From 6ea4d2c82de80efc87708e5e182034b7c6c2019e Mon Sep 17 00:00:00 2001 From: Gibheer Date: Thu, 5 Sep 2024 19:38:25 +0200 Subject: switch from github.com/lib/pq to github.com/jackc/pgx/v5 lib/pq is out of maintenance for some time now, so switch to the newer more active library. Looks like it finally stabilized after a long time. --- vendor/github.com/jackc/puddle/v2/CHANGELOG.md | 74 +++ vendor/github.com/jackc/puddle/v2/LICENSE | 22 + vendor/github.com/jackc/puddle/v2/README.md | 80 +++ vendor/github.com/jackc/puddle/v2/context.go | 24 + vendor/github.com/jackc/puddle/v2/doc.go | 11 + .../jackc/puddle/v2/internal/genstack/gen_stack.go | 85 +++ .../jackc/puddle/v2/internal/genstack/stack.go | 39 ++ vendor/github.com/jackc/puddle/v2/log.go | 32 + vendor/github.com/jackc/puddle/v2/nanotime_time.go | 13 + .../github.com/jackc/puddle/v2/nanotime_unsafe.go | 12 + vendor/github.com/jackc/puddle/v2/pool.go | 696 +++++++++++++++++++++ vendor/github.com/jackc/puddle/v2/resource_list.go | 28 + 12 files changed, 1116 insertions(+) create mode 100644 vendor/github.com/jackc/puddle/v2/CHANGELOG.md create mode 100644 vendor/github.com/jackc/puddle/v2/LICENSE create mode 100644 vendor/github.com/jackc/puddle/v2/README.md create mode 100644 vendor/github.com/jackc/puddle/v2/context.go create mode 100644 vendor/github.com/jackc/puddle/v2/doc.go create mode 100644 vendor/github.com/jackc/puddle/v2/internal/genstack/gen_stack.go create mode 100644 vendor/github.com/jackc/puddle/v2/internal/genstack/stack.go create mode 100644 vendor/github.com/jackc/puddle/v2/log.go create mode 100644 vendor/github.com/jackc/puddle/v2/nanotime_time.go create mode 100644 vendor/github.com/jackc/puddle/v2/nanotime_unsafe.go create mode 100644 vendor/github.com/jackc/puddle/v2/pool.go create mode 100644 vendor/github.com/jackc/puddle/v2/resource_list.go (limited to 'vendor/github.com/jackc/puddle/v2') diff --git a/vendor/github.com/jackc/puddle/v2/CHANGELOG.md b/vendor/github.com/jackc/puddle/v2/CHANGELOG.md new file mode 100644 index 0000000..a15991c --- /dev/null +++ b/vendor/github.com/jackc/puddle/v2/CHANGELOG.md @@ -0,0 +1,74 @@ +# 2.2.1 (July 15, 2023) + +* Fix: CreateResource cannot overflow pool. This changes documented behavior of CreateResource. Previously, + CreateResource could create a resource even if the pool was full. This could cause the pool to overflow. While this + was documented, it was documenting incorrect behavior. CreateResource now returns an error if the pool is full. + +# 2.2.0 (February 11, 2023) + +* Use Go 1.19 atomics and drop go.uber.org/atomic dependency + +# 2.1.2 (November 12, 2022) + +* Restore support to Go 1.18 via go.uber.org/atomic + +# 2.1.1 (November 11, 2022) + +* Fix create resource concurrently with Stat call race + +# 2.1.0 (October 28, 2022) + +* Concurrency control is now implemented with a semaphore. This simplifies some internal logic, resolves a few error conditions (including a deadlock), and improves performance. (Jan Dubsky) +* Go 1.19 is now required for the improved atomic support. + +# 2.0.1 (October 28, 2022) + +* Fix race condition when Close is called concurrently with multiple constructors + +# 2.0.0 (September 17, 2022) + +* Use generics instead of interface{} (Столяров Владимир Алексеевич) +* Add Reset +* Do not cancel resource construction when Acquire is canceled +* NewPool takes Config + +# 1.3.0 (August 27, 2022) + +* Acquire creates resources in background to allow creation to continue after Acquire is canceled (James Hartig) + +# 1.2.1 (December 2, 2021) + +* TryAcquire now does not block when background constructing resource + +# 1.2.0 (November 20, 2021) + +* Add TryAcquire (A. Jensen) +* Fix: remove memory leak / unintentionally pinned memory when shrinking slices (Alexander Staubo) +* Fix: Do not leave pool locked after panic from nil context + +# 1.1.4 (September 11, 2021) + +* Fix: Deadlock in CreateResource if pool was closed during resource acquisition (Dmitriy Matrenichev) + +# 1.1.3 (December 3, 2020) + +* Fix: Failed resource creation could cause concurrent Acquire to hang. (Evgeny Vanslov) + +# 1.1.2 (September 26, 2020) + +* Fix: Resource.Destroy no longer removes itself from the pool before its destructor has completed. +* Fix: Prevent crash when pool is closed while resource is being created. + +# 1.1.1 (April 2, 2020) + +* Pool.Close can be safely called multiple times +* AcquireAllIDle immediately returns nil if pool is closed +* CreateResource checks if pool is closed before taking any action +* Fix potential race condition when CreateResource and Close are called concurrently. CreateResource now checks if pool is closed before adding newly created resource to pool. + +# 1.1.0 (February 5, 2020) + +* Use runtime.nanotime