| Index: gecko-sdk/include/prshma.h
|
| ===================================================================
|
| --- gecko-sdk/include/prshma.h (revision 0)
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| +++ gecko-sdk/include/prshma.h (revision 0)
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| @@ -0,0 +1,271 @@
|
| +/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
|
| +/* ***** BEGIN LICENSE BLOCK *****
|
| + * Version: MPL 1.1/GPL 2.0/LGPL 2.1
|
| + *
|
| + * The contents of this file are subject to the Mozilla Public License Version
|
| + * 1.1 (the "License"); you may not use this file except in compliance with
|
| + * the License. You may obtain a copy of the License at
|
| + * http://www.mozilla.org/MPL/
|
| + *
|
| + * Software distributed under the License is distributed on an "AS IS" basis,
|
| + * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
|
| + * for the specific language governing rights and limitations under the
|
| + * License.
|
| + *
|
| + * The Original Code is the Netscape Portable Runtime (NSPR).
|
| + *
|
| + * The Initial Developer of the Original Code is
|
| + * Netscape Communications Corporation.
|
| + * Portions created by the Initial Developer are Copyright (C) 1999-2000
|
| + * the Initial Developer. All Rights Reserved.
|
| + *
|
| + * Contributor(s):
|
| + *
|
| + * Alternatively, the contents of this file may be used under the terms of
|
| + * either the GNU General Public License Version 2 or later (the "GPL"), or
|
| + * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
|
| + * in which case the provisions of the GPL or the LGPL are applicable instead
|
| + * of those above. If you wish to allow use of your version of this file only
|
| + * under the terms of either the GPL or the LGPL, and not to allow others to
|
| + * use your version of this file under the terms of the MPL, indicate your
|
| + * decision by deleting the provisions above and replace them with the notice
|
| + * and other provisions required by the GPL or the LGPL. If you do not delete
|
| + * the provisions above, a recipient may use your version of this file under
|
| + * the terms of any one of the MPL, the GPL or the LGPL.
|
| + *
|
| + * ***** END LICENSE BLOCK ***** */
|
| +
|
| +/*
|
| +** prshma.h -- NSPR Anonymous Shared Memory
|
| +**
|
| +** NSPR provides an anonymous shared memory based on NSPR's PRFileMap
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| +** type. The anonymous file-mapped shared memory provides an inheritable
|
| +** shared memory, as in: the child process inherits the shared memory.
|
| +** Compare the file-mapped anonymous shared memory to to a named shared
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| +** memory described in prshm.h. The intent is to provide a shared
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| +** memory that is accessable only by parent and child processes. ...
|
| +** It's a security thing.
|
| +**
|
| +** Depending on the underlying platform, the file-mapped shared memory
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| +** may be backed by a file. ... surprise! ... On some platforms, no
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| +** real file backs the shared memory. On platforms where the shared
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| +** memory is backed by a file, the file's name in the filesystem is
|
| +** visible to other processes for only the duration of the creation of
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| +** the file, hopefully a very short time. This restricts processess
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| +** that do not inherit the shared memory from opening the file and
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| +** reading or writing its contents. Further, when all processes
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| +** using an anonymous shared memory terminate, the backing file is
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| +** deleted. ... If you are not paranoid, you're not paying attention.
|
| +**
|
| +** The file-mapped shared memory requires a protocol for the parent
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| +** process and child process to share the memory. NSPR provides two
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| +** protocols. Use one or the other; don't mix and match.
|
| +**
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| +** In the first protocol, the job of passing the inheritable shared
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| +** memory is done via helper-functions with PR_CreateProcess(). In the
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| +** second protocol, the parent process is responsible for creating the
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| +** child process; the parent and child are mutually responsible for
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| +** passing a FileMap string. NSPR provides helper functions for
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| +** extracting data from the PRFileMap object. ... See the examples
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| +** below.
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| +**
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| +** Both sides should adhere strictly to the protocol for proper
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| +** operation. The pseudo-code below shows the use of a file-mapped
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| +** shared memory by a parent and child processes. In the examples, the
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| +** server creates the file-mapped shared memory, the client attaches to
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| +** it.
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| +**
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| +** First protocol.
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| +** Server:
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| +**
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| +** fm = PR_OpenAnonFileMap(dirName, size, FilemapProt);
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| +** addr = PR_MemMap(fm);
|
| +** attr = PR_NewProcessAttr();
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| +** PR_ProcessAttrSetInheritableFileMap( attr, fm, shmname );
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| +** PR_CreateProcess(Client);
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| +** PR_DestroyProcessAttr(attr);
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| +** ... yadda ...
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| +** PR_MemUnmap( addr );
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| +** PR_CloseFileMap(fm);
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| +**
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| +**
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| +** Client:
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| +** ... started by server via PR_CreateProcess()
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| +** fm = PR_GetInheritedFileMap( shmname );
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| +** addr = PR_MemMap(fm);
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| +** ... yadda ...
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| +** PR_MemUnmap(addr);
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| +** PR_CloseFileMap(fm);
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| +**
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| +**
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| +** Second Protocol:
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| +** Server:
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| +**
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| +** fm = PR_OpenAnonFileMap(dirName, size, FilemapProt);
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| +** fmstring = PR_ExportFileMapAsString( fm );
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| +** addr = PR_MemMap(fm);
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| +** ... application specific technique to pass fmstring to child
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| +** ... yadda ... Server uses his own magic to create child
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| +** PR_MemUnmap( addr );
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| +** PR_CloseFileMap(fm);
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| +**
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| +**
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| +** Client:
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| +** ... started by server via his own magic
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| +** ... application specific technique to find fmstring from parent
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| +** fm = PR_ImportFileMapFromString( fmstring )
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| +** addr = PR_MemMap(fm);
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| +** ... yadda ...
