Struct FtraceEventBundle

pub struct FtraceEventBundle {
    pub cpu: Option<u32>,
    pub event: Vec<FtraceEvent>,
    pub lost_events: Option<bool>,
    pub compact_sched: Option<CompactSched>,
    pub ftrace_clock: Option<i32>,
    pub ftrace_timestamp: Option<i64>,
    pub boot_timestamp: Option<i64>,
    pub error: Vec<FtraceError>,
    pub last_read_event_timestamp: Option<u64>,
    pub previous_bundle_end_timestamp: Option<u64>,
}

The result of tracing one or more ftrace data pages from a single per-cpu kernel ring buffer. If collating multiple pages’ worth of events, all of them come from contiguous pages, with no kernel data loss in between.

Fields

cpu: Option<u32>

event: Vec<FtraceEvent>

lost_events: Option<bool>

Set to true if there was data loss between the last time we’ve read from the corresponding per-cpu kernel buffer, and the earliest event recorded in this bundle.

compact_sched: Option<CompactSched>

ftrace_clock: Option<i32>

traced_probes always sets the ftrace_clock to “boot”. That is not available in older kernels (v3.x). In that case we fallback on “global” or “local”. When we do that, we report the fallback clock in each bundle so we can do proper clock syncing at parsing time in TraceProcessor. We cannot use the TracePacket timestamp_clock_id because: (1) there is no per-packet timestamp for ftrace bundles; (2) “global” does not match CLOCK_MONOTONIC. Having a dedicated and explicit flag allows us to correct further misakes in future by looking at the kernel version. This field has been introduced in perfetto v19 / Android T (13). This field is omitted when the ftrace clock is just “boot”, as that is the default assumption (and for consistency with the past).

ftrace_timestamp: Option<i64>

The timestamp according to the ftrace clock, taken at the same instant as |boot_timestamp|. This is used to sync ftrace events when a non-boot clock is used as the ftrace clock. We don’t use the ClockSnapshot packet because the ftrace global/local clocks don’t match any of the clock_gettime domains and can be only read by traced_probes.

Only set when |ftrace_clock| != FTRACE_CLOCK_UNSPECIFIED.

Implementation note: Populated by reading the ‘now ts:’ field in tracefs/per_cpu/cpuX/stat.

boot_timestamp: Option<i64>

The timestamp according to CLOCK_BOOTTIME, taken at the same instant as |ftrace_timestamp|. See documentation of |ftrace_timestamp| for more info.

Only set when |ftrace_clock| != FTRACE_CLOCK_UNSPECIFIED.

error: Vec<FtraceError>

last_read_event_timestamp: Option<u64>

Superseded by |previous_bundle_end_timestamp| in perfetto v47+. The primary difference is that this field tracked the last timestamp read from the per-cpu buffer, while the newer field tracks events that get serialised into the trace. Added in: perfetto v44.

previous_bundle_end_timestamp: Option<u64>

The timestamp (using ftrace clock) of the last event written into this data source on this cpu. In other words: the last event in the previous bundle. Lets the trace processing find an initial timestamp after which ftrace data is known to be valid across all cpus. Of particular importance when the perfetto trace buffer is a ring buffer as well, as the overwriting of oldest bundles can skew the first valid timestamp per cpu significantly. Added in: perfetto v47.

Implementations

impl FtraceEventBundle

pub fn cpu(&self) -> u32

Returns the value of cpu, or the default value if cpu is unset.

pub fn lost_events(&self) -> bool

Returns the value of lost_events, or the default value if lost_events is unset.

pub fn ftrace_clock(&self) -> FtraceClock

Returns the enum value of ftrace_clock, or the default if the field is unset or set to an invalid enum value.

pub fn set_ftrace_clock(&mut self, value: FtraceClock)

Sets ftrace_clock to the provided enum value.

pub fn ftrace_timestamp(&self) -> i64

Returns the value of ftrace_timestamp, or the default value if ftrace_timestamp is unset.

pub fn boot_timestamp(&self) -> i64

Returns the value of boot_timestamp, or the default value if boot_timestamp is unset.

pub fn last_read_event_timestamp(&self) -> u64

Returns the value of last_read_event_timestamp, or the default value if last_read_event_timestamp is unset.

pub fn previous_bundle_end_timestamp(&self) -> u64

Returns the value of previous_bundle_end_timestamp, or the default value if previous_bundle_end_timestamp is unset.

Trait Implementations

impl Clone for FtraceEventBundle

fn clone(&self) -> FtraceEventBundle

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for FtraceEventBundle

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for FtraceEventBundle

fn default() -> Self

Returns the “default value” for a type.

impl Message for FtraceEventBundle

fn encoded_len(&self) -> usize

Returns the encoded length of the message without a length delimiter.

fn clear(&mut self)

Clears the message, resetting all fields to their default.

fn encode<B>(&self, buf: &mut B) -> Result<(), EncodeError>

where B: BufMut, Self: Sized,

Encodes the message to a buffer.

fn encode_to_vec(&self) -> Vec<u8>

where Self: Sized,

Encodes the message to a newly allocated buffer.

fn encode_length_delimited<B>(&self, buf: &mut B) -> Result<(), EncodeError>

where B: BufMut, Self: Sized,

Encodes the message with a length-delimiter to a buffer.

fn encode_length_delimited_to_vec(&self) -> Vec<u8>

where Self: Sized,

Encodes the message with a length-delimiter to a newly allocated buffer.

fn decode<B>(buf: B) -> Result<Self, DecodeError>

where B: Buf, Self: Default,

Decodes an instance of the message from a buffer.

fn decode_length_delimited<B>(buf: B) -> Result<Self, DecodeError>

where B: Buf, Self: Default,

Decodes a length-delimited instance of the message from the buffer.

fn merge<B>(&mut self, buf: B) -> Result<(), DecodeError>

where B: Buf, Self: Sized,

Decodes an instance of the message from a buffer, and merges it into self.

fn merge_length_delimited<B>(&mut self, buf: B) -> Result<(), DecodeError>

where B: Buf, Self: Sized,

Decodes a length-delimited instance of the message from buffer, and merges it into self.

impl PartialEq for FtraceEventBundle

fn eq(&self, other: &FtraceEventBundle) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for FtraceEventBundle