tls.h

glibc 2.9,最新版的C语言库函数

		     TLS_EBX_ARG (&_segdescr.desc), "m" (_segdescr.desc));    \
									      \
     if (_result == 0)							      \
       /* We know the index in the GDT, now load the segment register.	      \
	  The use of the GDT is described by the value 3 in the lower	      \
	  three bits of the segment descriptor value.			      \
									      \
	  Note that we have to do this even if the numeric value of	      \
	  the descriptor does not change.  Loading the segment register	      \
	  causes the segment information from the GDT to be loaded	      \
	  which is necessary since we have changed it.   */		      \
       TLS_SET_GS (_segdescr.desc.entry_number * 8 + 3);		      \
									      \
     _result == 0 ? NULL						      \
     : "set_thread_area failed when setting up thread-local storage\n"; })


/* Return the address of the dtv for the current thread.  */
# define THREAD_DTV() \
  ({ struct pthread *__pd;						      \
     THREAD_GETMEM (__pd, header.dtv); })


/* Return the thread descriptor for the current thread.

   The contained asm must *not* be marked volatile since otherwise
   assignments like
        pthread_descr self = thread_self();
   do not get optimized away.  */
# define THREAD_SELF \
  ({ struct pthread *__self;						      \
     asm ("movl %%gs:%c1,%0" : "=r" (__self)				      \
	  : "i" (offsetof (struct pthread, header.self)));		      \
     __self;})

/* Magic for libthread_db to know how to do THREAD_SELF.  */
# define DB_THREAD_SELF \
  REGISTER_THREAD_AREA (32, offsetof (struct user_regs_struct, xgs), 3) \
  REGISTER_THREAD_AREA (64, 26 * 8, 3) /* x86-64's user_regs_struct->gs */


/* Read member of the thread descriptor directly.  */
# define THREAD_GETMEM(descr, member) \
  ({ __typeof (descr->member) __value;					      \
     if (sizeof (__value) == 1)						      \
       asm volatile ("movb %%gs:%P2,%b0"				      \
		     : "=q" (__value)					      \
		     : "0" (0), "i" (offsetof (struct pthread, member)));     \
     else if (sizeof (__value) == 4)					      \
       asm volatile ("movl %%gs:%P1,%0"					      \
		     : "=r" (__value)					      \
		     : "i" (offsetof (struct pthread, member)));	      \
     else								      \
       {								      \
	 if (sizeof (__value) != 8)					      \
	   /* There should not be any value with a size other than 1,	      \
	      4 or 8.  */						      \
	   abort ();							      \
									      \
	 asm volatile ("movl %%gs:%P1,%%eax\n\t"			      \
		       "movl %%gs:%P2,%%edx"				      \
		       : "=A" (__value)					      \
		       : "i" (offsetof (struct pthread, member)),	      \
			 "i" (offsetof (struct pthread, member) + 4));	      \
       }								      \
     __value; })


/* Same as THREAD_GETMEM, but the member offset can be non-constant.  */
# define THREAD_GETMEM_NC(descr, member, idx) \
  ({ __typeof (descr->member[0]) __value;				      \
     if (sizeof (__value) == 1)						      \
       asm volatile ("movb %%gs:%P2(%3),%b0"				      \
		     : "=q" (__value)					      \
		     : "0" (0), "i" (offsetof (struct pthread, member[0])),   \
		     "r" (idx));					      \
     else if (sizeof (__value) == 4)					      \
       asm volatile ("movl %%gs:%P1(,%2,4),%0"				      \
		     : "=r" (__value)					      \
		     : "i" (offsetof (struct pthread, member[0])),	      \
		       "r" (idx));					      \
     else								      \
       {								      \
	 if (sizeof (__value) != 8)					      \
	   /* There should not be any value with a size other than 1,	      \
	      4 or 8.  */						      \
	   abort ();							      \
									      \
	 asm volatile  ("movl %%gs:%P1(,%2,8),%%eax\n\t"		      \
			"movl %%gs:4+%P1(,%2,8),%%edx"			      \
			: "=&A" (__value)				      \
			: "i" (offsetof (struct pthread, member[0])),	      \
			  "r" (idx));					      \
       }								      \
     __value; })