for faster tracking of acquire time and last usage time. +* Track resource idle time to enable client health check logic. (Patrick Ellul) +* Add CreateResource to construct a new resource without acquiring it. (Patrick Ellul) +* Fix deadlock race when acquire is cancelled. (Michael Tharp) diff --git a/vendor/github.com/jackc/puddle/v2/LICENSE b/vendor/github.com/jackc/puddle/v2/LICENSE new file mode 100644 index 0000000..bcc286c --- /dev/null +++ b/vendor/github.com/jackc/puddle/v2/LICENSE @@ -0,0 +1,22 @@ +Copyright (c) 2018 Jack Christensen + +MIT License + +Permission is hereby granted, free of charge, to any person obtaining +a copy of this software and associated documentation files (the +"Software"), to deal in the Software without restriction, including +without limitation the rights to use, copy, modify, merge, publish, +distribute, sublicense, and/or sell copies of the Software, and to +permit persons to whom the Software is furnished to do so, subject to +the following conditions: + +The above copyright notice and this permission notice shall be +included in all copies or substantial portions of the Software. + +THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, +EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF +MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND +NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE +LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION +OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION +WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. diff --git a/vendor/github.com/jackc/puddle/v2/README.md b/vendor/github.com/jackc/puddle/v2/README.md new file mode 100644 index 0000000..0ad07ec --- /dev/null +++ b/vendor/github.com/jackc/puddle/v2/README.md @@ -0,0 +1,80 @@ +[![](https://godoc.org/github.com/jackc/puddle?status.svg)](https://godoc.org/github.com/jackc/puddle) +![Build Status](https://github.com/jackc/puddle/actions/workflows/ci.yml/badge.svg) + +# Puddle + +Puddle is a tiny generic resource pool library for Go that uses the standard +context library to signal cancellation of acquires. It is designed to contain +the minimum functionality required for a resource pool. It can be used directly +or it can be used as the base for a domain specific resource pool. For example, +a database connection pool may use puddle internally and implement health checks +and keep-alive behavior without needing to implement any concurrent code of its +own. + +## Features + +* Acquire cancellation via context standard library +* Statistics API for monitoring pool pressure +* No dependencies outside of standard library and golang.org/x/sync +* High performance +* 100% test coverage of reachable code + +## Example Usage + +```go +package main + +import ( + "context" + "log" + "net" + + "github.com/jackc/puddle/v2" +) + +func main() { + constructor := func(context.Context) (net.Conn, error) { + return net.Dial("tcp", "127.0.0.1:8080") + } + destructor := func(value net.Conn) { + value.Close() + } + maxPoolSize := int32(10) + + pool, err := puddle.NewPool(&puddle.Config[net.Conn]{Constructor: constructor, Destructor: destructor, MaxSize: maxPoolSize}) + if err != nil { + log.Fatal(err) + } + + // Acquire resource from the pool. + res, err := pool.Acquire(context.Background()) + if err != nil { + log.Fatal(err) + } + + // Use resource. + _, err = res.Value().Write([]byte{1}) + if err != nil { + log.Fatal(err) + } + + // Release when done. + res.Release() +} +``` + +## Status + +Puddle is stable and feature complete. + +* Bug reports and fixes are welcome. +* New features will usually not be accepted if they can be feasibly implemented in a wrapper. +* Performance optimizations will usually not be accepted unless the performance issue rises to the level of a bug. + +## Supported Go Versions + +puddle supports the same versions of Go that are supported by the Go project. For [Go](https://golang.org/doc/devel/release.html#policy) that is the two most recent major releases. This means puddle supports Go 1.19 and higher. + +## License + +MIT diff --git a/vendor/github.com/jackc/puddle/v2/context.go b/vendor/github.com/jackc/puddle/v2/context.go new file mode 100644 index 0000000..e19d2a6 --- /dev/null +++ b/vendor/github.com/jackc/puddle/v2/context.go @@ -0,0 +1,24 @@ +package puddle + +import ( + "context" + "time" +) + +// valueCancelCtx combines two contexts into one. One context is used for values and the other is used for cancellation. +type valueCancelCtx struct { + valueCtx context.Context + cancelCtx context.Context +} + +func (ctx *valueCancelCtx) Deadline() (time.Time, bool) { return ctx.cancelCtx.Deadline() } +func (ctx *valueCancelCtx) Done() <-chan struct{} { return ctx.cancelCtx.Done() } +func (ctx *valueCancelCtx) Err() error { return ctx.cancelCtx.Err() } +func (ctx *valueCancelCtx) Value(key any) any { return ctx.valueCtx.Value(key) } + +func newValueCancelCtx(valueCtx, cancelContext context.Context) context.Context { + return &valueCancelCtx{ + valueCtx: valueCtx, + cancelCtx: cancelContext, + } +} diff --git a/vendor/github.com/jackc/puddle/v2/doc.go b/vendor/github.com/jackc/puddle/v2/doc.go new file mode 100644 index 0000000..818e4a6 --- /dev/null +++ b/vendor/github.com/jackc/puddle/v2/doc.go @@ -0,0 +1,11 @@ +// Package puddle is a generic resource pool with type-parametrized api. +/* + +Puddle is a tiny generic resource pool library for Go that uses the standard +context library to signal cancellation of acquires. It is designed to contain +the minimum functionality a resource pool needs that cannot be implemented +without concurrency concerns. For example, a database connection pool may use +puddle internally and implement health checks and keep-alive behavior without +needing to implement any concurrent code of its own. +*/ +package puddle diff --git a/vendor/github.com/jackc/puddle/v2/internal/genstack/gen_stack.go b/vendor/github.com/jackc/puddle/v2/internal/genstack/gen_stack.go new file mode 100644 index 0000000..7e4660c --- /dev/null +++ b/vendor/github.com/jackc/puddle/v2/internal/genstack/gen_stack.go @@ -0,0 +1,85 @@ +package genstack + +// GenStack implements a generational stack. +// +// GenStack works as common stack except for the fact that all elements in the +// older generation are guaranteed to be popped before any element in the newer +// generation. New elements are always pushed to the current (newest) +// generation. +// +// We could also say that GenStack behaves as a stack in case of a single +// generation, but it behaves as a queue of individual generation stacks. +type GenStack[T any] struct { + // We can represent arbitrary number of generations using 2 stacks. The + // new stack stores all new pushes and the old stack serves all reads. + // Old stack can represent multiple generations. If old == new, then all + // elements pushed in previous (not current) generations have already + // been popped. + + old *stack[T] + new *stack[T] +} + +// NewGenStack creates a new empty GenStack. +func NewGenStack[T any]() *GenStack[T] { + s := &stack[T]{} + return &GenStack[T]{ + old: s, + new: s, + } +} + +func (s *GenStack[T]) Pop() (T, bool) { + // Pushes always append to the new stack, so if the old once becomes + // empty, it will remail empty forever. + if s.old.len() == 0 && s.old != s.new { + s.old = s.new + } + + if s.old.len() == 0 { + var zero T + return zero, false + } + + return s.old.pop(), true +} + +// Push pushes a new element at the top of the stack. +func (s *GenStack[T]) Push(v T) { s.new.push(v) } + +// NextGen starts a new stack generation. +func (s *GenStack[T]) NextGen() { + if s.old == s.new { + s.new = &stack[T]{} + return + } + + // We need to pop from the old stack to the top of the new stack. Let's + // have an example: + // + // Old: 4 3 2 1 + // New: 8 7 6 5 + // PopOrder: 1 2 3 4 5 6 7 8 + // + // + // To preserve pop order, we have to take all elements from the old + // stack and push them to the top of new stack: + // + // New: 8 7 6 5 4 3 2 1 + // + s.new.push(s.old.takeAll()...) + + // We have the old stack allocated and empty, so why not to reuse it as + // new new stack. + s.old, s.new = s.new, s.old +} + +// Len returns number of elements in the stack. +func (s *GenStack[T]) Len() int { + l := s.old.len() + if s.old != s.new { + l += s.new.len() + } + + return l +} diff --git a/vendor/github.com/jackc/puddle/v2/internal/genstack/stack.go b/vendor/github.com/jackc/puddle/v2/internal/genstack/stack.go new file mode 100644 index 0000000..dbced0c --- /dev/null +++ b/vendor/github.com/jackc/puddle/v2/internal/genstack/stack.go @@ -0,0 +1,39 @@ +package genstack + +// stack is a wrapper around an array implementing a stack. +// +// We cannot use slice to represent the stack because append might change the +// pointer value of the slice. That would be an issue in GenStack +// implementation. +type stack[T any] struct { + arr []T +} + +// push pushes a new element at the top of a stack. +func (s *stack[T]) push(vs ...T) { s.arr = append(s.arr, vs...) } + +// pop pops the stack top-most element. +// +// If stack length is zero, this method panics. +func (s *stack[T]) pop() T { + idx := s.len() - 1 + val := s.arr[idx] + + // Avoid memory leak + var zero T + s.arr[idx] = zero + + s.arr = s.arr[:idx] + return val +} + +// takeAll returns all elements in the stack in order as they are stored - i.e. +// the top-most stack element is the last one. +func (s *stack[T]) takeAll() []T { + arr := s.arr + s.arr = nil + return