sdk/fidl/fuchsia.tracing.controller/index.md

Project: /_project.yaml
Book: /_book.yaml

# fuchsia.tracing.controller


## **PROTOCOLS**

## Controller {:#Controller}
*Defined in [fuchsia.tracing.controller/trace_controller.fidl](https://fuchsia.googlesource.com/fuchsia/+/master/sdk/fidl/fuchsia.tracing.controller/trace_controller.fidl#9)*


### StartTracing {:#StartTracing}


#### Request
<table>
    <tr><th>Name</th><th>Type</th></tr>
    <tr>
            <td><code>options</code></td>
            <td>
                <code><a class='link' href='../fuchsia.tracing.controller/index.html#TraceOptions'>TraceOptions</a></code>
            </td>
        </tr><tr>
            <td><code>output</code></td>
            <td>
                <code>handle&lt;socket&gt;</code>
            </td>
        </tr></table>


#### Response
<table>
    <tr><th>Name</th><th>Type</th></tr>
    </table>

### StopTracing {:#StopTracing}


#### Request
<table>
    <tr><th>Name</th><th>Type</th></tr>
    </table>



### GetKnownCategories {:#GetKnownCategories}


#### Request
<table>
    <tr><th>Name</th><th>Type</th></tr>
    </table>


#### Response
<table>
    <tr><th>Name</th><th>Type</th></tr>
    <tr>
            <td><code>categories</code></td>
            <td>
                <code>vector&lt;<a class='link' href='../fuchsia.tracing.controller/index.html#KnownCategory'>KnownCategory</a>&gt;</code>
            </td>
        </tr></table>



## **STRUCTS**

### KnownCategory {:#KnownCategory}
*Defined in [fuchsia.tracing.controller/trace_controller.fidl](https://fuchsia.googlesource.com/fuchsia/+/master/sdk/fidl/fuchsia.tracing.controller/trace_controller.fidl#40)*





<table>
    <tr><th>Name</th><th>Type</th><th>Description</th><th>Default</th></tr><tr>
            <td><code>name</code></td>
            <td>
                <code>string[100]</code>
            </td>
            <td></td>
            <td>No default</td>
        </tr><tr>
            <td><code>description</code></td>
            <td>
                <code>string</code>
            </td>
            <td></td>
            <td>No default</td>
        </tr>
</table>



## **ENUMS**

### BufferingMode {:#BufferingMode}
Type: <code>uint8</code>

*Defined in [fuchsia.tracing.controller/trace_controller.fidl](https://fuchsia.googlesource.com/fuchsia/+/master/sdk/fidl/fuchsia.tracing.controller/trace_controller.fidl#46)*



<table>
    <tr><th>Name</th><th>Value</th><th>Description</th></tr><tr>
            <td><code>ONESHOT</code></td>
            <td><code>0</code></td>
            <td></td>
        </tr><tr>
            <td><code>CIRCULAR</code></td>
            <td><code>1</code></td>
            <td></td>
        </tr><tr>
            <td><code>STREAMING</code></td>
            <td><code>2</code></td>
            <td></td>
        </tr></table>



## **TABLES**

### ProviderSpec {:#ProviderSpec}


*Defined in [fuchsia.tracing.controller/trace_controller.fidl](https://fuchsia.googlesource.com/fuchsia/+/master/sdk/fidl/fuchsia.tracing.controller/trace_controller.fidl#53)*



<table>
    <tr><th>Ordinal</th><th>Name</th><th>Type</th><th>Description</th></tr>
    <tr>
            <td>1</td>
            <td><code>name</code></td>
            <td>
                <code>string[100]</code>
            </td>
            <td></td>
        </tr><tr>
            <td>2</td>
            <td><code>buffer_size_megabytes_hint</code></td>
            <td>
                <code>uint32</code>
            </td>
            <td></td>
        </tr></table>

### TraceOptions {:#TraceOptions}


*Defined in [fuchsia.tracing.controller/trace_controller.fidl](https://fuchsia.googlesource.com/fuchsia/+/master/sdk/fidl/fuchsia.tracing.controller/trace_controller.fidl#59)*

 Provides options for the trace.


<table>
    <tr><th>Ordinal</th><th>Name</th><th>Type</th><th>Description</th></tr>
    <tr>
            <td>1</td>
            <td><code>categories</code></td>
            <td>
                <code>vector&lt;string&gt;[100]</code>
            </td>
            <td> The trace categories to record, or an empty array for all.
</td>
        </tr><tr>
            <td>2</td>
            <td><code>buffer_size_megabytes_hint</code></td>
            <td>
                <code>uint32</code>
            </td>
            <td> Suggested size of trace buffer which each provider should receive.
</td>
        </tr><tr>
            <td>3</td>
            <td><code>start_timeout_milliseconds</code></td>
            <td>
                <code>uint64</code>
            </td>
            <td> Acknowledge start request after at most `start_timeout_milliseconds`.
</td>
        </tr><tr>
            <td>4</td>
            <td><code>buffering_mode</code></td>
            <td>
                <code><a class='link' href='../fuchsia.tracing.controller/index.html#BufferingMode'>BufferingMode</a></code>
            </td>
            <td></td>
        </tr><tr>
            <td>5</td>
            <td><code>provider_specs</code></td>
            <td>
                <code>vector&lt;<a class='link' href='../fuchsia.tracing.controller/index.html#ProviderSpec'>ProviderSpec</a>&gt;[100]</code>
            </td>
            <td> Overrides for particular providers.
</td>
        </tr></table>