Single-producer ring buffer whose storage is allocated exactly once. More...
#include <armarx/navigation/platform_controller/Diagnostics.h>
Public Member Functions | |
| std::size_t | capacity () const noexcept |
| void | init (const std::size_t capacity) |
| Allocate the storage. | |
| std::uint64_t | overwritten () const noexcept |
| How many samples the ring has overwritten over its whole lifetime. | |
| void | record (const Sample &sample) noexcept |
| Ring ()=default | |
| Ring (const std::size_t capacity) | |
| void | snapshot (const std::uint64_t episode, std::vector< Sample > &out) const |
Copy the retained samples of episode into out, oldest first. | |
| bool | truncated (const std::uint64_t episode) const noexcept |
Whether samples of episode were overwritten before they could be read. | |
| std::uint64_t | written () const noexcept |
Detailed Description
class armarx::navigation::platform_controller::diagnostics::Ring< Sample >
Single-producer ring buffer whose storage is allocated exactly once.
record() is the whole real-time surface: one assignment into pre-sized storage and one atomic increment. No allocation, no lock, no branch beyond the modulo.
The ring is not reset between episodes. Resetting the counter would race a drain that is still running; instead every sample carries its episode and snapshot() filters, so a re-activation during a dump shows up as missing samples rather than as silently interleaved ones.
Definition at line 178 of file Diagnostics.h.
Constructor & Destructor Documentation
◆ Ring() [1/2]
|
default |
◆ Ring() [2/2]
|
inlineexplicit |
Member Function Documentation
◆ capacity()
|
inlinenoexcept |
◆ init()
|
inline |
Allocate the storage.
Call exactly once, before the producer starts.
Separate from the constructor because the capacity comes from the controller's config, which is only available inside its constructor body – and because std::atomic makes the ring non-assignable, so re-seating it after the fact is not an option.
Definition at line 195 of file Diagnostics.h.
Here is the call graph for this function:◆ overwritten()
|
inlinenoexcept |
How many samples the ring has overwritten over its whole lifetime.
Not the same as "this episode lost data": the ring is never reset, so this grows across every episode the controller ever ran and says nothing about whether the one being dumped fitted. Use truncated() for that.
Definition at line 235 of file Diagnostics.h.
Here is the call graph for this function:◆ record()
|
inlinenoexcept |
Definition at line 202 of file Diagnostics.h.
◆ snapshot()
|
inline |
Copy the retained samples of episode into out, oldest first.
Non-real-time.
Safe to call while the producer is running, as long as it cannot lap the reader: the entries between the write cursor and one capacity behind it are only rewritten once the producer has come all the way round. At the shipped sizes that is 60 s of recording against a copy measured in milliseconds. The episode filter is what keeps the result meaningful across that boundary – samples the producer adds during the copy belong to the next episode and are excluded rather than mixed in.
out is cleared first.
Definition at line 276 of file Diagnostics.h.
Here is the call graph for this function:◆ truncated()
|
inlinenoexcept |
Whether samples of episode were overwritten before they could be read.
True only when the ring has wrapped and the oldest sample still held belongs to this episode – if an older episode is still in there, nothing of this one was lost. The lifetime overwritten() count answers a different question and reports a long-running controller as lossy even when every episode fitted comfortably.
Definition at line 250 of file Diagnostics.h.
Here is the call graph for this function:◆ written()
|
inlinenoexcept |
The documentation for this class was generated from the following file:
- armarx/navigation/platform_controller/Diagnostics.h
