Libc-498.1.5.tar.gz

[apple/libc.git] / sys / OSMemoryNotification.c

diff --git a/sys/OSMemoryNotification.c b/sys/OSMemoryNotification.c
new file mode 100644 (file)
index 0000000..b0f1ae4
--- /dev/null
+++ b/sys/OSMemoryNotification.c
@@ -0,0 +1,143 @@
+/*
+ * Copyright (c) 2006 Apple Computer, Inc. All rights reserved.
+ *
+ * @APPLE_LICENSE_HEADER_START@
+ * 
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this
+ * file.
+ * 
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
+ * 
+ * @APPLE_LICENSE_HEADER_END@
+ */
+
+#include <errno.h>
+#include <libkern/OSMemoryNotification.h>
+#include <mach/mach.h>
+#include <notify.h>
+#include <stdlib.h>
+#include <sys/time.h>
+
+const char *kOSMemoryNotificationName = "com.apple.system.memorystatus";
+
+struct _OSMemoryNotification {
+       int token;
+       mach_port_t port;
+};
+
+int
+OSMemoryNotificationCreate(OSMemoryNotificationRef *note)
+{
+       OSMemoryNotificationRef ref = malloc(sizeof(struct _OSMemoryNotification));
+
+       if (NULL == ref) {
+               return ENOMEM;
+       }
+       
+       if (NOTIFY_STATUS_OK != notify_register_mach_port(kOSMemoryNotificationName, &ref->port, 0, &ref->token))
+               return ENOMEM;
+
+       *note = ref;
+
+       return 0;
+}
+
+int
+OSMemoryNotificationDestroy(OSMemoryNotificationRef note)
+{
+       if (NOTIFY_STATUS_OK != notify_cancel(note->token))
+               return EINVAL;
+
+       if (KERN_SUCCESS != mach_port_deallocate(mach_task_self(), note->port))
+               return EINVAL;
+
+       free(note);
+
+       return 0;
+}
+               
+int
+OSMemoryNotificationWait(OSMemoryNotificationRef note, OSMemoryNotificationLevel *level)
+{
+
+       return OSMemoryNotificationTimedWait(note, level, NULL);
+}
+
+static mach_msg_timeout_t
+abs_to_timeout(const struct timeval *abstime)
+{
+       struct timeval rel, now;
+
+       gettimeofday(&now, NULL);
+
+       rel.tv_usec = abstime->tv_usec - now.tv_usec;
+       rel.tv_sec = abstime->tv_sec - now.tv_sec;
+       if (rel.tv_usec < 0) {
+               rel.tv_usec += 1000000;
+               rel.tv_sec--;
+       }
+       if (((int)rel.tv_sec < 0) || ((rel.tv_sec == 0) && (rel.tv_usec == 0))) {
+               return 0;
+       }
+       return rel.tv_sec * 1000 + rel.tv_usec / 1000;
+}
+
+int
+OSMemoryNotificationTimedWait(OSMemoryNotificationRef note, OSMemoryNotificationLevel *level, const struct timeval *abstime)
+{
+       mach_msg_empty_rcv_t msg = {{0}};
+       mach_msg_return_t ret;
+       uint64_t val;
+
+       if (abstime) {
+               mach_msg_timeout_t timeout = abs_to_timeout(abstime);
+
+               if (0 == timeout)
+                       return ETIMEDOUT;
+
+               ret = mach_msg(&msg.header, MACH_RCV_MSG | MACH_RCV_TIMEOUT, 0, sizeof msg, note->port, timeout, MACH_PORT_NULL);
+
+               if (MACH_RCV_TIMED_OUT == ret) {
+                       return ETIMEDOUT;
+               } 
+       } else {
+               ret = mach_msg(&msg.header, MACH_RCV_MSG, 0, sizeof msg, note->port, MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL);
+       }
+
+       if (MACH_MSG_SUCCESS != ret)
+               return EINVAL;
+
+       if (NOTIFY_STATUS_OK != notify_get_state(note->token, &val))
+               return EINVAL;
+
+       *level = (OSMemoryNotificationLevel)val;
+
+       return 0;
+}
+
+OSMemoryNotificationLevel OSMemoryNotificationCurrentLevel(void)
+{
+       uint64_t val;
+       int token;
+
+       if (NOTIFY_STATUS_OK != notify_register_check(kOSMemoryNotificationName, &token))
+               return OSMemoryNotificationLevelAny;
+
+       if (NOTIFY_STATUS_OK != notify_get_state(token, &val))
+               return OSMemoryNotificationLevelAny;
+
+       if (NOTIFY_STATUS_OK != notify_cancel(token))
+               return OSMemoryNotificationLevelAny;
+
+       return (OSMemoryNotificationLevel)val;
+}