1  /* Copyright (C) 2003-2023 Free Software Foundation, Inc.
       2     This file is part of the GNU C Library.
       3  
       4     The GNU C Library is free software; you can redistribute it and/or
       5     modify it under the terms of the GNU Lesser General Public
       6     License as published by the Free Software Foundation; either
       7     version 2.1 of the License, or (at your option) any later version.
       8  
       9     The GNU C Library is distributed in the hope that it will be useful,
      10     but WITHOUT ANY WARRANTY; without even the implied warranty of
      11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      12     Lesser General Public License for more details.
      13  
      14     You should have received a copy of the GNU Lesser General Public
      15     License along with the GNU C Library; if not, see
      16     <https://www.gnu.org/licenses/>.  */
      17  
      18  #include <errno.h>
      19  #include "pthreadP.h"
      20  #include <shlib-compat.h>
      21  
      22  int
      23  __pthread_spin_trylock (pthread_spinlock_t *lock)
      24  {
      25    unsigned int old;
      26    int err = EBUSY;
      27  
      28    asm ("1:	lwarx	%0,0,%2" MUTEX_HINT_ACQ "\n"
      29         "	cmpwi	0,%0,0\n"
      30         "	bne	2f\n"
      31         "	stwcx.	%3,0,%2\n"
      32         "	bne-	1b\n"
      33         "	li	%1,0\n"
      34                  __ARCH_ACQ_INSTR "\n"
      35         "2:	"
      36         : "=&r" (old), "=&r" (err)
      37         : "r" (lock), "r" (1), "1" (err)
      38         : "cr0", "memory");
      39  
      40    return err;
      41  }
      42  versioned_symbol (libc, __pthread_spin_trylock, pthread_spin_trylock,
      43  		  GLIBC_2_34);
      44  
      45  #if OTHER_SHLIB_COMPAT (libpthread, GLIBC_2_2, GLIBC_2_34)
      46  compat_symbol (libpthread, __pthread_spin_trylock, pthread_spin_trylock,
      47  	       GLIBC_2_2);
      48  #endif