| /* Copyright (c) 2016 Google Inc. |
| * Barret Rhoden <brho@cs.berkeley.edu> |
| * See LICENSE for details. |
| * |
| * fork() callbacks. |
| * |
| * These are called after a process forks by the child. |
| * |
| * To register a cb, do your own allocation of a fork_cb, fill in func, then |
| * call register_fork_cb. You cannot remove your CB. Concurrent calls to |
| * fork() may or may not run your callback. |
| * |
| * Due to the plethora of user-level implementations of things normally in the |
| * kernel, such as select(), those systems may need to deal with fork() in a |
| * special way. Imagine a process that forks, but does not exec. The state of |
| * those systems may no longer be valid, since they may rely on kernel state |
| * that is no longer present. |
| * |
| * Specifically, select is built in taps, and select is supposed to be |
| * stateless, but ours relies on kernel state (taps). Taps are not inherited |
| * (via fork or dup). If you forked, select() would think it had taps set up, |
| * when in fact it didn't. */ |
| |
| #pragma once |
| |
| #include <sys/types.h> |
| |
| /* 2LSs need to set these CBs if they want to be able to fork. */ |
| extern void (*pre_fork_2ls)(void); |
| extern void (*post_fork_2ls)(pid_t ret); |
| |
| struct fork_cb { |
| struct fork_cb *next; |
| void (*func)(void); |
| }; |
| |
| extern struct fork_cb *fork_callbacks; /* for use within glibc */ |
| |
| void register_fork_cb(struct fork_cb *cb); |
