73 lines
2.0 KiB
Go
73 lines
2.0 KiB
Go
// Copyright 2016 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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// Package plugin implements loading and symbol resolution of Go plugins.
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//
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// A plugin is a Go main package with exported functions and variables that
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// has been built with:
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//
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// go build -buildmode=plugin
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//
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// When a plugin is first opened, the init functions of all packages not
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// already part of the program are called. The main function is not run.
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// A plugin is only initialized once, and cannot be closed.
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//
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// Currently plugins are only supported on Linux and macOS.
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// Please report any issues.
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package plugin
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// Plugin is a loaded Go plugin.
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type Plugin struct {
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pluginpath string
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err string // set if plugin failed to load
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loaded chan struct{} // closed when loaded
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syms map[string]interface{}
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}
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// Open opens a Go plugin.
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// If a path has already been opened, then the existing *Plugin is returned.
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// It is safe for concurrent use by multiple goroutines.
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func Open(path string) (*Plugin, error) {
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return open(path)
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}
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// Lookup searches for a symbol named symName in plugin p.
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// A symbol is any exported variable or function.
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// It reports an error if the symbol is not found.
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// It is safe for concurrent use by multiple goroutines.
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func (p *Plugin) Lookup(symName string) (Symbol, error) {
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return lookup(p, symName)
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}
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// A Symbol is a pointer to a variable or function.
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//
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// For example, a plugin defined as
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//
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// package main
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//
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// import "fmt"
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//
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// var V int
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//
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// func F() { fmt.Printf("Hello, number %d\n", V) }
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//
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// may be loaded with the Open function and then the exported package
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// symbols V and F can be accessed
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//
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// p, err := plugin.Open("plugin_name.so")
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// if err != nil {
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// panic(err)
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// }
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// v, err := p.Lookup("V")
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// if err != nil {
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// panic(err)
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// }
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// f, err := p.Lookup("F")
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// if err != nil {
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// panic(err)
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// }
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// *v.(*int) = 7
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// f.(func())() // prints "Hello, number 7"
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type Symbol interface{}
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