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-rw-r--r--linuxthreads/Examples/ex11.c152
1 files changed, 152 insertions, 0 deletions
diff --git a/linuxthreads/Examples/ex11.c b/linuxthreads/Examples/ex11.c
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+/* 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;
+}