arr +} + +// len returns number of elements in the stack. +func (s *stack[T]) len() int { return len(s.arr) } diff --git a/vendor/github.com/jackc/puddle/v2/log.go b/vendor/github.com/jackc/puddle/v2/log.go new file mode 100644 index 0000000..b21b946 --- /dev/null +++ b/vendor/github.com/jackc/puddle/v2/log.go @@ -0,0 +1,32 @@ +package puddle + +import "unsafe" + +type ints interface { + int | int8 | int16 | int32 | int64 | uint | uint8 | uint16 | uint32 | uint64 +} + +// log2Int returns log2 of an integer. This function panics if val < 0. For val +// == 0, returns 0. +func log2Int[T ints](val T) uint8 { + if val <= 0 { + panic("log2 of non-positive number does not exist") + } + + return log2IntRange(val, 0, uint8(8*unsafe.Sizeof(val))) +} + +func log2IntRange[T ints](val T, begin, end uint8) uint8 { + length := end - begin + if length == 1 { + return begin + } + + delim := begin + length/2 + mask := T(1) << delim + if mask > val { + return log2IntRange(val, begin, delim) + } else { + return log2IntRange(val, delim, end) + } +} diff --git a/vendor/github.com/jackc/puddle/v2/nanotime_time.go b/vendor/github.com/jackc/puddle/v2/nanotime_time.go new file mode 100644 index 0000000..f8e7593 --- /dev/null +++ b/vendor/github.com/jackc/puddle/v2/nanotime_time.go @@ -0,0 +1,13 @@ +//go:build purego || appengine || js + +// This file contains the safe implementation of nanotime using time.Now(). + +package puddle + +import ( + "time" +) + +func nanotime() int64 { + return time.Now().UnixNano() +} diff --git a/vendor/github.com/jackc/puddle/v2/nanotime_unsafe.go b/vendor/github.com/jackc/puddle/v2/nanotime_unsafe.go new file mode 100644 index 0000000..fc3b8a2 --- /dev/null +++ b/vendor/github.com/jackc/puddle/v2/nanotime_unsafe.go @@ -0,0 +1,12 @@ +//go:build !purego && !appengine && !js + +// This file contains the implementation of nanotime using runtime.nanotime. + +package puddle + +import "unsafe" + +var _ = unsafe.Sizeof(0) + +//go:linkname nanotime runtime.nanotime +func nanotime() int64 diff --git a/vendor/github.com/jackc/puddle/v2/pool.go b/vendor/github.com/jackc/puddle/v2/pool.go new file mode 100644 index 0000000..c8edc0f --- /dev/null +++ b/vendor/github.com/jackc/puddle/v2/pool.go @@ -0,0 +1,696 @@ +package puddle + +import ( + "context" + "errors" + "sync" + "sync/atomic" + "time" + + "github.com/jackc/puddle/v2/internal/genstack" + "golang.org/x/sync/semaphore" +) + +const ( + resourceStatusConstructing = 0 + resourceStatusIdle = iota + resourceStatusAcquired = iota + resourceStatusHijacked = iota +) + +// ErrClosedPool occurs on an attempt to acquire a connection from a closed pool +// or a pool that is closed while the acquire is waiting. +var ErrClosedPool = errors.New("closed pool") + +// ErrNotAvailable occurs on an attempt to acquire a resource from a pool +// that is at maximum capacity and has no available resources. +var ErrNotAvailable = errors.New("resource not available") + +// Constructor is a function called by the pool to construct a resource. +type Constructor[T any] func(ctx context.Context) (res T, err error) + +// Destructor is a function called by the pool to destroy a resource. +type Destructor[T any] func(res T) + +// Resource is the resource handle returned by acquiring from the pool. +type Resource[T any] struct { + value T + pool *Pool[T] + creationTime time.Time + lastUsedNano int64 + poolResetCount int + status byte +} + +// Value returns the resource value. +func (res *Resource[T]) Value() T { + if !(res.status == resourceStatusAcquired || res.status == resourceStatusHijacked) { + panic("tried to access resource that is not acquired or hijacked") + } + return res.value +} + +// Release returns the resource to the pool. res must not be subsequently used. +func (res *Resource[T]) Release() { + if res.status != resourceStatusAcquired { + panic("tried to release resource that is not acquired") + } + res.pool.releaseAcquiredResource(res, nanotime()) +} + +// ReleaseUnused returns the resource to the pool without updating when it was last used used. i.e. LastUsedNanotime +// will not change. res must not be subsequently used. +func (res *Resource[T]) ReleaseUnused() { + if res.status != resourceStatusAcquired { + panic("tried to release resource that is not acquired") + } + res.pool.releaseAcquiredResource(res, res.lastUsedNano) +} + +// Destroy returns the resource to the pool for destruction. res must not be +// subsequently used. +func (res *Resource[T]) Destroy() { + if res.status != resourceStatusAcquired { + panic("tried to destroy resource that is not acquired") + } + go res.pool.destroyAcquiredResource(res) +} + +// Hijack assumes ownership of the resource from the pool. Caller is responsible +// for cleanup of resource value. +func (res *Resource[T]) Hijack() { + if res.status != resourceStatusAcquired { + panic("tried to hijack resource that is not acquired") + } + res.pool.hijackAcquiredResource(res) +} + +// CreationTime returns when the resource was created by the pool. +func (res *Resource[T]) CreationTime() time.Time { + if !