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Diffstat (limited to 'mysql/mysys/my_lock.c')
-rw-r--r--mysql/mysys/my_lock.c221
1 files changed, 0 insertions, 221 deletions
diff --git a/mysql/mysys/my_lock.c b/mysql/mysys/my_lock.c
deleted file mode 100644
index 1b4336c..0000000
--- a/mysql/mysys/my_lock.c
+++ /dev/null
@@ -1,221 +0,0 @@
-/* Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.
-
- 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; version 2 of the License.
-
- 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */
-
-#include "mysys_priv.h"
-#include "my_sys.h"
-#include "mysys_err.h"
-#include <errno.h>
-#include "my_thread_local.h"
-
-
-#ifndef _WIN32
-#include <signal.h>
-
-static int volatile my_have_got_alarm= 0;
-static uint my_time_to_wait_for_lock= 2; /* In seconds */
-
-void my_set_alarm_variable(int signo MY_ATTRIBUTE((unused)))
-{
- my_have_got_alarm= 1; /* Tell program that time expired */
-}
-#endif /* !_WIN32 */
-
-#ifdef _WIN32
-#define WIN_LOCK_INFINITE -1
-#define WIN_LOCK_SLEEP_MILLIS 100
-
-static int win_lock(File fd, int locktype, my_off_t start, my_off_t length,
- int timeout_sec)
-{
- LARGE_INTEGER liOffset,liLength;
- DWORD dwFlags;
- OVERLAPPED ov= {0};
- HANDLE hFile= (HANDLE)my_get_osfhandle(fd);
- DWORD lastError= 0;
- int i;
- int timeout_millis= timeout_sec * 1000;
-
- DBUG_ENTER("win_lock");
-
- liOffset.QuadPart= start;
- liLength.QuadPart= length;
-
- ov.Offset= liOffset.LowPart;
- ov.OffsetHigh= liOffset.HighPart;
-
- if (locktype == F_UNLCK)
- {
- if (UnlockFileEx(hFile, 0, liLength.LowPart, liLength.HighPart, &ov))
- DBUG_RETURN(0);
- /*
- For compatibility with fcntl implementation, ignore error,
- if region was not locked
- */
- if (GetLastError() == ERROR_NOT_LOCKED)
- {
- SetLastError(0);
- DBUG_RETURN(0);
- }
- goto error;
- }
- else if (locktype == F_RDLCK)
- /* read lock is mapped to a shared lock. */
- dwFlags= 0;
- else
- /* write lock is mapped to an exclusive lock. */
- dwFlags= LOCKFILE_EXCLUSIVE_LOCK;
-
- /*
- Drop old lock first to avoid double locking.
- During analyze of Bug#38133 (Myisamlog test fails on Windows)
- I met the situation that the program myisamlog locked the file
- exclusively, then additionally shared, then did one unlock, and
- then blocked on an attempt to lock it exclusively again.
- Unlocking before every lock fixed the problem.
- Note that this introduces a race condition. When the application
- wants to convert an exclusive lock into a shared one, it will now
- first unlock the file and then lock it shared. A waiting exclusive
- lock could step in here. For reasons described in Bug#38133 and
- Bug#41124 (Server hangs on Windows with --external-locking after
- INSERT...SELECT) and in the review thread at
- http://lists.mysql.com/commits/60721 it seems to be the better
- option than not to unlock here.
- If one day someone notices a way how to do file lock type changes
- on Windows without unlocking before taking the new lock, please
- change this code accordingly to fix the race condition.
