Struct SessionSemaphore

pub struct SessionSemaphore {
    pub name: Option<String>,
    pub max_other_session_count: Option<u64>,
}

When non-empty, ensures that for a each semaphore named name at most max_other_session_count`` other sessions (whose value is taken of the minimum of all values specified by this config or any already-running session) can be be running.

If a semaphore “acquisition” fails, EnableTracing will return an error and the tracing session will not be started (or elgible to start in the case of deferred sessions).

This is easiest to explain with an example. Suppose the tracing service has the following active tracing sessions: S1 = [{name=foo, max_other_session_count=2}, {name=bar, max_other_session_count=0}] S2 = [{name=foo, max_other_session_count=1}, {name=baz, max_other_session_count=1}]

Then, for a new session, the following would be the expected behaviour of EnableSession given the state of session_semaphores. Q: session_semaphores = [] A: Allowed because it does not specify any semaphores. Will be allowed no matter the state of any other tracing session. Q: session_semaphores = [{name=baz, max_other_session_count=1}] A: Allowed because both S2 and this config specify max_other_session_count=1 for baz. Q: session_semaphores = [{name=foo, max_other_session_count=3}] A: Denied because S2 specified max_other_session_count=1 for foo and S1 takes that slot. Q: session_semaphores = [{name=bar, max_other_session_count=0}] A: Denied because S1 takes the the slot specified by both S1 and this config.

Introduced in 24Q3 (Android V).

Fields

name: Option<String>

The name of the semaphore. Acts as a unique identifier across all tracing sessions (including the one being started).

max_other_session_count: Option<u64>

The maximum number of other sesssions which specify the same semaphore which can be active. The minimum of this value across all tracing sessions and the value specified by the config is used when deciding whether the tracing session can be started.

Implementations

impl SessionSemaphore

pub fn name(&self) -> &str

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

pub fn max_other_session_count(&self) -> u64

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

Trait Implementations

impl Clone for SessionSemaphore

fn clone(&self) -> SessionSemaphore

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for SessionSemaphore

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

Formats the value using the given formatter.

impl Default for SessionSemaphore

fn default() -> Self

Returns the “default value” for a type.

impl Message for SessionSemaphore

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 SessionSemaphore

fn eq(&self, other: &SessionSemaphore) -> 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 SessionSemaphore