OS/2 Memory Manager API Differences

The following describes the implementation differences between the OS2Linux library and the real OS/2 memory manager APIs.

These APIs are included in your application by including the following definition in your application source file.

#define INCL_DOSMEMMGR

DosAllocMem

APIRET APIENTRY DosAllocMem(PPVOID ppb, ULONG cb, ULONG flag);

• The argument flag is ignored.
• The system memory page size might not be 4096 bytes.
• The memory returned is allocated using the malloc function.

DosFreeMem

APIRET APIENTRY DosFreeMem(PVOID pb);

• The specified memory is freed using the free function.

DosSetMem

APIRET APIENTRY DosSetMem(PVOID pb, ULONG cb, ULONG flag);

• This function is not supported and always returns ERROR_ACCESS_DENIED.

DosGiveSharedMem

APIRET APIENTRY DosGiveSharedMem(PVOID pb, PID pid, ULONG flag);

• This function is not supported and always returns ERROR_ACCESS_DENIED.

DosGetSharedMem

APIRET APIENTRY DosGetSharedMem(PVOID pb, ULONG flag);

• This function is not supported and always returns ERROR_ACCESS_DENIED.

DosGetNamedSharedMem

APIRET APIENTRY DosGetNamedSharedMem(PPVOID ppb, PSZ pszName, ULONG flag);

• If the argument flag PAG_WRITE bit is not set then the memory will be read only, otherwise the memory will be set to read/write.
• All other bits in the argument flag are ignored.
• The argument pszName must be non-NULL.
• The system memory page size might not be 4096 bytes.
• The memory returned is allocated using the shmget and shmat functions.

DosAllocSharedMem

APIRET APIENTRY DosAllocSharedMem(PPVOID ppb, PSZ pszName, ULONG cb,
                                  ULONG flag);

• If the argument flag PAG_WRITE bit is not set then the memory will be read only, otherwise the memory will be set to read/write.
• All other bits in the argument flag are ignored.
• The argument pszName must be non-NULL.
• The system memory page size might not be 4096 bytes.
• The memory returned is allocated using the shmget and shmat functions.

DosQueryMem

APIRET APIENTRY DosQueryMem(PVOID pb, PULONG pcb, PULONG pFlag);

• This function is not supported and always returns ERROR_ACCESS_DENIED.

DosSubAllocMem

APIRET APIENTRY DosSubAllocMem(PVOID pbBase, PPVOID ppb, ULONG cb);

• This function is not supported and always returns ERROR_ACCESS_DENIED.

DosSubFreeMem

APIRET APIENTRY DosSubFreeMem(PVOID pbBase, PVOID pb, ULONG cb);

• This function is not supported and always returns ERROR_ACCESS_DENIED.

DosSubSetMem

APIRET APIENTRY DosSubSetMem(PVOID pbBase, ULONG flag, ULONG cb);

• This function is not supported and always returns ERROR_ACCESS_DENIED.

DosSubUnsetMem

APIRET APIENTRY DosSubUnsetMem(PVOID pbBase);

• This function is not supported and always returns ERROR_ACCESS_DENIED.