htl: Reimplement GSCOPE

[glibc.git] / sysdeps / mach / hurd / i386 / tls.h

diff --git a/sysdeps/mach/hurd/i386/tls.h b/sysdeps/mach/hurd/i386/tls.h
index 057b2613f3e62b0316ae77bed97acf71a8bfbe19..2ac65df921bc89cdd4222ae1e98907ea69f284d9 100644 (file)
--- a/sysdeps/mach/hurd/i386/tls.h
+++ b/sysdeps/mach/hurd/i386/tls.h
@@ -369,6 +369,27 @@ _hurd_tls_new (thread_t child, struct i386_thread_state *state, tcbhead_t *tcb)
   return err;
 }
 
+/* Global scope switch support.  */
+# define THREAD_GSCOPE_IN_TCB      1
+
+# define THREAD_GSCOPE_FLAG_UNUSED 0
+# define THREAD_GSCOPE_FLAG_USED   1
+# define THREAD_GSCOPE_FLAG_WAIT   2
+
+# define THREAD_GSCOPE_SET_FLAG() \
+  THREAD_SETMEM (THREAD_SELF, gscope_flag, THREAD_GSCOPE_FLAG_USED)
+
+# define THREAD_GSCOPE_RESET_FLAG() \
+  ({                                                                         \
+    int __flag;                                                              \
+    asm volatile ("xchgl %0, %%gs:%P1"                                       \
+                  : "=r" (__flag)                                            \
+                  : "i" (offsetof (tcbhead_t, gscope_flag)),                 \
+                    "0" (THREAD_GSCOPE_FLAG_UNUSED));                        \
+    if (__flag == THREAD_GSCOPE_FLAG_WAIT)                                   \
+      lll_wake (THREAD_SELF->gscope_flag, LLL_PRIVATE);                      \
+  })
+
 #endif /* !__ASSEMBLER__ */
 
 #endif /* i386/tls.h */