- */
- if (!UnlockFileEx(hFile, 0, liLength.LowPart, liLength.HighPart, &ov) &&
- (GetLastError() != ERROR_NOT_LOCKED))
- goto error;
-
- if (timeout_sec == WIN_LOCK_INFINITE)
- {
- if (LockFileEx(hFile, dwFlags, 0, liLength.LowPart, liLength.HighPart, &ov))
- DBUG_RETURN(0);
- goto error;
- }
-
- dwFlags|= LOCKFILE_FAIL_IMMEDIATELY;
- timeout_millis= timeout_sec * 1000;
- /* Try lock in a loop, until the lock is acquired or timeout happens */
- for(i= 0; ;i+= WIN_LOCK_SLEEP_MILLIS)
- {
- if (LockFileEx(hFile, dwFlags, 0, liLength.LowPart, liLength.HighPart, &ov))
- DBUG_RETURN(0);
-
- if (GetLastError() != ERROR_LOCK_VIOLATION)
- goto error;
-
- if (i >= timeout_millis)
- break;
- Sleep(WIN_LOCK_SLEEP_MILLIS);
- }
-
- /* timeout */
- errno= EAGAIN;
- DBUG_RETURN(-1);
-
-error:
- my_osmaperr(GetLastError());
- DBUG_RETURN(-1);
-}
-#endif
-
-
-
-/*
- Lock a part of a file
-
- RETURN VALUE
- 0 Success
- -1 An error has occured and 'my_errno' is set
- to indicate the actual error code.
-*/
-
-int my_lock(File fd, int locktype, my_off_t start, my_off_t length,
- myf MyFlags)
-{
- DBUG_ENTER("my_lock");
- DBUG_PRINT("my",("fd: %d Op: %d start: %ld Length: %ld MyFlags: %d",
- fd,locktype,(long) start,(long) length,MyFlags));
- if (my_disable_locking)
- DBUG_RETURN(0);
-
-#if defined(_WIN32)
- {
- int timeout_sec;
- if (MyFlags & MY_DONT_WAIT)
- timeout_sec= 0;
- else
- timeout_sec= WIN_LOCK_INFINITE;
-
- if (win_lock(fd, locktype, start, length, timeout_sec) == 0)
- DBUG_RETURN(0);
- }
-#else
- {
- struct flock lock;
-
- lock.l_type= (short) locktype;
- lock.l_whence= SEEK_SET;
- lock.l_start= (off_t) start;
- lock.l_len= (off_t) length;
-
- if (MyFlags & MY_DONT_WAIT)
- {
- int value;
- uint alarm_old;
- sig_return alarm_signal;
-
- if (fcntl(fd,F_SETLK,&lock) != -1) /* Check if we can lock */
- DBUG_RETURN(0); /* Ok, file locked */
- DBUG_PRINT("info",("Was locked, trying with alarm"));
- my_have_got_alarm= 0;
- alarm_old= alarm(my_time_to_wait_for_lock);
- alarm_signal= signal(SIGALRM, my_set_alarm_variable);
- while ((value= fcntl(fd, F_SETLKW, &lock)) && !my_have_got_alarm &&
- errno == EINTR)
- { /* Setup again so we don`t miss it */
- (void) alarm(my_time_to_wait_for_lock);
- my_have_got_alarm= 0;
- }
- (void) signal(SIGALRM, alarm_signal);
- (void) alarm(alarm_old);
- if (value != -1)
- DBUG_RETURN(0);
- if (errno == EINTR)
- errno=EAGAIN;
- }
- else if (fcntl(fd,F_SETLKW,&lock) != -1) /* Wait until a lock */
- DBUG_RETURN(0);
- }
-#endif /* _WIN32 */
-
- /* We got an error. We don't want EACCES errors */
- set_my_errno((errno == EACCES) ? EAGAIN : errno ? errno : -1);
-
- if (MyFlags & MY_WME)
- {
- char errbuf[MYSYS_STRERROR_SIZE];
- if (locktype == F_UNLCK)
- my_error(EE_CANTUNLOCK, MYF(0),
- my_errno(), my_strerror(errbuf, sizeof(errbuf), my_errno()));
- else
- my_error(EE_CANTLOCK, MYF(0),
- my_errno(), my_strerror(errbuf, sizeof(errbuf), my_errno()));
- }
- DBUG_PRINT("error",("my_errno: %d (%d)",my_errno(),errno));
- DBUG_RETURN(-1);
-} /* my_lock */
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