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| +** PR_MemUnmap(addr);
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| +** PR_CloseFileMap(fm);
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| +**
|
| +**
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| +** lth. 2-Jul-1999.
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| +**
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| +** Note: The second protocol was requested by NelsonB (7/1999); this is
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| +** to accomodate servers which already create their own child processes
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| +** using platform native methods.
|
| +**
|
| +*/
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| +
|
| +#ifndef prshma_h___
|
| +#define prshma_h___
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| +
|
| +#include "prtypes.h"
|
| +#include "prio.h"
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| +#include "prproces.h"
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| +
|
| +PR_BEGIN_EXTERN_C
|
| +
|
| +/*
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| +** PR_OpenAnonFileMap() -- Creates an anonymous file-mapped shared memory
|
| +**
|
| +** Description:
|
| +** PR_OpenAnonFileMap() creates an anonymous shared memory. If the
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| +** shared memory already exists, a handle is returned to that shared
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| +** memory object.
|
| +**
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| +** On Unix platforms, PR_OpenAnonFileMap() uses 'dirName' as a
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| +** directory name, without the trailing '/', to contain the anonymous
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| +** file. A filename is generated for the name.
|
| +**
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| +** On Windows platforms, dirName is ignored.
|
| +**
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| +** Inputs:
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| +** dirName -- A directory name to contain the anonymous file.
|
| +** size -- The size of the shared memory
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| +** prot -- How the shared memory is mapped. See prio.h
|
| +**
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| +** Outputs:
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| +** PRFileMap *
|
| +**
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| +** Returns:
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| +** Pointer to PRFileMap or NULL on error.
|
| +**
|
| +*/
|
| +NSPR_API( PRFileMap *)
|
| +PR_OpenAnonFileMap(
|
| + const char *dirName,
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| + PRSize size,
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| + PRFileMapProtect prot
|
| +);
|
| +
|
| +/*
|
| +** PR_ProcessAttrSetInheritableFileMap() -- Prepare FileMap for export
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| +** to my children processes via PR_CreateProcess()
|
| +**
|
| +** Description:
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| +** PR_ProcessAttrSetInheritableFileMap() connects the PRFileMap to
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| +** PRProcessAttr with shmname. A subsequent call to PR_CreateProcess()
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| +** makes the PRFileMap importable by the child process.
|
| +**
|
| +** Inputs:
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| +** attr -- PRProcessAttr, used to pass data to PR_CreateProcess()
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| +** fm -- PRFileMap structure to be passed to the child process
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| +** shmname -- The name for the PRFileMap; used by child.
|
| +**
|
| +** Outputs:
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| +** PRFileMap *
|
| +**
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| +** Returns:
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| +** PRStatus
|
| +**
|
| +*/
|
| +NSPR_API(PRStatus)
|
| +PR_ProcessAttrSetInheritableFileMap(
|
| + PRProcessAttr *attr,
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| + PRFileMap *fm,
|
| + const char *shmname
|
| +);
|
| +
|
| +/*
|
| +** PR_GetInheritedFileMap() -- Import a PRFileMap previously exported
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| +** by my parent process via PR_CreateProcess()
|
| +**
|
| +** Description:
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| +** PR_GetInheritedFileMap() retrieves a PRFileMap object exported from
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| +** its parent process via PR_CreateProcess().
|
| +**
|
| +** Inputs:
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| +** shmname -- The name provided to PR_ProcessAttrSetInheritableFileMap()
|
| +**
|
| +** Outputs:
|
| +** PRFileMap *
|
| +**
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| +** Returns:
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| +** PRFileMap pointer or NULL.
|
| +**
|
| +*/
|
| +NSPR_API( PRFileMap *)
|
| +PR_GetInheritedFileMap(
|
| + const char *shmname
|
| +);
|
| +
|
| +/*
|
| +** PR_ExportFileMapAsString() -- Creates a string identifying a PRFileMap
|
| +**
|
| +** Description:
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| +** Creates an identifier, as a string, from a PRFileMap object
|
| +** previously created with PR_OpenAnonFileMap().
|
| +**
|
| +** Inputs:
|
| +** fm -- PRFileMap pointer to be represented as a string.
|
| +** bufsize -- sizeof(buf)
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| +** buf -- a buffer of length PR_FILEMAP_STRING_BUFSIZE
|
| +**
|
| +** Outputs:
|
| +** buf contains the stringized PRFileMap identifier
|
| +**
|
| +** Returns:
|
| +** PRStatus
|
| +**
|
| +*/
|
| +NSPR_API( PRStatus )
|
| +PR_ExportFileMapAsString(
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| + PRFileMap *fm,
|
| + PRSize bufsize,
|
| + char *buf
|
| +);
|
| +#define PR_FILEMAP_STRING_BUFSIZE 128
|
| +
|
| +/*
|
| +** PR_ImportFileMapFromString() -- Creates a PRFileMap from the identifying string
|
| +**
|
| +** Description:
|
| +** PR_ImportFileMapFromString() creates a PRFileMap object from a
|
| +** string previously created by PR_ExportFileMapAsString().
|
| +**
|
| +** Inputs:
|
| +** fmstring -- string created by PR_ExportFileMapAsString()
|
| +**
|
| +** Returns:
|
| +** PRFileMap pointer or NULL.
|
| +**
|
| +*/
|
| +NSPR_API( PRFileMap * )
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| +PR_ImportFileMapFromString(
|
| + const char *fmstring
|
| +);
|
| +
|
| +PR_END_EXTERN_C
|
| +#endif /* prshma_h___ */
|
|
|
| Property changes on: gecko-sdk\include\prshma.h
|
| ___________________________________________________________________
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| Added: svn:eol-style
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| + LF
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