libpthread/nptl: core of the "Native Posix Threading Library" for uClibc

targetting arm,sh,i386,mips,sparc for now

Signed-off-by: Austin Foxley <austinf@cetoncorp.com>

1 files changed, 484 insertions, 0 deletions

diff --git a/libpthread/nptl/pthread_create.c b/libpthread/nptl/pthread_create.c
new file mode 100644
index 000000000..81da5b93a
--- /dev/null
+++ b/libpthread/nptl/pthread_create.c
@@ -0,0 +1,484 @@
+/* Copyright (C) 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
+
+   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.  */
+
+#include <errno.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+#include "pthreadP.h"
+#include <hp-timing.h>
+#include <ldsodefs.h>
+#include <atomic.h>
+#include <libc-internal.h>
+#include <resolv.h>
+
+
+/* Local function to start thread and handle cleanup.  */
+static int start_thread (void *arg);
+
+
+/* Nozero if debugging mode is enabled.  */
+int __pthread_debug;
+
+/* Globally enabled events.  */
+static td_thr_events_t __nptl_threads_events;
+
+/* Pointer to descriptor with the last event.  */
+static struct pthread *__nptl_last_event;
+
+/* Number of threads running.  */
+unsigned int __nptl_nthreads = 1;
+
+
+/* Code to allocate and deallocate a stack.  */
+#include "allocatestack.c"
+
+/* Code to create the thread.  */
+#include "createthread.c"
+
+
+struct pthread *
+internal_function
+__find_in_stack_list (pd)
+     struct pthread *pd;
+{
+  list_t *entry;
+  struct pthread *result = NULL;
+
+  lll_lock (stack_cache_lock);
+
+  list_for_each (entry, &stack_used)
+    {
+      struct pthread *curp;
+
+      curp = list_entry (entry, struct pthread, list);
+      if (curp == pd)
+	{
+	  result = curp;
+	  break;
+	}
+    }
+
+  if (result == NULL)
+    list_for_each (entry, &__stack_user)
+      {
+	struct pthread *curp;
+
+	curp = list_entry (entry, struct pthread, list);
+	if (curp == pd)
+	  {
+	    result = curp;
+	    break;
+	  }
+      }
+
+  lll_unlock (stack_cache_lock);
+
+  return result;
+}
+
+
+/* Deallocate POSIX thread-local-storage.  */
+void
+attribute_hidden
+__nptl_deallocate_tsd (void)
+{
+  struct pthread *self = THREAD_SELF;
+
+  /* Maybe no data was ever allocated.  This happens often so we have
+     a flag for this.  */
+  if (THREAD_GETMEM (self, specific_used))
+    {
+      size_t round;
+      size_t cnt;
+
+      round = 0;
+      do
+	{
+	  size_t idx;
+
+	  /* So far no new nonzero data entry.  */
+	  THREAD_SETMEM (self, specific_used, false);
+
+	  for (cnt = idx = 0; cnt < PTHREAD_KEY_1STLEVEL_SIZE; ++cnt)
+	    {
+	      struct pthread_key_data *level2;
+
+	      level2 = THREAD_GETMEM_NC (self, specific, cnt);
+
+	      if (level2 != NULL)
+		{
+		  size_t inner;
+
+		  for (inner = 0; inner < PTHREAD_KEY_2NDLEVEL_SIZE;
+		       ++inner, ++idx)
+		    {
+		      void *data = level2[inner].data;
+
+		      if (data != NULL)
+			{
+			  /* Always clear the data.  */
+			  level2[inner].data = NULL;
+
+			  /* Make sure the data corresponds to a valid
+			     key.  This test fails if the key was
+			     deallocated and also if it was
+			     re-allocated.  It is the user's
+			     responsibility to free the memory in this
+			     case.  */
+			  if (level2[inner].seq
+			      == __pthread_keys[idx].seq
+			      /* It is not necessary to register a destructor
+				 function.  */
+			      && __pthread_keys[idx].destr != NULL)
