mirror of
https://github.com/ergochat/ergo.git
synced 2024-11-22 20:09:41 +01:00
42 lines
1.4 KiB
Go
42 lines
1.4 KiB
Go
// Copyright (c) 2018 Shivaram Lingamneni
|
|
|
|
package irc
|
|
|
|
import (
|
|
"runtime"
|
|
|
|
"github.com/ergochat/ergo/irc/utils"
|
|
)
|
|
|
|
// See #237 for context. Operations that might allocate large amounts of temporary
|
|
// garbage, or temporarily tie up some other resource, may cause thrashing unless
|
|
// their concurrency is artificially restricted. We use `chan bool` as a
|
|
// (regrettably, unary-encoded) counting semaphore to enforce these restrictions.
|
|
|
|
const (
|
|
// this is a tradeoff between exploiting CPU-level parallelism (higher values better)
|
|
// and not thrashing the allocator (lower values better). really this is all just
|
|
// guesswork. oragono *can* make use of cores beyond this limit --- just not for
|
|
// the protected operations.
|
|
MaxServerSemaphoreCapacity = 32
|
|
)
|
|
|
|
// ServerSemaphores includes a named Semaphore corresponding to each concurrency-limited
|
|
// sever operation.
|
|
type ServerSemaphores struct {
|
|
// each distinct operation MUST have its own semaphore;
|
|
// methods that acquire a semaphore MUST NOT call methods that acquire another
|
|
ClientDestroy utils.Semaphore
|
|
IPCheckScript utils.Semaphore
|
|
AuthScript utils.Semaphore
|
|
}
|
|
|
|
// Initialize initializes a set of server semaphores.
|
|
func (serversem *ServerSemaphores) Initialize() {
|
|
capacity := runtime.NumCPU()
|
|
if capacity > MaxServerSemaphoreCapacity {
|
|
capacity = MaxServerSemaphoreCapacity
|
|
}
|
|
serversem.ClientDestroy = utils.NewSemaphore(capacity)
|
|
}
|