1 /* 2 * pte_relmillisecs.c 3 * 4 * Description: 5 * This translation unit implements miscellaneous thread functions. 6 * 7 * -------------------------------------------------------------------------- 8 * 9 * Pthreads-embedded (PTE) - POSIX Threads Library for embedded systems 10 * Copyright(C) 2008 Jason Schmidlapp 11 * 12 * Contact Email: jschmidlapp@users.sourceforge.net 13 * 14 * 15 * Based upon Pthreads-win32 - POSIX Threads Library for Win32 16 * Copyright(C) 1998 John E. Bossom 17 * Copyright(C) 1999,2005 Pthreads-win32 contributors 18 * 19 * Contact Email: rpj@callisto.canberra.edu.au 20 * 21 * The original list of contributors to the Pthreads-win32 project 22 * is contained in the file CONTRIBUTORS.ptw32 included with the 23 * source code distribution. The list can also be seen at the 24 * following World Wide Web location: 25 * http://sources.redhat.com/pthreads-win32/contributors.html 26 * 27 * This library is free software; you can redistribute it and/or 28 * modify it under the terms of the GNU Lesser General Public 29 * License as published by the Free Software Foundation; either 30 * version 2 of the License, or (at your option) any later version. 31 * 32 * This library is distributed in the hope that it will be useful, 33 * but WITHOUT ANY WARRANTY; without even the implied warranty of 34 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 35 * Lesser General Public License for more details. 36 * 37 * You should have received a copy of the GNU Lesser General Public 38 * License along with this library in the file COPYING.LIB; 39 * if not, write to the Free Software Foundation, Inc., 40 * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA 41 */ 42 43 #include <pte_osal.h> 44 45 #include "pthread.h" 46 #include "implement.h" 47 48 typedef long long int64_t; 49 50 unsigned int 51 pte_relmillisecs (const struct timespec * abstime) 52 { 53 const long long NANOSEC_PER_MILLISEC = 1000000; 54 const long long MILLISEC_PER_SEC = 1000; 55 unsigned int milliseconds; 56 long long tmpAbsMilliseconds; 57 long tmpCurrMilliseconds; 58 struct timeb currSysTime; 59 60 /* 61 * Calculate timeout as milliseconds from current system time. 62 */ 63 64 /* 65 * subtract current system time from abstime in a way that checks 66 * that abstime is never in the past, or is never equivalent to the 67 * defined INFINITE value (0xFFFFFFFF). 68 * 69 * Assume all integers are unsigned, i.e. cannot test if less than 0. 70 */ 71 tmpAbsMilliseconds = (int64_t)abstime->tv_sec * MILLISEC_PER_SEC; 72 tmpAbsMilliseconds += ((int64_t)abstime->tv_nsec + (NANOSEC_PER_MILLISEC/2)) / NANOSEC_PER_MILLISEC; 73 74 /* get current system time */ 75 76 _ftime(&currSysTime); 77 78 tmpCurrMilliseconds = (int64_t) currSysTime.time * MILLISEC_PER_SEC; 79 tmpCurrMilliseconds += (int64_t) currSysTime.millitm; 80 81 if (tmpAbsMilliseconds > tmpCurrMilliseconds) 82 { 83 milliseconds = (unsigned int) (tmpAbsMilliseconds - tmpCurrMilliseconds); 84 if (milliseconds == 0xFFFFFFFF) 85 { 86 /* Timeouts must be finite */ 87 milliseconds--; 88 } 89 } 90 else 91 { 92 /* The abstime given is in the past */ 93 milliseconds = 0; 94 } 95 96 return milliseconds; 97 } 98