From ef467338e4a290b0f8978a0701b404e17c5bb048 Mon Sep 17 00:00:00 2001
From: Jeff Johnston <jjohnstn@redhat.com>
Date: Wed, 19 Jun 2002 22:17:33 +0000
Subject: 2002-06-19  Jeff Johnston  <jjohnstn@redhat.com>

        * libc/sys/linux/Makefile.am: Add support for message queue routines,
        ipc routines, and ftok.
        * libc/sys/linux/Makefile.in: Regenerated.
        * libc/sys/linux/ftok.c: New file.
        * libc/sys/linux/ipc.c: Ditto.
        * libc/sys/linux/mq_close.c: Ditto.
        * libc/sys/linux/mq_getattr.c: Ditto.
        * libc/sys/linux/mq_notify.c: Ditto.
        * libc/sys/linux/mq_open.c: Ditto.
        * libc/sys/linux/mq_receive.c: Ditto.
        * libc/sys/linux/mq_send.c: Ditto.
        * libc/sys/linux/mq_setattr.c: Ditto.
        * libc/sys/linux/mq_unlink.c: Ditto.
        * libc/sys/linux/mqlocal.h: Ditto.
        * libc/sys/linux/include/mqueue.h: Ditto.
        * libc/sys/linux/sys/types.h: Define __gid_t_defined and
        __uid_t_defined.
---
 newlib/libc/sys/linux/mq_receive.c | 67 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 67 insertions(+)
 create mode 100644 newlib/libc/sys/linux/mq_receive.c

(limited to 'newlib/libc/sys/linux/mq_receive.c')

diff --git a/newlib/libc/sys/linux/mq_receive.c b/newlib/libc/sys/linux/mq_receive.c
new file mode 100644
index 000000000..1aa7b9fb3
--- /dev/null
+++ b/newlib/libc/sys/linux/mq_receive.c
@@ -0,0 +1,67 @@
+/* Copyright 2002, Red Hat Inc. */
+
+#include <mqueue.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <sys/ipc.h>
+#include <sys/sem.h>
+#include <string.h>
+#define _LIBC
+#include <sys/lock.h>
+#undef _LIBC
+
+#include "mqlocal.h"
+
+__LOCK_INIT(static, mq_rdbuf_lock);
+
+ssize_t
+mq_receive (mqd_t msgid, char *msg, size_t msg_len, unsigned int *msg_prio)
+{
+  struct libc_mq *info;
+  struct sembuf sb2 = {2, 1, 0};
+  struct sembuf sb3 = {3, -1, IPC_NOWAIT};
+  struct sembuf sb5 = {5, 1, IPC_NOWAIT};
+  ssize_t num_bytes;
+  int ipcflag;
+
+  info = __find_mq (msgid);
+
+  if (info == NULL || (info->oflag & O_ACCMODE) == O_WRONLY)
+    {
+      errno = EBADF;
+      return -1;
+    }
+
+  if (msg_len < info->attr->mq_msgsize)
+    {
+      errno = EMSGSIZE;
+      return -1;
+    }
+
+  __lock_acquire (mq_rdbuf_lock);
+
+  ipcflag = (info->attr->mq_flags & O_NONBLOCK) ? IPC_NOWAIT : 0;
+
+  semop (info->semid, &sb5, 1); /* increase number of readers */
+  num_bytes = msgrcv (info->msgqid, info->rdbuf, msg_len, -MQ_PRIO_MAX, ipcflag);
+  sb5.sem_op = -1;
+  semop (info->semid, &sb5, 1); /* decrease number of readers */
+
+  if (num_bytes != (ssize_t)-1)
+    {
+      semop (info->semid, &sb2, 1); /* add one to messages left to write */
+      semop (info->semid, &sb3, 1); /* subtract one from messages to read */
+      memcpy (msg, info->rdbuf->text, num_bytes);
+      if (msg_prio != NULL)
+	*msg_prio = MQ_PRIO_MAX - info->rdbuf->type;
+    }
+  
+  __lock_release (mq_rdbuf_lock);
+  return num_bytes;
+}
+      
+
+
+
+
+
-- 
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