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by brian
clean slate |
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/* Copyright (C) 2000-2003 MySQL AB
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; version 2 of the License.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
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#if defined(__NETWARE__)
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#include "../mysys/my_lock.c" |
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#else
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#undef MAP_TO_USE_RAID /* Avoid RAID mappings */ |
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#include <my_global.h> |
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#include <my_sys.h> |
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#include <mysys_err.h> |
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#include <my_pthread.h> |
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#include <thr_alarm.h> |
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#include <errno.h> |
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/* Lock a part of a file */
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int my_lock(File fd,int locktype,my_off_t start,my_off_t length,myf MyFlags) |
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{
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thr_alarm_t alarmed; |
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ALARM alarm_buff; |
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uint wait_for_alarm; |
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struct flock m_lock; |
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DBUG_ENTER("my_lock"); |
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DBUG_PRINT("my",("Fd: %d Op: %d start: %ld Length: %ld MyFlags: %d", |
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fd,locktype,(ulong) start,(ulong) length,MyFlags)); |
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if (my_disable_locking) |
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DBUG_RETURN(0); /* purecov: inspected */ |
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m_lock.l_type=(short) locktype; |
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m_lock.l_whence=0L; |
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m_lock.l_start=(long) start; |
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m_lock.l_len=(long) length; |
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wait_for_alarm=(MyFlags & MY_DONT_WAIT ? MY_HOW_OFTEN_TO_ALARM : |
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(uint) 12*60*60); |
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if (fcntl(fd,F_SETLK,&m_lock) != -1) /* Check if we can lock */ |
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DBUG_RETURN(0); /* Ok, file locked */ |
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DBUG_PRINT("info",("Was locked, trying with alarm")); |
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if (!thr_alarm(&alarmed,wait_for_alarm,&alarm_buff)) |
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{
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int value; |
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while ((value=fcntl(fd,F_SETLKW,&m_lock)) && !thr_got_alarm(&alarmed) && |
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errno == EINTR) ; |
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thr_end_alarm(&alarmed); |
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if (value != -1) |
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DBUG_RETURN(0); |
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}
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else
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{
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errno=EINTR; |
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}
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if (errno == EINTR || errno == EACCES) |
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my_errno=EAGAIN; /* Easier to check for this */ |
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else
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my_errno=errno; |
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if (MyFlags & MY_WME) |
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{
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if (locktype == F_UNLCK) |
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my_error(EE_CANTUNLOCK,MYF(ME_BELL+ME_WAITTANG),errno); |
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else
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my_error(EE_CANTLOCK,MYF(ME_BELL+ME_WAITTANG),errno); |
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}
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DBUG_PRINT("error",("errno: %d",errno)); |
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DBUG_RETURN(-1); |
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}
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#endif
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