+			    /* Call the user-provided destructor.  */
+			    __pthread_keys[idx].destr (data);
+			}
+		    }
+		}
+	      else
+		idx += PTHREAD_KEY_1STLEVEL_SIZE;
+	    }
+
+	  if (THREAD_GETMEM (self, specific_used) == 0)
+	    /* No data has been modified.  */
+	    goto just_free;
+	}
+      /* We only repeat the process a fixed number of times.  */
+      while (__builtin_expect (++round < PTHREAD_DESTRUCTOR_ITERATIONS, 0));
+
+      /* Just clear the memory of the first block for reuse.  */
+      memset (&THREAD_SELF->specific_1stblock, '\0',
+	      sizeof (self->specific_1stblock));
+
+    just_free:
+      /* Free the memory for the other blocks.  */
+      for (cnt = 1; cnt < PTHREAD_KEY_1STLEVEL_SIZE; ++cnt)
+	{
+	  struct pthread_key_data *level2;
+
+	  level2 = THREAD_GETMEM_NC (self, specific, cnt);
+	  if (level2 != NULL)
+	    {
+	      /* The first block is allocated as part of the thread
+		 descriptor.  */
+	      free (level2);
+	      THREAD_SETMEM_NC (self, specific, cnt, NULL);
+	    }
+	}
+
+      THREAD_SETMEM (self, specific_used, false);
+    }
+}
+
+
+/* Deallocate a thread's stack after optionally making sure the thread
+   descriptor is still valid.  */
+void
+internal_function
+__free_tcb (struct pthread *pd)
+{
+  /* The thread is exiting now.  */
+  if (__builtin_expect (atomic_bit_test_set (&pd->cancelhandling,
+					     TERMINATED_BIT) == 0, 1))
+    {
+      /* Remove the descriptor from the list.  */
+      if (DEBUGGING_P && __find_in_stack_list (pd) == NULL)
+	/* Something is really wrong.  The descriptor for a still
+	   running thread is gone.  */
+	abort ();
+
+      /* Queue the stack memory block for reuse and exit the process.  The
+	 kernel will signal via writing to the address returned by
+	 QUEUE-STACK when the stack is available.  */
+      __deallocate_stack (pd);
+    }
+}
+
+
+static int
+start_thread (void *arg)
+{
+  struct pthread *pd = (struct pthread *) arg;
+
+#if HP_TIMING_AVAIL
+  /* Remember the time when the thread was started.  */
+  hp_timing_t now;
+  HP_TIMING_NOW (now);
+  THREAD_SETMEM (pd, cpuclock_offset, now);
+#endif
+
+  /* Initialize resolver state pointer.  */
+  __resp = &pd->res;
+
+  /* This is where the try/finally block should be created.  For
+     compilers without that support we do use setjmp.  */
+  struct pthread_unwind_buf unwind_buf;
+
+  /* No previous handlers.  */
+  unwind_buf.priv.data.prev = NULL;
+  unwind_buf.priv.data.cleanup = NULL;
+
+  int not_first_call;
+  not_first_call = setjmp ((struct __jmp_buf_tag *) unwind_buf.cancel_jmp_buf);
+  if (__builtin_expect (! not_first_call, 1))
+    {
+      /* Store the new cleanup handler info.  */
+      THREAD_SETMEM (pd, cleanup_jmp_buf, &unwind_buf);
+
+      if (__builtin_expect (pd->stopped_start, 0))
+	{
+	  int oldtype = CANCEL_ASYNC ();
+
+	  /* Get the lock the parent locked to force synchronization.  */
+	  lll_lock (pd->lock);
+	  /* And give it up right away.  */
+	  lll_unlock (pd->lock);
+
+	  CANCEL_RESET (oldtype);
+	}
+
+      /* Run the code the user provided.  */
+#ifdef CALL_THREAD_FCT
+      THREAD_SETMEM (pd, result, CALL_THREAD_FCT (pd));
+#else
+      THREAD_SETMEM (pd, result, pd->start_routine (pd->arg));
+#endif
+    }
+
+  /* Run the destructor for the thread-local data.  */
+  __nptl_deallocate_tsd ();
+
+  /* If this is the last thread we terminate the process now.  We
