pool

type Allocator func() (*worker.Process, error)

type Command func(cmd string) *exec.Cmd

type Config struct {
	// Debug flag creates new fresh worker before every request.
	Debug bool

	// Command used to override the server command with the custom one
	Command string `mapstructure:"command"`

	// NumWorkers defines how many sub-processes can be run at once. This value
	// might be doubled by Swapper while hot-swap. Defaults to number of CPU cores.
	NumWorkers uint64 `mapstructure:"num_workers"`

	// MaxJobs defines how many executions is allowed for the worker until
	// its destruction. set 1 to create new process for each new task, 0 to let
	// worker handle as many tasks as it can.
	MaxJobs uint64 `mapstructure:"max_jobs"`

	// AllocateTimeout defines for how long pool will be waiting for a worker to
	// be freed to handle the task. Defaults to 60s.
	AllocateTimeout time.Duration `mapstructure:"allocate_timeout"`

	// DestroyTimeout defines for how long pool should be waiting for worker to
	// properly destroy, if timeout reached worker will be killed. Defaults to 60s.
	DestroyTimeout time.Duration `mapstructure:"destroy_timeout"`

	// ResetTimeout defines how long pool should wait before start killing workers
	ResetTimeout time.Duration `mapstructure:"reset_timeout"`

	// Supervision config to limit worker and pool memory usage.
	Supervisor *SupervisorConfig `mapstructure:"supervisor"`
}

type Factory interface {
	// SpawnWorkerWithTimeout creates new WorkerProcess process based on given command with context.
	// Process must not be started.
	SpawnWorkerWithTimeout(context.Context, *exec.Cmd) (*worker.Process, error)
	// SpawnWorker creates new WorkerProcess process based on given command.
	// Process must not be started.
	SpawnWorker(*exec.Cmd) (*worker.Process, error)
	// Close the factory and underlying connections.
	Close() error
}

type SupervisorConfig struct {
	// WatchTick defines how often to check the state of worker.
	WatchTick time.Duration `mapstructure:"watch_tick"`

	// TTL defines maximum time for the worker is allowed to live.
	TTL time.Duration `mapstructure:"ttl"`

	// IdleTTL defines maximum duration worker can spend in idle mode. Disabled when 0.
	IdleTTL time.Duration `mapstructure:"idle_ttl"`

	// ExecTTL defines maximum lifetime per job.
	ExecTTL time.Duration `mapstructure:"exec_ttl"`

	// MaxWorkerMemory limits memory per worker.
	MaxWorkerMemory uint64 `mapstructure:"max_worker_memory"`
}