Update.

2003-04-04  Ulrich Drepper  <drepper@redhat.com>

	* sysdeps/pthread/createthread.c (create_thread): Add some more
	comments explaining when to set multiple_threads and when not.

	* pthreadP.h: Define THREAD_ATOMIC_CMPXCHG_VAL and
	THREAD_ATOMIC_BIT_SET if not already defined.
	* sysdeps/i386/tls.h: Define THREAD_ATOMIC_CMPXCHG_VAL and
	THREAD_ATOMIC_BIT_SET:
	* sysdeps/x86_64/tls.h: Likewise.
	* cleanup_defer.c (_pthread_cleanup_push_defer): Rewrite to use
	THREAD_ATOMIC_CMPXCHG_VAL.
	(_pthread_cleanup_pop_restore): Likewise.
	* cancellation.c (__pthread_enable_asynccancel): Likewise.
	(__pthread_enable_asynccancel_2): Likewise.
	(__pthread_disable_asynccancel): Likewise.
	* libc-cancellation.c (__libc_enable_asynccancel): Likewise.
	(__libc_disable_asynccancel): Likewise.
	* init.c (sigcancel_handler): Likewise.
	* pthread_setcancelstate.c (__pthread_setcancelstate): Likewise.
	* pthread_setcanceltype.c (__pthread_setcanceltype): Likewise.

3 files changed, 67 insertions, 5 deletions

diff --git a/nptl/sysdeps/i386/tls.h b/nptl/sysdeps/i386/tls.h
index 7fe2222c68..4f2e8180d3 100644
--- a/nptl/sysdeps/i386/tls.h
+++ b/nptl/sysdeps/i386/tls.h
@@ -169,6 +169,14 @@ union user_desc_init
 # define INIT_SYSINFO
 #endif
 
+#ifndef LOCK
+# ifdef UP
+#  define LOCK  /* nothing */
+# else
+#  define LOCK "lock;"
+# endif
+#endif
+
 /* Code to initially initialize the thread pointer.  This might need
    special attention since 'errno' is not yet available and if the
    operation can cause a failure 'errno' must not be touched.  */
@@ -352,6 +360,32 @@ union user_desc_init
        }})
 
 
+/* Atomic compare and exchange on TLS, returning old value.  */
+#define THREAD_ATOMIC_CMPXCHG_VAL(descr, member, newval, oldval) \
+  ({ __typeof (descr->member) __ret;					      \
+     __typeof (oldval) __old = (oldval);				      \
+     if (sizeof (descr->member) == 4)					      \
+       asm volatile (LOCK "cmpxchgl %2, %%gs:%P3"			      \
+		     : "=a" (__ret)					      \
+		     : "0" (__old), "r" (newval),			      \
+		       "i" (offsetof (struct pthread, member)));	      \
+     else								      \
+       /* Not necessary for other sizes in the moment.  */		      \
+       abort ();							      \
+     __ret; })
+
+
+/* Atomic set bit.  */
+#define THREAD_ATOMIC_BIT_SET(descr, member, bit) \
+  (void) ({ if (sizeof ((descr)->member) == 4)				      \
+	      asm volatile (LOCK "orl %1, %%gs:%P0"			      \
+			    :: "i" (offsetof (struct pthread, member)),	      \
+			       "ir" (1 << (bit)));			      \
+	    else							      \
+	      /* Not necessary for other sizes in the moment.  */	      \
+	      abort (); })
+
+
 /* Call the user-provided thread function.  */
 #define CALL_THREAD_FCT(descr) \
   ({ void *__res;							      \
diff --git a/nptl/sysdeps/pthread/createthread.c b/nptl/sysdeps/pthread/createthread.c
index fae744f298..9d00e4e135 100644
--- a/nptl/sysdeps/pthread/createthread.c
+++ b/nptl/sysdeps/pthread/createthread.c
@@ -83,11 +83,11 @@ create_thread (struct pthread *pd, STACK_VARIABLES_PARMS)
 	    /* Failed.  */
 	    return errno;
 
+	  /* We now have for sure more than one thread.  The main
+	     thread might not yet have the flag set.  No need to set
+	     the global variable again if this is what we use.  */
 #ifdef TLS_MULTIPLE_THREADS_IN_TCB
-	  /* We now have for sure more than one thread.  */
-	  pd->header.multiple_threads = 1;
-#else
-	  __pthread_multiple_threads = *__libc_multiple_threads_ptr = 1;
+	  THREAD_SETMEM (THREAD_SELF, header.multiple_threads, 1);
 #endif
 
 	  /* Now fill in the information about the new thread in
@@ -155,8 +155,10 @@ create_thread (struct pthread *pd, STACK_VARIABLES_PARMS)
     /* Failed.  */
     return errno;
 
+  /* We now have for sure more than one thread.  The main thread might
+     not yet have the flag set.  No need to set the global variable
+     again if this is what we use.  */
 #ifdef TLS_MULTIPLE_THREADS_IN_TCB
-  /* We now have for sure more than one thread.  */
   THREAD_SETMEM (THREAD_SELF, header.multiple_threads, 1);
 #endif
 
diff --git a/nptl/sysdeps/x86_64/tls.h b/nptl/sysdeps/x86_64/tls.h
index f382db2861..dec1b5d1b7 100644
--- a/nptl/sysdeps/x86_64/tls.h
+++ b/nptl/sysdeps/x86_64/tls.h
@@ -253,6 +253,32 @@ typedef struct
        }})
 
 
+/* Atomic compare and exchange on TLS, returning old value.  */
+#define THREAD_ATOMIC_CMPXCHG_VAL(descr, member, newval, oldval) \
+  ({ __typeof (descr->member) __ret;					      \
+     __typeof (oldval) __old = (oldval);				      \
+     if (sizeof (descr->member) == 4)					      \
+       asm volatile (LOCK "cmpxchgl %2, %%fs:%P3"			      \
+		     : "=a" (__ret)					      \
+		     : "0" (__old), "r" (newval),			      \
+		       "i" (offsetof (struct pthread, member)));	      \
+     else								      \
+       /* Not necessary for other sizes in the moment.  */		      \
+       abort ();							      \
+     __ret; })
+
+
+/* Atomic set bit.  */
+#define THREAD_ATOMIC_BIT_SET(descr, member, bit) \
+  (void) ({ if (sizeof ((descr)->member) == 4)				      \
+	      asm volatile (LOCK "orl %1, %%fs:%P0"			      \
+			    :: "i" (offsetof (struct pthread, member)),	      \
+			       "ir" (1 << (bit)));			      \
+	    else							      \
+	      /* Not necessary for other sizes in the moment.  */	      \
+	      abort (); })
+
+
 #define CALL_THREAD_FCT(descr) \
   ({ void *__res;							      \
      asm volatile ("movq %%fs:%P2, %%rdi\n\t"				      \