1 /* Copyright (C) 2006 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, write to the Free
16 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
19 /* We define a special synchronization primitive for AIO. POSIX
20 conditional variables would be ideal but the pthread_cond_*wait
21 operations do not return on EINTR. This is a requirement for
22 correct aio_suspend and lio_listio implementations. */
27 #include <lowlevellock.h>
29 #define DONT_NEED_GAI_MISC_COND 1
31 #define GAI_MISC_NOTIFY(waitlist) \
33 if (*waitlist->counterp > 0 && --*waitlist->counterp == 0) \
34 lll_futex_wake (waitlist->counterp, 1); \
37 #define GAI_MISC_WAIT(result, futex, timeout, cancel) \
39 volatile int *futexaddr = &futex; \
44 pthread_mutex_unlock (&__gai_requests_mutex); \
48 oldtype = LIBC_CANCEL_ASYNC (); \
53 status = lll_futex_timed_wait (futexaddr, oldval, timeout); \
54 if (status != -EWOULDBLOCK) \
57 oldval = *futexaddr; \
59 while (oldval != 0); \
62 LIBC_CANCEL_RESET (oldtype); \
64 if (status == -EINTR) \
66 else if (status == -ETIMEDOUT) \
69 assert (status == 0 || status == -EWOULDBLOCK); \
71 pthread_mutex_lock (&__gai_requests_mutex); \
76 #define gai_start_notify_thread __gai_start_notify_thread
77 #define gai_create_helper_thread __gai_create_helper_thread
80 __gai_start_notify_thread (void)
84 INTERNAL_SYSCALL_DECL (err
);
85 INTERNAL_SYSCALL (rt_sigprocmask
, err
, 4, SIG_SETMASK
, &ss
, NULL
, _NSIG
/ 8);
89 __gai_create_helper_thread (pthread_t
*threadp
, void *(*tf
) (void *),
94 /* Make sure the thread is created detached. */
95 pthread_attr_init (&attr
);
96 pthread_attr_setdetachstate (&attr
, PTHREAD_CREATE_DETACHED
);
98 /* The helper thread needs only very little resources. */
99 (void) pthread_attr_setstacksize (&attr
, PTHREAD_STACK_MIN
);
101 /* Block all signals in the helper thread. To do this thoroughly we
102 temporarily have to block all signals here. */
106 INTERNAL_SYSCALL_DECL (err
);
107 INTERNAL_SYSCALL (rt_sigprocmask
, err
, 4, SIG_SETMASK
, &ss
, &oss
, _NSIG
/ 8);
109 int ret
= pthread_create (threadp
, &attr
, tf
, arg
);
111 /* Restore the signal mask. */
112 INTERNAL_SYSCALL (rt_sigprocmask
, err
, 4, SIG_SETMASK
, &oss
, NULL
,
115 (void) pthread_attr_destroy (&attr
);
119 #include_next <gai_misc.h>