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shmid_ds.md 7.05 KB

# shmid\_ds<a name="ZH-CN_TOPIC_0000001054799647"></a>

## **Overview**<a name="section755670664084843"></a>

**Related Modules:**

[MEM](MEM.md)

**Description:**

Stores information about a shared memory segment.

## **Summary**<a name="section147201603084843"></a>

## Data Fields<a name="pub-attribs"></a>

<a name="table564929440084843"></a>
<table><thead align="left"><tr id="row234180560084843"><th class="cellrowborder" valign="top" width="50%" id="mcps1.1.3.1.1"><p id="p1237944728084843"><a name="p1237944728084843"></a><a name="p1237944728084843"></a>Variable Name</p>
</th>
<th class="cellrowborder" valign="top" width="50%" id="mcps1.1.3.1.2"><p id="p2037590540084843"><a name="p2037590540084843"></a><a name="p2037590540084843"></a>Description</p>
</th>
</tr>
</thead>
<tbody><tr id="row957020521084843"><td class="cellrowborder" valign="top" width="50%" headers="mcps1.1.3.1.1 "><p id="p974537141084843"><a name="p974537141084843"></a><a name="p974537141084843"></a><a href="shmid_ds.md#aa211c549a679c1b3eed093b44958a18a">shm_perm</a></p>
</td>
<td class="cellrowborder" valign="top" width="50%" headers="mcps1.1.3.1.2 "><p id="p1820805910084843"><a name="p1820805910084843"></a><a name="p1820805910084843"></a>struct ipc_perm&nbsp;</p>
</td>
</tr>
<tr id="row2040793703084843"><td class="cellrowborder" valign="top" width="50%" headers="mcps1.1.3.1.1 "><p id="p1859549464084843"><a name="p1859549464084843"></a><a name="p1859549464084843"></a><a href="shmid_ds.md#a0c5defd6c73b4224d9944c770bfa77b9">shm_segsz</a></p>
</td>
<td class="cellrowborder" valign="top" width="50%" headers="mcps1.1.3.1.2 "><p id="p1732391669084843"><a name="p1732391669084843"></a><a name="p1732391669084843"></a>size_t&nbsp;</p>
</td>
</tr>
<tr id="row1221074886084843"><td class="cellrowborder" valign="top" width="50%" headers="mcps1.1.3.1.1 "><p id="p147649883084843"><a name="p147649883084843"></a><a name="p147649883084843"></a><a href="shmid_ds.md#af82fd8f5fdd9d93e3985f5b888382bf8">shm_atime</a></p>
</td>
<td class="cellrowborder" valign="top" width="50%" headers="mcps1.1.3.1.2 "><p id="p1131227469084843"><a name="p1131227469084843"></a><a name="p1131227469084843"></a>time_t&nbsp;</p>
</td>
</tr>
<tr id="row1002680230084843"><td class="cellrowborder" valign="top" width="50%" headers="mcps1.1.3.1.1 "><p id="p504942136084843"><a name="p504942136084843"></a><a name="p504942136084843"></a><a href="shmid_ds.md#a27ee9289548d67c2036b695a25dca11b">shm_dtime</a></p>
</td>
<td class="cellrowborder" valign="top" width="50%" headers="mcps1.1.3.1.2 "><p id="p194472592084843"><a name="p194472592084843"></a><a name="p194472592084843"></a>time_t&nbsp;</p>
</td>
</tr>
<tr id="row1812805979084843"><td class="cellrowborder" valign="top" width="50%" headers="mcps1.1.3.1.1 "><p id="p1057330059084843"><a name="p1057330059084843"></a><a name="p1057330059084843"></a><a href="shmid_ds.md#a1bee5edd96bfc138b5ca07cb558a10c5">shm_ctime</a></p>
</td>
<td class="cellrowborder" valign="top" width="50%" headers="mcps1.1.3.1.2 "><p id="p1584891796084843"><a name="p1584891796084843"></a><a name="p1584891796084843"></a>time_t&nbsp;</p>
</td>
</tr>
<tr id="row1256609788084843"><td class="cellrowborder" valign="top" width="50%" headers="mcps1.1.3.1.1 "><p id="p200455511084843"><a name="p200455511084843"></a><a name="p200455511084843"></a><a href="shmid_ds.md#afe5c739b33bfa41eb55563571410e52c">shm_cpid</a></p>
</td>
<td class="cellrowborder" valign="top" width="50%" headers="mcps1.1.3.1.2 "><p id="p1469298692084843"><a name="p1469298692084843"></a><a name="p1469298692084843"></a>pid_t&nbsp;</p>
</td>
</tr>
<tr id="row548502811084843"><td class="cellrowborder" valign="top" width="50%" headers="mcps1.1.3.1.1 "><p id="p205035749084843"><a name="p205035749084843"></a><a name="p205035749084843"></a><a href="shmid_ds.md#a5539fd4cdac73e375697bbd59c39c29f">shm_lpid</a></p>
</td>
<td class="cellrowborder" valign="top" width="50%" headers="mcps1.1.3.1.2 "><p id="p1572672140084843"><a name="p1572672140084843"></a><a name="p1572672140084843"></a>pid_t&nbsp;</p>
</td>
</tr>
<tr id="row1642347287084843"><td class="cellrowborder" valign="top" width="50%" headers="mcps1.1.3.1.1 "><p id="p332269176084843"><a name="p332269176084843"></a><a name="p332269176084843"></a><a href="shmid_ds.md#a68a95433988a55ce183358e4e9fe4d41">shm_nattch</a></p>
</td>
<td class="cellrowborder" valign="top" width="50%" headers="mcps1.1.3.1.2 "><p id="p33674199084843"><a name="p33674199084843"></a><a name="p33674199084843"></a>unsigned long&nbsp;</p>
</td>
</tr>
<tr id="row657563257084843"><td class="cellrowborder" valign="top" width="50%" headers="mcps1.1.3.1.1 "><p id="p889286911084843"><a name="p889286911084843"></a><a name="p889286911084843"></a><a href="shmid_ds.md#a34a4da4fb1e217399487b201f8f3c621">__pad1</a></p>
</td>
<td class="cellrowborder" valign="top" width="50%" headers="mcps1.1.3.1.2 "><p id="p1800957066084843"><a name="p1800957066084843"></a><a name="p1800957066084843"></a>unsigned long&nbsp;</p>
</td>
</tr>
<tr id="row212090519084843"><td class="cellrowborder" valign="top" width="50%" headers="mcps1.1.3.1.1 "><p id="p1917089486084843"><a name="p1917089486084843"></a><a name="p1917089486084843"></a><a href="shmid_ds.md#ae9dd2a694b91cf85c9989a42e7ce07cb">__pad2</a></p>
</td>
<td class="cellrowborder" valign="top" width="50%" headers="mcps1.1.3.1.2 "><p id="p833314025084843"><a name="p833314025084843"></a><a name="p833314025084843"></a>unsigned long&nbsp;</p>
</td>
</tr>
</tbody>
</table>

