Prompts for GPT

User

Next, I would like to know how to implement Error Handling and Task Result Retrieval for tasks.

DevChat

To implement error handling and result retrieval for tasks, we can modify the task type to return a result and an error. In this way, each task can return a result and a possible error. Then, we can handle this error in the worker and store the result in an appropriate place for later retrieval.

Here's how to modify the code to implement this feature:

First, we need to modify the task type to return a result and an error:

// Task represents a function that will be executed by a worker.
// It returns a result and an error.
type Task func() (interface{}, error)

Then, we need to handle the task's error in the worker and store the result in an appropriate place. This might require us to add a new field in the goPool structure to store task results, or provide a callback function to handle task results.

func (w *worker) start(pool *goPool, workerIndex int) {
    go func() {
        for t := range w.taskQueue {
            if t != nil {
                result, err := t()
                if err != nil {
                    // Handle error
                    fmt.Println("Task error:", err)
                } else {
                    // Store or handle result
                    fmt.Println("Task result:", result)
                }
            }
            pool.pushWorker(workerIndex)
        }
    }()
}

This is just a basic implementation, the actual implementation may vary depending on your specific needs. For example, you might want to provide an error callback function to handle task errors, or provide a result callback function to handle task results. You might also want to add a field in the goPool structure to store the results of all tasks for later retrieval.

User

worker.go

package gopool

import ( "context" "fmt" )

// worker represents a worker in the pool. type worker struct { taskQueue chan task }

func newWorker() *worker { return &worker{ taskQueue: make(chan task, 1), } }

func (w *worker) start(pool *goPool, workerIndex int) { go func() { for t := range w.taskQueue { if t != nil { if pool.timeout > 0 { // Create a context with timeout ctx, cancel := context.WithTimeout(context.Background(), pool.timeout) defer cancel()

                // Create a channel to receive the result of the task
                done := make(chan struct{})

                // Run the task in a separate goroutine
                go func() {
                    t()
                    close(done)
                }()

                // Wait for the task to finish or for the context to timeout
                select {
                case <-done:
                    // The task finished successfully
                case <-ctx.Done():
                    // The context timed out, the task took too long
                    fmt.Println("Task timed out")
                }
            } else {
                // If timeout is not set or is zero, just run the task
                t()
            }
        }
        pool.pushWorker(workerIndex)
    }
}()

}

option.go

package gopool

import ( "sync" "time" )

// Option represents an option for the pool. type Option func(*goPool)

// WithLock sets the lock for the pool. func WithLock(lock sync.Locker) Option { return func(p *goPool) { p.lock = lock p.cond = sync.NewCond(p.lock) } }

// WithMinWorkers sets the minimum number of workers for the pool. func WithMinWorkers(minWorkers int) Option { return func(p *goPool) { p.minWorkers = minWorkers } }

// WithTimeout sets the timeout for the pool. func WithTimeout(timeout time.Duration) Option { return func(p *goPool) { p.timeout = timeout } }

gopool.go

package gopool

import ( "sync" "time" )

// Task represents a function that will be executed by a worker. type task func()

// goPool represents a pool of workers. type goPool struct { workers []*worker maxWorkers int minWorkers int workerStack []int taskQueue chan task lock sync.Locker cond *sync.Cond timeout time.Duration }

// NewGoPool creates a new pool of workers. func NewGoPool(maxWorkers int, opts ...Option) *goPool { pool := &goPool{ maxWorkers: maxWorkers, minWorkers: maxWorkers, // Set minWorkers to maxWorkers by default workers: make([]*worker, maxWorkers), workerStack: make([]int, maxWorkers), taskQueue: make(chan task, 1e6), lock: new(sync.Mutex), timeout: 0, } for _, opt := range opts { opt(pool) } if pool.cond == nil { pool.cond = sync.NewCond(pool.lock) } for i := 0; i < pool.minWorkers; i++ { worker := newWorker() pool.workers[i] = worker pool.workerStack[i] = i worker.start(pool, i) } go pool.dispatch() return pool }

