Commit Graph

4 Commits

Author SHA1 Message Date
Andres Suarez 8bd3edec88 Update copyright headers from Facebook to Meta
Reviewed By: aaronabramov

Differential Revision: D33367752

fbshipit-source-id: 4ce94d184485e5ee0a62cf67ad2d3ba16e285c8f
2021-12-30 15:11:21 -08:00
Samuel Susla 5fa6c5a941 Enable modernize-pass-by-value clang tidy rule
Summary:
changelog: [internal]

You can read more about this rule on https://clang.llvm.org/extra/clang-tidy/checks/modernize-pass-by-value.html

# Isn't it wasteful to copy? Isn't reference more efficient?

This rule of thumb is no longer true since C++11 with move semantics. Let's look at some examples.

# Option one

```
class TextHolder
{
public:
   TextBox(std::string const &text) : text_(text) {}
private:
   std::string text_;
};
```

By using reference here, we prevent the caller from using rvalue to and avoiding copy. Regardless of what the caller passes in, copy always happens.

# Option two

```
class TextHolder
{
public:
   TextBox(std::string const &text) : text_(text) {}
   TextBox(std::string &&text) : text_(std::move(text)) {}
private:
   std::string text_;
};
```
Here, we provide two constructors, one for const reference and one for rvalue reference. This gives the caller option to avoid copy. But now we have two constructors, which is not ideal.

# Option three (what we do in this diff)

```
class TextHolder
{
public:
   TextBox(std::string text) : text_(std::move(text)) {}
private:
   std::string text_;
};
```
Here, the caller has option to avoid copy and we only have single constructor.

Reviewed By: fkgozali, JoshuaGross

Differential Revision: D33276841

fbshipit-source-id: 619d5123d2e28937b22874650366629f24f20a63
2021-12-23 07:53:48 -08:00
Micha Reiser 46acfcb8fc Allow swapping the clock implementation for TransactionTelemetry
Summary:
The `TransactionalTelemetryTest`s are flaky because they use a real clock and assert on how much time has passed (with a threshold, but that's no good either).

Using the real clock in the test is the cause for the test to be flaky because it depends on the assumption that it's the sole process running, never risking to be put in the process-queue of the OS. However, that's not the case and is why the test sporadically fails if the OS decided to schedule other threads/process in the middle of the test.

This diff allows parametrising the `TransactionTelemetry` class with the clock implementation so that tests can use a Mock Clock if desired (separate diff).

Changelog: [Internal] Fabric-specific internal change.

Reviewed By: sammy-SC

Differential Revision: D27618516

fbshipit-source-id: 5a08e115b388398ca2b05b9d5ae0fd281dfe3b04
2021-04-08 09:27:18 -07:00
Samuel Susla 79090c4802 Fabric: Decoupling Telemetry aggregation classes into a separate module
Summary:
We need to do this to break a dependency cycle that would happen if we try to have `view` depend on `mounting` just to add some telemetry to `view`.

Changelog: [Internal] Fabric-specific internal change.

Reviewed By: mdvacca

Differential Revision: D26827446

fbshipit-source-id: 4c415ebf5be3a02c18c80ea8a4a77068cae0f0fe
2021-03-29 05:12:42 -07:00