scheduler/sysdeps.c

   1 /*
   2  * System-dependent scheduler support
   3  *
   4  * Copyright 1998 Alexandre Julliard
   5  */
   6
   7 /* Get pointers to the static errno and h_errno variables used by Xlib. This
   8    must be done before including <errno.h> makes the variables invisible.  */
   9 extern int errno;
  10 static int *perrno = &errno;
  11 extern int h_errno;
  12 static int *ph_errno = &h_errno;
  13
  14 #include <signal.h>
  15 #include <stdio.h>
  16 #include <unistd.h>
  17 #include "thread.h"
  18 #include "winbase.h"
  19
  20 /* FIXME: X libs compiled w/o -D_REENTRANT should be detected by autoconf. */
  21 #define NO_REENTRANT_X11
  22
  23 #ifdef NO_REENTRANT_X11
  24 /* Xlib critical section (FIXME: does not belong here) */
  25 CRITICAL_SECTION X11DRV_CritSection = { 0, };
  26 #endif
  27
  28 #ifdef __linux__
  29 # ifdef HAVE_SCHED_H
  30 #  include <sched.h>
  31 # endif
  32 # ifndef CLONE_VM
  33 #  define CLONE_VM      0x00000100
  34 #  define CLONE_FS      0x00000200
  35 #  define CLONE_FILES   0x00000400
  36 #  define CLONE_SIGHAND 0x00000800
  37 #  define CLONE_PID     0x00001000
  38 /* If we didn't get the flags, we probably didn't get the prototype either */
  39 extern int clone( int (*fn)(void *arg), void *stack, int flags, void *arg );
  40 # endif  /* CLONE_VM */
  41 #endif  /* __linux__ */
  42
  43
  44 #ifdef __linux__
  45 /***********************************************************************
  46  *           __errno_location
  47  *
  48  * Get the per-thread errno location.
  49  */
  50 int *__errno_location()
  51 {
  52     THDB *thdb = THREAD_Current();
  53     if (!thdb) return perrno;
  54 #ifdef NO_REENTRANT_X11
  55     /* Use static libc errno while running in Xlib. */
  56     if (X11DRV_CritSection.OwningThread == THDB_TO_THREAD_ID(thdb))
  57         return perrno;
  58 #endif
  59     return &thdb->thread_errno;
  60 }
  61
  62 /***********************************************************************
  63  *           __h_errno_location
  64  *
  65  * Get the per-thread h_errno location.
  66  */
  67 int *__h_errno_location()
  68 {
  69     THDB *thdb = THREAD_Current();
  70     if (!thdb) return ph_errno;
  71 #ifdef NO_REENTRANT_X11
  72     /* Use static libc h_errno while running in Xlib. */
  73     if (X11DRV_CritSection.OwningThread == THDB_TO_THREAD_ID(thdb))
  74         return ph_errno;
  75 #endif
  76     return &thdb->thread_h_errno;
  77 }
  78
  79 /***********************************************************************
  80  *           SYSDEPS_StartThread
  81  *
  82  * Startup routine for a new thread.
  83  */
  84 static void SYSDEPS_StartThread( THDB *thdb )
  85 {
  86     LPTHREAD_START_ROUTINE func = (LPTHREAD_START_ROUTINE)thdb->entry_point;
  87     thdb->unix_pid = getpid();
  88     SET_FS( thdb->teb_sel );
  89     ExitThread( func( thdb->entry_arg ) );
  90 }
  91 #endif  /* __linux__ */
  92
  93
  94 /***********************************************************************
  95  *           SYSDEPS_SpawnThread
  96  *
  97  * Start running a new thread.
  98  * Return -1 on error, 0 if OK.
  99  */
 100 int SYSDEPS_SpawnThread( THDB *thread )
 101 {
 102 #ifdef __linux__
 103     if (clone( (int (*)(void *))SYSDEPS_StartThread, thread->teb.stack_top,
 104                CLONE_VM | CLONE_FS | CLONE_FILES | SIGCHLD, thread ) < 0)
 105         return -1;
 106 #else
 107     fprintf( stderr, "CreateThread: stub\n" );
 108 #endif  /* __linux__ */
 109     return 0;
 110 }
 111
 112
 113 /***********************************************************************
 114  *           SYSDEPS_ExitThread
 115  *
 116  * Exit a running thread; must not return.
 117  */
 118 void SYSDEPS_ExitThread(void)
 119 {
 120     _exit( 0 );
 121 }
 122
 123
 124 /**********************************************************************
 125  *           NtCurrentTeb   (NTDLL.89)
 126  */
 127 TEB * WINAPI NtCurrentTeb(void)
 128 {
 129 #ifdef __i386__
 130     TEB *teb;
 131     WORD ds, fs;
 132
 133     /* Check if we have a current thread */
 134     GET_FS( fs );
 135     if (!fs) return NULL;
 136     GET_DS( ds );
 137     if (fs == ds) return NULL; /* FIXME: should be an assert */
 138     /* Get the TEB self-pointer */
 139     __asm__( ".byte 0x64\n\tmovl (%1),%0"
 140              : "=r" (teb) : "r" (&((TEB *)0)->self) );
 141     return teb;
 142 #else
 143     if (!pCurrentThread) return NULL;
 144     return &pCurrentThread->teb;
 145 #endif  /* __i386__ */
 146 }