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-rw-r--r--mach/setup-thread.c99
1 files changed, 99 insertions, 0 deletions
diff --git a/mach/setup-thread.c b/mach/setup-thread.c
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+++ b/mach/setup-thread.c
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+/* Copyright (C) 1991, 1994, 1995 Free Software Foundation, Inc.
+This file is part of the GNU C Library.
+
+The GNU C Library is free software; you can redistribute it and/or
+modify it under the terms of the GNU Library General Public License as
+published by the Free Software Foundation; either version 2 of the
+License, or (at your option) any later version.
+
+The GNU C Library is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+Library General Public License for more details.
+
+You should have received a copy of the GNU Library General Public
+License along with the GNU C Library; see the file COPYING.LIB.  If
+not, write to the Free Software Foundation, Inc., 675 Mass Ave,
+Cambridge, MA 02139, USA.  */
+
+#include <mach.h>
+#include "thread_state.h"
+#include <string.h>
+#include <mach/machine/vm_param.h>
+#include "sysdep.h"		/* Defines stack direction.  */
+
+#define	STACK_SIZE	(16 * 1024 * 1024) /* 16MB, arbitrary.  */
+
+/* Give THREAD a stack and set it to run at PC when resumed.
+   If *STACK_SIZE is nonzero, that size of stack is allocated.
+   If *STACK_BASE is nonzero, that stack location is used.
+   If STACK_BASE is not null it is filled in with the chosen stack base.
+   If STACK_SIZE is not null it is filled in with the chosen stack size.
+   Regardless, an extra page of red zone is allocated off the end; this
+   is not included in *STACK_SIZE.  */
+
+kern_return_t
+__mach_setup_thread (task_t task, thread_t thread, void *pc,
+		     vm_address_t *stack_base, vm_size_t *stack_size)
+{
+  kern_return_t error;
+  struct machine_thread_state ts;
+  mach_msg_type_number_t tssize = MACHINE_THREAD_STATE_COUNT;
+  vm_address_t stack;
+  vm_size_t size;
+  int anywhere = 0;
+
+  size = stack_size ? *stack_size ? : STACK_SIZE : STACK_SIZE;
+
+  if (stack_base && *stack_base)
+    stack = *stack_base;
+  else if (size == STACK_SIZE)
+    {
+      /* Cthreads has a bug that makes its stack-probing code fail if
+	 the stack is too low in memory.  It's bad to try and fix it there
+	 until cthreads is integrated into libc, so we'll just do it here
+	 by requesting a high address.  When the cthreads bug is fixed,
+	 this assignment to STACK should be changed to 0, and the ANYWHERE
+	 argument to vm_allocate should be changed to 0.  This comment should
+	 be left, however, in order to confuse people who wonder why its
+	 here.  (Though perhaps that last sentence (and this one) should
+	 be deleted to maximize the effect.)  */
+#ifdef STACK_GROWTH_DOWN
+      stack = VM_MAX_ADDRESS - size - __vm_page_size;
+#else
+      stack = VM_MIN_ADDRESS;
+#endif
+    }
+  else
+    anywhere = 1;
+
+  if (error = __vm_allocate (task, &stack, size + __vm_page_size, anywhere))
+    return error;
+
+  if (stack_size)
+    *stack_size = size;
+
+  memset (&ts, 0, sizeof (ts));
+  MACHINE_THREAD_STATE_SET_PC (&ts, pc);
+#ifdef STACK_GROWTH_DOWN
+  if (stack_base)
+    *stack_base = stack + __vm_page_size;
+  ts.SP = stack + __vm_page_size + size;
+#elif defined (STACK_GROWTH_UP)
+  if (stack_base)
+    *stack_base = stack;
+  ts.SP = stack;
+  stack += size;
+#else
+  #error stack direction unknown
+#endif
+
+  /* Create the red zone.  */
+  if (error = __vm_protect (task, stack, __vm_page_size, 0, VM_PROT_NONE))
+    return error;
+  
+  return __thread_set_state (thread, MACHINE_THREAD_STATE_FLAVOR,
+			     (int *) &ts, tssize);
+}
+
+weak_alias (__mach_setup_thread, mach_setup_thread)