[PATCH] Use default_attr to store default pthread attributes

[Siddhesh Poyarekar <siddhesh at redhat dot com>]

Hi,

This is a preparatory patch for the upcoming patch to add a new API
function to set default pthread attributes for a process[1][2].  These
attributes would be used to create all threads in that process that do
not provide their own pthread_attr_t.  This patch moves the
__default_stacksize into default_attr, which is now shared within
libpthread.so and is not just static to pthread_create.c.  Verified on
x86_64 to verify that there were no regressions due to this change.
OK to commit?

Siddhesh

[1] http://sourceware.org/ml/libc-alpha/2013-03/msg00300.html
[2] Code is on siddhesh/pthread_attr_default

nptl/ChangeLog:

	* allocatestack.c (allocate_stack): Use DEFAULT_ATTR.
	* nptl-init.c (__pthread_initialize_minimal_internal):
	Likewise.
	* pthreadP.h (default_attr): Declare.
	* pthread_attr_getstacksize.c (__pthread_attr_getstacksize):
	Use DEFAULT_ATTR.
	* pthread_barrier_init.c (default_attr); Rename to
	default_barrierattr.
	(pthread_barrier_init): Adjust for the rename.
	* pthread_create.c (default_attr): Move definition...
	* vars.c: ... here.
	(default_attr): Initialize member STACKSIZE.
	* pthread_mutex_init.c (default_attr): Rename to
	default_mutexattr.
	(__pthread_mutex_init): Adjust for the rename.
	* pthread_rwlock_init.c )default_attr_: Rename to
	default_rwlockattr.
	(__pthread_rwlock_init): Adjust for the rename.


diff --git a/nptl/allocatestack.c b/nptl/allocatestack.c
index 31c8829..d617262 100644
--- a/nptl/allocatestack.c
+++ b/nptl/allocatestack.c
@@ -358,7 +358,7 @@ allocate_stack (const struct pthread_attr *attr, struct pthread **pdp,
 
   /* Get the stack size from the attribute if it is set.  Otherwise we
      use the default we determined at start time.  */
-  size = attr->stacksize ?: __default_stacksize;
+  size = attr->stacksize ?: default_attr.stacksize;
 
   /* Get memory for the stack.  */
   if (__builtin_expect (attr->flags & ATTR_FLAG_STACKADDR, 0))
diff --git a/nptl/nptl-init.c b/nptl/nptl-init.c
index 19e6616..23d3430 100644
--- a/nptl/nptl-init.c
+++ b/nptl/nptl-init.c
@@ -423,7 +423,7 @@ __pthread_initialize_minimal_internal (void)
 
   /* Round the resource limit up to page size.  */
   limit.rlim_cur = (limit.rlim_cur + pagesz - 1) & -pagesz;
-  __default_stacksize = limit.rlim_cur;
+  default_attr.stacksize = limit.rlim_cur;
 
 #ifdef SHARED
   /* Transfer the old value from the dynamic linker's internal location.  */
diff --git a/nptl/pthreadP.h b/nptl/pthreadP.h
index d08b219..73dfba6 100644
--- a/nptl/pthreadP.h
+++ b/nptl/pthreadP.h
@@ -147,8 +147,9 @@ enum
 /* Internal variables.  */
 
 
-/* Default stack size.  */
-extern size_t __default_stacksize attribute_hidden;
+/* Default pthread attributes.  */
+extern struct pthread_attr default_attr;
+hidden_proto (default_attr);
 
 /* Size and alignment of static TLS block.  */
 extern size_t __static_tls_size attribute_hidden;
diff --git a/nptl/pthread_attr_getstacksize.c b/nptl/pthread_attr_getstacksize.c
index 6df7062..915cbb7 100644
--- a/nptl/pthread_attr_getstacksize.c
+++ b/nptl/pthread_attr_getstacksize.c
@@ -32,7 +32,7 @@ __pthread_attr_getstacksize (attr, stacksize)
 
   /* If the user has not set a stack size we return what the system
      will use as the default.  */
-  *stacksize = iattr->stacksize ?: __default_stacksize;
+  *stacksize = iattr->stacksize ?: default_attr.stacksize;
 
   return 0;
 }
diff --git a/nptl/pthread_barrier_init.c b/nptl/pthread_barrier_init.c
index d5891fd..6d2910e 100644
--- a/nptl/pthread_barrier_init.c
+++ b/nptl/pthread_barrier_init.c
@@ -22,7 +22,7 @@
 #include <kernel-features.h>
 
