ceph/src/dpdk/lib/librte_eal/common/include/rte_alarm.h

   1 /*-
   2  *   BSD LICENSE
   3  *
   4  *   Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
   5  *   All rights reserved.
   6  *
   7  *   Redistribution and use in source and binary forms, with or without
   8  *   modification, are permitted provided that the following conditions
   9  *   are met:
  10  *
  11  *     * Redistributions of source code must retain the above copyright
  12  *       notice, this list of conditions and the following disclaimer.
  13  *     * Redistributions in binary form must reproduce the above copyright
  14  *       notice, this list of conditions and the following disclaimer in
  15  *       the documentation and/or other materials provided with the
  16  *       distribution.
  17  *     * Neither the name of Intel Corporation nor the names of its
  18  *       contributors may be used to endorse or promote products derived
  19  *       from this software without specific prior written permission.
  20  *
  21  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  22  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  23  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  24  *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  25  *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  26  *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  27  *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  28  *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  29  *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  30  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  31  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  32  */
  33
  34 #ifndef _RTE_ALARM_H_
  35 #define _RTE_ALARM_H_
  36
  37 /**
  38  * @file
  39  *
  40  * Alarm functions
  41  *
  42  * Simple alarm-clock functionality supplied by eal.
  43  * Does not require hpet support.
  44  */
  45
  46 #ifdef __cplusplus
  47 extern "C" {
  48 #endif
  49
  50 #include <stdint.h>
  51
  52 /**
  53  * Signature of callback back function called when an alarm goes off.
  54  */
  55 typedef void (*rte_eal_alarm_callback)(void *arg);
  56
  57 /**
  58  * Function to set a callback to be triggered when us microseconds
  59  * have expired. Accuracy of timing to the microsecond is not guaranteed. The
  60  * alarm function will not be called *before* the requested time, but may
  61  * be called a short period of time afterwards.
  62  * The alarm handler will be called only once. There is no need to call
  63  * "rte_eal_alarm_cancel" from within the callback function.
  64  *
  65  * @param us
  66  *   The time in microseconds before the callback is called
  67  * @param cb
  68  *   The function to be called when the alarm expires
  69  * @param cb_arg
  70  *   Pointer parameter to be passed to the callback function
  71  *
  72  * @return
  73  *   On success, zero.
  74  *   On failure, a negative error number
  75  */
  76 int rte_eal_alarm_set(uint64_t us, rte_eal_alarm_callback cb, void *cb_arg);
  77
  78 /**
  79  * Function to cancel an alarm callback which has been registered before. If
  80  * used outside alarm callback it wait for all callbacks to finish execution.
  81  *
  82  * @param cb_fn
  83  *  alarm callback
  84  * @param cb_arg
  85  *  Pointer parameter to be passed to the callback function. To remove all
  86  *  copies of a given callback function, irrespective of parameter, (void *)-1
  87  *  can be used here.
  88  *
  89  * @return
  90  *    - value greater than 0 and rte_errno not changed - returned value is
  91  *      the number of canceled alarm callback functions
  92  *    - value greater or equal 0 and rte_errno set to EINPROGRESS, at least one
  93  *      alarm could not be canceled because cancellation was requested from alarm
  94  *      callback context. Returned value is the number of succesfuly canceled
  95  *      alarm callbacks
  96  *    -  0 and rte_errno set to ENOENT - no alarm found
  97  *    - -1 and rte_errno set to EINVAL - invalid parameter (NULL callback)
  98  */
  99 int rte_eal_alarm_cancel(rte_eal_alarm_callback cb_fn, void *cb_arg);
 100
 101 #ifdef __cplusplus
 102 }
 103 #endif
 104
 105
 106 #endif /* _RTE_ALARM_H_ */