rs2322tcp/internal/client/virtual_port_manager_open.go

163 lines
3.3 KiB
Go

/*
* ============================================================================
* Projekt.....: rs2322tcp
* Datei.......: internal/client/virtual_port_manager_open.go
* Copyright (C) 2026 Dieter Lang
*
* SPDX-License-Identifier: GPL-3.0-or-later
*
* Beschreibung:
* Plattformneutrale Verwaltung geöffneter virtueller Ports.
*
* Die konkrete Erzeugung eines virtuellen seriellen Ports erfolgt über
* openVirtualPort() in der jeweiligen Plattformimplementierung.
* ============================================================================
*/
package client
import (
"fmt"
"sync"
)
///////////////////////////////////////////////////////////////////////////////
// Managed virtual port
///////////////////////////////////////////////////////////////////////////////
// ManagedVirtualPort verbindet einen reservierten Port mit einer
// VirtualSerial-Instanz und verwaltet deren Lebenszyklus.
type ManagedVirtualPort struct {
mu sync.Mutex
port *VirtualPort
manager *VirtualPortManager
number int
}
// Path returns the device path visible to the external application.
func (p *ManagedVirtualPort) Path() string {
if p == nil {
return ""
}
p.mu.Lock()
defer p.mu.Unlock()
if p.port == nil {
return ""
}
return p.port.Path()
}
// Read reads data from the underlying virtual serial device.
func (p *ManagedVirtualPort) Read(b []byte) (int, error) {
if p == nil {
return 0, fmt.Errorf("managed virtual port is nil")
}
p.mu.Lock()
port := p.port
p.mu.Unlock()
if port == nil {
return 0, fmt.Errorf("managed virtual port is closed")
}
return port.Read(b)
}
// Write writes data to the underlying virtual serial device.
func (p *ManagedVirtualPort) Write(b []byte) (int, error) {
if p == nil {
return 0, fmt.Errorf("managed virtual port is nil")
}
p.mu.Lock()
port := p.port
p.mu.Unlock()
if port == nil {
return 0, fmt.Errorf("managed virtual port is closed")
}
return port.Write(b)
}
// Close closes the managed virtual port and releases its reservation.
func (p *ManagedVirtualPort) Close() error {
if p == nil {
return nil
}
p.mu.Lock()
port := p.port
p.port = nil
manager := p.manager
number := p.number
p.mu.Unlock()
if port == nil {
return nil
}
err := port.Close()
if manager != nil {
manager.Release(number)
}
return err
}
///////////////////////////////////////////////////////////////////////////////
// Open
///////////////////////////////////////////////////////////////////////////////
// Open creates a new virtual serial port using the next free port number.
func (m *VirtualPortManager) Open() (*ManagedVirtualPort, error) {
if m == nil {
return nil, fmt.Errorf("virtual port manager is nil")
}
number, err := m.Reserve()
if err != nil {
return nil, err
}
port, err := openVirtualPort(m, number)
if err != nil {
m.Release(number)
return nil, err
}
return port, nil
}
// OpenSpecific creates a new virtual serial port using exactly the specified
// port number.
func (m *VirtualPortManager) OpenSpecific(
number int,
) (*ManagedVirtualPort, error) {
if m == nil {
return nil, fmt.Errorf("virtual port manager is nil")
}
if err := m.ReserveSpecific(number); err != nil {
return nil, err
}
port, err := openVirtualPort(m, number)
if err != nil {
m.Release(number)
return nil, err
}
return port, nil
}