+     do not notify the debugger, it might just irritate it if there
+     is no thread left.  */
+  if (__builtin_expect (atomic_decrement_and_test (&__nptl_nthreads), 0))
+    /* This was the last thread.  */
+    exit (0);
+
+  /* Report the death of the thread if this is wanted.  */
+  if (__builtin_expect (pd->report_events, 0))
+    {
+      /* See whether TD_DEATH is in any of the mask.  */
+      const int idx = __td_eventword (TD_DEATH);
+      const uint32_t mask = __td_eventmask (TD_DEATH);
+
+      if ((mask & (__nptl_threads_events.event_bits[idx]
+		   | pd->eventbuf.eventmask.event_bits[idx])) != 0)
+	{
+	  /* Yep, we have to signal the death.  Add the descriptor to
+	     the list but only if it is not already on it.  */
+	  if (pd->nextevent == NULL)
+	    {
+	      pd->eventbuf.eventnum = TD_DEATH;
+	      pd->eventbuf.eventdata = pd;
+
+	      do
+		pd->nextevent = __nptl_last_event;
+	      while (atomic_compare_and_exchange_bool_acq (&__nptl_last_event,
+							   pd, pd->nextevent));
+	    }
+
+	  /* Now call the function to signal the event.  */
+	  __nptl_death_event ();
+	}
+    }
+
+  /* The thread is exiting now.  Don't set this bit until after we've hit
+     the event-reporting breakpoint, so that td_thr_get_info on us while at
+     the breakpoint reports TD_THR_RUN state rather than TD_THR_ZOMBIE.  */
+  atomic_bit_set (&pd->cancelhandling, EXITING_BIT);
+
+  /* If the thread is detached free the TCB.  */
+  if (IS_DETACHED (pd))
+    /* Free the TCB.  */
+    __free_tcb (pd);
+
+  /* We cannot call '_exit' here.  '_exit' will terminate the process.
+
+     The 'exit' implementation in the kernel will signal when the
+     process is really dead since 'clone' got passed the CLONE_CLEARTID
+     flag.  The 'tid' field in the TCB will be set to zero.
+
+     The exit code is zero since in case all threads exit by calling
+     'pthread_exit' the exit status must be 0 (zero).  */
+  __exit_thread_inline (0);
+
+  /* NOTREACHED */
+  return 0;
+}
+
+
+/* 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;
+     const pthread_attr_t *attr;
+     void *(*start_routine) (void *);
+     void *arg;
+{
+  STACK_VARIABLES;
+
+  const struct pthread_attr *iattr = (struct pthread_attr *) attr;
+  if (iattr == NULL)
+    /* Is this the best idea?  On NUMA machines this could mean
+       accessing far-away memory.  */
+    iattr = &default_attr;
+
+  struct pthread *pd = 0;
+  int err = ALLOCATE_STACK (iattr, &pd);
+  if (__builtin_expect (err != 0, 0))
+    /* Something went wrong.  Maybe a parameter of the attributes is
+       invalid or we could not allocate memory.  */
+    return err;
+
+
+  /* Initialize the TCB.  All initializations with zero should be
+     performed in 'get_cached_stack'.  This way we avoid doing this if
+     the stack freshly allocated with 'mmap'.  */
+
+#ifdef TLS_TCB_AT_TP
+  /* Reference to the TCB itself.  */
+  pd->header.self = pd;
+
+  /* Self-reference for TLS.  */
+  pd->header.tcb = pd;
+#endif
+
+  /* Store the address of the start routine and the parameter.  Since
+     we do not start the function directly the stillborn thread will
+     get the information from its thread descriptor.  */
+  pd->start_routine = start_routine;
+  pd->arg = arg;
+
+  /* Copy the thread attribute flags.  */
+  struct pthread *self = THREAD_SELF;
+  pd->flags = ((iattr->flags & ~(ATTR_FLAG_SCHED_SET | ATTR_FLAG_POLICY_SET))