/* Same as THREAD_SETMEM, but the member offset can be non-constant.  */
# define THREAD_SETMEM(descr, member, value) \
  ({ if (sizeof (descr->member) == 1)					      \
       asm volatile ("movb %b0,%%gs:%P1" :				      \
		     : "iq" (value),					      \
		       "i" (offsetof (struct pthread, member)));	      \
     else if (sizeof (descr->member) == 4)				      \
       asm volatile ("movl %0,%%gs:%P1" :				      \
		     : "ir" (value),					      \
		       "i" (offsetof (struct pthread, member)));	      \
     else								      \
       {								      \
	 if (sizeof (descr->member) != 8)				      \
	   /* There should not be any value with a size other than 1,	      \
	      4 or 8.  */						      \
	   abort ();							      \
									      \
	 asm volatile ("movl %%eax,%%gs:%P1\n\t"			      \
		       "movl %%edx,%%gs:%P2" :				      \
		       : "A" (value),					      \
			 "i" (offsetof (struct pthread, member)),	      \
			 "i" (offsetof (struct pthread, member) + 4));	      \
       }})


/* Set member of the thread descriptor directly.  */
# define THREAD_SETMEM_NC(descr, member, idx, value) \
  ({ if (sizeof (descr->member[0]) == 1)				      \
       asm volatile ("movb %b0,%%gs:%P1(%2)" :				      \
		     : "iq" (value),					      \
		       "i" (offsetof (struct pthread, member)),		      \
		       "r" (idx));					      \
     else if (sizeof (descr->member[0]) == 4)				      \
       asm volatile ("movl %0,%%gs:%P1(,%2,4)" :			      \
		     : "ir" (value),					      \
		       "i" (offsetof (struct pthread, member)),		      \
		       "r" (idx));					      \
     else								      \
       {								      \
	 if (sizeof (descr->member[0]) != 8)				      \
	   /* There should not be any value with a size other than 1,	      \
	      4 or 8.  */						      \
	   abort ();							      \
									      \
	 asm volatile ("movl %%eax,%%gs:%P1(,%2,8)\n\t"			      \
		       "movl %%edx,%%gs:4+%P1(,%2,8)" :			      \
		       : "A" (value),					      \
			 "i" (offsetof (struct pthread, member)),	      \
			 "r" (idx));					      \
       }})


/* 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_PREFIX "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_PREFIX "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;							      \
     int __ignore1, __ignore2;						      \
     asm volatile ("pushl %%eax\n\t"					      \
		   "pushl %%eax\n\t"					      \
		   "pushl %%eax\n\t"					      \
		   "pushl %%gs:%P4\n\t"					      \
		   "call *%%gs:%P3\n\t"					      \
		   "addl $16, %%esp"					      \
		   : "=a" (__res), "=c" (__ignore1), "=d" (__ignore2)	      \
		   : "i" (offsetof (struct pthread, start_routine)),	      \
		     "i" (offsetof (struct pthread, arg)));		      \
     __res; })


/* Set the stack guard field in TCB head.  */
#define THREAD_SET_STACK_GUARD(value) \
  THREAD_SETMEM (THREAD_SELF, header.stack_guard, value)
#define THREAD_COPY_STACK_GUARD(descr) \
  ((descr)->header.stack_guard						      \
   = THREAD_GETMEM (THREAD_SELF, header.stack_guard))


/* Set the pointer guard field in the TCB head.  */
#define THREAD_SET_POINTER_GUARD(value) \
  THREAD_SETMEM (THREAD_SELF, header.pointer_guard, value)
#define THREAD_COPY_POINTER_GUARD(descr) \
  ((descr)->header.pointer_guard					      \
   = THREAD_GETMEM (THREAD_SELF, header.pointer_guard))


/* Get and set the global scope generation counter in the TCB head.  */
#define THREAD_GSCOPE_FLAG_UNUSED 0
#define THREAD_GSCOPE_FLAG_USED   1
#define THREAD_GSCOPE_FLAG_WAIT   2
#define THREAD_GSCOPE_RESET_FLAG() \
  do									      \
    { int __res;							      \
      asm volatile ("xchgl %0, %%gs:%P1"				      \
		    : "=r" (__res)					      \
		    : "i" (offsetof (struct pthread, header.gscope_flag)),    \
		      "0" (THREAD_GSCOPE_FLAG_UNUSED));			      \
      if (__res == THREAD_GSCOPE_FLAG_WAIT)				      \
	lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE);    \
    }									      \
  while (0)
#define THREAD_GSCOPE_SET_FLAG() \
  THREAD_SETMEM (THREAD_SELF, header.gscope_flag, THREAD_GSCOPE_FLAG_USED)
#define THREAD_GSCOPE_WAIT() \
  GL(dl_wait_lookup_done) ()

#endif /* __ASSEMBLER__ */

#endif	/* tls.h */