tinygo/cgo/sync.go
Ayke van Laethem 11567c62d4 cgo: refactor; support multiple cgo files in a single package
This is a big commit that does a few things:

  * It moves CGo processing into a separate package. It never really
    belonged in the loader package, and certainly not now that the
    loader package may be refactored into a driver package.
  * It adds support for multiple CGo files (files that import package
    "C") in a single package. Previously, this led to multiple
    definition errors in the Go typecheck phase because certain C
    symbols were defined multiple times in all the files. Now it
    generates a new fake AST that defines these, to avoid multiple
    definition errors.
  * It improves debug info in a few edge cases that are probably not
    relevant outside of bugs in cgo itself.
2019-05-12 10:49:15 +02:00

46 строки
1,1 КиБ
Go

package cgo
import (
"sync"
"unsafe"
)
// #include <stdlib.h>
import "C"
// refMap is a convenient way to store opaque references that can be passed to
// C. It is useful if an API uses function pointers and you cannot pass a Go
// pointer but only a C pointer.
type refMap struct {
refs map[unsafe.Pointer]interface{}
lock sync.Mutex
}
// Put stores a value in the map. It can later be retrieved using Get. It must
// be removed using Remove to avoid memory leaks.
func (m *refMap) Put(v interface{}) unsafe.Pointer {
m.lock.Lock()
defer m.lock.Unlock()
if m.refs == nil {
m.refs = make(map[unsafe.Pointer]interface{}, 1)
}
ref := C.malloc(1)
m.refs[ref] = v
return ref
}
// Get returns a stored value previously inserted with Put. Use the same
// reference as you got from Put.
func (m *refMap) Get(ref unsafe.Pointer) interface{} {
m.lock.Lock()
defer m.lock.Unlock()
return m.refs[ref]
}
// Remove deletes a single reference from the map.
func (m *refMap) Remove(ref unsafe.Pointer) {
m.lock.Lock()
defer m.lock.Unlock()
delete(m.refs, ref)
C.free(ref)
}