#include <e32std.h>
class RChunk : public RHandleBase |
Public Member Enumerations | |
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enum | TRestrictions { EPreventAdjust } |
Inherited Attributes | |
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RHandleBase::iHandle |
Inherited Enumerations | |
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RHandleBase:TAttributes |
A handle to a chunk.
The chunk itself is a kernel side object.
Enumerator | Value | Description |
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EPreventAdjust | 0x01 |
Prevent Adjust, Commit, Allocate and Decommit |
Changes the number of bytes committed to the chunk.
This value is always rounded up to the next nearest processor page boundary.
Parameters | |
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aNewSize | The number of bytes to be committed to this chunk. |
Panic Codes | |
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USER | 102 if aNewSize is negative. |
Changes the number of bytes and the position of this double ended chunk's committed region.
The difference between aTop and aBottom gives the new size of the committed region; aBottom gives the offset of the bottom of the committed region from the base of the chunk's reserved region.
Both aBottom and aTop are rounded up to the next nearest processor page boundary.
The function fails if this chunk is not a double ended chunk; for a standard chunk, use the Adjust() function.
Note that if the initial and final committed regions intersect, the contents of the intersection are unchanged. Other parts of the committed region have undefined contents.
Note also that:
1. the lowest valid address in a double ended chunk is the sum of the base of the chunk's reserved region plus the adjusted value of aBottom
2. the highest valid address in a double ended chunk is the the sum of the base of the chunk's reserved region plus the adjusted value of aTop - 1.
Parameters | |
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aBottom | The offset from the base of the chunk of the bottom of the committed region. |
aTop | The offset from the base of the chunk of the top of the committed region. |
Panic Codes | |
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USER | 124 if aBottom is negative. |
USER | 125 if aTop is negative. |
USER | 126 if aBottom is greater than the supplied value of aTop. |
IMPORT_C TUint8 * | Base | ( | ) | const |
Gets a pointer to the base of the chunk's reserved region.
IMPORT_C TInt | Bottom | ( | ) | const |
Gets the offset of the bottom of the double ended chunk's committed region from the base of the chunk's reserved region.
Note that the lowest valid address in a double ended chunk is the sum of the base of the chunk's reserved region plus the value of Bottom().
Commits memory to a disconnected chunk.
TInt pageSize; HAL::Get(HAL::EMemoryPageSize,pageSize)
Parameters | |
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anOffset | The offset of the committed region from the base of the chunk's reserved region. |
aSize | The size of the committed region. |
Panic Codes | |
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USER | 157 if anOffset is negative. |
USER | 158 if aSize is negative. |
IMPORT_C TInt | Create | ( | TChunkCreateInfo & | aCreateInfo | ) |
Creates a chunk of the type specified by the parameter aCreateInfo.
Panic Codes | |
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USER | 99 if the specified maximum size is negative. |
USER | 120 if any specified initial bottom is negative. |
USER | 121 if any specified initial top is negative. |
USER | 122 if any specified initial bottom is greater than the supplied value for the intial top. |
USER | 123 if any specified initial top is greater than the supplied value for the maximum size. |
USER | 214 if any of the specified attributes is invalid. |
USER | 215 if the version number of aCreateInfo is invalid. |
IMPORT_C TInt | CreateDisconnectedGlobal | ( | const TDesC & | aName, |
TInt | aInitialBottom, | |||
TInt | aInitialTop, | |||
TInt | aMaxSize, | |||
TOwnerType | aType = EOwnerProcess | |||
) |
Creates a global, disconnected, chunk.
The chunk is global; i.e. it is visible to all processes and is intended for access by other user processes.
A disconnected chunk has a committed region consisting of an arbitrary set of MMU pages within the reserved region, i.e. each page-sized address range within the reserved region which begins on a page boundary may be committed independently.
aMaxSize specifies the maximum size of the chunk.
The difference between aInitialTop and aInitialBottom gives the number of bytes to be committed, on creation of the chunk; aInitialBottom gives the offset of the bottom of the committed region from the base of the chunk's reserved region; aInitialTop gives the offset of the top of the committed region from the base of the chunk's reserved region.
