CVS: winex/library ldt.c,1.8,1.9

Subject: winex/library ldt.c,1.8,1.9Update of /var/lib/cvsd/cvsroot/winex/library
In directory agravaine:/tmp/cvs-serv4784/library

Modified Files:
	ldt.c 
Log Message:
Work around MacOS X kernel issue - avoid doing multiple calls to ldt 
setting kernel API from simultaneous threads.


Index: ldt.c
===================================================================
RCS file: /var/lib/cvsd/cvsroot/winex/library/ldt.c,v
retrieving revision 1.8
retrieving revision 1.9
diff -u -d -r1.8 -r1.9
--- ldt.c	27 Mar 2007 22:23:15 -0000	1.8
+++ ldt.c	30 Mar 2007 18:34:06 -0000	1.9
@@ -21,6 +21,13 @@
 #ifdef HAVE_SYS_SYSCALL_H
 # include <sys/syscall.h>
 #endif
+
+#ifdef __APPLE__
+/* MacOS X requires a pthread mutex around ldt calls to prevent kernel panics (?) */
+#include <pthread.h>
+pthread_mutex_t LDT_pthread_mutex;
+#endif
+
 struct modify_ldt_s
 {
     unsigned int  entry_number;
@@ -213,8 +220,11 @@
         if ((ret = sysi86(SI86DSCR, &ldt_mod)) == -1) perror("sysi86");
     }
 #elif defined(__APPLE__)
+    /* First, lock the critsec to prevent kernel panics */
     {
 	LDT_ENTRY entry_copy = *entry;
+	pthread_mutex_lock(&LDT_pthread_mutex);
+
 	/* The kernel will only let us set LDTs with user priority level (true on darwin??) */
 	if (entry_copy.HighWord.Bits.Pres
 	    && entry_copy.HighWord.Bits.Dpl != 3)
@@ -225,6 +235,7 @@
             perror("i386_set_ldt");
             fprintf( stderr, "Problem with MacOS i386_set_ldt function!\n" );
         }
+	pthread_mutex_unlock(&LDT_pthread_mutex);
 
     }
 #else