1 files changed, 106 insertions, 0 deletions
diff --git a/newlib/libc/sys/linux/linuxthreads/mq_notify.c b/newlib/libc/sys/linux/linuxthreads/mq_notify.c
new file mode 100644
index 000000000..46492e470
--- /dev/null
+++ b/newlib/libc/sys/linux/linuxthreads/mq_notify.c
@@ -0,0 +1,106 @@
+/* Copyright 2002, Red Hat Inc. */
+
+#include <mqueue.h>
+#include <unistd.h>
+#include <errno.h>
+#include <sys/ipc.h>
+#include <sys/sem.h>
+#include <string.h>
+
+#include "internals.h"
+#include <sys/lock.h>
+
+#include "mqlocal.h"
+
+static void *mq_notify_process (void *);
+
+void
+__cleanup_mq_notify (struct libc_mq *info)
+{
+  struct sembuf sb4 = {4, 1, 0};
+  /* kill notification thread and allow other processes to set a notification */
+  pthread_cancel ((pthread_t)info->th);
+  semop (info->semid, &sb4, 1);
+}
+  
+static void *
+mq_notify_process (void *arg)
+{
+  struct libc_mq *info = (struct libc_mq *)arg;
+  struct sembuf sb3[2] = {{3, 0, 0}, {5, 0, 0}};
+  struct sembuf sb4 = {4, 1, 0};
+  int rc;
+
+  /* wait until queue is empty */
+  while (!(rc = semop (info->semid, sb3, 1)) && errno == EINTR)
+    /* empty */ ;
+
+  if (!rc)
+    {
+      /* now wait until there are 0 readers and the queue has something in it */
+      sb3[0].sem_op = -1;
+      while (!(rc = semop (info->semid, sb3, 2)) && errno == EINTR)
+	/* empty */ ;
+      /* restore value since we have not actually performed a read */
+      sb3[0].sem_op = 1;
+      semop (info->semid, sb3, 1);
+      /* perform desired notification - either run function in this thread or pass signal */
+      if (!rc)
+	{
+	  if (info->sigevent->sigev_notify == SIGEV_SIGNAL)
+	    raise (info->sigevent->sigev_signo);
+	  else if (info->sigevent->sigev_notify == SIGEV_THREAD)
+	    info->sigevent->sigev_notify_function (info->sigevent->sigev_value);
+	  /* allow other processes to now mq_notify */
+	  semop (info->semid, &sb4, 1);
+	}
+    }
+  pthread_exit (NULL);
+}
+
+int
+mq_notify (mqd_t msgid, const struct sigevent *notification)
+{
+  struct libc_mq *info;
+  struct sembuf sb4 = {4, -1, IPC_NOWAIT};
+  int rc;
+  pthread_attr_t *attr = NULL;
+
+  info = __find_mq (msgid);
+
+  if (info == NULL)
+    {
+      errno = EBADF;
+      return -1;
+    }
+
+  /* get notification lock */
+  rc = semop (info->semid, &sb4, 1);
+
+  if (rc == -1)
+    {
+      errno = EBUSY;
+      return -1;
+    }
+
+  /* to get the notification running we use a pthread - if the user has requested
+     an action in a pthread, we use the user's attributes when setting up the thread */
+  info->sigevent = (struct sigevent *)notification;
+  if (info->sigevent->sigev_notify == SIGEV_THREAD)
+    attr = (pthread_attr_t *)info->sigevent->sigev_notify_attributes;
+  rc = pthread_create ((pthread_t *)&info->th, attr, mq_notify_process, (void *)info);
+
+  if (rc != 0)
+    rc = -1;
+  else
+    info->cleanup_notify = &__cleanup_mq_notify;
+
+  return rc;
+}
+
+      
+
+
+
+
+