Both aInitialBottom and aInitialTop are rounded up to the next nearest processor page boundary value, if they are not already on a processor page boundary value.
The descriptor aName contains the name to be assigned to this global chunk.
By default, ownership of this chunk handle is vested in the current process. Ownership of the chunk handle can be vested in the current thread by passing EOwnerThread as the third parameter to this function.
Parameters | |
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aName | A reference to a descriptor containing the name to be assigned to this global chunk. The length of the descriptor must be no greater than that allowed for a TKName type. |
aInitialBottom | The offset of the bottom of the new committed region from the base of the chunk's reserved region. |
aInitialTop | The offset of the top of the new committed region from the base of the chunk's reserved region. |
aMaxSize | The maximum size to which the reserved region of this chunk can grow. |
aType | An enumeration whose enumerators define the ownership of this chunk handle. If not explicitly specified, EOwnerProcess is taken as default. |
Panic Codes | |
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USER | 99 if aMaxSize is negative. |
USER | 120 if aInitialBottom is negative. |
USER | 121 if aInitialTop is negative. |
USER | 122 if aInitialBottom is greater than the supplied value of aInitialTop. |
USER | 123 if aInitialTop is greater than the supplied value of aMaxSize. |
IMPORT_C TInt | CreateDisconnectedLocal | ( | TInt | aInitialBottom, |
TInt | aInitialTop, | |||
TInt | aMaxSize, | |||
TOwnerType | aType = EOwnerProcess | |||
) |
Creates a local, disconnected chunk.
The chunk is local to the process creating it; i.e. it is private to the process creating it and is not intended for access by other user processes.
A disconnected chunk has a committed region consisting of an arbitrary set of MMU pages within the reserved region, i.e. each page-sized address range within the reserved region which begins on a page boundary may be committed independently.
aMaxSize specifies the maximum size of the chunk.
The difference between aInitialTop and aInitialBottom gives the number of bytes to be committed, on creation of the chunk; aInitialBottom gives the offset of the bottom of the committed region from the base of the chunk's reserved region; aInitialTop gives the offset of the top of the committed region from the base of the chunk's reserved region.
Both aInitialBottom and aInitialTop are rounded up to the next nearest processor page boundary value, if they are not already on a processor page boundary value.
By default, ownership of this chunk handle is vested in the current process. Ownership of the chunk handle can be vested in the current thread by passing EOwnerThread as the third parameter to this function.
Parameters | |
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aInitialBottom | The offset of the bottom of the new committed region from the base of the chunk's reserved region. |
aInitialTop | The offset of the top of the new committed region from the base of the chunk's reserved region. |
aMaxSize | The maximum size to which the reserved region of this chunk can grow. |
aType | An enumeration whose enumerators define the ownership of this chunk handle. If not explicitly specified, EOwnerProcess is taken as default. |
Panic Codes | |
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USER | 99 if aMaxSize is negative. |
USER | 120 if aInitialBottom is negative. |
USER | 121 if aInitialTop is negative. |
USER | 122 if aInitialBottom is greater than the supplied value of aInitialTop. |
USER | 123 if aInitialTop is greater than the supplied value of aMaxSize. |
IMPORT_C TInt | CreateDoubleEndedGlobal | ( | const TDesC & | aName, |
TInt | aInitialBottom, | |||
TInt | aInitialTop, | |||
TInt | aMaxSize, | |||
TOwnerType | aType = EOwnerProcess | |||
) |
Creates a global, double ended, chunk.
The chunk is global; i.e. it is visible to all processes and is intended for access by other user processes.
The committed region of a double ended chunk can be any contiguous subset of the reserved region.
aMaxSize specifies the maximum size of the chunk.
The difference between aInitialTop and aInitialBottom gives the number of bytes to be committed, on creation of the chunk; aInitialBottom gives the offset of the bottom of the committed region from the base of the chunk's reserved region; aInitialTop gives the offset of the top of the committed region from the base of the chunk's reserved region.