(res.status == resourceStatusAcquired || res.status == resourceStatusHijacked) { + panic("tried to access resource that is not acquired or hijacked") + } + return res.creationTime +} + +// LastUsedNanotime returns when Release was last called on the resource measured in nanoseconds from an arbitrary time +// (a monotonic time). Returns creation time if Release has never been called. This is only useful to compare with +// other calls to LastUsedNanotime. In almost all cases, IdleDuration should be used instead. +func (res *Resource[T]) LastUsedNanotime() int64 { + if !(res.status == resourceStatusAcquired || res.status == resourceStatusHijacked) { + panic("tried to access resource that is not acquired or hijacked") + } + + return res.lastUsedNano +} + +// IdleDuration returns the duration since Release was last called on the resource. This is equivalent to subtracting +// LastUsedNanotime to the current nanotime. +func (res *Resource[T]) IdleDuration() time.Duration { + if !(res.status == resourceStatusAcquired || res.status == resourceStatusHijacked) { + panic("tried to access resource that is not acquired or hijacked") + } + + return time.Duration(nanotime() - res.lastUsedNano) +} + +// Pool is a concurrency-safe resource pool. +type Pool[T any] struct { + // mux is the pool internal lock. Any modification of shared state of + // the pool (but Acquires of acquireSem) must be performed only by + // holder of the lock. Long running operations are not allowed when mux + // is held. + mux sync.Mutex + // acquireSem provides an allowance to acquire a resource. + // + // Releases are allowed only when caller holds mux. Acquires have to + // happen before mux is locked (doesn't apply to semaphore.TryAcquire in + // AcquireAllIdle). + acquireSem *semaphore.Weighted + destructWG sync.WaitGroup + + allResources resList[T] + idleResources *genstack.GenStack[*Resource[T]] + + constructor Constructor[T] + destructor Destructor[T] + maxSize int32 + + acquireCount int64 + acquireDuration time.Duration + emptyAcquireCount int64 + canceledAcquireCount atomic.Int64 + + resetCount int + + baseAcquireCtx context.Context + cancelBaseAcquireCtx context.CancelFunc + closed bool +} + +type Config[T any] struct { + Constructor Constructor[T] + Destructor Destructor[T] + MaxSize int32 +} + +// NewPool creates a new pool. Panics if maxSize is less than 1. +func NewPool[T any](config *Config[T]) (*Pool[T], error) { + if config.MaxSize < 1 { + return nil, errors.New("MaxSize must be >= 1") + } + + baseAcquireCtx, cancelBaseAcquireCtx := context.WithCancel(context.Background()) + + return &Pool[T]{ + acquireSem: semaphore.NewWeighted(int64(config.MaxSize)), + idleResources: genstack.NewGenStack[*Resource[T]](), + maxSize: config.MaxSize, + constructor: config.Constructor, + destructor: config.Destructor, + baseAcquireCtx: baseAcquireCtx, + cancelBaseAcquireCtx: cancelBaseAcquireCtx, + }, nil +} + +// Close destroys all resources in the pool and rejects future Acquire calls. +// Blocks until all resources are returned to pool and destroyed. +func (p *Pool[T]) Close() { + defer p.destructWG.Wait() + + p.mux.Lock() + defer p.mux.Unlock() + + if p.closed { + return + } + p.closed = true + p.cancelBaseAcquireCtx() + + for res, ok := p.idleResources.Pop(); ok; res, ok = p.idleResources.Pop() { + p.allResources.remove(res) + go p.destructResourceValue(res.value) + } +} + +// Stat is a snapshot of Pool statistics. +type Stat struct { + constructingResources int32 + acquiredResources int32 + idleResources int32 + maxResources int32 + acquireCount int64 + acquireDuration time.Duration + emptyAcquireCount int64 + canceledAcquireCount int64 +} + +// TotalResources returns the total number of resources currently in the pool. +// The value is the sum of ConstructingResources, AcquiredResources, and +// IdleResources. +func (s *Stat) TotalResources() int32 { + return s.constructingResources + s.acquiredResources + s.idleResources +} + +// ConstructingResources returns the number of resources with construction in progress in +// the pool. +func (s *Stat) ConstructingResources() int32 { + return s.constructingResources +} + +// AcquiredResources returns the number of currently acquired resources in the pool. +func (s *Stat) AcquiredResources() int32 { + return s.acquiredResources +} + +// IdleResources returns the number of currently idle resources in the pool. +func (s *Stat) IdleResources() int32 { + return