// AddTask adds a task to the pool. func (p *goPool) AddTask(t task) { p.taskQueue <- t }

// Release stops all workers and releases resources. func (p *goPool) Release() { close(p.taskQueue) p.cond.L.Lock() for len(p.workerStack) != p.maxWorkers { p.cond.Wait() } p.cond.L.Unlock() for _, worker := range p.workers { close(worker.taskQueue) } p.workers = nil p.workerStack = nil }

func (p *goPool) popWorker() int { p.lock.Lock() workerIndex := p.workerStack[len(p.workerStack)-1] p.workerStack = p.workerStack[:len(p.workerStack)-1] p.lock.Unlock() return workerIndex }

func (p *goPool) pushWorker(workerIndex int) { p.lock.Lock() p.workerStack = append(p.workerStack, workerIndex) p.lock.Unlock() p.cond.Signal() }

func (p *goPool) dispatch() { for t := range p.taskQueue { p.cond.L.Lock() for len(p.workerStack) == 0 { p.cond.Wait() } p.cond.L.Unlock() workerIndex := p.popWorker() p.workers[workerIndex].taskQueue <- t if len(p.taskQueue) > (p.maxWorkers-p.minWorkers)/2+p.minWorkers && len(p.workerStack) < p.maxWorkers { worker := newWorker() p.workers = append(p.workers, worker) p.workerStack = append(p.workerStack, len(p.workers)-1) worker.start(p, len(p.workers)-1) } else if len(p.taskQueue) < p.minWorkers && len(p.workerStack) > p.minWorkers { p.workers = p.workers[:len(p.workers)-1] p.workerStack = p.workerStack[:len(p.workerStack)-1] } } }

I think the callback function is a good idea. We can add an Option configuration function to the goPool to set the callback function, allowing users to customize how to handle the results and errors of the task. Please continue coding based on the existing code.

DevChat

First, we need to modify the task type to return a result and an error:

// Task represents a function that will be executed by a worker.
// It returns a result and an error.
type Task func() (interface{}, error)

Then, we need to add two new fields in the goPool structure to store the callback functions:

// goPool represents a pool of workers.
type goPool struct {
    // ...
    resultCallback func(interface{})
    errorCallback func(error)
    // ...
}

Next, we need to create two new Option functions to set these callback functions:

// WithResultCallback sets the result callback for the pool.
func WithResultCallback(callback func(interface{})) Option {
    return func(p *goPool) {
        p.resultCallback = callback
    }
}

// WithErrorCallback sets the error callback for the pool.
func WithErrorCallback(callback func(error)) Option {
    return func(p *goPool) {
        p.errorCallback = callback
    }
}

Finally, we need to call these callback functions in the worker:

func (w *worker) start(pool *goPool, workerIndex int) {
    go func() {
        for t := range w.taskQueue {
            if t != nil {
                result, err := t()
                if err != nil {
                    // Call the error callback
                    if pool.errorCallback != nil {
                        pool.errorCallback(err)
                    }
                } else {
                    // Call the result callback
                    if pool.resultCallback != nil {
                        pool.resultCallback(result)
                    }
                }
            }
            pool.pushWorker(workerIndex)
        }
    }()
}

In this way, users can customize how to handle the results and errors of tasks through the WithResultCallback and WithErrorCallback functions.

User

worker.go

                // Create a channel to receive the result of the task
                done := make(chan struct{})

                // Run the task in a separate goroutine
                go func() {
                    t()
                    close(done)
                }()

                // Wait for the task to finish or for the context to timeout
                select {
                case <-done:
                    // The task finished successfully
                case <-ctx.Done():
                    // The context timed out, the task took too long
                    fmt.Println("Task timed out")
                }
            } else {
                // If timeout is not set or is zero, just run the task
                t()
            }
        }
        pool.pushWorker(workerIndex)
    }
}()

}

The current start function is as follows, please expand on this basis, do not lose the timeout function.

