projects / apple / xnu.git / blame
| Commit | Line | Data |
|---|---|---|
| 13fec989 A |
1 | <h2>vm_msync</h2> |
| 2 | <hr> | |
| 3 | <p> | |
| 4 | <strong>Function</strong> - Synchronize the specified region of virtual memory. | |
| 5 | <h3>SYNOPSIS</h3> | |
| 6 | <pre> | |
| 7 | <strong>kern_return_t vm_msync</strong> | |
| 8 | <strong>(vm_task_t</strong> <var>target_task</var>, | |
| 9 | <strong>vm_address_t</strong> <var>address</var>, | |
| 10 | <strong>vm_size_t</strong> <var>size</var>, | |
| 11 | <strong>target_task</strong> <var>sync_flags</var><strong>);</strong> | |
| 12 | </pre> | |
| 13 | <h3>PARAMETERS</h3> | |
| 14 | <dl> | |
| 15 | <p> | |
| 16 | <dt> <var>target_task</var> | |
| 17 | <dd> | |
| 18 | [in task send right] | |
| 19 | The port for the task whose address space contains | |
| 20 | the region. | |
| 21 | <p> | |
| 22 | <dt> <var>address</var> | |
| 23 | <dd> | |
| 24 | [in scalar] | |
| 25 | The starting address for the region. | |
| 26 | <p> | |
| 27 | <dt> <var>size</var> | |
| 28 | <dd> | |
| 29 | [in scalar] | |
| 30 | The number of bytes in the region. | |
| 31 | <p> | |
| 32 | <dt> <var>sync_flags</var> | |
| 33 | <dd> | |
| 34 | [in scalar] | |
| 35 | The bit-wise <strong>OR</strong> of flags affecting the synchronization. | |
| 36 | Specifying both <strong>VM_SYNC_SYNCHRONOUS</strong> and | |
| 37 | <strong>VM_SYNC_ASYNCHRONOUS</strong> is invalid. | |
| 38 | <dl> | |
| 39 | <p> | |
| 40 | <dt> <strong>VM_SYNC_INVALIDATE</strong> | |
| 41 | <dd> | |
| 42 | Flushes pages in the range. Only precious pages are returned to | |
| 43 | the memory manager unless either <strong>VM_SYNC_SYNCHRONOUS</strong> or | |
| 44 | <strong>VM_SYNC_ASYNCHRONOUS</strong> is also set. | |
| 45 | <p> | |
| 46 | <dt> <strong>VM_SYNC_SYNCHRONOUS</strong> | |
| 47 | <dd> | |
| 48 | Writes dirty and precious pages back to the memory manager, | |
| 49 | waits for pages to reach backing storage. | |
| 50 | <p> | |
| 51 | <dt> <strong>VM_SYNC_ASYNCHRONOUS</strong> | |
| 52 | <dd> | |
| 53 | Writes dirty and precious pages back to the memory manager, | |
| 54 | returns without waiting for pages to reach backing storage. | |
| 55 | </dl> | |
| 56 | </dl> | |
| 57 | <h3>DESCRIPTION</h3> | |
| 58 | <p> | |
| 59 | The <strong>vm_msync</strong> function synchronizes the contents of | |
| 60 | a memory range with its | |
| 61 | backing store image by flushing or cleaning the contents of the | |
| 62 | specified range | |
| 63 | to the range's memory manager, engaging in a synchronization protocol with | |
| 64 | the manager (<strong>memory_object_synchronize</strong>). | |
| 65 | The client does not return from | |
| 66 | this call until the memory manager responds (to the kernel) with | |
| 67 | <strong>memory_object_synchronize_completed</strong>. | |
| 68 | <h3>NOTES</h3> | |
| 69 | <p> | |
| 70 | This interface is machine word length specific because of the virtual address | |
| 71 | parameter. | |
| 72 | <h3>RETURN VALUES</h3> | |
| 73 | <dl> | |
| 74 | <p> | |
| 75 | <dt> <strong>KERN_INVALID_ADDRESS</strong> | |
| 76 | <dd> | |
| 77 | The address is illegal or specifies a non-allocated region. | |
| 78 | </dl> | |
| 79 | <h3>RELATED INFORMATION</h3> | |
| 80 | <p> | |
| 81 | Functions: | |
| 82 | <a href="memory_object_synchronize.html"><strong>memory_object_synchronize</strong></a>, | |
| 83 | <a href="MO_SY_completed.html"><strong>memory_object_synchronize_completed</strong></a>. |