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 THDB *pCurrentThread;
  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     THDB *thdb;
  82     if (!init_done) return perrno;
  83     thdb = THREAD_Current();
  84 #ifdef NO_REENTRANT_X11
  85     /* Use static libc errno while running in Xlib. */
  86     if (X11DRV_CritSection.OwningThread == (HANDLE)thdb->teb.tid)
  87         return perrno;
  88 #endif
  89     return &thdb->thread_errno;
  90 }
  91
  92 /***********************************************************************
  93  *           __h_errno_location
  94  *
  95  * Get the per-thread h_errno location.
  96  */
  97 int *__h_errno_location()
  98 {
  99     THDB *thdb;
 100     if (!init_done) return ph_errno;
 101     thdb = THREAD_Current();
 102 #ifdef NO_REENTRANT_X11
 103     /* Use static libc h_errno while running in Xlib. */
 104     if (X11DRV_CritSection.OwningThread == (HANDLE)thdb->teb.tid)
 105         return ph_errno;
 106 #endif
 107     return &thdb->thread_h_errno;
 108 }
 109
 110 #endif /* NO_REENTRANT_LIBC */
 111
 112 /***********************************************************************
 113  *           SYSDEPS_SetCurThread
 114  *
 115  * Make 'thread' the current thread.
 116  */
 117 void SYSDEPS_SetCurThread( THDB *thread )
 118 {
 119 #ifdef __i386__
 120     /* On the i386, the current thread is in the %fs register */
 121     SET_FS( thread->teb_sel );
 122 #else
 123     /* FIXME: only works if there is no preemptive task-switching going on... */
 124     pCurrentThread = thread;
 125 #endif  /* __i386__ */
 126     init_done = 1;  /* now we can use threading routines */
 127 }
 128
 129 /***********************************************************************
 130  *           SYSDEPS_StartThread
 131  *
 132  * Startup routine for a new thread.
 133  */
 134 static void SYSDEPS_StartThread( THDB *thdb )
 135 {
 136     SYSDEPS_SetCurThread( thdb );
 137     CLIENT_InitThread();
 138     thdb->startup();
 139     SYSDEPS_ExitThread();  /* should never get here */
 140 }
 141
 142
 143 /***********************************************************************
 144  *           SYSDEPS_SpawnThread
 145  *
 146  * Start running a new thread.
 147  * Return -1 on error, 0 if OK.
 148  */
 149 int SYSDEPS_SpawnThread( THDB *thread )
 150 {
 151 #ifndef NO_REENTRANT_LIBC
 152
 153 #ifdef HAVE_CLONE_SYSCALL
 154     if (clone( (int (*)(void *))SYSDEPS_StartThread, thread->teb.stack_top,
 155                CLONE_VM | CLONE_FS | CLONE_FILES | SIGCHLD, thread ) < 0)
 156         return -1;
 157     /* FIXME: close the child socket in the parent process */
 158 /*    close( thread->socket );*/
 159     return 0;
 160 #endif
 161
 162 #ifdef HAVE_RFORK
 163     DWORD *sp = (DWORD *)thread->teb.stack_top;
 164     *--sp = (DWORD)thread;
 165     *--sp = 0;
 166     *--sp = (DWORD)SYSDEPS_StartThread;
 167     __asm__(
 168     "pushl %2;\n\t"             /* RFPROC|RMEM */
 169     "pushl $0;\n\t"             /* 0 ? */
 170     "movl %1,%%eax;\n\t"        /* SYS_rfork */
 171     ".byte 0x9a; .long 0; .word 7;\n\t" /* lcall 7:0... FreeBSD syscall */
 172     "cmpl $0, %%edx;\n\t"
 173     "je 1f;\n\t"
 174     "movl %0,%%esp;\n\t"        /* father -> new thread */
 175     "ret;\n"
 176     "1:\n\t"            /* child -> caller thread */
 177     "addl $8,%%esp" :
 178     : "r" (sp), "g" (SYS_rfork), "g" (RFPROC|RFMEM)
 179     : "eax", "edx");
 180     return 0;
 181 #endif
 182
 183 #ifdef HAVE__LWP_CREATE
 184     ucontext_t context;
 185     _lwp_makecontext( &context, (void(*)(void *))SYSDEPS_StartThread, thread,
 186                       NULL, thread->stack_base, (char *) thread->teb.stack_top - (char *) thread->stack_base );
 187     if ( _lwp_create( &context, 0, NULL ) )
 188         return -1;
 189     return 0;
 190 #endif
 191
 192 #endif /* NO_REENTRANT_LIBC */
 193
 194     FIXME("CreateThread: stub\n" );
 195     return 0;
 196 }
 197
 198
 199
 200 /***********************************************************************
 201  *           SYSDEPS_ExitThread
 202  *
 203  * Exit a running thread; must not return.
 204  * Must not make any reference to the thread structures (THDB etc.) as
 205  * they have already been deleted.
 206  */
 207 void SYSDEPS_ExitThread(void)
 208 {
 209 #ifdef HAVE__LWP_CREATE
 210     _lwp_exit();
 211 #endif
 212
 213     _exit( 0 );
 214 }
 215
 216
 217 /**********************************************************************
 218  *           NtCurrentTeb   (NTDLL.89)
 219  *
 220  * This will crash and burn if called before threading is initialized
 221  */
 222 TEB * WINAPI NtCurrentTeb(void)
 223 {
 224 #ifdef __i386__
 225     return CURRENT();
 226 #else
 227     return &pCurrentThread->teb;
 228 #endif  /* __i386__ */
 229 }