 
-static const struct pthread_barrierattr default_attr =
+static const struct pthread_barrierattr default_barrierattr =
   {
     .pshared = PTHREAD_PROCESS_PRIVATE
   };
@@ -42,7 +42,7 @@ pthread_barrier_init (barrier, attr, count)
   const struct pthread_barrierattr *iattr
     = (attr != NULL
        ? iattr = (struct pthread_barrierattr *) attr
-       : &default_attr);
+       : &default_barrierattr);
 
   if (iattr->pshared != PTHREAD_PROCESS_PRIVATE
       && __builtin_expect (iattr->pshared != PTHREAD_PROCESS_SHARED, 0))
diff --git a/nptl/pthread_create.c b/nptl/pthread_create.c
index c6f2fdd..f81dcce 100644
--- a/nptl/pthread_create.c
+++ b/nptl/pthread_create.c
@@ -435,15 +435,6 @@ start_thread (void *arg)
 }
 
 
-/* Default thread attributes for the case when the user does not
-   provide any.  */
-static const struct pthread_attr default_attr =
-  {
-    /* Just some value > 0 which gets rounded to the nearest page size.  */
-    .guardsize = 1,
-  };
-
-
 int
 __pthread_create_2_1 (newthread, attr, start_routine, arg)
      pthread_t *newthread;
diff --git a/nptl/pthread_mutex_init.c b/nptl/pthread_mutex_init.c
index 36da3f8..174d900 100644
--- a/nptl/pthread_mutex_init.c
+++ b/nptl/pthread_mutex_init.c
@@ -24,7 +24,7 @@
 
 #include <stap-probe.h>
 
-static const struct pthread_mutexattr default_attr =
+static const struct pthread_mutexattr default_mutexattr =
   {
     /* Default is a normal mutex, not shared between processes.  */
     .mutexkind = PTHREAD_MUTEX_NORMAL
@@ -45,7 +45,8 @@ __pthread_mutex_init (mutex, mutexattr)
 
   assert (sizeof (pthread_mutex_t) <= __SIZEOF_PTHREAD_MUTEX_T);
 
-  imutexattr = (const struct pthread_mutexattr *) mutexattr ?: &default_attr;
+  imutexattr = ((const struct pthread_mutexattr *) mutexattr
+		?: &default_mutexattr);
 
   /* Sanity checks.  */
   switch (__builtin_expect (imutexattr->mutexkind
diff --git a/nptl/pthread_rwlock_init.c b/nptl/pthread_rwlock_init.c
index 16bfe2d..29bef71 100644
--- a/nptl/pthread_rwlock_init.c
+++ b/nptl/pthread_rwlock_init.c
@@ -21,7 +21,7 @@
 #include <kernel-features.h>
 
 
-static const struct pthread_rwlockattr default_attr =
+static const struct pthread_rwlockattr default_rwlockattr =
   {
     .lockkind = PTHREAD_RWLOCK_DEFAULT_NP,
     .pshared = PTHREAD_PROCESS_PRIVATE
@@ -35,7 +35,7 @@ __pthread_rwlock_init (rwlock, attr)
 {
   const struct pthread_rwlockattr *iattr;
 
-  iattr = ((const struct pthread_rwlockattr *) attr) ?: &default_attr;
+  iattr = ((const struct pthread_rwlockattr *) attr) ?: &default_rwlockattr;
 
   memset (rwlock, '\0', sizeof (*rwlock));
 
diff --git a/nptl/vars.c b/nptl/vars.c
index 2bcd1f8..727c570 100644
--- a/nptl/vars.c
+++ b/nptl/vars.c
@@ -20,13 +20,17 @@
 #include <tls.h>
 #include <unistd.h>
 
-/* Default stack size.  */
-size_t __default_stacksize attribute_hidden
-#ifdef SHARED
-;
-#else
-  = PTHREAD_STACK_MIN;
+/* Default thread attributes for the case when the user does not
+   provide any.  */
+struct pthread_attr default_attr =
+  {
+    /* Just some value > 0 which gets rounded to the nearest page size.  */
+    .guardsize = 1,
+#ifndef SHARED
+    .stacksize = PTHREAD_STACK_MIN,
 #endif
+  };
+hidden_data_def (default_attr)
 
 /* Flag whether the machine is SMP or not.  */
 int __is_smp attribute_hidden;