mirror of https://github.com/postgres/postgres
Uses same underlying tech as before, but not the sysv emulation layer.REL8_3_STABLE
Magnus Hagander
19 years ago
parent
3b765dba78
commit
18d82d03b5
@ -1,128 +0,0 @@ |
||||
/*-------------------------------------------------------------------------
|
||||
* |
||||
* shmem.c |
||||
* Microsoft Windows Win32 Shared Memory Emulation |
||||
* |
||||
* Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group |
||||
* |
||||
* IDENTIFICATION |
||||
* $PostgreSQL: pgsql/src/backend/port/win32/shmem.c,v 1.14 2007/01/05 22:19:35 momjian Exp $ |
||||
* |
||||
*------------------------------------------------------------------------- |
||||
*/ |
||||
|
||||
#include "postgres.h" |
||||
|
||||
static DWORD s_segsize = 0; |
||||
|
||||
/* Detach from a shared mem area based on its address */ |
||||
int |
||||
shmdt(const void *shmaddr) |
||||
{ |
||||
if (UnmapViewOfFile((LPCVOID *) shmaddr)) |
||||
return 0; |
||||
else |
||||
return -1; |
||||
} |
||||
|
||||
/* Attach to an existing area */ |
||||
void * |
||||
shmat(int memId, void *shmaddr, int flag) |
||||
{ |
||||
/* TODO -- shmat needs to count # attached to shared mem */ |
||||
void *lpmem = MapViewOfFileEx((HANDLE) memId, |
||||
FILE_MAP_WRITE | FILE_MAP_READ, |
||||
0, 0, /* (DWORD)pshmdsc->segsize */ 0 /* s_segsize */ , shmaddr); |
||||
|
||||
if (lpmem == NULL) |
||||
{ |
||||
lpmem = (void *) -1; |
||||
_dosmaperr(GetLastError()); |
||||
} |
||||
|
||||
return lpmem; |
||||
} |
||||
|
||||
/* Control a shared mem area */ |
||||
int |
||||
shmctl(int shmid, int flag, struct shmid_ds * dummy) |
||||
{ |
||||
if (flag == IPC_RMID) |
||||
{ |
||||
/* Delete the area */ |
||||
CloseHandle((HANDLE) shmid); |
||||
return 0; |
||||
} |
||||
if (flag == IPC_STAT) |
||||
{ |
||||
/* Can only test for if exists */ |
||||
int hmap = shmget(shmid, 0, 0); |
||||
|
||||
if (hmap < 0) |
||||
{ |
||||
/* Shared memory does not exist */ |
||||
errno = EINVAL; |
||||
return -1; |
||||
} |
||||
else |
||||
{ |
||||
/* Shared memory does exist and must be in use */ |
||||
shmctl(hmap, IPC_RMID, NULL); /* Release our hold on it */ |
||||
errno = 0; |
||||
return 0; |
||||
} |
||||
} |
||||
|
||||
errno = EINVAL; |
||||
return -1; |
||||
} |
||||
|
||||
/* Get an area based on the IPC key */ |
||||
int |
||||
shmget(int memKey, int size, int flag) |
||||
{ |
||||
HANDLE hmap; |
||||
char szShareMem[32]; |
||||
DWORD dwRet; |
||||
|
||||
s_segsize = size; |
||||
sprintf(szShareMem, "PostgreSQL.%d", memKey); |
||||
|
||||
if (flag & IPC_CREAT) |
||||
{ |
||||
hmap = CreateFileMapping((HANDLE) 0xFFFFFFFF, /* Use the swap file */ |
||||
NULL, |
||||
PAGE_READWRITE, /* Memory is Read/Write */ |
||||
0L, /* Size Upper 32 Bits */ |
||||
(DWORD) s_segsize, /* Size Lower 32 bits */ |
||||
szShareMem); |
||||
} |
||||
else |
||||
{ |
||||
hmap = OpenFileMapping(FILE_MAP_ALL_ACCESS, |
||||
FALSE, |
||||
szShareMem); |
||||
if (!hmap) |
||||
{ |
||||
errno = ENOENT; |
||||
return -1; |
||||
} |
||||
} |
||||
|
||||
dwRet = GetLastError(); |
||||
