#include <unistd.h>
#include <fcntl.h>
#include <stdlib.h>
+#include <errno.h>
#include <cstring>
/*}}}*/
// ---------------------------------------------------------------------
/* */
MMap::MMap(FileFd &F,unsigned long Flags) : Flags(Flags), iSize(0),
- Base(0)
+ Base(0), SyncToFd(NULL)
{
if ((Flags & NoImmMap) != NoImmMap)
Map(F);
// ---------------------------------------------------------------------
/* */
MMap::MMap(unsigned long Flags) : Flags(Flags), iSize(0),
- Base(0)
+ Base(0), SyncToFd(NULL)
{
}
/*}}}*/
// Map it.
Base = mmap(0,iSize,Prot,Map,Fd.Fd(),0);
if (Base == (void *)-1)
- return _error->Errno("mmap",_("Couldn't make mmap of %lu bytes"),iSize);
+ {
+ if (errno == ENODEV || errno == EINVAL)
+ {
+ // The filesystem doesn't support this particular kind of mmap.
+ // So we allocate a buffer and read the whole file into it.
+ int const dupped_fd = dup(Fd.Fd());
+ if (dupped_fd == -1)
+ return _error->Errno("mmap", _("Couldn't duplicate file descriptor %i"), Fd.Fd());
+
+ Base = new unsigned char[iSize];
+ SyncToFd = new FileFd (dupped_fd);
+ if (!SyncToFd->Seek(0L) || !SyncToFd->Read(Base, iSize))
+ return false;
+ }
+ else
+ return _error->Errno("mmap",_("Couldn't make mmap of %lu bytes"),
+ iSize);
+ }
return true;
}
if (DoSync == true)
Sync();
-
- if (munmap((char *)Base,iSize) != 0)
- _error->Warning("Unable to munmap");
-
+
+ if (SyncToFd != NULL)
+ {
+ delete[] (char *)Base;
+ delete SyncToFd;
+ SyncToFd = NULL;
+ }
+ else
+ {
+ if (munmap((char *)Base, iSize) != 0)
+ _error->WarningE("mmap", _("Unable to close mmap"));
+ }
+
iSize = 0;
Base = 0;
return true;
#ifdef _POSIX_SYNCHRONIZED_IO
if ((Flags & ReadOnly) != ReadOnly)
- if (msync((char *)Base,iSize,MS_SYNC) < 0)
- return _error->Errno("msync","Unable to write mmap");
+ {
+ if (SyncToFd != NULL)
+ {
+ if (!SyncToFd->Seek(0) || !SyncToFd->Write(Base, iSize))
+ return false;
+ }
+ else
+ {
+ if (msync((char *)Base, iSize, MS_SYNC) < 0)
+ return _error->Errno("msync", _("Unable to synchronize mmap"));
+ }
+ }
#endif
return true;
}
#ifdef _POSIX_SYNCHRONIZED_IO
unsigned long PSize = sysconf(_SC_PAGESIZE);
if ((Flags & ReadOnly) != ReadOnly)
- if (msync((char *)Base+(int)(Start/PSize)*PSize,Stop - Start,MS_SYNC) < 0)
- return _error->Errno("msync","Unable to write mmap");
+ {
+ if (SyncToFd != 0)
+ {
+ if (!SyncToFd->Seek(0) ||
+ !SyncToFd->Write (((char *)Base)+Start, Stop-Start))
+ return false;
+ }
+ else
+ {
+ if (msync((char *)Base+(int)(Start/PSize)*PSize,Stop - Start,MS_SYNC) < 0)
+ return _error->Errno("msync", _("Unable to synchronize mmap"));
+ }
+ }
#endif
return true;
}
/*}}}*/
- /*}}}*/
// DynamicMMap::DynamicMMap - Constructor /*{{{*/
// ---------------------------------------------------------------------
/* */
-DynamicMMap::DynamicMMap(FileFd &F,unsigned long Flags,unsigned long WorkSpace) :
- MMap(F,Flags | NoImmMap), Fd(&F), WorkSpace(WorkSpace)
+DynamicMMap::DynamicMMap(FileFd &F,unsigned long Flags,unsigned long const &Workspace,
+ unsigned long const &Grow, unsigned long const &Limit) :
+ MMap(F,Flags | NoImmMap), Fd(&F), WorkSpace(Workspace),
+ GrowFactor(Grow), Limit(Limit)
{
if (_error->PendingError() == true)
return;
/* We try here to use mmap to reserve some space - this is much more
cooler than the fallback solution to simply allocate a char array
and could come in handy later than we are able to grow such an mmap */
-DynamicMMap::DynamicMMap(unsigned long Flags,unsigned long WorkSpace) :
- MMap(Flags | NoImmMap | UnMapped), Fd(0), WorkSpace(WorkSpace)
+DynamicMMap::DynamicMMap(unsigned long Flags,unsigned long const &WorkSpace,
+ unsigned long const &Grow, unsigned long const &Limit) :
+ MMap(Flags | NoImmMap | UnMapped), Fd(0), WorkSpace(WorkSpace),
+ GrowFactor(Grow), Limit(Limit)
{
- if (_error->PendingError() == true)
- return;
+ if (_error->PendingError() == true)
+ return;
+
+ // disable Moveable if we don't grow
+ if (Grow == 0)
+ Flags &= ~Moveable;
+
+#ifndef __linux__
+ // kfreebsd doesn't have mremap, so we use the fallback
+ if ((Flags & Moveable) == Moveable)
+ Flags |= Fallback;
+#endif
#ifdef _POSIX_MAPPED_FILES
- // use anonymous mmap() to get the memory
- Base = (unsigned char*) mmap(0, WorkSpace, PROT_READ|PROT_WRITE,
- MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
- if(Base != MAP_FAILED)
- return;
+ if ((Flags & Fallback) != Fallback) {
+ // Set the permissions.
