Update.

2000-06-26  Ulrich Drepper  <drepper@redhat.com>

	* Makefile (tests): Add ex11.  Add rules to build it.
	* Examples/ex11.c: New file.
	* rwlock.c: Fix complete braindamaged previous try to implement
	timedout functions.

	* spinlock.c: Pretty print.

linuxthreads/ChangeLog

@@ -1,3 +1,12 @@
+2000-06-26  Ulrich Drepper  <drepper@redhat.com>
+
+	* Makefile (tests): Add ex11.  Add rules to build it.
+	* Examples/ex11.c: New file.
+	* rwlock.c: Fix complete braindamaged previous try to implement
+	timedout functions.
+
+	* spinlock.c: Pretty print.
+
 2000-06-25  Ulrich Drepper  <drepper@redhat.com>
 
 	* Makefile (tests): Add ex10.  Add rules to build it.

linuxthreads/Examples/ex11.c

@@ -0,0 +1,152 @@
+/* Test program for timedout read/write lock functions.
+   Copyright (C) 2000 Free Software Foundation, Inc.
+   Contributed by Ulrich Drepper <drepper@redhat.com>, 2000.
+
+   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., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+#include <errno.h>
+#include <error.h>
+#include <pthread.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
+#include <unistd.h>
+
+
+#define NWRITERS 15
+#define WRITETRIES 10
+#define NREADERS 15
+#define READTRIES 15
+
+#define TIMEOUT 1000000
+#define DELAY   1000000
+
+static pthread_rwlock_t lock = PTHREAD_RWLOCK_WRITER_NONRECURSIVE_INITIALIZER_NP;
+
+
+static void *
+writer_thread (void *nr)
+{
+  struct timespec ts;
+  struct timespec delay;
+  int n;
+
+  ts.tv_sec = 0;
+  ts.tv_nsec = TIMEOUT;
+
+  delay.tv_sec = 0;
+  delay.tv_nsec = DELAY;
+
+  for (n = 0; n < WRITETRIES; ++n)
+    {
+      do
+	{
+	  clock_gettime (CLOCK_REALTIME, &ts);
+
+	  ts.tv_nsec += 2 * TIMEOUT;
+
+	  printf ("writer thread %ld tries again\n", (long int) nr);
+	}
+      //while (pthread_rwlock_wrlock (&lock), 0);
+      while (pthread_rwlock_timedwrlock (&lock, &ts) == ETIMEDOUT);
+
+      printf ("writer thread %ld succeeded\n", (long int) nr);
+
+      nanosleep (&delay, NULL);
+
+      pthread_rwlock_unlock (&lock);
+
+      printf ("writer thread %ld released\n", (long int) nr);
+    }
+
+  return NULL;
+}
+
+
+static void *
+reader_thread (void *nr)
+{
+  struct timespec ts;
+  struct timespec delay;
+  int n;
+
+  delay.tv_sec = 0;
+  delay.tv_nsec = DELAY;
+
+  for (n = 0; n < READTRIES; ++n)
+    {
+      do
+	{
+	  clock_gettime (CLOCK_REALTIME, &ts);
+
+	  ts.tv_nsec += TIMEOUT;
+
+	  printf ("reader thread %ld tries again\n", (long int) nr);
+	}
+      //while (pthread_rwlock_rdlock (&lock), 0);
+      while (pthread_rwlock_timedrdlock (&lock, &ts) == ETIMEDOUT);
+
+      printf ("reader thread %ld succeeded\n", (long int) nr);
+
+      nanosleep (&delay, NULL);
+
+      pthread_rwlock_unlock (&lock);
+
+      printf ("reader thread %ld released\n", (long int) nr);
+    }
+
+  return NULL;
+}
+
+
+int
+main (void)
+{
+  pthread_t thwr[NWRITERS];
+  pthread_t thrd[NREADERS];
+  int n;
+  void *res;
+
+  /* Make standard error the same as standard output.  */
+  dup2 (1, 2);
+
+  /* Make sure we see all message, even those on stdout.  */
+  setvbuf (stdout, NULL, _IONBF, 0);
+
+  for (n = 0; n < NWRITERS; ++n)
+    {
+      int err = pthread_create (&thwr[n], NULL, writer_thread, (void *) n);
+
+      if (err != 0)
+	error (EXIT_FAILURE, err, "cannot create writer thread");
+    }
+
+  for (n = 0; n < NREADERS; ++n)
+    {
+      int err = pthread_create (&thrd[n], NULL, reader_thread, (void *) n);
+
+      if (err != 0)
+	error (EXIT_FAILURE, err, "cannot create reader thread");
+    }
+
+  /* Wait for all the threads.  */
+  for (n = 0; n < NWRITERS; ++n)
+    pthread_join (thwr[n], &res);
+  for (n = 0; n < NREADERS; ++n)
+    pthread_join (thrd[n], &res);
+
+  return 0;
+}

