• Davide Libenzi's avatar
    timerfd: new timerfd API · 4d672e7a
    Davide Libenzi authored
    This is the new timerfd API as it is implemented by the following patch:
    
    int timerfd_create(int clockid, int flags);
    int timerfd_settime(int ufd, int flags,
    		    const struct itimerspec *utmr,
    		    struct itimerspec *otmr);
    int timerfd_gettime(int ufd, struct itimerspec *otmr);
    
    The timerfd_create() API creates an un-programmed timerfd fd.  The "clockid"
    parameter can be either CLOCK_MONOTONIC or CLOCK_REALTIME.
    
    The timerfd_settime() API give new settings by the timerfd fd, by optionally
    retrieving the previous expiration time (in case the "otmr" parameter is not
    NULL).
    
    The time value specified in "utmr" is absolute, if the TFD_TIMER_ABSTIME bit
    is set in the "flags" parameter.  Otherwise it's a relative time.
    
    The timerfd_gettime() API returns the next expiration time of the timer, or
    {0, 0} if the timerfd has not been set yet.
    
    Like the previous timerfd API implementation, read(2) and poll(2) are
    supported (with the same interface).  Here's a simple test program I used to
    exercise the new timerfd APIs:
    
    http://www.xmailserver.org/timerfd-test2.c
    
    [akpm@linux-foundation.org: coding-style cleanups]
    [akpm@linux-foundation.org: fix ia64 build]
    [akpm@linux-foundation.org: fix m68k build]
    [akpm@linux-foundation.org: fix mips build]
    [akpm@linux-foundation.org: fix alpha, arm, blackfin, cris, m68k, s390, sparc and sparc64 builds]
    [heiko.carstens@de.ibm.com: fix s390]
    [akpm@linux-foundation.org: fix powerpc build]
    [akpm@linux-foundation.org: fix sparc64 more]
    Signed-off-by: default avatarDavide Libenzi <davidel@xmailserver.org>
    Cc: Michael Kerrisk <mtk-manpages@gmx.net>
    Cc: Thomas Gleixner <tglx@linutronix.de>
    Cc: Davide Libenzi <davidel@xmailserver.org>
    Cc: Michael Kerrisk <mtk-manpages@gmx.net>
    Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
    Signed-off-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
    Cc: Michael Kerrisk <mtk.manpages@gmail.com>
    Cc: Davide Libenzi <davidel@xmailserver.org>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    4d672e7a
timerfd.c 6.66 KB