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 #include "thread.h"
  23 #include "server.h"
  24 #include "winbase.h"
  25 #include "debug.h"
  26
  27
  28 /* Xlib critical section (FIXME: does not belong here) */
  29 CRITICAL_SECTION X11DRV_CritSection = { 0, };
  30
  31 #ifdef HAVE_CLONE_SYSCALL
  32 # ifdef HAVE_SCHED_H
  33 #  include <sched.h>
  34 # endif
  35 # ifndef CLONE_VM
  36 #  define CLONE_VM      0x00000100
  37 #  define CLONE_FS      0x00000200
  38 #  define CLONE_FILES   0x00000400
  39 #  define CLONE_SIGHAND 0x00000800
  40 #  define CLONE_PID     0x00001000
  41 /* If we didn't get the flags, we probably didn't get the prototype either */
  42 extern int clone( int (*fn)(void *arg), void *stack, int flags, void *arg );
  43 # endif  /* CLONE_VM */
  44 #endif  /* HAVE_CLONE_SYSCALL */
  45
  46
  47 #ifdef USE_THREADS
  48 #ifdef linux
  49 /***********************************************************************
  50  *           __errno_location
  51  *
  52  * Get the per-thread errno location.
  53  */
  54 int *__errno_location()
  55 {
  56     THDB *thdb = THREAD_Current();
  57     if (!thdb) return perrno;
  58 #ifdef NO_REENTRANT_X11
  59     /* Use static libc errno while running in Xlib. */
  60     if (X11DRV_CritSection.OwningThread == (HANDLE)thdb->server_tid)
  61         return perrno;
  62 #endif
  63     return &thdb->thread_errno;
  64 }
  65
  66 /***********************************************************************
  67  *           __h_errno_location
  68  *
  69  * Get the per-thread h_errno location.
  70  */
  71 int *__h_errno_location()
  72 {
  73     THDB *thdb = THREAD_Current();
  74     if (!thdb) return ph_errno;
  75 #ifdef NO_REENTRANT_X11
  76     /* Use static libc h_errno while running in Xlib. */
  77     if (X11DRV_CritSection.OwningThread == (HANDLE)thdb->server_tid)
  78         return ph_errno;
  79 #endif
  80     return &thdb->thread_h_errno;
  81 }
  82 #endif
  83
  84 #ifdef __FreeBSD__
  85 int *__error() {
  86     THDB *thdb = THREAD_Current();
  87     if (!thdb) return perrno;
  88 #ifdef NO_REENTRANT_X11
  89     /* Use static libc errno while running in Xlib. */
  90     if (X11DRV_CritSection.OwningThread == (HANDLE)thdb->server_tid)
  91         return perrno;
  92 #endif
  93     return &thdb->thread_errno;
  94 }
  95 #endif
  96
  97 /***********************************************************************
  98  *           SYSDEPS_StartThread
  99  *
 100  * Startup routine for a new thread.
 101  */
 102 static void SYSDEPS_StartThread( THDB *thdb )
 103 {
 104     SET_CUR_THREAD( thdb );
 105     CLIENT_InitThread();
 106     thdb->startup();
 107     _exit(0);  /* should never get here */
 108 }
 109 #endif  /* USE_THREADS */
 110
 111
 112 /***********************************************************************
 113  *           SYSDEPS_SpawnThread
 114  *
 115  * Start running a new thread.
 116  * Return -1 on error, 0 if OK.
 117  */
 118 int SYSDEPS_SpawnThread( THDB *thread )
 119 {
 120 #ifdef USE_THREADS
 121
 122 #ifdef HAVE_CLONE_SYSCALL
 123     if (clone( (int (*)(void *))SYSDEPS_StartThread, thread->teb.stack_top,
 124                CLONE_VM | CLONE_FS | CLONE_FILES | SIGCHLD, thread ) < 0)
 125         return -1;
 126     /* FIXME: close the child socket in the parent process */
 127 /*    close( thread->socket );*/
 128 #endif
 129
 130 #ifdef HAVE_RFORK
 131     DWORD *sp = (DWORD *)thread->teb.stack_top;
 132     *--sp = (DWORD)thread;
 133     *--sp = 0;
 134     *--sp = (DWORD)SYSDEPS_StartThread;
 135     __asm__(
 136     "pushl %2;\n\t"             /* RFPROC|RMEM */
 137     "pushl $0;\n\t"             /* 0 ? */
 138     "movl %1,%%eax;\n\t"        /* SYS_rfork */
 139     ".byte 0x9a; .long 0; .word 7;\n\t" /* lcall 7:0... FreeBSD syscall */
 140     "cmpl $0, %%edx;\n\t"
 141     "je 1f;\n\t"
 142     "movl %0,%%esp;\n\t"        /* father -> new thread */
 143     "ret;\n"
 144     "1:\n\t"            /* child -> caller thread */
 145     "addl $8,%%esp" :
 146     : "r" (sp), "g" (SYS_rfork), "g" (RFPROC|RFMEM)
 147     : "eax", "edx");
 148 #endif
 149
 150 #else  /* !USE_THREADS */
 151     FIXME(thread, "CreateThread: stub\n" );
 152 #endif  /* USE_THREADS */
 153     return 0;
 154 }
 155
 156
 157 /***********************************************************************
 158  *           SYSDEPS_ExitThread
 159  *
 160  * Exit a running thread; must not return.
 161  * Must not make any reference to the thread structures (THDB etc.) as
 162  * they have already been deleted.
 163  */
 164 void SYSDEPS_ExitThread(void)
 165 {
 166     _exit( 0 );
 167 }
 168
 169
 170 /**********************************************************************
 171  *           NtCurrentTeb   (NTDLL.89)
 172  *
 173  * This will crash and burn if called before threading is initialized
 174  */
 175 TEB * WINAPI NtCurrentTeb(void)
 176 {
 177 #ifdef __i386__
 178     TEB *teb;
 179
 180     /* Get the TEB self-pointer */
 181     __asm__( ".byte 0x64\n\tmovl (%1),%0"
 182              : "=r" (teb) : "r" (&((TEB *)0)->self) );
 183     return teb;
 184 #else
 185     return &pCurrentThread->teb;
 186 #endif  /* __i386__ */
 187 }