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 "debug.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
  58 #ifndef NO_REENTRANT_LIBC
  59
  60 /***********************************************************************
  61  *           __errno_location/__error/___errno
  62  *
  63  * Get the per-thread errno location.
  64  */
  65 #ifdef HAVE__ERRNO_LOCATION
  66 int *__errno_location()
  67 #endif
  68 #ifdef HAVE__ERROR
  69 int *__error()
  70 #endif
  71 #ifdef HAVE___ERRNO
  72 int *___errno()
  73 #endif
  74 {
  75     THDB *thdb = THREAD_Current();
  76     if (!thdb) return perrno;
  77 #ifdef NO_REENTRANT_X11
  78     /* Use static libc errno while running in Xlib. */
  79     if (X11DRV_CritSection.OwningThread == (HANDLE)thdb->server_tid)
  80         return perrno;
  81 #endif
  82     return &thdb->thread_errno;
  83 }
  84
  85 /***********************************************************************
  86  *           __h_errno_location
  87  *
  88  * Get the per-thread h_errno location.
  89  */
  90 int *__h_errno_location()
  91 {
  92     THDB *thdb = THREAD_Current();
  93     if (!thdb) return ph_errno;
  94 #ifdef NO_REENTRANT_X11
  95     /* Use static libc h_errno while running in Xlib. */
  96     if (X11DRV_CritSection.OwningThread == (HANDLE)thdb->server_tid)
  97         return ph_errno;
  98 #endif
  99     return &thdb->thread_h_errno;
 100 }
 101
 102 #endif /* NO_REENTRANT_LIBC */
 103
 104 /***********************************************************************
 105  *           SYSDEPS_StartThread
 106  *
 107  * Startup routine for a new thread.
 108  */
 109 static void SYSDEPS_StartThread( THDB *thdb )
 110 {
 111     SET_CUR_THREAD( thdb );
 112     CLIENT_InitThread();
 113     thdb->startup();
 114     _exit(0);  /* should never get here */
 115 }
 116
 117
 118 /***********************************************************************
 119  *           SYSDEPS_SpawnThread
 120  *
 121  * Start running a new thread.
 122  * Return -1 on error, 0 if OK.
 123  */
 124 int SYSDEPS_SpawnThread( THDB *thread )
 125 {
 126 #ifndef NO_REENTRANT_LIBC
 127
 128 #ifdef HAVE_CLONE_SYSCALL
 129     if (clone( (int (*)(void *))SYSDEPS_StartThread, thread->teb.stack_top,
 130                CLONE_VM | CLONE_FS | CLONE_FILES | SIGCHLD, thread ) < 0)
 131         return -1;
 132     /* FIXME: close the child socket in the parent process */
 133 /*    close( thread->socket );*/
 134     return 0;
 135 #endif
 136
 137 #ifdef HAVE_RFORK
 138     DWORD *sp = (DWORD *)thread->teb.stack_top;
 139     *--sp = (DWORD)thread;
 140     *--sp = 0;
 141     *--sp = (DWORD)SYSDEPS_StartThread;
 142     __asm__(
 143     "pushl %2;\n\t"             /* RFPROC|RMEM */
 144     "pushl $0;\n\t"             /* 0 ? */
 145     "movl %1,%%eax;\n\t"        /* SYS_rfork */
 146     ".byte 0x9a; .long 0; .word 7;\n\t" /* lcall 7:0... FreeBSD syscall */
 147     "cmpl $0, %%edx;\n\t"
 148     "je 1f;\n\t"
 149     "movl %0,%%esp;\n\t"        /* father -> new thread */
 150     "ret;\n"
 151     "1:\n\t"            /* child -> caller thread */
 152     "addl $8,%%esp" :
 153     : "r" (sp), "g" (SYS_rfork), "g" (RFPROC|RFMEM)
 154     : "eax", "edx");
 155     return 0;
 156 #endif
 157
 158 #ifdef HAVE__LWP_CREATE
 159     ucontext_t context;
 160     _lwp_makecontext( &context, (void(*)(void *))SYSDEPS_StartThread, thread,
 161                       NULL, thread->stack_base, (char *) thread->teb.stack_top - (char *) thread->stack_base );
 162     if ( _lwp_create( &context, 0, NULL ) )
 163         return -1;
 164     return 0;
 165 #endif
 166
 167 #endif /* NO_REENTRANT_LIBC */
 168
 169     FIXME(thread, "CreateThread: stub\n" );
 170     return 0;
 171 }
 172
 173
 174
 175 /***********************************************************************
 176  *           SYSDEPS_ExitThread
 177  *
 178  * Exit a running thread; must not return.
 179  * Must not make any reference to the thread structures (THDB etc.) as
 180  * they have already been deleted.
 181  */
 182 void SYSDEPS_ExitThread(void)
 183 {
 184 #ifdef HAVE__LWP_CREATE
 185     _lwp_exit();
 186 #endif
 187
 188     _exit( 0 );
 189 }
 190
 191
 192 /**********************************************************************
 193  *           NtCurrentTeb   (NTDLL.89)
 194  *
 195  * This will crash and burn if called before threading is initialized
 196  */
 197 TEB * WINAPI NtCurrentTeb(void)
 198 {
 199 #ifdef __i386__
 200     TEB *teb;
 201
 202     /* Get the TEB self-pointer */
 203     __asm__( ".byte 0x64\n\tmovl (%1),%0"
 204              : "=r" (teb) : "r" (&((TEB *)0)->self) );
 205     return teb;
 206 #else
 207     return &pCurrentThread->teb;
 208 #endif  /* __i386__ */
 209 }