| // Copyright 2015 RedHat, Inc. |
| // Copyright 2015 CoreOS, Inc. |
| // |
| // 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. |
| |
| package sdjournal |
| |
| import ( |
| "github.com/coreos/pkg/dlopen" |
| "sync" |
| "unsafe" |
| ) |
| |
| var ( |
| // lazy initialized |
| libsystemdHandle *dlopen.LibHandle |
| |
| libsystemdMutex = &sync.Mutex{} |
| libsystemdFunctions = map[string]unsafe.Pointer{} |
| libsystemdNames = []string{ |
| // systemd < 209 |
| "libsystemd-journal.so.0", |
| "libsystemd-journal.so", |
| |
| // systemd >= 209 merged libsystemd-journal into libsystemd proper |
| "libsystemd.so.0", |
| "libsystemd.so", |
| } |
| ) |
| |
| func getFunction(name string) (unsafe.Pointer, error) { |
| libsystemdMutex.Lock() |
| defer libsystemdMutex.Unlock() |
| |
| if libsystemdHandle == nil { |
| h, err := dlopen.GetHandle(libsystemdNames) |
| if err != nil { |
| return nil, err |
| } |
| |
| libsystemdHandle = h |
| } |
| |
| f, ok := libsystemdFunctions[name] |
| if !ok { |
| var err error |
| f, err = libsystemdHandle.GetSymbolPointer(name) |
| if err != nil { |
| return nil, err |
| } |
| |
| libsystemdFunctions[name] = f |
| } |
| |
| return f, nil |
| } |