Adding upstream version 1:10.11.6.upstream/1%10.11.6upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 228 insertions, 0 deletions

diff --git a/mysys/my_lock.c b/mysys/my_lock.c
new file mode 100644
index 00000000..7597436f
--- /dev/null
+++ b/mysys/my_lock.c
@@ -0,0 +1,228 @@
+/* Copyright (c) 2000, 2010, 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 02110-1335  USA */
+
+#include "mysys_priv.h"
+#include "mysys_err.h"
+#include <errno.h>
+#undef MY_HOW_OFTEN_TO_ALARM
+#define MY_HOW_OFTEN_TO_ALARM ((int) my_time_to_wait_for_lock)
+#ifdef NO_ALARM_LOOP
+#undef NO_ALARM_LOOP
+#endif
+#include <my_alarm.h>
+
+#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);
+  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 occurred 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)
+{
+#ifdef HAVE_FCNTL
+  int value;
+  ALARM_VARIABLES;
+#endif
+
+  DBUG_ENTER("my_lock");
+  DBUG_PRINT("my",("fd: %d  Op: %d  start: %ld  Length: %ld  MyFlags: %lu",
+		   fd,locktype,(long) start,(long) length,MyFlags));
+  if (my_disable_locking && ! (MyFlags & MY_FORCE_LOCK))
+    DBUG_RETURN(0);
+
+#if defined(_WIN32)
+  {
+    int timeout_sec;
+    if (MyFlags & MY_NO_WAIT)
+      timeout_sec= 0;
+    else
+      timeout_sec= WIN_LOCK_INFINITE;
+
+    if (win_lock(fd, locktype, start, length, timeout_sec) == 0)
+      DBUG_RETURN(0);
+  }
+#else
+#if defined(HAVE_FCNTL)
+  {
+    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_NO_WAIT | MY_SHORT_WAIT))
+    {
+      if (fcntl(fd,F_SETLK,&lock) != -1)	/* Check if we can lock */
+	DBUG_RETURN(0);                         /* Ok, file locked */
+      if (MyFlags & MY_NO_WAIT)
+      {
+        my_errno= (errno == EACCES) ? EAGAIN : errno ? errno : -1;
+        DBUG_RETURN(-1);
+      }
+
+      DBUG_PRINT("info",("Was locked, trying with alarm"));
+      ALARM_INIT;
+      while ((value=fcntl(fd,F_SETLKW,&lock)) && ! ALARM_TEST &&
+	     errno == EINTR)
+      {			/* Setup again so we don`t miss it */
+	ALARM_REINIT;
+      }
+      ALARM_END;
+      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);
+  }
+#else
+  if (MyFlags & MY_SEEK_NOT_DONE)
+  {
+    if (my_seek(fd,start,MY_SEEK_SET,MYF(MyFlags & ~MY_SEEK_NOT_DONE))
+        == MY_FILEPOS_ERROR)
+    {
+      /*
+        If an error has occurred in my_seek then we will already
+        have an error code in my_errno; Just return error code.
+      */
+      DBUG_RETURN(-1);
+    }
+  }
+  if (lockf(fd,locktype,length) != -1)
+    DBUG_RETURN(0);
+#endif /* HAVE_FCNTL */
+#endif /* _WIN32 */
+
+  /* We got an error. We don't want EACCES errors */
+  my_errno=(errno == EACCES) ? EAGAIN : errno ? errno : -1;
+
+  if (MyFlags & MY_WME)
+  {
+    if (locktype == F_UNLCK)
+      my_error(EE_CANTUNLOCK,MYF(ME_BELL),my_errno);
+    else
+      my_error(EE_CANTLOCK,MYF(ME_BELL),my_errno);
+  }
+  DBUG_PRINT("error",("my_errno: %d (%d)",my_errno,errno));
+  DBUG_RETURN(-1);
+} /* my_lock */