Major update for pthreads, based in large part on improvements

from glibc 2.3.  This should make threads much more efficient.
 -Erik

1 files changed, 183 insertions, 0 deletions

diff --git a/libpthread/linuxthreads/sysdeps/i386/tls.h b/libpthread/linuxthreads/sysdeps/i386/tls.h
new file mode 100644
index 000000000..5d1551e57
--- /dev/null
+++ b/libpthread/linuxthreads/sysdeps/i386/tls.h
@@ -0,0 +1,183 @@
+/* Definition for thread-local data handling.  linuxthreads/i386 version.
+   Copyright (C) 2002 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 Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#ifndef _TLS_H
+#define _TLS_H
+
+# include <pt-machine.h>
+
+#ifndef __ASSEMBLER__
+# include <stddef.h>
+
+/* Type for the dtv.  */
+typedef union dtv
+{
+  size_t counter;
+  void *pointer;
+} dtv_t;
+
+
+typedef struct
+{
+  void *tcb;		/* Pointer to the TCB.  Not necessary the
+			   thread descriptor used by libpthread.  */
+  dtv_t *dtv;
+  void *self;		/* Pointer to the thread descriptor.  */
+} tcbhead_t;
+#endif
+
+
+/* We can support TLS only if the floating-stack support is available.  */
+#if defined FLOATING_STACKS && defined HAVE_TLS_SUPPORT
+
+/* Signal that TLS support is available.  */
+//# define USE_TLS	1
+
+# ifndef __ASSEMBLER__
+/* Get system call information.  */
+#  include <sysdep.h>
+
+
+/* Get the thread descriptor definition.  */
+#  include <linuxthreads/descr.h>
+
+/* This is the size of the initial TCB.  */
+#  define TLS_INIT_TCB_SIZE sizeof (tcbhead_t)
+
+/* Alignment requirements for the initial TCB.  */
+#  define TLS_INIT_TCB_ALIGN __alignof__ (tcbhead_t)
+
+/* This is the size of the TCB.  */
+#  define TLS_TCB_SIZE sizeof (struct _pthread_descr_struct)
+
+/* Alignment requirements for the TCB.  */
+#  define TLS_TCB_ALIGN __alignof__ (struct _pthread_descr_struct)
+
+/* The TCB can have any size and the memory following the address the
+   thread pointer points to is unspecified.  Allocate the TCB there.  */
+#  define TLS_TCB_AT_TP	1
+
+
+/* Install the dtv pointer.  The pointer passed is to the element with
+   index -1 which contain the length.  */
+#  define INSTALL_DTV(descr, dtvp) \
+  ((tcbhead_t *) (descr))->dtv = (dtvp) + 1
+
+/* Install new dtv for current thread.  */
+#  define INSTALL_NEW_DTV(dtv) \
+  ({ struct _pthread_descr_struct *__descr;				      \
+     THREAD_SETMEM (__descr, p_header.data.dtvp, (dtv)); })
+
+/* Return dtv of given thread descriptor.  */
+#  define GET_DTV(descr) \
+  (((tcbhead_t *) (descr))->dtv)
+
+#  ifdef __PIC__
+#   define TLS_EBX_ARG "r"
+#   define TLS_LOAD_EBX "xchgl %3, %%ebx\n\t"
+#  else
+#   define TLS_EBX_ARG "b"
+#   define TLS_LOAD_EBX
+#  endif
+
+#  define TLS_DO_MODIFY_LDT(descr, nr)					      \
+({									      \
+  struct modify_ldt_ldt_s ldt_entry =					      \
+    { nr, (unsigned long int) (descr), 0xfffff /* 4GB in pages */,	      \
+      1, 0, 0, 1, 0, 1, 0 };						      \
+  int result;								      \
+  asm volatile (TLS_LOAD_EBX						      \
+		"int $0x80\n\t"						      \
+		TLS_LOAD_EBX						      \
+		: "=a" (result)						      \
+		: "0" (__NR_modify_ldt),				      \
+		/* The extra argument with the "m" constraint is necessary    \
+		   to let the compiler know that we are accessing LDT_ENTRY   \
+		   here.  */						      \
+		"m" (ldt_entry), TLS_EBX_ARG (1), "c" (&ldt_entry),	      \
+		"d" (sizeof (ldt_entry)));				      \
+  __builtin_expect (result, 0) != 0 ? -1 : nr * 8 + 7;			      \
+})
+
+#  define TLS_DO_SET_THREAD_AREA(descr, secondcall)			      \
+({									      \
+  struct modify_ldt_ldt_s ldt_entry =					      \
+    { -1, (unsigned long int) (descr), 0xfffff /* 4GB in pages */,	      \
+      1, 0, 0, 1, 0, 1, 0 };						      \
+  int result;								      \
+  if (secondcall)							      \
+    ldt_entry.entry_number = ({ int _gs;				      \
+				asm ("movw %%gs, %w0" : "=q" (_gs));	      \
+				(_gs & 0xffff) >> 3; });		      \
+  asm volatile (TLS_LOAD_EBX						      \
+		"int $0x80\n\t"						      \
+		TLS_LOAD_EBX						      \
+		: "=a" (result), "=m" (ldt_entry.entry_number)		      \
+		: "0" (__NR_set_thread_area),				      \
+		/* The extra argument with the "m" constraint is necessary    \
+		   to let the compiler know that we are accessing LDT_ENTRY   \
+		   here.  */						      \
+		TLS_EBX_ARG (&ldt_entry), "m" (ldt_entry));		      \
+    __builtin_expect (result, 0) == 0 ? ldt_entry.entry_number * 8 + 3 : -1;  \
+})
+
+#  ifdef __ASSUME_SET_THREAD_AREA_SYSCALL
+#   define TLS_SETUP_GS_SEGMENT(descr, secondcall) \
+  TLS_DO_SET_THREAD_AREA (descr, firstcall)
+#  elif defined __NR_set_thread_area
+#   define TLS_SETUP_GS_SEGMENT(descr, secondcall) \
+  ({ int __seg = TLS_DO_SET_THREAD_AREA (descr, secondcall); \
+     __seg == -1 ? TLS_DO_MODIFY_LDT (descr, 0) : __seg; })
+#  else
+#   define TLS_SETUP_GS_SEGMENT(descr, secondcall) \
+  TLS_DO_MODIFY_LDT ((descr), 0)
+#  endif
+
+/* Code to initially initialize the thread pointer.  This might need
+   special attention since 'errno' is not yet available and if the
+   operation can cause a failure 'errno' must not be touched.  */
+#  define TLS_INIT_TP(descr, secondcall)				      \
+  ({									      \
+    void *_descr = (descr);						      \
+    tcbhead_t *head = _descr;						      \
+    int __gs;								      \
+									      \
+    head->tcb = _descr;							      \
+    /* For now the thread descriptor is at the same address.  */	      \
+    head->self = _descr;						      \
+									      \
+    __gs = TLS_SETUP_GS_SEGMENT (_descr, secondcall);			      \
+    if (__builtin_expect (__gs, 7) != -1)				      \
+      {									      \
+	asm ("movw %w0, %%gs" : : "q" (__gs));				      \
+	__gs = 0;							      \
+      }									      \
+    __gs;								      \
+  })
+
+
+/* Return the address of the dtv for the current thread.  */
+#  define THREAD_DTV() \
+  ({ struct _pthread_descr_struct *__descr;				      \
+     THREAD_GETMEM (__descr, p_header.data.dtvp); })
+
+# endif	/* FLOATING_STACKS && HAVE_TLS_SUPPORT */
+#endif /* __ASSEMBLER__ */
+
+#endif	/* tls.h */