+ int Prot = PROT_READ;
+ int Map = MAP_PRIVATE | MAP_ANONYMOUS;
+ if ((Flags & ReadOnly) != ReadOnly)
+ Prot |= PROT_WRITE;
+ if ((Flags & Public) == Public)
+ Map = MAP_SHARED | MAP_ANONYMOUS;
+
+ // use anonymous mmap() to get the memory
+ Base = (unsigned char*) mmap(0, WorkSpace, Prot, Map, -1, 0);
+
+ if(Base == MAP_FAILED)
+ _error->Errno("DynamicMMap",_("Couldn't make mmap of %lu bytes"),WorkSpace);
+
+ iSize = 0;
+ return;
+ }
#endif
- // fallback to a static allocated space
- Base = new unsigned char[WorkSpace];
- memset(Base,0,WorkSpace);
- iSize = 0;
+ // fallback to a static allocated space
+ Base = new unsigned char[WorkSpace];
+ memset(Base,0,WorkSpace);
+ iSize = 0;
}
/*}}}*/
// DynamicMMap::~DynamicMMap - Destructor /*{{{*/
/*}}}*/
// DynamicMMap::Grow - Grow the mmap /*{{{*/
// ---------------------------------------------------------------------
-/* This method will try to grow the mmap we currently use. This doesn't
- work most of the time because we can't move the mmap around in the
- memory for now as this would require to adjust quite a lot of pointers
- but why we should not at least try to grow it before we give up? */
-bool DynamicMMap::Grow()
-{
-#ifdef _POSIX_MAPPED_FILES
- unsigned long newSize = WorkSpace + 1024*1024;
+/* This method is a wrapper around different methods to (try to) grow
+ a mmap (or our char[]-fallback). Encounterable environments:
+ 1. Moveable + !Fallback + linux -> mremap with MREMAP_MAYMOVE
+ 2. Moveable + !Fallback + !linux -> not possible (forbidden by constructor)
+ 3. Moveable + Fallback -> realloc
+ 4. !Moveable + !Fallback + linux -> mremap alone - which will fail in 99,9%
+ 5. !Moveable + !Fallback + !linux -> not possible (forbidden by constructor)
+ 6. !Moveable + Fallback -> not possible
+ [ While Moveable and Fallback stands for the equally named flags and
+ "linux" indicates a linux kernel instead of a freebsd kernel. ]
+ So what you can see here is, that a MMAP which want to be growable need
+ to be moveable to have a real chance but that this method will at least try
+ the nearly impossible 4 to grow it before it finally give up: Never say never. */
+bool DynamicMMap::Grow() {
+ if (Limit != 0 && WorkSpace >= Limit)
+ return _error->Error(_("Unable to increase the size of the MMap as the "
+ "limit of %lu bytes is already reached."), Limit);
- if(Fd != 0)
- {
- Fd->Seek(newSize - 1);
- char C = 0;
- Fd->Write(&C,sizeof(C));
- }
+ unsigned long const newSize = WorkSpace + 1024*1024;
- Base = mremap(Base, WorkSpace, newSize, 0);
- if(Base == MAP_FAILED)
- return false;
+ if(Fd != 0) {
+ Fd->Seek(newSize - 1);
+ char C = 0;
+ Fd->Write(&C,sizeof(C));
+ }
+ if ((Flags & Fallback) != Fallback) {
+#if defined(_POSIX_MAPPED_FILES) && defined(__linux__)
+ #ifdef MREMAP_MAYMOVE
+ if ((Flags & Moveable) == Moveable)
+ Base = mremap(Base, WorkSpace, newSize, MREMAP_MAYMOVE);
+ else
+ #endif
+ Base = mremap(Base, WorkSpace, newSize, 0);
- WorkSpace = newSize;
- return true;
+ if(Base == MAP_FAILED)
+ return false;
#else
- return false;
+ return false;
#endif
+ } else {
+ if ((Flags & Moveable) != Moveable)
+ return false;
+
+ Base = realloc(Base, newSize);
+ if (Base == NULL)
+ return false;
+ }
+
+ WorkSpace = newSize;
+ return true;
}
/*}}}*/
projects / apt.git / blobdiff