DevChat

Based on the current start function, we can modify the task type to return results and errors, and then call the corresponding callback functions after the task is executed. Here is the modified code:

// Task represents a function that will be executed by a worker.
// It returns a result and an error.
type Task func() (interface{}, error)

// goPool represents a pool of workers.
type goPool struct {
    // ...
    resultCallback func(interface{})
    errorCallback func(error)
    // ...
}

// WithResultCallback sets the result callback for the pool.
func WithResultCallback(callback func(interface{})) Option {
    return func(p *goPool) {
        p.resultCallback = callback
    }
}

// WithErrorCallback sets the error callback for the pool.
func WithErrorCallback(callback func(error)) Option {
    return func(p *goPool) {
        p.errorCallback = callback
    }
}

func (w *worker) start(pool *goPool, workerIndex int) {
    go func() {
        for t := range w.taskQueue {
            if t != nil {
                var result interface{}
                var err error

                if pool.timeout > 0 {
                    // Create a context with timeout
                    ctx, cancel := context.WithTimeout(context.Background(), pool.timeout)
                    defer cancel()

                    // Create a channel to receive the result of the task
                    done := make(chan struct{})

                    // Run the task in a separate goroutine
                    go func() {
                        result, err = t()
                        close(done)
                    }()

                    // Wait for the task to finish or for the context to timeout
                    select {
                    case <-done:
                        // The task finished successfully
                        if err != nil && pool.errorCallback != nil {
                            pool.errorCallback(err)
                        } else if pool.resultCallback != nil {
                            pool.resultCallback(result)
                        }
                    case <-ctx.Done():
                        // The context timed out, the task took too long
                        if pool.errorCallback != nil {
                            pool.errorCallback(fmt.Errorf("Task timed out"))
                        }
                    }
                } else {
                    // If timeout is not set or is zero, just run the task
                    result, err = t()
                    if err != nil && pool.errorCallback != nil {
                        pool.errorCallback(err)
                    } else if pool.resultCallback != nil {
                        pool.resultCallback(result)
                    }
                }
            }
            pool.pushWorker(workerIndex)
        }
    }()
}

In this way, we have added error handling and result callback functions while retaining the timeout feature.

User

gopool_test.go

package gopool

import ( "sync" "testing" "time"

"github.com/daniel-hutao/spinlock"

)

func TestGoPoolWithMutex(t *testing.T) { pool := NewGoPool(100, WithLock(new(sync.Mutex))) for i := 0; i < 1000; i++ { pool.AddTask(func() (interface{}, error) { time.Sleep(10 * time.Millisecond) return nil, nil }) } pool.Release() }

func TestGoPoolWithSpinLock(t *testing.T) { pool := NewGoPool(100, WithLock(new(spinlock.SpinLock))) for i := 0; i < 1000; i++ { pool.AddTask(func() (interface{}, error) { time.Sleep(10 * time.Millisecond) return nil, nil }) } pool.Release() }

func BenchmarkGoPoolWithMutex(b *testing.B) { var wg sync.WaitGroup var taskNum = int(1e6) pool := NewGoPool(5e4, WithLock(new(sync.Mutex)))

b.ResetTimer()
for i := 0; i < b.N; i++ {
    wg.Add(taskNum)
    for num := 0; num < taskNum; num++ {
        pool.AddTask(func() (interface{}, error) {
            time.Sleep(10 * time.Millisecond)
            wg.Done()
            return nil, nil
        })
    }
}
wg.Wait()
b.StopTimer()
pool.Release()

}

func BenchmarkGoPoolWithSpinLock(b *testing.B) { var wg sync.WaitGroup var taskNum = int(1e6) pool := NewGoPool(5e4, WithLock(new(spinlock.SpinLock)))

b.ResetTimer()
for i := 0; i < b.N; i++ {
    wg.Add(taskNum)
    for num := 0; num < taskNum; num++ {
        pool.AddTask(func() (interface{}, error) {
            time.Sleep(10 * time.Millisecond)
            wg.Done()
            return nil, nil
        })
    }
}
wg.Wait()
b.StopTimer()
pool.Release()

}

func BenchmarkGoroutines(b *testing.B) { var wg sync.WaitGroup var taskNum = int(1e6)

for i := 0; i < b.N; i++ {
    wg.Add(taskNum)
    for num := 0; num < taskNum; num++ {
        go func() (interface{}, error) {
            time.Sleep(10 * time.Millisecond)
            wg.Done()
            return nil, nil
        }()
    }
}

}

I have already added return values to the existing task functions in the UT. Please continue to help me improve the test cases, adding test cases related to error handling and result retrieval of tasks.

