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| version 1.1, 2012/02/21 22:57:48 | version 1.1.1.2, 2012/05/29 09:29:43 |
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| Line 1 | Line 1 |
| /* POSIX compatible signal blocking. | /* POSIX compatible signal blocking. |
| Copyright (C) 2006-2008 Free Software Foundation, Inc. | Copyright (C) 2006-2011 Free Software Foundation, Inc. |
| Written by Bruno Haible <bruno@clisp.org>, 2006. | Written by Bruno Haible <bruno@clisp.org>, 2006. |
| This program is free software: you can redistribute it and/or modify | This program is free software: you can redistribute it and/or modify |
| Line 72 ext_signal (int sig, handler_t handler) | Line 72 ext_signal (int sig, handler_t handler) |
| { | { |
| case SIGPIPE: | case SIGPIPE: |
| { | { |
| handler_t old_handler = SIGPIPE_handler; | handler_t old_handler = SIGPIPE_handler; |
| SIGPIPE_handler = handler; | SIGPIPE_handler = handler; |
| return old_handler; | return old_handler; |
| } | } |
| default: /* System defined signal */ | default: /* System defined signal */ |
| return signal (sig, handler); | return signal (sig, handler); |
| Line 90 sigismember (const sigset_t *set, int sig) | Line 90 sigismember (const sigset_t *set, int sig) |
| { | { |
| #ifdef SIGABRT_COMPAT | #ifdef SIGABRT_COMPAT |
| if (sig == SIGABRT_COMPAT) | if (sig == SIGABRT_COMPAT) |
| sig = SIGABRT; | sig = SIGABRT; |
| #endif | #endif |
| return (*set >> sig) & 1; | return (*set >> sig) & 1; |
| Line 113 sigaddset (sigset_t *set, int sig) | Line 113 sigaddset (sigset_t *set, int sig) |
| { | { |
| #ifdef SIGABRT_COMPAT | #ifdef SIGABRT_COMPAT |
| if (sig == SIGABRT_COMPAT) | if (sig == SIGABRT_COMPAT) |
| sig = SIGABRT; | sig = SIGABRT; |
| #endif | #endif |
| *set |= 1U << sig; | *set |= 1U << sig; |
| Line 133 sigdelset (sigset_t *set, int sig) | Line 133 sigdelset (sigset_t *set, int sig) |
| { | { |
| #ifdef SIGABRT_COMPAT | #ifdef SIGABRT_COMPAT |
| if (sig == SIGABRT_COMPAT) | if (sig == SIGABRT_COMPAT) |
| sig = SIGABRT; | sig = SIGABRT; |
| #endif | #endif |
| *set &= ~(1U << sig); | *set &= ~(1U << sig); |
| Line 204 sigprocmask (int operation, const sigset_t *set, sigse | Line 204 sigprocmask (int operation, const sigset_t *set, sigse |
| sigset_t to_block; | sigset_t to_block; |
| switch (operation) | switch (operation) |
| { | { |
| case SIG_BLOCK: | case SIG_BLOCK: |
| new_blocked_set = blocked_set | *set; | new_blocked_set = blocked_set | *set; |
| break; | break; |
| case SIG_SETMASK: | case SIG_SETMASK: |
| new_blocked_set = *set; | new_blocked_set = *set; |
| break; | break; |
| case SIG_UNBLOCK: | case SIG_UNBLOCK: |
| new_blocked_set = blocked_set & ~*set; | new_blocked_set = blocked_set & ~*set; |
| break; | break; |
| default: | default: |
| errno = EINVAL; | errno = EINVAL; |
| return -1; | return -1; |
| } | } |
| to_unblock = blocked_set & ~new_blocked_set; | to_unblock = blocked_set & ~new_blocked_set; |
| to_block = new_blocked_set & ~blocked_set; | to_block = new_blocked_set & ~blocked_set; |
| if (to_block != 0) | if (to_block != 0) |
| { | { |
| int sig; | int sig; |
| for (sig = 0; sig < NSIG; sig++) | for (sig = 0; sig < NSIG; sig++) |
| if ((to_block >> sig) & 1) | if ((to_block >> sig) & 1) |
| { | { |
| pending_array[sig] = 0; | pending_array[sig] = 0; |
| if ((old_handlers[sig] = signal (sig, blocked_handler)) != SIG_ERR) | if ((old_handlers[sig] = signal (sig, blocked_handler)) != SIG_ERR) |
| blocked_set |= 1U << sig; | blocked_set |= 1U << sig; |
| } | } |
| } | } |
