1 files changed, 82 insertions, 0 deletions
diff --git a/sql/my_lock.c b/sql/my_lock.c
new file mode 100644
index 00000000000..6c35634203f
--- /dev/null
+++ b/sql/my_lock.c
@@ -0,0 +1,82 @@
+/* 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 */
+
+#ifdef __EMX__
+#include "../mysys/my_lock.c"
+#else
+
+#undef MAP_TO_USE_RAID			/* Avoid RAID mappings */
+#include <global.h>
+#include <my_sys.h>
+#include <mysys_err.h>
+#include <my_pthread.h>
+#include <thr_alarm.h>
+#include <errno.h>
+
+#ifdef HAVE_FCNTL
+static struct flock lock;		/* Must be static for sun-sparc */
+#endif
+
+	/* 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;
+  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 */
+  lock.l_type=(short) locktype;
+  lock.l_whence=0L;
+  lock.l_start=(long) start;
+  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,&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,&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