DevChat

Based on the existing test cases, we can add some new test cases to test the error handling and result retrieval functions of tasks. Here are some possible test cases:

func TestGoPoolWithError(t *testing.T) {
    var errTaskError = errors.New("task error")
    pool := NewGoPool(100, WithErrorCallback(func(err error) {
        if err != errTaskError {
            t.Errorf("Expected error %v, but got %v", errTaskError, err)
        }
    }))
    pool.AddTask(func() (interface{}, error) {
        return nil, errTaskError
    })
    pool.Release()
}

func TestGoPoolWithResult(t *testing.T) {
    var expectedResult = "task result"
    pool := NewGoPool(100, WithResultCallback(func(result interface{}) {
        if result != expectedResult {
            t.Errorf("Expected result %v, but got %v", expectedResult, result)
        }
    }))
    pool.AddTask(func() (interface{}, error) {
        return expectedResult, nil
    })
    pool.Release()
}

In the TestGoPoolWithError test case, we created a task that returns an error and set an error callback function to check if the task's error is correct.

In the TestGoPoolWithResult test case, we created a task that returns a result and set a result callback function to check if the task's result is correct.

These test cases ensure that our error handling and result retrieval functions work properly.

User

gopool_test.go

package gopool

import ( "sync" "testing" "time" "errors"

"github.com/daniel-hutao/spinlock"

)

func BenchmarkGoPoolWithMutex(b *testing.B) { var wg sync.WaitGroup var taskNum = int(1e6) pool := NewGoPool(5e4, WithLock(new(sync.Mutex)))

b.ResetTimer()
for i := 0; i < b.N; i++ {
    wg.Add(taskNum)
    for num := 0; num < taskNum; num++ {
        pool.AddTask(func() (interface{}, error) {
            time.Sleep(10 * time.Millisecond)
            wg.Done()
            return nil, nil
        })
    }
}
wg.Wait()
b.StopTimer()
pool.Release()

}

func BenchmarkGoPoolWithSpinLock(b *testing.B) { var wg sync.WaitGroup var taskNum = int(1e6) pool := NewGoPool(5e4, WithLock(new(spinlock.SpinLock)))

b.ResetTimer()
for i := 0; i < b.N; i++ {
    wg.Add(taskNum)
    for num := 0; num < taskNum; num++ {
        pool.AddTask(func() (interface{}, error) {
            time.Sleep(10 * time.Millisecond)
            wg.Done()
            return nil, nil
        })
    }
}
wg.Wait()
b.StopTimer()
pool.Release()

}

func BenchmarkGoroutines(b *testing.B) { var wg sync.WaitGroup var taskNum = int(1e6)

for i := 0; i < b.N; i++ {
    wg.Add(taskNum)
    for num := 0; num < taskNum; num++ {
        go func() (interface{}, error) {
            time.Sleep(10 * time.Millisecond)
            wg.Done()
            return nil, nil
        }()
    }
}

}

func TestGoPoolWithError(t *testing.T) { var errTaskError = errors.New("task error") pool := NewGoPool(100, WithErrorCallback(func(err error) { if err != errTaskError { t.Errorf("Expected error %v, but got %v", errTaskError, err) } })) for i := 0; i< 1000; i++ { pool.AddTask(func() (interface{}, error) { return nil, errTaskError }) } pool.Release() }

func TestGoPoolWithResult(t *testing.T) { var expectedResult = "task result" pool := NewGoPool(100, WithResultCallback(func(result interface{}) { if result != expectedResult { t.Errorf("Expected result %v, but got %v", expectedResult, result) } })) for i := 0; i< 1000; i++ { pool.AddTask(func() (interface{}, error) { return expectedResult, nil }) } pool.Release() }

