1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
|
/* Copyright (C) 2000 MySQL AB & MySQL Finland AB & TCX DataKonsult AB
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
#if defined(__EMX__) || defined(__NETWARE__)
#include "../mysys/my_lock.c"
#else
#undef MAP_TO_USE_RAID /* Avoid RAID mappings */
#include <my_global.h>
#include <my_sys.h>
#include <mysys_err.h>
#include <my_pthread.h>
#include <thr_alarm.h>
#include <errno.h>
/* Lock a part of a file */
int my_lock(File fd,int locktype,my_off_t start,my_off_t length,myf MyFlags)
{
thr_alarm_t alarmed;
ALARM alarm_buff;
uint wait_for_alarm;
struct flock m_lock;
DBUG_ENTER("my_lock");
DBUG_PRINT("my",("Fd: %d Op: %d start: %ld Length: %ld MyFlags: %d",
fd,locktype,(ulong) start,(ulong) length,MyFlags));
if (my_disable_locking)
DBUG_RETURN(0); /* purecov: inspected */
m_lock.l_type=(short) locktype;
m_lock.l_whence=0L;
m_lock.l_start=(long) start;
m_lock.l_len=(long) length;
wait_for_alarm=(MyFlags & MY_DONT_WAIT ? MY_HOW_OFTEN_TO_ALARM :
(uint) 12*60*60);
if (fcntl(fd,F_SETLK,&m_lock) != -1) /* Check if we can lock */
DBUG_RETURN(0); /* Ok, file locked */
DBUG_PRINT("info",("Was locked, trying with alarm"));
if (!thr_alarm(&alarmed,wait_for_alarm,&alarm_buff))
{
int value;
while ((value=fcntl(fd,F_SETLKW,&m_lock)) && !thr_got_alarm(&alarmed) &&
errno == EINTR) ;
thr_end_alarm(&alarmed);
if (value != -1)
DBUG_RETURN(0);
}
else
{
errno=EINTR;
}
if (errno == EINTR || errno == EACCES)
my_errno=EAGAIN; /* Easier to check for this */
else
my_errno=errno;
if (MyFlags & MY_WME)
{
if (locktype == F_UNLCK)
my_error(EE_CANTUNLOCK,MYF(ME_BELL+ME_WAITTANG),errno);
else
my_error(EE_CANTLOCK,MYF(ME_BELL+ME_WAITTANG),errno);
}
DBUG_PRINT("error",("errno: %d",errno));
DBUG_RETURN(-1);
}
#endif
|
