scheduler/sysdeps.c

   1 /*
   2  * System-dependent scheduler support
   3  *
   4  * Copyright 1998 Alexandre Julliard
   5  */
   6
   7 #include "config.h"
   8
   9 /* Get pointers to the static errno and h_errno variables used by Xlib. This
  10    must be done before including <errno.h> makes the variables invisible.  */
  11 extern int errno;
  12 static int *perrno = &errno;
  13 extern int h_errno;
  14 static int *ph_errno = &h_errno;
  15
  16 #include <signal.h>
  17 #include <stdio.h>
  18 #include <unistd.h>
  19 #ifdef HAVE_SYS_SYSCALL_H
  20 # include <sys/syscall.h>
  21 #endif
  22 #ifdef HAVE_SYS_LWP_H
  23 # include <sys/lwp.h>
  24 #endif
  25 #ifdef HAVE_UCONTEXT_H
  26 # include <ucontext.h>
  27 #endif
  28 #include "thread.h"
  29 #include "server.h"
  30 #include "winbase.h"
  31 #include "debugtools.h"
  32
  33 DEFAULT_DEBUG_CHANNEL(thread)
  34
  35 #ifdef linux
  36 #define HAVE_CLONE_SYSCALL
  37 #endif
  38
  39 /* Xlib critical section (FIXME: does not belong here) */
  40 CRITICAL_SECTION X11DRV_CritSection = { 0, };
  41
  42 #ifdef HAVE_CLONE_SYSCALL
  43 # ifdef HAVE_SCHED_H
  44 #  include <sched.h>
  45 # endif
  46 # ifndef CLONE_VM
  47 #  define CLONE_VM      0x00000100
  48 #  define CLONE_FS      0x00000200
  49 #  define CLONE_FILES   0x00000400
  50 #  define CLONE_SIGHAND 0x00000800
  51 #  define CLONE_PID     0x00001000
  52 /* If we didn't get the flags, we probably didn't get the prototype either */
  53 extern int clone( int (*fn)(void *arg), void *stack, int flags, void *arg );
  54 # endif  /* CLONE_VM */
  55 #endif  /* HAVE_CLONE_SYSCALL */
  56
  57 static int init_done;
  58
  59 #ifndef __i386__
  60 static TEB *pCurrentTeb;
  61 #endif
  62
  63
  64 #ifndef NO_REENTRANT_LIBC
  65
  66 /***********************************************************************
  67  *           __errno_location/__error/___errno
  68  *
  69  * Get the per-thread errno location.
  70  */
  71 #ifdef HAVE__ERRNO_LOCATION
  72 int *__errno_location()
  73 #endif
  74 #ifdef HAVE__ERROR
  75 int *__error()
  76 #endif
  77 #ifdef HAVE___ERRNO
  78 int *___errno()
  79 #endif
  80 {
  81     if (!init_done) return perrno;
  82 #ifdef NO_REENTRANT_X11
  83     /* Use static libc errno while running in Xlib. */
  84     if (X11DRV_CritSection.OwningThread == GetCurrentThreadId())
  85         return perrno;
  86 #endif
  87     return &NtCurrentTeb()->thread_errno;
  88 }
  89
  90 /***********************************************************************
  91  *           __h_errno_location
  92  *
  93  * Get the per-thread h_errno location.
  94  */
  95 int *__h_errno_location()
  96 {
  97     if (!init_done) return ph_errno;
  98 #ifdef NO_REENTRANT_X11
  99     /* Use static libc h_errno while running in Xlib. */
 100     if (X11DRV_CritSection.OwningThread == GetCurrentThreadId())
 101         return ph_errno;
 102 #endif
 103     return &NtCurrentTeb()->thread_h_errno;
 104 }
 105
 106 #endif /* NO_REENTRANT_LIBC */
 107
 108 /***********************************************************************
 109  *           SYSDEPS_SetCurThread
 110  *
 111  * Make 'thread' the current thread.
 112  */
 113 void SYSDEPS_SetCurThread( TEB *teb )
 114 {
 115 #ifdef __i386__
 116     /* On the i386, the current thread is in the %fs register */
 117     SET_FS( teb->teb_sel );
 118 #else
 119     /* FIXME: only works if there is no preemptive task-switching going on... */
 120     pCurrentTeb = teb;
 121 #endif  /* __i386__ */
 122     init_done = 1;  /* now we can use threading routines */
 123 }
 124
 125 /***********************************************************************
 126  *           SYSDEPS_StartThread
 127  *
 128  * Startup routine for a new thread.
