33de701263
* refactor(atomicx): move outside the engine package
After merging probe-engine into probe-cli, my impression is that we have
too much unnecessary nesting of packages in this repository.
The idea of this commit and of a bunch of following commits will instead
be to reduce the nesting and simplify the structure.
While there, improve the documentation.
* fix: always use the atomicx package
For consistency, never use sync/atomic and always use ./internal/atomicx
so we can just grep and make sure we're not risking to crash if we make
a subtle mistake on a 32 bit platform.
While there, mention in the contributing guidelines that we want to
always prefer the ./internal/atomicx package over sync/atomic.
* fix(atomicx): remove unnecessary constructor
We don't need a constructor here. The default constructed `&Int64{}`
instance is already usable and the constructor does not add anything to
what we are doing, rather it just creates extra confusion.
* cleanup(atomicx): we are not using Float64
Because atomicx.Float64 is unused, we can safely zap it.
* cleanup(atomicx): simplify impl and improve tests
We can simplify the implementation by using defer and by letting
the Load() method call Add(0).
We can improve tests by making many goroutines updated the
atomic int64 value concurrently.
* refactor(fsx): can live in the ./internal pkg
Let us reduce the amount of nesting. While there, ensure that the
package only exports the bare minimum, and improve the documentation
of the tests, to ease reading the code.
* refactor: move runtimex to ./internal
* refactor: move shellx into the ./internal package
While there, remove unnecessary dependency between packages.
While there, specify in the contributing guidelines that
one should use x/sys/execabs instead of os/exec.
* refactor: move ooapi into the ./internal pkg
* refactor(humanize): move to ./internal and better docs
* refactor: move platform to ./internal
* refactor(randx): move to ./internal
* refactor(multierror): move into the ./internal pkg
* refactor(kvstore): all kvstores in ./internal
Rather than having part of the kvstore inside ./internal/engine/kvstore
and part in ./internal/engine/kvstore.go, let us put every piece of code
that is kvstore related into the ./internal/kvstore package.
* fix(kvstore): always return ErrNoSuchKey on Get() error
It should help to use the kvstore everywhere removing all the
copies that are lingering around the tree.
* sessionresolver: make KVStore mandatory
Simplifies implementation. While there, use the ./internal/kvstore
package rather than having our private implementation.
* fix(ooapi): use the ./internal/kvstore package
* fix(platform): better documentation
44 lines
1.4 KiB
Go
44 lines
1.4 KiB
Go
// Package atomicx extends sync/atomic.
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//
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// Sync/atomic fails when using int64 atomic operations on 32 bit platforms
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// when the access is not aligned. As specified in the documentation, in
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// fact, "it is the caller's responsibility to arrange for 64-bit alignment
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// of 64-bit words accessed atomically". For more information on this
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// issue, see https://golang.org/pkg/sync/atomic/#pkg-note-BUG.
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//
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// As explained in CONTRIBUTING.md, probe-cli SHOULD use this package rather
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// than sync/atomic to avoid these alignment issues on 32 bit.
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//
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// It is of course possible to write atomic code using 64 bit variables on a
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// 32 bit platform, but that's difficult to do correctly. This package
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// provides an easier-to-use interface. We use allocated
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// structures protected by a mutex that encapsulate a int64 value.
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//
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// While there we also added support for atomic float64 operations, again
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// by using structures protected by a mutex variable.
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package atomicx
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import "sync"
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// Int64 is an int64 with atomic semantics.
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type Int64 struct {
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// mu provides mutual exclusion.
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mu sync.Mutex
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// v is the underlying value.
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v int64
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}
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// Add behaves like atomic.AddInt64.
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func (i64 *Int64) Add(delta int64) int64 {
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i64.mu.Lock()
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defer i64.mu.Unlock()
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i64.v += delta
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return i64.v
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}
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// Load behaves like atomic.LoadInt64.
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func (i64 *Int64) Load() (v int64) {
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return i64.Add(0)
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}
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