Line data    Source code

       1             : /* posix-thread.c - GPGRT thread functions for POSIX systems
       2             :    Copyright (C) 2014 g10 Code GmbH
       3             : 
       4             :    This file is part of libgpg-error.
       5             : 
       6             :    libgpg-error is free software; you can redistribute it and/or
       7             :    modify it under the terms of the GNU Lesser General Public License
       8             :    as published by the Free Software Foundation; either version 2.1 of
       9             :    the License, or (at your option) any later version.
      10             : 
      11             :    libgpg-error is distributed in the hope that it will be useful, but
      12             :    WITHOUT ANY WARRANTY; without even the implied warranty of
      13             :    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      14             :    Lesser General Public License for more details.
      15             : 
      16             :    You should have received a copy of the GNU Lesser General Public
      17             :    License along with this program; if not, see <https://www.gnu.org/licenses/>.
      18             :  */
      19             : 
      20             : #if HAVE_CONFIG_H
      21             : #include <config.h>
      22             : #endif
      23             : 
      24             : #ifdef HAVE_W32_SYSTEM
      25             : # error This module may not be build for Windows.
      26             : #endif
      27             : 
      28             : #include <stdlib.h>
      29             : #include <stdio.h>
      30             : #include <string.h>
      31             : #include <errno.h>
      32             : #include <unistd.h>  /* Get posix option macros.  */
      33             : 
      34             : #if USE_POSIX_THREADS
      35             : # ifdef _POSIX_PRIORITY_SCHEDULING
      36             : #  include <sched.h>
      37             : # endif
      38             : #elif USE_SOLARIS_THREADS
      39             : # include <thread.h>
      40             : #endif
      41             : 
      42             : #include "gpg-error.h"
      43             : 
      44             : #include "thread.h"
      45             : 
      46             : /*
      47             :  * Functions called before and after blocking syscalls.
      48             :  * gpgrt_set_syscall_clamp is used to set them.
      49             :  */
      50             : static void (*pre_syscall_func)(void);
      51             : static void (*post_syscall_func)(void);
      52             : 
      53             : 
      54             : /* Helper to set the clamp functions.  This is called as a helper from
      55             :  * _gpgrt_set_syscall_clamp to keep the function pointers local. */
      56             : void
      57           6 : _gpgrt_thread_set_syscall_clamp (void (*pre)(void), void (*post)(void))
      58             : {
      59           6 :   pre_syscall_func = pre;
      60           6 :   post_syscall_func = post;
      61           6 : }
      62             : 
      63             : 
      64             : 
      65             : gpg_err_code_t
      66        2495 : _gpgrt_yield (void)
      67             : {
      68             : #if USE_POSIX_THREADS
      69             : # ifdef _POSIX_PRIORITY_SCHEDULING
      70        2495 :    if (pre_syscall_func)
      71           0 :      pre_syscall_func ();
      72        2495 :    sched_yield ();
      73        2485 :    if (post_syscall_func)
      74           0 :      post_syscall_func ();
      75             : # else
      76             :    return GPG_ERR_NOT_SUPPORTED;
      77             : # endif
      78             : #elif USE_SOLARIS_THREADS
      79             :   if (pre_syscall_func)
      80             :     pre_syscall_func ();
      81             :   thr_yield ();
      82             :   if (post_syscall_func)
      83             :     post_syscall_func ();
      84             : #else
      85             :   return GPG_ERR_NOT_SUPPORTED;
      86             : #endif
      87             : 
      88        2485 :   return 0;
      89             : }