| if (to_unblock != 0) | if (to_unblock != 0) |
| { | { |
| sig_atomic_t received[NSIG]; | sig_atomic_t received[NSIG]; |
| int sig; | int sig; |
| for (sig = 0; sig < NSIG; sig++) | for (sig = 0; sig < NSIG; sig++) |
| if ((to_unblock >> sig) & 1) | if ((to_unblock >> sig) & 1) |
| { | { |
| if (signal (sig, old_handlers[sig]) != blocked_handler) | if (signal (sig, old_handlers[sig]) != blocked_handler) |
| /* The application changed a signal handler while the signal | /* The application changed a signal handler while the signal |
| was blocked, bypassing our rpl_signal replacement. | was blocked, bypassing our rpl_signal replacement. |
| We don't support this. */ | We don't support this. */ |
| abort (); | abort (); |
| received[sig] = pending_array[sig]; | received[sig] = pending_array[sig]; |
| blocked_set &= ~(1U << sig); | blocked_set &= ~(1U << sig); |
| pending_array[sig] = 0; | pending_array[sig] = 0; |
| } | } |
| else | else |
| received[sig] = 0; | received[sig] = 0; |
| for (sig = 0; sig < NSIG; sig++) | for (sig = 0; sig < NSIG; sig++) |
| if (received[sig]) | if (received[sig]) |
| raise (sig); | raise (sig); |
| } | } |
| } | } |
| return 0; | return 0; |
| } | } |
| Line 274 rpl_signal (int sig, handler_t handler) | Line 274 rpl_signal (int sig, handler_t handler) |
| { | { |
| #ifdef SIGABRT_COMPAT | #ifdef SIGABRT_COMPAT |
| if (sig == SIGABRT_COMPAT) | if (sig == SIGABRT_COMPAT) |
| sig = SIGABRT; | sig = SIGABRT; |
| #endif | #endif |
| if (blocked_set & (1U << sig)) | if (blocked_set & (1U << sig)) |
| { | { |
| /* POSIX states that sigprocmask and signal are both | /* POSIX states that sigprocmask and signal are both |
| async-signal-safe. This is not true of our | async-signal-safe. This is not true of our |
| implementation - there is a slight data race where an | implementation - there is a slight data race where an |
| asynchronous interrupt on signal A can occur after we | asynchronous interrupt on signal A can occur after we |
| install blocked_handler but before we have updated | install blocked_handler but before we have updated |
| old_handlers for signal B, such that handler A can see | old_handlers for signal B, such that handler A can see |
| stale information if it calls signal(B). Oh well - | stale information if it calls signal(B). Oh well - |
| signal handlers really shouldn't try to manipulate the | signal handlers really shouldn't try to manipulate the |
| installed handlers of unrelated signals. */ | installed handlers of unrelated signals. */ |
| handler_t result = old_handlers[sig]; | handler_t result = old_handlers[sig]; |
| old_handlers[sig] = handler; | old_handlers[sig] = handler; |
| return result; | return result; |
| } | } |
| else | else |
| return signal (sig, handler); | return signal (sig, handler); |
| } | } |
| else | else |
| { | { |
| Line 312 rpl_raise (int sig) | Line 312 rpl_raise (int sig) |
| { | { |
| case SIGPIPE: | case SIGPIPE: |
| if (blocked_set & (1U << sig)) | if (blocked_set & (1U << sig)) |
| pending_array[sig] = 1; | pending_array[sig] = 1; |
| else | else |
| { | { |
| handler_t handler = SIGPIPE_handler; | handler_t handler = SIGPIPE_handler; |
| if (handler == SIG_DFL) | if (handler == SIG_DFL) |
| exit (128 + SIGPIPE); | exit (128 + SIGPIPE); |
| else if (handler != SIG_IGN) | else if (handler != SIG_IGN) |
| (*handler) (sig); | (*handler) (sig); |
| } | } |
| return 0; | return 0; |
| default: /* System defined signal */ | default: /* System defined signal */ |
| return raise (sig); | return raise (sig); |