s.idleResources +} + +// MaxResources returns the maximum size of the pool. +func (s *Stat) MaxResources() int32 { + return s.maxResources +} + +// AcquireCount returns the cumulative count of successful acquires from the pool. +func (s *Stat) AcquireCount() int64 { + return s.acquireCount +} + +// AcquireDuration returns the total duration of all successful acquires from +// the pool. +func (s *Stat) AcquireDuration() time.Duration { + return s.acquireDuration +} + +// EmptyAcquireCount returns the cumulative count of successful acquires from the pool +// that waited for a resource to be released or constructed because the pool was +// empty. +func (s *Stat) EmptyAcquireCount() int64 { + return s.emptyAcquireCount +} + +// CanceledAcquireCount returns the cumulative count of acquires from the pool +// that were canceled by a context. +func (s *Stat) CanceledAcquireCount() int64 { + return s.canceledAcquireCount +} + +// Stat returns the current pool statistics. +func (p *Pool[T]) Stat() *Stat { + p.mux.Lock() + defer p.mux.Unlock() + + s := &Stat{ + maxResources: p.maxSize, + acquireCount: p.acquireCount, + emptyAcquireCount: p.emptyAcquireCount, + canceledAcquireCount: p.canceledAcquireCount.Load(), + acquireDuration: p.acquireDuration, + } + + for _, res := range p.allResources { + switch res.status { + case resourceStatusConstructing: + s.constructingResources += 1 + case resourceStatusIdle: + s.idleResources += 1 + case resourceStatusAcquired: + s.acquiredResources += 1 + } + } + + return s +} + +// tryAcquireIdleResource checks if there is any idle resource. If there is +// some, this method removes it from idle list and returns it. If the idle pool +// is empty, this method returns nil and doesn't modify the idleResources slice. +// +// WARNING: Caller of this method must hold the pool mutex! +func (p *Pool[T]) tryAcquireIdleResource() *Resource[T] { + res, ok := p.idleResources.Pop() + if !ok { + return nil + } + + res.status = resourceStatusAcquired + return res +} + +// createNewResource creates a new resource and inserts it into list of pool +// resources. +// +// WARNING: Caller of this method must hold the pool mutex! +func (p *Pool[T]) createNewResource() *Resource[T] { + res := &Resource[T]{ + pool: p, + creationTime: time.Now(), + lastUsedNano: nanotime(), + poolResetCount: p.resetCount, + status: resourceStatusConstructing, + } + + p.allResources.append(res) + p.destructWG.Add(1) + + return res +} + +// Acquire gets a resource from the pool. If no resources are available and the pool is not at maximum capacity it will +// create a new resource. If the pool is at maximum capacity it will block until a resource is available. ctx can be +// used to cancel the Acquire. +// +// If Acquire creates a new resource the resource constructor function will receive a context that delegates Value() to +// ctx. Canceling ctx will cause Acquire to return immediately but it will not cancel the resource creation. This avoids +// the problem of it being impossible to create resources when the time to create a resource is greater than any one +// caller of Acquire is willing to wait. +func (p *Pool[T]) Acquire(ctx context.Context) (_ *Resource[T], err error) { + select { + case <-ctx.Done(): + p.canceledAcquireCount.Add(1) + return nil, ctx.Err() + default: + } + + return p.acquire(ctx) +} + +// acquire is a continuation of Acquire function that doesn't check context +// validity. +// +// This function exists solely only for benchmarking purposes. +func (p *Pool[T]) acquire(ctx context.Context) (*Resource[T], error) { + startNano := nanotime() + + var waitedForLock bool + if !p.acquireSem.TryAcquire(1) { + waitedForLock = true + err := p.acquireSem.Acquire(ctx, 1) + if err != nil { + p.canceledAcquireCount.Add(1) + return nil, err + } + } + + p.mux.Lock() + if p.closed { + p.acquireSem.Release(1) + p.mux.Unlock() + return nil, ErrClosedPool + } + + // If a resource is available in the pool. + if res := p.tryAcquireIdleResource(); res != nil { + if waitedForLock { + p.emptyAcquireCount += 1 + } + p.acquireCount += 1 + p.acquireDuration += time.Duration(nanotime() - startNano) + p.mux.Unlock() + return res, nil + } + + if len(p.allResources) >= int(p.maxSize) { + // Unreachable code. + panic("bug: semaphore allowed more acquires than pool allows") + } + + // The resource is not idle, but there is enough space to create one. + res := p.createNewResource() + p.mux.Unlock() + + res, err := p.initResourceValue(ctx, res) + if err != nil { + return nil, err + } + + p.mux.Lock() + defer p.mux.Unlock() + + p.emptyAcquireCount += 1 + p.acquireCount += 1 + p.acquireDuration += time.Duration(nanotime() - startNano) + + return res, nil +} + +func (p *Pool[T]) initResourceValue(ctx