED_SNAPSHOT_NOT_FOUND	5	The requested StoredSnapshot does not exist.

TABLES

Allocation

Defined in fuchsia.memory.heapdump.client/client.fidl

An allocated memory block.

Ordinal	Field	Type	Description
1	address	uint64	The address of the memory block.
2	size	uint64	Block size, in bytes.
3	stack_trace_key	StackTraceKey	The stack trace of the allocation site.
4	timestamp	zx/Time	Allocation timestamp.
5	thread_info_key	ThreadInfoKey	The allocating thread.

BlockContents

Defined in fuchsia.memory.heapdump.client/client.fidl

The contents of an allocated memory block.

In order to avoid exceeding the channel's maximum message size, bigger blocks can be split in chunks. Receivers should be prepared to handle multiple BlockContents with the same address and reassemble them by concatenating their payloads. Each block's reassembled size always matches the size field of the corresponding Allocation.

Ordinal	Field	Type	Description
1	address	uint64	The address of the corresponding memory block.
2	contents	vector<uint8>	The payload.

CollectorDownloadStoredSnapshotRequest resource

Defined in fuchsia.memory.heapdump.client/client.fidl

Ordinal	Field	Type	Description
1	snapshot_id	uint32	The identifier of the snapshot to be downloaded. The list of the available snapshots can be retrieved with ListStoredSnapshots. Required.
2	receiver	SnapshotReceiver	Where the elements of the requested snapshot will be sent to. Required.

CollectorListStoredSnapshotsRequest resource

Defined in fuchsia.memory.heapdump.client/client.fidl

Ordinal	Field	Type	Description
1	iterator	server_end<StoredSnapshotIterator>	The server_end of the StoredSnapshotIterator that will be used to retrieve the results. Required.
2	process_selector	ProcessSelector	If present, only retrieve snapshots that refer to matching processes.

CollectorTakeLiveSnapshotRequest resource

Defined in fuchsia.memory.heapdump.client/client.fidl

Ordinal	Field	Type	Description
1	process_selector	ProcessSelector	The instrumented process to operate on. Required.
2	receiver	SnapshotReceiver	Where the elements of the requested snapshot will be sent to. Required.
3	with_contents	bool	Whether the snapshot should include the contents of each memory block. If not set, false is assumed.

ExecutableRegion

Defined in fuchsia.memory.heapdump.client/client.fidl

A memory region containing code loaded from an ELF file.

Ordinal	Field	Type	Description
1	address	uint64	The address of the memory region.
2	size	uint64	Region size, in bytes.
3	file_offset	uint64	The file offset corresponding to the first byte within the region.
4	build_id	BuildId	The build ID of the ELF file.

StackTrace

Defined in fuchsia.memory.heapdump.client/client.fidl

A stack trace.

In order to avoid exceeding the channel's maximum message size, stack traces can be split in multiple chunks. Receivers should be prepared to handle multiple StackTrace elements with the same key and reassemble them by concatenating their program addresses.

Ordinal	Field	Type	Description
1	stack_trace_key	StackTraceKey	A number that uniquely identifies this stack trace within the parent snapshot.
2	program_addresses	vector<uint64>	The program counters corresponding to stack each frame. Entries are listed in reverse call order: the first entry refers to the leaf frame, and the last entry refers to the frame at the root of the call stack.

StoredSnapshot

Defined in fuchsia.memory.heapdump.client/client.fidl

A snapshot that is stored on the device and that can be downloaded.

Application-initiated snapshots belong to this category.

Ordinal	Field	Type	Description
1	snapshot_id	uint32	A number that uniquely identifies this snapshot within a Collector.
2	snapshot_name	string[32]	The name given to this snapshot.
3	process_koid	zx/Koid	The koid of the process that this snapshot refers to.
4	process_name	string[32]	The name of the process that this snapshot refers to.

ThreadInfo

Defined in fuchsia.memory.heapdump.client/client.fidl

Information on a given thread.

Note: Under some circumstances, more than one entry could exist for a given koid (e.g. if the thread changed its name between different allocations).

Ordinal	Field	Type	Description
1	thread_info_key	ThreadInfoKey	A number that uniquely identifies this entry within the parent snapshot.
2	koid	zx/Koid	The koid of the thread that this entry refers to.
3	name	string[32]	The name of the thread that this entry refers to.

UNIONS

ProcessSelector flexible

Defined in fuchsia.memory.heapdump.client/client.fidl

Filter to restrict an operation to a subset of the available processes.

Ordinal	Variant	Type	Description
1	by_name	string[32]	Matches any process with the given ZX_PROP_NAME.
2	by_koid	zx/Koid	Matches the process with the given koid.

SnapshotElement flexible

Defined in fuchsia.memory.heapdump.client/client.fidl

An element that is part of a snapshot.

Ordinal	Variant	Type	Description
1	allocation	Allocation
2	stack_trace	StackTrace
3	executable_region	ExecutableRegion
4	block_contents	BlockContents
5	thread_info	ThreadInfo

StoredSnapshotIterator_GetNext_Result strict

Defined in fuchsia.memory.heapdump.client/client.fidl

Ordinal	Variant	Type	Description
1	response	StoredSnapshotIterator_GetNext_Response
2	err	CollectorError

CONSTANTS

Name	Value	Type	Description
MAX_BUILD_ID_LENGTH	32	uint32

ALIASES

Name	Value	Description
StackTraceKey	uint64
ThreadInfoKey	uint64