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Diffstat (limited to 'Documentation/technical/api-sigchain.txt')
-rw-r--r-- | Documentation/technical/api-sigchain.txt | 41 |
1 files changed, 0 insertions, 41 deletions
diff --git a/Documentation/technical/api-sigchain.txt b/Documentation/technical/api-sigchain.txt deleted file mode 100644 index 9e1189ef01..0000000000 --- a/Documentation/technical/api-sigchain.txt +++ /dev/null @@ -1,41 +0,0 @@ -sigchain API -============ - -Code often wants to set a signal handler to clean up temporary files or -other work-in-progress when we die unexpectedly. For multiple pieces of -code to do this without conflicting, each piece of code must remember -the old value of the handler and restore it either when: - - 1. The work-in-progress is finished, and the handler is no longer - necessary. The handler should revert to the original behavior - (either another handler, SIG_DFL, or SIG_IGN). - - 2. The signal is received. We should then do our cleanup, then chain - to the next handler (or die if it is SIG_DFL). - -Sigchain is a tiny library for keeping a stack of handlers. Your handler -and installation code should look something like: - ------------------------------------------- - void clean_foo_on_signal(int sig) - { - clean_foo(); - sigchain_pop(sig); - raise(sig); - } - - void other_func() - { - sigchain_push_common(clean_foo_on_signal); - mess_up_foo(); - clean_foo(); - } ------------------------------------------- - -Handlers are given the typedef of sigchain_fun. This is the same type -that is given to signal() or sigaction(). It is perfectly reasonable to -push SIG_DFL or SIG_IGN onto the stack. - -You can sigchain_push and sigchain_pop individual signals. For -convenience, sigchain_push_common will push the handler onto the stack -for many common signals. |