+	       | (self->flags & (ATTR_FLAG_SCHED_SET | ATTR_FLAG_POLICY_SET)));
+
+  /* Initialize the field for the ID of the thread which is waiting
+     for us.  This is a self-reference in case the thread is created
+     detached.  */
+  pd->joinid = iattr->flags & ATTR_FLAG_DETACHSTATE ? pd : NULL;
+
+  /* The debug events are inherited from the parent.  */
+  pd->eventbuf = self->eventbuf;
+
+
+  /* Copy the parent's scheduling parameters.  The flags will say what
+     is valid and what is not.  */
+  pd->schedpolicy = self->schedpolicy;
+  pd->schedparam = self->schedparam;
+
+  /* Copy the stack guard canary.  */
+#ifdef THREAD_COPY_STACK_GUARD
+  THREAD_COPY_STACK_GUARD (pd);
+#endif
+
+  /* Determine scheduling parameters for the thread.  */
+  if (attr != NULL
+      && __builtin_expect ((iattr->flags & ATTR_FLAG_NOTINHERITSCHED) != 0, 0)
+      && (iattr->flags & (ATTR_FLAG_SCHED_SET | ATTR_FLAG_POLICY_SET)) != 0)
+    {
+      INTERNAL_SYSCALL_DECL (scerr);
+
+      /* Use the scheduling parameters the user provided.  */
+      if (iattr->flags & ATTR_FLAG_POLICY_SET)
+	pd->schedpolicy = iattr->schedpolicy;
+      else if ((pd->flags & ATTR_FLAG_POLICY_SET) == 0)
+	{
+	  pd->schedpolicy = INTERNAL_SYSCALL (sched_getscheduler, scerr, 1, 0);
+	  pd->flags |= ATTR_FLAG_POLICY_SET;
+	}
+
+      if (iattr->flags & ATTR_FLAG_SCHED_SET)
+	memcpy (&pd->schedparam, &iattr->schedparam,
+		sizeof (struct sched_param));
+      else if ((pd->flags & ATTR_FLAG_SCHED_SET) == 0)
+	{
+	  INTERNAL_SYSCALL (sched_getparam, scerr, 2, 0, &pd->schedparam);
+	  pd->flags |= ATTR_FLAG_SCHED_SET;
+	}
+
+      /* Check for valid priorities.  */
+      int minprio = INTERNAL_SYSCALL (sched_get_priority_min, scerr, 1,
+				      iattr->schedpolicy);
+      int maxprio = INTERNAL_SYSCALL (sched_get_priority_max, scerr, 1,
+				      iattr->schedpolicy);
+      if (pd->schedparam.sched_priority < minprio
+	  || pd->schedparam.sched_priority > maxprio)
+	{
+	  err = EINVAL;
+	  goto errout;
+	}
+    }
+
+  /* Pass the descriptor to the caller.  */
+  *newthread = (pthread_t) pd;
+
+  /* Remember whether the thread is detached or not.  In case of an
+     error we have to free the stacks of non-detached stillborn
+     threads.  */
+  bool is_detached = IS_DETACHED (pd);
+
+  /* Start the thread.  */
+  err = create_thread (pd, iattr, STACK_VARIABLES_ARGS);
+  if (err != 0)
+    {
+      /* Something went wrong.  Free the resources.  */
+      if (!is_detached)
+	{
+	errout:
+	  __deallocate_stack (pd);
+	}
+      return err;
+    }
+
+  return 0;
+}
+weak_alias(__pthread_create_2_1, pthread_create)
+
+/* Information for libthread_db.  */
+
+#include "../nptl_db/db_info.c"
+
+/* If pthread_create is present, libgcc_eh.a and libsupc++.a expects some other POSIX thread
+   functions to be present as well.  */
+PTHREAD_STATIC_FN_REQUIRE (pthread_mutex_lock)
+PTHREAD_STATIC_FN_REQUIRE (pthread_mutex_unlock)
+
+PTHREAD_STATIC_FN_REQUIRE (pthread_once)
+PTHREAD_STATIC_FN_REQUIRE (pthread_cancel)
+
+PTHREAD_STATIC_FN_REQUIRE (pthread_key_create)
+PTHREAD_STATIC_FN_REQUIRE (pthread_setspecific)
+PTHREAD_STATIC_FN_REQUIRE (pthread_getspecific)
+
+/* UCLIBC_MUTEX_xxx macros expects to have these as well */
+PTHREAD_STATIC_FN_REQUIRE (pthread_mutex_init)
+PTHREAD_STATIC_FN_REQUIRE (_pthread_cleanup_push_defer)
+PTHREAD_STATIC_FN_REQUIRE (_pthread_cleanup_pop_restore)