## **Details**<a name="section1924226704084843"></a>

## **Field Documentation**<a name="section590097039084843"></a>

## \_\_pad1<a name="a34a4da4fb1e217399487b201f8f3c621"></a>

```
unsigned long shmid_ds::__pad1
```

**Description:**

Padding field

## \_\_pad2<a name="ae9dd2a694b91cf85c9989a42e7ce07cb"></a>

```
unsigned long shmid_ds::__pad2
```

**Description:**

Padding field

## shm\_atime<a name="af82fd8f5fdd9d93e3985f5b888382bf8"></a>

```
time_t shmid_ds::shm_atime
```

**Description:**

Time when the last process is attached to this segment

## shm\_cpid<a name="afe5c739b33bfa41eb55563571410e52c"></a>

```
pid_t shmid_ds::shm_cpid
```

**Description:**

ID of the process that created this segment

## shm\_ctime<a name="a1bee5edd96bfc138b5ca07cb558a10c5"></a>

```
time_t shmid_ds::shm_ctime
```

**Description:**

Time when the last process modified this segment

## shm\_dtime<a name="a27ee9289548d67c2036b695a25dca11b"></a>

```
time_t shmid_ds::shm_dtime
```

**Description:**

Time when the last process is detached from this segment

## shm\_lpid<a name="a5539fd4cdac73e375697bbd59c39c29f"></a>

```
pid_t shmid_ds::shm_lpid
```

**Description:**

ID of the last process that operated this segment

## shm\_nattch<a name="a68a95433988a55ce183358e4e9fe4d41"></a>

```
unsigned long shmid_ds::shm_nattch
```

**Description:**

Number of processes attached to this segment

## shm\_perm<a name="aa211c549a679c1b3eed093b44958a18a"></a>

```
struct ipc_perm shmid_ds::shm_perm
```

**Description:**

Operation permissions on this segment

## shm\_segsz<a name="a0c5defd6c73b4224d9944c770bfa77b9"></a>

```
size_t shmid_ds::shm_segsz
```

**Description:**

Segment size, in bytes

Copy Edit Raw Blame History

authored 2020-09-08 10:08 . add OpenHarmony 1.0 baseline

shmid_ds

Overview

Related Modules:

Description:

Stores information about a shared memory segment.

Summary

Data Fields

Variable Name	Description
shm_perm	struct ipc_perm
shm_segsz	size_t
shm_atime	time_t
shm_dtime	time_t
shm_ctime	time_t
shm_cpid	pid_t
shm_lpid	pid_t
shm_nattch	unsigned long
__pad1	unsigned long
__pad2	unsigned long

Details

Field Documentation

__pad1

unsigned long shmid_ds::__pad1

Description:

Padding field

__pad2

unsigned long shmid_ds::__pad2

Description:

Padding field

shm_atime

time_t shmid_ds::shm_atime

Description:

Time when the last process is attached to this segment

shm_cpid

pid_t shmid_ds::shm_cpid

Description:

ID of the process that created this segment

shm_ctime

time_t shmid_ds::shm_ctime

Description:

Time when the last process modified this segment

shm_dtime

time_t shmid_ds::shm_dtime

Description:

Time when the last process is detached from this segment

shm_lpid

pid_t shmid_ds::shm_lpid

Description:

ID of the last process that operated this segment

shm_nattch

unsigned long shmid_ds::shm_nattch

Description:

Number of processes attached to this segment

shm_perm

struct ipc_perm shmid_ds::shm_perm

Description:

Operation permissions on this segment

shm_segsz

size_t shmid_ds::shm_segsz

Description:

Segment size, in bytes

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