Package org.apache.tomcat.jni
Class Shm
java.lang.Object
org.apache.tomcat.jni.Shm
Deprecated.
The scope of the APR/Native Library will be reduced in Tomcat
              10.1.x / Tomcat Native 2.x onwards to only include those
              components required to provide OpenSSL integration with the NIO
              and NIO2 connectors.
Shm
- Author:
- Mladen Turk
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Constructor SummaryConstructors
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Method SummaryModifier and TypeMethodDescriptionstatic longDeprecated.Attach to a shared memory segment that was created by another process.static longbaseaddr(long m) Deprecated.Retrieve the base address of the shared memory segment.static ByteBufferbuffer(long m) Deprecated.Retrieve new ByteBuffer base address of the shared memory segment.static longDeprecated.Create and make accessible a shared memory segment.static intdestroy(long m) Deprecated.Destroy a shared memory segment and associated memory.static intdetach(long m) Deprecated.Detach from a shared memory segment without destroying it.static intDeprecated.Remove shared memory segment associated with a filename.static longsize(long m) Deprecated.Retrieve the length of a shared memory segment in bytes.
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Constructor Details- 
Shmpublic Shm()Deprecated.
 
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Method Details- 
createDeprecated.Create and make accessible a shared memory segment.
 A note about Anonymous vs. Named shared memory segments:
 Not all platforms support anonymous shared memory segments, but in some cases it is preferred over other types of shared memory implementations. Passing a NULL 'file' parameter to this function will cause the subsystem to use anonymous shared memory segments. If such a system is not available, APR_ENOTIMPL is returned.
 A note about allocation sizes:
 On some platforms it is necessary to store some metainformation about the segment within the actual segment. In order to supply the caller with the requested size it may be necessary for the implementation to request a slightly greater segment length from the subsystem. In all cases, the apr_shm_baseaddr_get() function will return the first usable byte of memory.- Parameters:
- reqsize- The desired size of the segment.
- filename- The file to use for shared memory on platforms that require it.
- pool- the pool from which to allocate the shared memory structure.
- Returns:
- The created shared memory structure.
- Throws:
- Error- An error occurred
 
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removeDeprecated.Remove shared memory segment associated with a filename.
 This function is only supported on platforms which support name-based shared memory segments, and will return APR_ENOTIMPL on platforms without such support.- Parameters:
- filename- The filename associated with shared-memory segment which needs to be removed
- pool- The pool used for file operations
- Returns:
- the operation status
 
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destroypublic static int destroy(long m) Deprecated.Destroy a shared memory segment and associated memory.- Parameters:
- m- The shared memory segment structure to destroy.
- Returns:
- the operation status
 
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attachDeprecated.Attach to a shared memory segment that was created by another process.- Parameters:
- filename- The file used to create the original segment. (This MUST match the original filename.)
- pool- the pool from which to allocate the shared memory structure for this process.
- Returns:
- The created shared memory structure.
- Throws:
- Error- An error occurred
 
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detachpublic static int detach(long m) Deprecated.Detach from a shared memory segment without destroying it.- Parameters:
- m- The shared memory structure representing the segment to detach from.
- Returns:
- the operation status
 
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baseaddrpublic static long baseaddr(long m) Deprecated.Retrieve the base address of the shared memory segment. NOTE: This address is only usable within the callers address space, since this API does not guarantee that other attaching processes will maintain the same address mapping.- Parameters:
- m- The shared memory segment from which to retrieve the base address.
- Returns:
- address, aligned by APR_ALIGN_DEFAULT.
 
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sizepublic static long size(long m) Deprecated.Retrieve the length of a shared memory segment in bytes.- Parameters:
- m- The shared memory segment from which to retrieve the segment length.
- Returns:
- the length of the segment
 
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bufferDeprecated.Retrieve new ByteBuffer base address of the shared memory segment. NOTE: This address is only usable within the callers address space, since this API does not guarantee that other attaching processes will maintain the same address mapping.- Parameters:
- m- The shared memory segment from which to retrieve the base address.
- Returns:
- address, aligned by APR_ALIGN_DEFAULT.
 
 
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