Both aInitialBottom and aInitialTop are rounded up to the next nearest processor page boundary value, if they are not already on a processor page boundary value.
The descriptor aName contains the name to be assigned to this global chunk.
By default, ownership of this chunk handle is vested in the current process. Ownership of the chunk handle can be vested in the current thread by passing EOwnerThread as the third parameter to this function.
Note that:
1. the lowest valid address in a double ended chunk is the sum of the base of the chunk's reserved region plus the adjusted value of aInitialBottom
2. the highest valid address in a double ended chunk is the the sum of the base of the chunk's reserved region plus the adjusted value of aInitialTop - 1.
Parameters | |
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aName | A reference to a descriptor containing the name to be assigned to this global chunk. The length of the descriptor must be no greater than that allowed for a TKName type. |
aInitialBottom | The offset of the bottom of the new committed region from the base of the chunk's reserved region. |
aInitialTop | The offset of the top of the new committed region from the base of the chunk's reserved region. |
aMaxSize | The maximum size to which the reserved region of this chunk can grow. |
aType | An enumeration whose enumerators define the ownership of this chunk handle. If not explicitly specified, EOwnerProcess is taken as default. |
Panic Codes | |
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USER | 99 if aMaxSize is negative. |
USER | 120 if aInitialBottom is negative. |
USER | 121 if aInitialTop is negative. |
USER | 122 if aInitialBottom is greater than the supplied value of aInitialTop. |
USER | 123 if aInitialTop is greater than the supplied value of aMaxSize. |
USER | 163 if aName is empty. |
IMPORT_C TInt | CreateDoubleEndedLocal | ( | TInt | aInitialBottom, |
TInt | aInitialTop, | |||
TInt | aMaxSize, | |||
TOwnerType | aType = EOwnerProcess | |||
) |
Creates a local, double ended, chunk.
The chunk is local to the process creating it; i.e. it is private to the process creating it and is not intended for access by other user processes.
The committed region of a double ended chunk can be any contiguous subset of the reserved region.
aMaxSize specifies the maximum size of the chunk.
The difference between aInitialTop and aInitialBottom gives the number of bytes to be committed, on creation of the chunk; aInitialBottom gives the offset of the bottom of the committed region from the base of the chunk's reserved region; aInitialTop gives the offset of the top of the committed region from the base of the chunk's reserved region.
Both aInitialBottom and aInitialTop are rounded up to the next nearest processor page boundary value, if they are not already on a processor page boundary value.
By default, ownership of this chunk handle is vested in the current process. Ownership of the chunk handle can be vested in the current thread by passing EOwnerThread as the third parameter to this function.
Note that:
1. the lowest valid address in a double ended chunk is the sum of the base of the chunk's reserved region plus the adjusted value of aInitialBottom
2. the highest valid address in a double ended chunk is the the sum of the base of the chunk's reserved region plus the adjusted value of aInitialTop - 1.
Parameters | |
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aInitialBottom | The offset of the bottom of the new committed region from the base of the chunk's reserved region. |
aInitialTop | The offset of the top of the new committed region from the base of the chunk's reserved region. |
aMaxSize | The maximum size to which the reserved region of this chunk can grow. |
aType | An enumeration whose enumerators define the ownership of this chunk handle. If not explicitly specified, EOwnerProcess is taken as default. |
Panic Codes | |
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USER | 99 if aMaxSize is negative. |
USER | 120 if aInitialBottom is negative. |
USER | 121 if aInitialTop is negative. |
USER | 122 if aInitialBottom is greater than the supplied value of aInitialTop. |
USER | 123 if aInitialTop is greater than the supplied value of aMaxSize. |
IMPORT_C TInt | CreateGlobal | ( | const TDesC & | aName, |
TInt | aSize, | |||
TInt | aMaxSize, | |||
TOwnerType | aType = EOwnerProcess | |||
) |
Creates a global chunk.