context.Context, res *Resource[T]) (*Resource[T], error) { + // Create the resource in a goroutine to immediately return from Acquire + // if ctx is canceled without also canceling the constructor. + // + // See: + // - https://github.com/jackc/pgx/issues/1287 + // - https://github.com/jackc/pgx/issues/1259 + constructErrChan := make(chan error) + go func() { + constructorCtx := newValueCancelCtx(ctx, p.baseAcquireCtx) + value, err := p.constructor(constructorCtx) + if err != nil { + p.mux.Lock() + p.allResources.remove(res) + p.destructWG.Done() + + // The resource won't be acquired because its + // construction failed. We have to allow someone else to + // take that resouce. + p.acquireSem.Release(1) + p.mux.Unlock() + + select { + case constructErrChan <- err: + case <-ctx.Done(): + // The caller is cancelled, so no-one awaits the + // error. This branch avoid goroutine leak. + } + return + } + + // The resource is already in p.allResources where it might be read. So we need to acquire the lock to update its + // status. + p.mux.Lock() + res.value = value + res.status = resourceStatusAcquired + p.mux.Unlock() + + // This select works because the channel is unbuffered. + select { + case constructErrChan <- nil: + case <-ctx.Done(): + p.releaseAcquiredResource(res, res.lastUsedNano) + } + }() + + select { + case <-ctx.Done(): + p.canceledAcquireCount.Add(1) + return nil, ctx.Err() + case err := <-constructErrChan: + if err != nil { + return nil, err + } + return res, nil + } +} + +// TryAcquire gets a resource from the pool if one is immediately available. If not, it returns ErrNotAvailable. If no +// resources are available but the pool has room to grow, a resource will be created in the background. ctx is only +// used to cancel the background creation. +func (p *Pool[T]) TryAcquire(ctx context.Context) (*Resource[T], error) { + if !p.acquireSem.TryAcquire(1) { + return nil, ErrNotAvailable + } + + p.mux.Lock() + defer p.mux.Unlock() + + if p.closed { + p.acquireSem.Release(1) + return nil, ErrClosedPool + } + + // If a resource is available now + if res := p.tryAcquireIdleResource(); res != nil { + p.acquireCount += 1 + return res, nil + } + + if len(p.allResources) >= int(p.maxSize) { + // Unreachable code. + panic("bug: semaphore allowed more acquires than pool allows") + } + + res := p.createNewResource() + go func() { + value, err := p.constructor(ctx) + + p.mux.Lock() + defer p.mux.Unlock() + // We have to create the resource and only then release the + // semaphore - For the time being there is no resource that + // someone could acquire. + defer p.acquireSem.Release(1) + + if err != nil { + p.allResources.remove(res) + p.destructWG.Done() + return + } + + res.value = value + res.status = resourceStatusIdle + p.idleResources.Push(res) + }() + + return nil, ErrNotAvailable +} + +// acquireSemAll tries to acquire num free tokens from sem. This function is +// guaranteed to acquire at least the lowest number of tokens that has been +// available in the semaphore during runtime of this function. +// +// For the time being, semaphore doesn't allow to acquire all tokens atomically +// (see https://github.com/golang/sync/pull/19). We simulate this by trying all +// powers of 2 that are less or equal to num. +// +// For example, let's immagine we have 19 free tokens in the semaphore which in +// total has 24 tokens (i.e. the maxSize of the pool is 24 resources). Then if +// num is 24, the log2Uint(24) is 4 and we try to acquire 16, 8, 4, 2 and 1 +// tokens. Out of those, the acquire of 16, 2 and 1 tokens will succeed. +// +// Naturally, Acquires and Releases of the semaphore might take place +// concurrently. For this reason, it's not guaranteed that absolutely all free +// tokens in the semaphore will be acquired. But it's guaranteed that at least +// the minimal number of tokens that has been present over the whole process +// will be acquired. This is sufficient for the use-case we have in this +// package. +// +// TODO: Replace this with acquireSem.TryAcquireAll() if it gets to +// upstream. https://github.com/golang/sync/pull/19 +func acquireSemAll(sem *semaphore.Weighted, num int) int { + if sem.TryAcquire(int64(num)) { + return num + } + + var acquired int + for i := int(log2Int(num)); i >= 0; i-- { + val := 1 << i + if sem.TryAcquire(int64(val)) { + acquired += val + } + } + + return acquired +} + +// AcquireAllIdle acquires all currently idle resources. Its intended use is for +// health check and keep-alive functionality. It does not update pool +// statistics. +func (p *Pool[T]) AcquireAllIdle() []*Resource[T] { + p.mux.Lock() + defer p.mux.Unlock() + + if p.closed { + return nil + } + + numIdle := p.idleResources.Len() + if numIdle == 0 { + return nil + } + + // In