---
title: DISPATCH_SOURCE_TYPE_MEMORYPRESSURE
framework: dispatch
role: symbol
role_heading: Macro
path: dispatch/dispatch_source_type_memorypressure
---

# DISPATCH_SOURCE_TYPE_MEMORYPRESSURE

A type of dispatch source for monitoring memory pressure events.

## Declaration

```occ
#define DISPATCH_SOURCE_TYPE_MEMORYPRESSURE
```

## Discussion

Discussion A dispatch source that monitors the memory pressure of the system. The handle is unused and you should pass 0 for that parameter. The mask is a mask of desired events from Dispatch Source Memory Pressure Event Flags.

## See Also

### Dispatch Source Types

- [DISPATCH_SOURCE_TYPE_TIMER](dispatch/dispatch_source_type_timer.md)
- [DISPATCH_SOURCE_TYPE_READ](dispatch/dispatch_source_type_read.md)
- [DISPATCH_SOURCE_TYPE_WRITE](dispatch/dispatch_source_type_write.md)
- [DISPATCH_SOURCE_TYPE_VNODE](dispatch/dispatch_source_type_vnode.md)
- [DISPATCH_SOURCE_TYPE_SIGNAL](dispatch/dispatch_source_type_signal.md)
- [DISPATCH_SOURCE_TYPE_PROC](dispatch/dispatch_source_type_proc.md)
- [DISPATCH_SOURCE_TYPE_MACH_SEND](dispatch/dispatch_source_type_mach_send.md)
- [DISPATCH_SOURCE_TYPE_MACH_RECV](dispatch/dispatch_source_type_mach_recv.md)
- [DISPATCH_SOURCE_TYPE_DATA_ADD](dispatch/dispatch_source_type_data_add.md)
- [DISPATCH_SOURCE_TYPE_DATA_OR](dispatch/dispatch_source_type_data_or.md)