The chunk is global; i.e. it is potentially visible to all processes and is intended for access by other user processes.
aMaxSize specifies the maximum size of the chunk and aSize specifies the number of bytes to be committed on creation of the chunk. Both values are rounded up to the next nearest processor page boundary value ,if they are not already on a processor page boundary value.
The committed region always starts at the bottom of the reserved region.
The descriptor aName contains the name to be assigned to this global chunk. If this name is empty, the chunk will be anonymous. Anonymous chunks cannot be accessed by other processes unless the creator explicitly passes them a handle to the chunk - this can be used to transfer large amounts of data between processes in a secure fashion.
By default, ownership of this chunk handle is vested in the current process. Ownership of the chunk handle can be vested in the current thread by passing EOwnerThread as the third parameter to this function.
Parameters | |
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aName | A reference to a descriptor containing the name to be assigned to this global chunk. The length of the descriptor must be no greater than that allowed for a TKName type. |
aSize | The number of bytes committed to this chunk. |
aMaxSize | The maximum size to which the reserved region of this chunk can grow. |
aType | An enumeration whose enumerators define the ownership of this chunk handle. If not explicitly specified, EOwnerProcess is taken as default. |
Panic Codes | |
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USER | 99 if aMaxSize is negative. |
USER | 100 if aSize is negative. |
USER | 101 if aSize is greater than or equal to the supplied value of aMaxSize. |
IMPORT_C TInt | CreateLocal | ( | TInt | aSize, |
TInt | aMaxSize, | |||
TOwnerType | aType = EOwnerProcess | |||
) |
Creates a local chunk.
The chunk is local to the process creating it; i.e. it is private to the process creating it and is not intended for access by other user processes.
aMaxSize specifies the maximum size of the chunk and aSize specifies the number of bytes to be committed on creation of the chunk. Both values are rounded up to the next nearest processor page boundary value if they are not already on a processor page boundary.
The committed region always starts at the bottom of the reserved region.
By default, ownership of this chunk handle is vested in the current process. Ownership of the chunk handle can be vested in the current thread by passing EOwnerThread as the third parameter to this function.
Parameters | |
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aSize | The number of bytes committed to this chunk. |
aMaxSize | The maximum size to which the reserved region of this chunk can grow. |
aType | An enumeration whose enumerators define the ownership of this chunk handle. If not explicitly specified, EOwnerProcess is taken as default. |
Panic Codes | |
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USER | 99 if aMaxSize is negative. |
USER | 100 if aSize is negative. |
USER | 101 if aSize is greater than or equal to the supplied value of aMaxSize. |
IMPORT_C TInt | CreateLocalCode | ( | TInt | aSize, |
TInt | aMaxSize, | |||
TOwnerType | aType = EOwnerProcess | |||
) |
Creates a user writable chunk that is marked by the kernel as containing code.
The chunk is local to the process creating it, i.e. it is private to the process creating it and is not intended for access by other user processes.
On systems using a Harvard cache, this type of chunk removes the need to flush the instruction cache (I-Cache) on a context switch. However, the instruction Translation Look-aside Buffer (ITLB) still needs to be flushed when switching to or from a process with one of these chunks in its address space. Systems with a dynamic branch predictor may also need to flush their branch target buffer when switching from one process using this type of chunk to another.
See also: UserHeap::ChunkHeap User::IMB_Range
Parameters | |
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aSize | The number of bytes committed to this chunk. |
aMaxSize | The maximum size to which the reserved region of this chunk can grow. |
aType | An enumeration whose enumerators define the ownership of this chunk handle. If not explicitly specified, EOwnerProcess is taken as default. |
Panic Codes | |
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USER | 99 if aMaxSize is negative. |
USER | 100 if aSize is negative. |
USER | 101 if aSize is greater than or equal to the supplied value of aMaxSize. |
Decommits memory from a disconnected chunk.
TInt pageSize; HAL::Get(HAL::EMemoryPageSize,pageSize)
Parameters | |
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anOffset | The offset of the committed region from the base of the chunk's reserved region; |
aSize | The size of the committed region. |
Panic Codes | |
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USER | 160 if anOffset is negative. |
USER | 161 if aSize is negative. |
IMPORT_C TBool | IsPaged | ( | ) | const |
This can be used to determine whether the data for the chunk is demand paged or not.