acquireSemAll we use only TryAcquire and not Acquire. Because + // TryAcquire cannot block, the fact that we hold mutex locked and try + // to acquire semaphore cannot result in dead-lock. + // + // Because the mutex is locked, no parallel Release can run. This + // implies that the number of tokens can only decrease because some + // Acquire/TryAcquire call can consume the semaphore token. Consequently + // acquired is always less or equal to numIdle. Moreover if acquired < + // numIdle, then there are some parallel Acquire/TryAcquire calls that + // will take the remaining idle connections. + acquired := acquireSemAll(p.acquireSem, numIdle) + + idle := make([]*Resource[T], acquired) + for i := range idle { + res, _ := p.idleResources.Pop() + res.status = resourceStatusAcquired + idle[i] = res + } + + // We have to bump the generation to ensure that Acquire/TryAcquire + // calls running in parallel (those which caused acquired < numIdle) + // will consume old connections and not freshly released connections + // instead. + p.idleResources.NextGen() + + return idle +} + +// CreateResource constructs a new resource without acquiring it. It goes straight in the IdlePool. If the pool is full +// it returns an error. It can be useful to maintain warm resources under little load. +func (p *Pool[T]) CreateResource(ctx context.Context) error { + if !p.acquireSem.TryAcquire(1) { + return ErrNotAvailable + } + + p.mux.Lock() + if p.closed { + p.acquireSem.Release(1) + p.mux.Unlock() + return ErrClosedPool + } + + if len(p.allResources) >= int(p.maxSize) { + p.acquireSem.Release(1) + p.mux.Unlock() + return ErrNotAvailable + } + + res := p.createNewResource() + p.mux.Unlock() + + value, err := p.constructor(ctx) + p.mux.Lock() + defer p.mux.Unlock() + defer p.acquireSem.Release(1) + if err != nil { + p.allResources.remove(res) + p.destructWG.Done() + return err + } + + res.value = value + res.status = resourceStatusIdle + + // If closed while constructing resource then destroy it and return an error + if p.closed { + go p.destructResourceValue(res.value) + return ErrClosedPool + } + + p.idleResources.Push(res) + + return nil +} + +// Reset destroys all resources, but leaves the pool open. It is intended for use when an error is detected that would +// disrupt all resources (such as a network interruption or a server state change). +// +// It is safe to reset a pool while resources are checked out. Those resources will be destroyed when they are returned +// to the pool. +func (p *Pool[T]) Reset() { + p.mux.Lock() + defer p.mux.Unlock() + + p.resetCount++ + + for res, ok := p.idleResources.Pop(); ok; res, ok = p.idleResources.Pop() { + p.allResources.remove(res) + go p.destructResourceValue(res.value) + } +} + +// releaseAcquiredResource returns res to the the pool. +func (p *Pool[T]) releaseAcquiredResource(res *Resource[T], lastUsedNano int64) { + p.mux.Lock() + defer p.mux.Unlock() + defer p.acquireSem.Release(1) + + if p.closed || res.poolResetCount != p.resetCount { + p.allResources.remove(res) + go p.destructResourceValue(res.value) + } else { + res.lastUsedNano = lastUsedNano + res.status = resourceStatusIdle + p.idleResources.Push(res) + } +} + +// Remove removes res from the pool and closes it. If res is not part of the +// pool Remove will panic. +func (p *Pool[T]) destroyAcquiredResource(res *Resource[T]) { + p.destructResourceValue(res.value) + + p.mux.Lock() + defer p.mux.Unlock() + defer p.acquireSem.Release(1) + + p.allResources.remove(res) +} + +func (p *Pool[T]) hijackAcquiredResource(res *Resource[T]) { + p.mux.Lock() + defer p.mux.Unlock() + defer p.acquireSem.Release(1) + + p.allResources.remove(res) + res.status = resourceStatusHijacked + p.destructWG.Done() // not responsible for destructing hijacked resources +} + +func (p *Pool[T]) destructResourceValue(value T) { + p.destructor(value) + p.destructWG.Done() +} diff --git a/vendor/github.com/jackc/puddle/v2/resource_list.go b/vendor/github.com/jackc/puddle/v2/resource_list.go new file mode 100644 index 0000000..b243095 --- /dev/null +++ b/vendor/github.com/jackc/puddle/v2/resource_list.go @@ -0,0 +1,28 @@ +package puddle + +type resList[T any] []*Resource[T] + +func (l *resList[T]) append(val *Resource[T]) { *l = append(*l, val) } + +func (l *resList[T]) popBack() *Resource[T] { + idx := len(*l) - 1 + val := (*l)[idx] + (*l)[idx] = nil // Avoid memory leak + *l = (*l)[:idx] + + return val +} + +func (l *resList[T]) remove(val *Resource[T]) { + for i, elem := range *l { + if elem == val { + lastIdx := len(*l) - 1 + (*l)[i] = (*l)[lastIdx] + (*l)[lastIdx] = nil // Avoid memory leak + (*l) = (*l)[:lastIdx] + return + } + } + + panic("BUG: removeResource could not find res in slice") +} -- cgit v1.2.3-70-g09d2