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 NO_REENTRANT_LIBC
  60
  61 /***********************************************************************
  62  *           __errno_location/__error/___errno
  63  *
  64  * Get the per-thread errno location.
  65  */
  66 #ifdef HAVE__ERRNO_LOCATION
  67 int *__errno_location()
  68 #endif
  69 #ifdef HAVE__ERROR
  70 int *__error()
  71 #endif
  72 #ifdef HAVE___ERRNO
  73 int *___errno()
  74 #endif
  75 {
  76     if (!init_done) return perrno;
  77 #ifdef NO_REENTRANT_X11
  78     /* Use static libc errno while running in Xlib. */
  79     if (X11DRV_CritSection.OwningThread == GetCurrentThreadId())
  80         return perrno;
  81 #endif
  82     return &NtCurrentTeb()->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     if (!init_done) return ph_errno;
  93 #ifdef NO_REENTRANT_X11
  94     /* Use static libc h_errno while running in Xlib. */
  95     if (X11DRV_CritSection.OwningThread == GetCurrentThreadId())
  96         return ph_errno;
  97 #endif
  98     return &NtCurrentTeb()->thread_h_errno;
  99 }
 100
 101 #endif /* NO_REENTRANT_LIBC */
 102
 103 /***********************************************************************
 104  *           SYSDEPS_SetCurThread
 105  *
 106  * Make 'thread' the current thread.
 107  */
 108 void SYSDEPS_SetCurThread( TEB *teb )
 109 {
 110 #if defined(__i386__)
 111     /* On the i386, the current thread is in the %fs register */
 112     SET_FS( teb->teb_sel );
 113 #elif defined(HAVE__LWP_CREATE)
 114     /* On non-i386 Solaris, we use the LWP private pointer */
 115     _lwp_setprivate( teb );
 116 #endif
 117
 118     init_done = 1;  /* now we can use threading routines */
 119 }
 120
 121 /***********************************************************************
 122  *           SYSDEPS_StartThread
 123  *
 124  * Startup routine for a new thread.
 125  */
 126 static void SYSDEPS_StartThread( TEB *teb )
 127 {
 128     SYSDEPS_SetCurThread( teb );
 129     CLIENT_InitThread();
 130     teb->startup();
 131     SYSDEPS_ExitThread();  /* should never get here */
 132 }
 133
 134
 135 /***********************************************************************
 136  *           SYSDEPS_SpawnThread
 137  *
 138  * Start running a new thread.
 139  * Return -1 on error, 0 if OK.
 140  */
 141 int SYSDEPS_SpawnThread( TEB *teb )
 142 {
 143 #ifndef NO_REENTRANT_LIBC
 144
 145 #ifdef HAVE_CLONE_SYSCALL
 146     if (clone( (int (*)(void *))SYSDEPS_StartThread, teb->stack_top,
 147                CLONE_VM | CLONE_FS | CLONE_FILES | SIGCHLD, teb ) < 0)
 148         return -1;
 149     /* FIXME: close the child socket in the parent process */
 150 /*    close( thread->socket );*/
 151     return 0;
 152 #endif
 153
 154 #ifdef HAVE_RFORK
 155     DWORD *sp = (DWORD *)teb->stack_top;
 156     *--sp = (DWORD)teb;
 157     *--sp = 0;
 158     *--sp = (DWORD)SYSDEPS_StartThread;
 159     __asm__(
 160     "pushl %2;\n\t"             /* RFPROC|RMEM */
 161     "pushl $0;\n\t"             /* 0 ? */
 162     "movl %1,%%eax;\n\t"        /* SYS_rfork */
 163     ".byte 0x9a; .long 0; .word 7;\n\t" /* lcall 7:0... FreeBSD syscall */
 164     "cmpl $0, %%edx;\n\t"
 165     "je 1f;\n\t"
 166     "movl %0,%%esp;\n\t"        /* father -> new thread */
 167     "ret;\n"
 168     "1:\n\t"            /* child -> caller thread */
 169     "addl $8,%%esp" :
 170     : "r" (sp), "g" (SYS_rfork), "g" (RFPROC|RFMEM)
 171     : "eax", "edx");
 172     return 0;
 173 #endif
 174
 175 #ifdef HAVE__LWP_CREATE
 176     ucontext_t context;
 177     _lwp_makecontext( &context, (void(*)(void *))SYSDEPS_StartThread, teb,
 178                       NULL, teb->stack_base, (char *)teb->stack_top - (char *)teb->stack_base );
 179     if ( _lwp_create( &context, 0, NULL ) )
 180         return -1;
 181     return 0;
 182 #endif
 183
 184 #endif /* NO_REENTRANT_LIBC */
 185
 186     FIXME("CreateThread: stub\n" );
 187     return 0;
 188 }
 189
 190
 191
 192 /***********************************************************************
 193  *           SYSDEPS_ExitThread
 194  *
 195  * Exit a running thread; must not return.
 196  * Must not make any reference to the thread structures (THDB etc.) as
 197  * they have already been deleted.
 198  */
 199 void SYSDEPS_ExitThread(void)
 200 {
 201 #ifdef HAVE__LWP_CREATE
 202     _lwp_exit();
 203 #endif
 204
 205     _exit( 0 );
 206 }
 207
 208
 209 /**********************************************************************
 210  *           NtCurrentTeb   (NTDLL.89)
 211  *
 212  * This will crash and burn if called before threading is initialized
 213  */
 214
 215 /* if it was defined as a macro, we need to do some magic */
 216 #ifdef NtCurrentTeb
 217 #undef NtCurrentTeb
 218 #endif
 219
 220 struct _TEB * WINAPI NtCurrentTeb(void)
 221 {
 222     return __get_teb();
 223 }
 224