linuxthreads/Makefile

@@ -38,7 +38,7 @@ libpthread-routines := attr cancel condvar join manager mutex ptfork \
 		       oldsemaphore events getcpuclockid pspinlock barrier
 
 vpath %.c Examples
-tests = ex1 ex2 ex3 ex4 ex5 ex6 ex7 ex8 ex9 ex10 joinrace
+tests = ex1 ex2 ex3 ex4 ex5 ex6 ex7 ex8 ex9 ex10 ex11 joinrace
 
 include ../Rules
 
@@ -72,4 +72,5 @@ $(objpfx)ex7: $(libpthread)
 $(objpfx)ex8: $(libpthread)
 $(objpfx)ex9: $(libpthread)
 $(objpfx)ex10: $(libpthread) $(librt)
+$(objpfx)ex11: $(libpthread) $(librt)
 $(objpfx)joinrace: $(libpthread)

linuxthreads/rwlock.c

@@ -27,6 +27,35 @@
 #include "spinlock.h"
 #include "restart.h"
 
+/* Function called by pthread_cancel to remove the thread from
+   waiting inside pthread_rwlock_timedrdlock or pthread_rwlock_timedwrlock. */
+
+static int rwlock_rd_extricate_func(void *obj, pthread_descr th)
+{
+  volatile pthread_descr self = thread_self();
+  pthread_rwlock_t *rwlock = obj;
+  int did_remove = 0;
+
+  __pthread_lock((struct _pthread_fastlock *) &rwlock->__rw_lock, self);
+  did_remove = remove_from_queue(&rwlock->__rw_read_waiting, th);
+  __pthread_unlock((struct _pthread_fastlock *) &rwlock->__rw_lock);
+
+  return did_remove;
+}
+
+static int rwlock_wr_extricate_func(void *obj, pthread_descr th)
+{
+  volatile pthread_descr self = thread_self();
+  pthread_rwlock_t *rwlock = obj;
+  int did_remove = 0;
+
+  __pthread_lock((struct _pthread_fastlock *) &rwlock->__rw_lock, self);
+  did_remove = remove_from_queue(&rwlock->__rw_write_waiting, th);
+  __pthread_unlock((struct _pthread_fastlock *) &rwlock->__rw_lock);
+
+  return did_remove;
+}
+
 /*
  * Check whether the calling thread already owns one or more read locks on the
  * specified lock. If so, return a pointer to the read lock info structure
@@ -214,10 +243,10 @@ __pthread_rwlock_destroy (pthread_rwlock_t *rwlock)
   int readers;
   _pthread_descr writer;
 
-  __pthread_alt_lock (&rwlock->__rw_lock, NULL);
+  __pthread_lock (&rwlock->__rw_lock, NULL);
   readers = rwlock->__rw_readers;
   writer = rwlock->__rw_writer;
-  __pthread_alt_unlock (&rwlock->__rw_lock);
+  __pthread_unlock (&rwlock->__rw_lock);
 
   if (readers > 0 || writer != NULL)
     return EBUSY;
@@ -241,18 +270,18 @@ __pthread_rwlock_rdlock (pthread_rwlock_t *rwlock)
 
   for (;;)
     {
-      __pthread_alt_lock (&rwlock->__rw_lock, self);
+      __pthread_lock (&rwlock->__rw_lock, self);
 
       if (rwlock_can_rdlock(rwlock, have_lock_already))
 	break;
 
       enqueue (&rwlock->__rw_read_waiting, self);
-      __pthread_alt_unlock (&rwlock->__rw_lock);
+      __pthread_unlock (&rwlock->__rw_lock);
       suspend (self); /* This is not a cancellation point */
     }
 
   ++rwlock->__rw_readers;
-  __pthread_alt_unlock (&rwlock->__rw_lock);
+  __pthread_unlock (&rwlock->__rw_lock);
 
   if (have_lock_already || out_of_mem)
     {
@@ -273,6 +302,7 @@ __pthread_rwlock_timedrdlock (pthread_rwlock_t *rwlock,
   pthread_descr self = NULL;
   pthread_readlock_info *existing;
   int out_of_mem, have_lock_already;
+  pthread_extricate_if extr;
 
   if (abstime->tv_nsec < 0 || abstime->tv_nsec >= 1000000000)
     return EINVAL;
@@ -283,21 +313,46 @@ __pthread_rwlock_timedrdlock (pthread_rwlock_t *rwlock,
   if (self == NULL)
     self = thread_self ();
 
