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 "server.h"
  19 #include "winbase.h"
  20 #include "debug.h"
  21
  22 /* Xlib critical section (FIXME: does not belong here) */
  23 CRITICAL_SECTION X11DRV_CritSection = { 0, };
  24
  25 #ifdef HAVE_CLONE_SYSCALL
  26 # ifdef HAVE_SCHED_H
  27 #  include <sched.h>
  28 # endif
  29 # ifndef CLONE_VM
  30 #  define CLONE_VM      0x00000100
  31 #  define CLONE_FS      0x00000200
  32 #  define CLONE_FILES   0x00000400
  33 #  define CLONE_SIGHAND 0x00000800
  34 #  define CLONE_PID     0x00001000
  35 /* If we didn't get the flags, we probably didn't get the prototype either */
  36 extern int clone( int (*fn)(void *arg), void *stack, int flags, void *arg );
  37 # endif  /* CLONE_VM */
  38 #endif  /* HAVE_CLONE_SYSCALL */
  39
  40
  41 #ifdef USE_THREADS
  42 /***********************************************************************
  43  *           __errno_location
  44  *
  45  * Get the per-thread errno location.
  46  */
  47 int *__errno_location()
  48 {
  49     THDB *thdb = THREAD_Current();
  50     if (!thdb) return perrno;
  51 #ifdef NO_REENTRANT_X11
  52     /* Use static libc errno while running in Xlib. */
  53     if (X11DRV_CritSection.OwningThread == (HANDLE)thdb->server_tid)
  54         return perrno;
  55 #endif
  56     return &thdb->thread_errno;
  57 }
  58
  59 /***********************************************************************
  60  *           __h_errno_location
  61  *
  62  * Get the per-thread h_errno location.
  63  */
  64 int *__h_errno_location()
  65 {
  66     THDB *thdb = THREAD_Current();
  67     if (!thdb) return ph_errno;
  68 #ifdef NO_REENTRANT_X11
  69     /* Use static libc h_errno while running in Xlib. */
  70     if (X11DRV_CritSection.OwningThread == (HANDLE)thdb->server_tid)
  71         return ph_errno;
  72 #endif
  73     return &thdb->thread_h_errno;
  74 }
  75
  76 /***********************************************************************
  77  *           SYSDEPS_StartThread
  78  *
  79  * Startup routine for a new thread.
  80  */
  81 static void SYSDEPS_StartThread( THDB *thdb )
  82 {
  83     SET_CUR_THREAD( thdb );
  84     CLIENT_InitThread();
  85     thdb->startup();
  86     _exit(0);  /* should never get here */
  87 }
  88 #endif  /* USE_THREADS */
  89
  90
  91 /***********************************************************************
  92  *           SYSDEPS_SpawnThread
  93  *
  94  * Start running a new thread.
  95  * Return -1 on error, 0 if OK.
  96  */
  97 int SYSDEPS_SpawnThread( THDB *thread )
  98 {
  99 #ifdef USE_THREADS
 100
 101 #ifdef HAVE_CLONE_SYSCALL
 102     if (clone( (int (*)(void *))SYSDEPS_StartThread, thread->teb.stack_top,
 103                CLONE_VM | CLONE_FS | CLONE_FILES | SIGCHLD, thread ) < 0)
 104         return -1;
 105     /* FIXME: close the child socket in the parent process */
 106 /*    close( thread->socket );*/
 107 #endif
 108
 109 #ifdef HAVE_RFORK
 110     FIXME(thread, "Threads using rfork() not implemented\n" );
 111 #endif
 112
 113 #else  /* !USE_THREADS */
 114     FIXME(thread, "CreateThread: stub\n" );
 115 #endif  /* USE_THREADS */
 116     return 0;
 117 }
 118
 119
 120 /***********************************************************************
 121  *           SYSDEPS_ExitThread
 122  *
 123  * Exit a running thread; must not return.
 124  * Must not make any reference to the thread structures (THDB etc.) as
 125  * they have already been deleted.
 126  */
 127 void SYSDEPS_ExitThread(void)
 128 {
 129     _exit( 0 );
 130 }
 131
 132
 133 /**********************************************************************
 134  *           NtCurrentTeb   (NTDLL.89)
 135  *
 136  * This will crash and burn if called before threading is initialized
 137  */
 138 TEB * WINAPI NtCurrentTeb(void)
 139 {
 140 #ifdef __i386__
 141     TEB *teb;
 142
 143     /* Get the TEB self-pointer */
 144     __asm__( ".byte 0x64\n\tmovl (%1),%0"
 145              : "=r" (teb) : "r" (&((TEB *)0)->self) );
 146     return teb;
 147 #else
 148     return &pCurrentThread->teb;
 149 #endif  /* __i386__ */
 150 }