diff options
Diffstat (limited to 'rtkaio/sysdeps/unix/sysv/linux/kaio_misc.h')
| -rw-r--r-- | rtkaio/sysdeps/unix/sysv/linux/kaio_misc.h | 114 |
1 files changed, 113 insertions, 1 deletions
diff --git a/rtkaio/sysdeps/unix/sysv/linux/kaio_misc.h b/rtkaio/sysdeps/unix/sysv/linux/kaio_misc.h index bee75f3f2b..5e0ca19c31 100644 --- a/rtkaio/sysdeps/unix/sysv/linux/kaio_misc.h +++ b/rtkaio/sysdeps/unix/sysv/linux/kaio_misc.h @@ -1,4 +1,5 @@ -/* Copyright (C) 1997,1999,2000,2001,2002,2003 Free Software Foundation, Inc. +/* Copyright (C) 1997,1999,2000,2001,2002,2003,2006 + Free Software Foundation, Inc. This file is part of the GNU C Library. The GNU C Library is free software; you can redistribute it and/or @@ -34,6 +35,68 @@ #include <aio.h> #include <pthread.h> #include <stdint.h> +#include <signal.h> +#include <sysdep.h> +#include <limits.h> + +#ifdef HAVE_FORCED_UNWIND + +/* We define a special synchronization primitive for AIO. POSIX + conditional variables would be ideal but the pthread_cond_*wait + operations do not return on EINTR. This is a requirement for + correct aio_suspend and lio_listio implementations. */ + +#include <assert.h> +#include <pthreadP.h> +#include <lowlevellock.h> + +# define DONT_NEED_AIO_MISC_COND 1 + +# define AIO_MISC_NOTIFY(waitlist) \ + do { \ + if (*waitlist->counterp > 0 && --*waitlist->counterp == 0) \ + lll_futex_wake (waitlist->counterp, 1); \ + } while (0) + +# define AIO_MISC_WAIT(result, futex, timeout, cancel) \ + do { \ + volatile int *futexaddr = &futex; \ + int oldval = futex; \ + \ + if (oldval != 0) \ + { \ + pthread_mutex_unlock (&__aio_requests_mutex); \ + \ + int oldtype; \ + if (cancel) \ + oldtype = LIBC_CANCEL_ASYNC (); \ + \ + int status; \ + do \ + { \ + status = lll_futex_timed_wait (futexaddr, oldval, timeout); \ + if (status != -EWOULDBLOCK) \ + break; \ + \ + oldval = *futexaddr; \ + } \ + while (oldval != 0); \ + \ + if (cancel) \ + LIBC_CANCEL_RESET (oldtype); \ + \ + if (status == -EINTR) \ + result = EINTR; \ + else if (status == -ETIMEDOUT) \ + result = EAGAIN; \ + else \ + assert (status == 0 || status == -EWOULDBLOCK); \ + \ + pthread_mutex_lock (&__aio_requests_mutex); \ + } \ + } while (0) + +#endif typedef unsigned long kctx_t; #define KCTX_NONE ~0UL @@ -95,7 +158,12 @@ struct waitlist { struct waitlist *next; + /* The next two fields is used in synchronous io_listio' operations. */ +#ifndef DONT_NEED_AIO_MISC_COND pthread_cond_t *cond; +#endif + int *result; + volatile int *counterp; /* The next field is used in asynchronous `lio_listio' operations. */ struct sigevent *sigevp; @@ -212,5 +280,49 @@ extern int __aio_create_kernel_thread (void) extern int __have_no_kernel_aio attribute_hidden; extern int __kernel_thread_started attribute_hidden; +#ifndef BROKEN_THREAD_SIGNALS +# define aio_start_notify_thread __aio_start_notify_thread +# define aio_create_helper_thread __aio_create_helper_thread + +extern inline void +__aio_start_notify_thread (void) +{ + sigset_t ss; + sigemptyset (&ss); + INTERNAL_SYSCALL_DECL (err); + INTERNAL_SYSCALL (rt_sigprocmask, err, 4, SIG_SETMASK, &ss, NULL, _NSIG / 8); +} + +extern inline int +__aio_create_helper_thread (pthread_t *threadp, void *(*tf) (void *), void *arg) +{ + pthread_attr_t attr; + + /* Make sure the thread is created detached. */ + pthread_attr_init (&attr); + pthread_attr_setdetachstate (&attr, PTHREAD_CREATE_DETACHED); + + /* The helper thread needs only very little resources. */ + (void) pthread_attr_setstacksize (&attr, PTHREAD_STACK_MIN); + + /* Block all signals in the helper thread. To do this thoroughly we + temporarily have to block all signals here. */ + sigset_t ss; + sigset_t oss; + sigfillset (&ss); + INTERNAL_SYSCALL_DECL (err); + INTERNAL_SYSCALL (rt_sigprocmask, err, 4, SIG_SETMASK, &ss, &oss, _NSIG / 8); + + int ret = pthread_create (threadp, &attr, tf, arg); + + /* Restore the signal mask. */ + INTERNAL_SYSCALL (rt_sigprocmask, err, 4, SIG_SETMASK, &oss, NULL, + _NSIG / 8); + + (void) pthread_attr_destroy (&attr); + return ret; +} +#endif + #endif #endif /* aio_misc.h */ |