+  /* Set up extrication interface */
+  extr.pu_object = rwlock;
+  extr.pu_extricate_func = rwlock_rd_extricate_func;
+
+  /* Register extrication interface */
+  __pthread_set_own_extricate_if (self, &extr);
+
   for (;;)
     {
-      if (__pthread_alt_timedlock (&rwlock->__rw_lock, self, abstime) == 0)
-	return ETIMEDOUT;
+      __pthread_lock (&rwlock->__rw_lock, self);
 
       if (rwlock_can_rdlock(rwlock, have_lock_already))
 	break;
 
       enqueue (&rwlock->__rw_read_waiting, self);
-      __pthread_alt_unlock (&rwlock->__rw_lock);
-      suspend (self); /* This is not a cancellation point */
+      __pthread_unlock (&rwlock->__rw_lock);
+      /* This is not a cancellation point */
+      if (timedsuspend (self, abstime) == 0)
+	{
+	  int was_on_queue;
+
+	  __pthread_lock (&rwlock->__rw_lock, self);
+	  was_on_queue = remove_from_queue (&rwlock->__rw_read_waiting, self);
+	  __pthread_unlock (&rwlock->__rw_lock);
+
+	  if (was_on_queue)
+	    {
+	      __pthread_set_own_extricate_if (self, 0);
+	      return ETIMEDOUT;
+	    }
+
+	  /* Eat the outstanding restart() from the signaller */
+	  suspend (self);
+	}
     }
 
+  __pthread_set_own_extricate_if (self, 0);
+
   ++rwlock->__rw_readers;
-  __pthread_alt_unlock (&rwlock->__rw_lock);
+  __pthread_unlock (&rwlock->__rw_lock);
 
   if (have_lock_already || out_of_mem)
     {
@@ -322,7 +377,7 @@ __pthread_rwlock_tryrdlock (pthread_rwlock_t *rwlock)
   have_lock_already = rwlock_have_already(&self, rwlock,
       &existing, &out_of_mem);
 
-  __pthread_alt_lock (&rwlock->__rw_lock, self);
+  __pthread_lock (&rwlock->__rw_lock, self);
 
   /* 0 is passed to here instead of have_lock_already.
      This is to meet Single Unix Spec requirements:
@@ -336,7 +391,7 @@ __pthread_rwlock_tryrdlock (pthread_rwlock_t *rwlock)
       retval = 0;
     }
 
-  __pthread_alt_unlock (&rwlock->__rw_lock);
+  __pthread_unlock (&rwlock->__rw_lock);
 
   if (retval == 0)
     {
@@ -361,17 +416,17 @@ __pthread_rwlock_wrlock (pthread_rwlock_t *rwlock)
 
   while(1)
     {
-      __pthread_alt_lock (&rwlock->__rw_lock, self);
+      __pthread_lock (&rwlock->__rw_lock, self);
       if (rwlock->__rw_readers == 0 && rwlock->__rw_writer == NULL)
 	{
 	  rwlock->__rw_writer = self;
-	  __pthread_alt_unlock (&rwlock->__rw_lock);
+	  __pthread_unlock (&rwlock->__rw_lock);
 	  return 0;
 	}
 
       /* Suspend ourselves, then try again */
       enqueue (&rwlock->__rw_write_waiting, self);
-      __pthread_alt_unlock (&rwlock->__rw_lock);
+      __pthread_unlock (&rwlock->__rw_lock);
       suspend (self); /* This is not a cancellation point */
     }
 }
@@ -383,28 +438,53 @@ __pthread_rwlock_timedwrlock (pthread_rwlock_t *rwlock,
 			      const struct timespec *abstime)
 {
   pthread_descr self;
+  pthread_extricate_if extr;
 
   if (abstime->tv_nsec < 0 || abstime->tv_nsec >= 1000000000)
     return EINVAL;
 
   self = thread_self ();
 
+  /* Set up extrication interface */
+  extr.pu_object = rwlock;
+  extr.pu_extricate_func =  rwlock_wr_extricate_func;
+
+  /* Register extrication interface */
+  __pthread_set_own_extricate_if (self, &extr);
+
   while(1)
     {
-      if (__pthread_alt_timedlock (&rwlock->__rw_lock, self, abstime) == 0)
-	return ETIMEDOUT;
+      __pthread_lock (&rwlock->__rw_lock, self);
 
       if (rwlock->__rw_readers == 0 && rwlock->__rw_writer == NULL)
 	{
 	  rwlock->__rw_writer = self;
-	  __pthread_alt_unlock (&rwlock->__rw_lock);
+	  __pthread_set_own_extricate_if (self, 0);
+	  __pthread_unlock (&rwlock->__rw_lock);
 	  return 0;
 	}
 
