htl: Initialize ___pthread_self early

When using jemalloc, malloc() needs to use TSD, while libpthread
initialization needs malloc(). Having ___pthread_self set early to some
static storage allows TSD to work early, thus allowing jemalloc and
libpthread to initialize together.

This incidentaly simplifies __pthread_enable/disable_asynccancel and
__pthread_self, now that ___pthread_self is always initialized.

htl/cancellation.c

@@ -25,10 +25,6 @@ int __pthread_enable_asynccancel (void)
   struct __pthread *p = _pthread_self ();
   int oldtype;
 
-  if (___pthread_self == NULL)
-    /* We are not initialized yet, we can't be cancelled anyway.  */
-    return PTHREAD_CANCEL_DEFERRED;
-
   __pthread_mutex_lock (&p->cancel_lock);
   oldtype = p->cancel_type;
   p->cancel_type = PTHREAD_CANCEL_ASYNCHRONOUS;
@@ -43,10 +39,6 @@ void __pthread_disable_asynccancel (int oldtype)
 {
   struct __pthread *p = _pthread_self ();
 
-  if (___pthread_self == NULL)
-    /* We are not initialized yet, we can't be cancelled anyway.  */
-    return;
-
   __pthread_mutex_lock (&p->cancel_lock);
   p->cancel_type = oldtype;
   __pthread_mutex_unlock (&p->cancel_lock);

htl/pt-self.c

@@ -24,15 +24,7 @@
 pthread_t
 __pthread_self (void)
 {
-  struct __pthread *self;
-
-  if (___pthread_self == NULL)
-    /* We are not initialized yet, we are the first thread.  */
-    return 1;
-
-  self = _pthread_self ();
-  assert (self != NULL);
-
+  struct __pthread *self = _pthread_self ();
   return self->thread;
 }
 

sysdeps/mach/hurd/htl/pt-sysdep.c

@@ -26,6 +26,10 @@
 #include <pt-internal.h>
 #include <pthreadP.h>
 
+/* Initial thread structure used temporarily during initialization, so various
+ * functions can already work at least basically.  */
+static struct __pthread init_thread;
+
 static void
 reset_pthread_total (void)
 {
@@ -47,6 +51,10 @@ _init_routine (void *stack)
     /* Already initialized */
     return;
 
+  /* Initialize early thread structure.  */
+  init_thread.thread = 1;
+  ___pthread_self = &init_thread;
+
   /* Initialize the library.  */
   ___pthread_init ();
 
@@ -74,6 +82,12 @@ _init_routine (void *stack)
   __pthread_default_attr.__guardsize = __vm_page_size;
 #endif
 
+  /* Copy over the thread-specific state */
+  assert (!init_thread.thread_specifics);
+  memcpy (&thread->static_thread_specifics,
+          &init_thread.static_thread_specifics,
+          sizeof (thread->static_thread_specifics));
+
   ___pthread_self = thread;
 
   /* Decrease the number of threads, to take into account that the