 129  */
 130 static void SYSDEPS_StartThread( TEB *teb )
 131 {
 132     SYSDEPS_SetCurThread( teb );
 133     CLIENT_InitThread();
 134     teb->startup();
 135     SYSDEPS_ExitThread();  /* should never get here */
 136 }
 137
 138
 139 /***********************************************************************
 140  *           SYSDEPS_SpawnThread
 141  *
 142  * Start running a new thread.
 143  * Return -1 on error, 0 if OK.
 144  */
 145 int SYSDEPS_SpawnThread( TEB *teb )
 146 {
 147 #ifndef NO_REENTRANT_LIBC
 148
 149 #ifdef HAVE_CLONE_SYSCALL
 150     if (clone( (int (*)(void *))SYSDEPS_StartThread, teb->stack_top,
 151                CLONE_VM | CLONE_FS | CLONE_FILES | SIGCHLD, teb ) < 0)
 152         return -1;
 153     /* FIXME: close the child socket in the parent process */
 154 /*    close( thread->socket );*/
 155     return 0;
 156 #endif
 157
 158 #ifdef HAVE_RFORK
 159     DWORD *sp = (DWORD *)teb->stack_top;
 160     *--sp = (DWORD)teb;
 161     *--sp = 0;
 162     *--sp = (DWORD)SYSDEPS_StartThread;
 163     __asm__(
 164     "pushl %2;\n\t"             /* RFPROC|RMEM */
 165     "pushl $0;\n\t"             /* 0 ? */
 166     "movl %1,%%eax;\n\t"        /* SYS_rfork */
 167     ".byte 0x9a; .long 0; .word 7;\n\t" /* lcall 7:0... FreeBSD syscall */
 168     "cmpl $0, %%edx;\n\t"
 169     "je 1f;\n\t"
 170     "movl %0,%%esp;\n\t"        /* father -> new thread */
 171     "ret;\n"
 172     "1:\n\t"            /* child -> caller thread */
 173     "addl $8,%%esp" :
 174     : "r" (sp), "g" (SYS_rfork), "g" (RFPROC|RFMEM)
 175     : "eax", "edx");
 176     return 0;
 177 #endif
 178
 179 #ifdef HAVE__LWP_CREATE
 180     ucontext_t context;
 181     _lwp_makecontext( &context, (void(*)(void *))SYSDEPS_StartThread, teb,
 182                       NULL, teb->stack_base, (char *)teb->stack_top - (char *)teb->stack_base );
 183     if ( _lwp_create( &context, 0, NULL ) )
 184         return -1;
 185     return 0;
 186 #endif
 187
 188 #endif /* NO_REENTRANT_LIBC */
 189
 190     FIXME("CreateThread: stub\n" );
 191     return 0;
 192 }
 193
 194
 195
 196 /***********************************************************************
 197  *           SYSDEPS_ExitThread
 198  *
 199  * Exit a running thread; must not return.
 200  * Must not make any reference to the thread structures (THDB etc.) as
 201  * they have already been deleted.
 202  */
 203 void SYSDEPS_ExitThread(void)
 204 {
 205 #ifdef HAVE__LWP_CREATE
 206     _lwp_exit();
 207 #endif
 208
 209     _exit( 0 );
 210 }
 211
 212
 213 /**********************************************************************
 214  *           NtCurrentTeb   (NTDLL.89)
 215  *
 216  * This will crash and burn if called before threading is initialized
 217  */
 218
 219 #ifdef NtCurrentTeb
 220
 221 /* if it was defined as a macro, we need to do some magic */
 222 #undef NtCurrentTeb
 223 struct _TEB * WINAPI NtCurrentTeb(void)
 224 {
 225     return __get_teb();
 226 }
 227
 228 #else  /* NtCurrentTeb */
 229
 230 struct _TEB * WINAPI NtCurrentTeb(void)
 231 {
 232     return pCurrentTeb;
 233 }
 234
 235 #endif  /* NtCurrentTeb */