README.md

## Usage

Here is a simple example of how to use GoPool with sync.Mutex:

package main

import (
    "sync"
    "time"

    "github.com/devchat-ai/gopool"
)

func main() {
    pool := gopool.NewGoPool(100)
    for i := 0; i < 1000; i++ {
        pool.AddTask(func() {
            time.Sleep(10 * time.Millisecond)
        })
    }
    pool.Release()
}

And here is how to use GoPool with spinlock.SpinLock:

package main

import (
    "time"

    "github.com/daniel-hutao/spinlock"
    "github.com/devchat-ai/gopool"
)

func main() {
    pool := gopool.NewGoPool(100, gopool.WithLock(new(spinlock.SpinLock)))
    for i := 0; i < 1000; i++ {
        pool.AddTask(func() {
            time.Sleep(10 * time.Millisecond)
        })
    }
    pool.Release()
}

## Dynamic Worker Adjustment

GoPool supports dynamic worker adjustment. This means that the number of workers in the pool can increase or decrease based on the number of tasks in the queue. This feature can be enabled by setting the MinWorkers option when creating the pool.

Here is an example of how to use GoPool with dynamic worker adjustment:

package main

import (
    "time"

    "github.com/devchat-ai/gopool"
)

func main() {
    pool := gopool.NewGoPool(100, gopool.WithMinWorkers(50))
    for i := 0; i < 1000; i++ {
        pool.AddTask(func() {
            time.Sleep(10 * time.Millisecond)
        })
    }
    pool.Release()
}

In this example, the pool starts with 50 workers. If the number of tasks in the queue exceeds (MaxWorkers - MinWorkers) / 2 + MinWorkers, the pool will add more workers. If the number of tasks in the queue is less than MinWorkers, the pool will remove some workers.

Next, I would like you to continue to enhance the README file, adding introductions related to timeout, error handling, and Task Result Retrieval.

DevChat

In the README file, we can add the following content to introduce the new features:

Timeout

GoPool supports task timeout. If a task takes longer than the specified timeout, it will be cancelled. This feature can be enabled by setting the WithTimeout option when creating the pool.

Here is an example of how to use GoPool with task timeout:

package main

import (
    "time"

    "github.com/devchat-ai/gopool"
)

func main() {
    pool := gopool.NewGoPool(100, gopool.WithTimeout(1*time.Second))
    for i := 0; i < 1000; i++ {
        pool.AddTask(func() (interface{}, error) {
            time.Sleep(2 * time.Second)
            return nil, nil
        })
    }
    pool.Release()
}

In this example, the task will be cancelled if it takes longer than 1 second.

Error Handling

GoPool supports error handling. If a task returns an error, the error callback function will be called. This feature can be enabled by setting the WithErrorCallback option when creating the pool.

Here is an example of how to use GoPool with error handling:

package main

import (
    "errors"
    "fmt"

    "github.com/devchat-ai/gopool"
)

func main() {
    pool := gopool.NewGoPool(100, gopool.WithErrorCallback(func(err error) {
        fmt.Println("Task error:", err)
    }))
    for i := 0; i < 1000; i++ {
        pool.AddTask(func() (interface{}, error) {
            return nil, errors.New("task error")
        })
    }
    pool.Release()
}

In this example, if a task returns an error, the error will be printed to the console.

Task Result Retrieval

GoPool supports task result retrieval. If a task returns a result, the result callback function will be called. This feature can be enabled by setting the WithResultCallback option when creating the pool.

Here is an example of how to use GoPool with task result retrieval:

package main

import (
    "fmt"

    "github.com/devchat-ai/gopool"
)

func main() {
    pool := gopool.NewGoPool(100, gopool.WithResultCallback(func(result interface{}) {
        fmt.Println("Task result:", result)
    }))
    for i := 0; i < 1000; i++ {
        pool.AddTask(func() (interface{}, error) {
            return "task result", nil
        })
    }
    pool.Release()
}

In this example, if a task returns a result, the result will be printed to the console.

These new sections introduce how to use timeout, error handling, and task result retrieval features.