       /* Suspend ourselves, then try again */
       enqueue (&rwlock->__rw_write_waiting, self);
-      __pthread_alt_unlock (&rwlock->__rw_lock);
-      suspend (self); /* This is not a cancellation point */
+      __pthread_unlock (&rwlock->__rw_lock);
+      /* This is not a cancellation point */
+      if (timedsuspend (self, abstime) == 0)
+	{
+	  int was_on_queue;
+
+	  __pthread_lock (&rwlock->__rw_lock, self);
+	  was_on_queue = remove_from_queue (&rwlock->__rw_write_waiting, self);
+	  __pthread_unlock (&rwlock->__rw_lock);
+
+	  if (was_on_queue)
+	    {
+	      __pthread_set_own_extricate_if (self, 0);
+	      return ETIMEDOUT;
+	    }
+
+	  /* Eat the outstanding restart() from the signaller */
+	  suspend (self);
+	}
     }
 }
 strong_alias (__pthread_rwlock_timedwrlock, pthread_rwlock_timedwrlock)
@@ -415,13 +495,13 @@ __pthread_rwlock_trywrlock (pthread_rwlock_t *rwlock)
 {
   int result = EBUSY;
 
-  __pthread_alt_lock (&rwlock->__rw_lock, NULL);
+  __pthread_lock (&rwlock->__rw_lock, NULL);
   if (rwlock->__rw_readers == 0 && rwlock->__rw_writer == NULL)
     {
       rwlock->__rw_writer = thread_self ();
       result = 0;
     }
-  __pthread_alt_unlock (&rwlock->__rw_lock);
+  __pthread_unlock (&rwlock->__rw_lock);
 
   return result;
 }
@@ -434,13 +514,13 @@ __pthread_rwlock_unlock (pthread_rwlock_t *rwlock)
   pthread_descr torestart;
   pthread_descr th;
 
-  __pthread_alt_lock (&rwlock->__rw_lock, NULL);
+  __pthread_lock (&rwlock->__rw_lock, NULL);
   if (rwlock->__rw_writer != NULL)
     {
       /* Unlocking a write lock.  */
       if (rwlock->__rw_writer != thread_self ())
 	{
-	  __pthread_alt_unlock (&rwlock->__rw_lock);
+	  __pthread_unlock (&rwlock->__rw_lock);
 	  return EPERM;
 	}
       rwlock->__rw_writer = NULL;
@@ -452,14 +532,14 @@ __pthread_rwlock_unlock (pthread_rwlock_t *rwlock)
 	  /* Restart all waiting readers.  */
 	  torestart = rwlock->__rw_read_waiting;
 	  rwlock->__rw_read_waiting = NULL;
-	  __pthread_alt_unlock (&rwlock->__rw_lock);
+	  __pthread_unlock (&rwlock->__rw_lock);
 	  while ((th = dequeue (&torestart)) != NULL)
 	    restart (th);
 	}
       else
 	{
 	  /* Restart one waiting writer.  */
-	  __pthread_alt_unlock (&rwlock->__rw_lock);
+	  __pthread_unlock (&rwlock->__rw_lock);
 	  restart (th);
 	}
     }
@@ -468,7 +548,7 @@ __pthread_rwlock_unlock (pthread_rwlock_t *rwlock)
       /* Unlocking a read lock.  */
       if (rwlock->__rw_readers == 0)
 	{
-	  __pthread_alt_unlock (&rwlock->__rw_lock);
+	  __pthread_unlock (&rwlock->__rw_lock);
 	  return EPERM;
 	}
 
@@ -479,7 +559,7 @@ __pthread_rwlock_unlock (pthread_rwlock_t *rwlock)
       else
 	th = NULL;
 
-      __pthread_alt_unlock (&rwlock->__rw_lock);
+      __pthread_unlock (&rwlock->__rw_lock);
       if (th != NULL)
 	restart (th);
 

linuxthreads/spinlock.c

@@ -342,8 +342,8 @@ void __pthread_alt_unlock(struct _pthread_fastlock *lock)
 
     oldstatus = lock->__status;
     if (oldstatus == 0 || oldstatus == 1) {
-      if (compare_and_swap_with_release_semantics (&lock->__status,
-	  oldstatus, 0, &lock->__spinlock))
+      if (compare_and_swap_with_release_semantics (&lock->__status, oldstatus,
+						   0, &lock->__spinlock))
 	return;
       else
 	continue;