| // Copyright 2015 Peter Mattis. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or |
| // implied. See the License for the specific language governing |
| // permissions and limitations under the License. See the AUTHORS file |
| // for names of contributors. |
| |
| // +build go1.4,!go1.5 |
| |
| package goid |
| |
| import "unsafe" |
| |
| var pointerSize = unsafe.Sizeof(uintptr(0)) |
| |
| // Backdoor access to runtime·getg(). |
| func getg() uintptr // in goid_go1.4.s |
| |
| // Get returns the id of the current goroutine. |
| func Get() int64 { |
| // The goid is the 16th field in the G struct where each field is a |
| // pointer, uintptr or padded to that size. See runtime.h from the |
| // Go sources. I'm not aware of a cleaner way to determine the |
| // offset. |
| return *(*int64)(unsafe.Pointer(getg() + 16*pointerSize)) |
| } |