TBool | IsReadable | ( | ) | const [inline] |
Tests whether the chunk is mapped into its process address space.
TBool | IsWritable | ( | ) | const [inline] |
Tests whether the chunk mapped into its process address space and is writable.
IMPORT_C TInt | MaxSize | ( | ) | const |
Gets the maximum size of this chunk.
This maximum size of this chunk is set when the chunk is created.
TInt | Open | ( | const TFindChunk & | aFind, |
TOwnerType | aType = EOwnerProcess | |||
) | [inline] |
Opens a handle to the global chunk found using a TFindChunk object.
A TFindChunk object is used to find all chunks whose full names match a specified pattern.
By default, ownership of this chunk handle is vested in the current process, but can be vested in the current thread by passing EOwnerThread as the second parameter to this function.
Parameters | |
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aFind | A reference to the TFindChunk object used to find the chunk. |
aType | An enumeration whose enumerators define the ownership of this chunk handle. If not explicitly specified, EOwnerProcess is taken as default. |
IMPORT_C TInt | Open | ( | RMessagePtr2 | aMessage, |
TInt | aParam, | |||
TBool | isReadOnly, | |||
TOwnerType | aType = EOwnerProcess | |||
) |
Opens a handle to a chunk using a handle number sent by a client to a server.
This function is called by the server.
Parameters | |
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aMessage | The message pointer. |
aParam | An index specifying which of the four message arguments contains the handle number. |
isReadOnly | This is currently not implemented and setting it to ETrue will have no effect. (Intended implementation will be as below: Defines the type of access to the chunk: Specify ETrue if access is limited to read only, otherwise specify EFalse for full read/write access.) |
aType | An enumeration whose enumerators define the ownership of this chunk handle. If not explicitly specified, EOwnerProcess is taken as default. |
IMPORT_C TInt | Open | ( | TInt | aArgumentIndex, |
TOwnerType | aType = EOwnerProcess | |||
) |
Opens a handle to a chunk using a handle number passed as an environment data item to the child process during the creation of that child process.
Note that this function can only be called successfully once.
See also: RProcess::SetParameter()
Parameters | |
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aArgumentIndex | An index that identifies the slot in the process environment data that contains the handle number. This is a value relative to zero, i.e. 0 is the first item/slot. This can range from 0 to 15. |
aType | An enumeration whose enumerators define the ownership of this chunk handle. If not explicitly specified, EOwnerProcess is taken as default. |
IMPORT_C TInt | OpenGlobal | ( | const TDesC & | aName, |
TBool | isReadOnly, | |||
TOwnerType | aType = EOwnerProcess | |||
) |
Opens a handle to a specific named global chunk.
Full read/write access can be allowed or access can be limited to read only.
By default, ownership of this process handle is vested in the current process, but can be vested in the current thread by passing EOwnerThread as the second parameter to this function.
Parameters | |
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aName | A reference to the descriptor containing the name of the chunk to be opened. |
isReadOnly | This is currently not implemented and setting it to ETrue will have no effect. (Intended implementation will be as below: Defines the type of access to the chunk: Specify ETrue if access is limited to read only, otherwise specify EFalse for full read/write access.) |
aType | An enumeration whose enumerators define ownership of this chunk handle. If not explicitly specified, EOwnerProcess is taken as default. |
Sets or removes restrictions on the ability of the chunk to change.
For example, to adjust, commit etc
See also: RChunk::TRestrictions()
Parameters | |
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aFlags | One of the values defined by TRestrictions. |
IMPORT_C TInt | Size | ( | ) | const |
Gets the current size of this chunk's committed region.
IMPORT_C TInt | Top | ( | ) | const |
Gets the offset of the top of the double ended chunk's committed region from the base of the chunk's reserved region.
Note that the highest valid address in a double ended chunk is the the sum of the base of the chunk's reserved region plus the value of Top() - 1.