if (dwRet == ERROR_ALREADY_EXISTS && hmap && (flag & (IPC_CREAT | IPC_EXCL))) |
||||
{ |
||||
/* Caller wanted to create the segment -- error if already exists */ |
||||
CloseHandle(hmap); |
||||
errno = EEXIST; |
||||
return -1; |
||||
} |
||||
else if (!hmap) |
||||
{ |
||||
/* Unable to get shared memory */ |
||||
_dosmaperr(GetLastError()); |
||||
return -1; |
||||
} |
||||
|
||||
return (int) hmap; |
||||
} |
||||
@ -0,0 +1,287 @@ |
||||
/*-------------------------------------------------------------------------
|
||||
* |
||||
* win32_shmem.c |
||||
* Implement shared memory using win32 facilities |
||||
* |
||||
* Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group |
||||
* |
||||
* IDENTIFICATION |
||||
* $PostgreSQL: pgsql/src/backend/port/win32_shmem.c,v 1.1 2007/03/21 14:39:23 mha Exp $ |
||||
* |
||||
*------------------------------------------------------------------------- |
||||
*/ |
||||
#include "postgres.h" |
||||
|
||||
#include "miscadmin.h" |
||||
#include "storage/ipc.h" |
||||
#include "storage/pg_shmem.h" |
||||
|
||||
unsigned long UsedShmemSegID = 0; |
||||
void *UsedShmemSegAddr = NULL; |
||||
|
||||
static void pgwin32_SharedMemoryDelete(int status, Datum shmId); |
||||
|
||||
/*
|
||||
* Generate shared memory segment name. Expand the data directory, to generate |
||||
* an identifier unique for this data directory. Then replace all backslashes |
||||
* with forward slashes, since backslashes aren't permitted in global object names. |
||||
* |
||||
* Store the shared memory segment in the Global\ namespace (requires NT2 TSE or |
||||
* 2000, but that's all we support for other reasons as well), to make sure you can't |
||||
* open two postmasters in different sessions against the same data directory. |
||||
* |
||||
* XXX: What happens with junctions? It's only someone breaking things on purpose, |
||||
* and this is still better than before, but we might want to do something about |
||||
* that sometime in the future. |
||||
*/ |
||||
static char * |
||||
GetSharedMemName(void) |
||||
{ |
||||
char *retptr; |
||||
DWORD bufsize; |
||||
DWORD r; |
||||
char *cp; |
||||
|
||||
bufsize = GetFullPathName(DataDir, 0, NULL, NULL); |
||||
if (bufsize == 0) |
||||
elog(FATAL, "could not get size for full pathname of datadir %s: %lu", |
||||
DataDir, GetLastError()); |
||||
|
||||
retptr = malloc(bufsize + 1 + 18); /* 1 NULL and 18 for
|
||||
* Global\PostgreSQL: */ |
||||
if (retptr == NULL) |
||||
elog(FATAL, "could not allocate memory for shared memory name"); |
||||
|
||||
strcpy(retptr, "Global\\PostgreSQL:"); |
||||
r = GetFullPathName(DataDir, bufsize, retptr + 11, NULL); |
||||
if (r == 0 || r > bufsize) |
||||
elog(FATAL, "could not generate full pathname for datadir %s: %lu", |
||||
DataDir, GetLastError()); |
||||
|
||||
for (cp = retptr; *cp; cp++) |
||||
if (*cp == '\\') |
||||
*cp = '/'; |
||||
|
||||
return retptr; |
||||
} |
||||
|
||||
|
||||
/*
|
||||
* PGSharedMemoryIsInUse |
||||
* |
||||
* Is a previously-existing shmem segment still existing and in use? |
||||
* |
||||
* The point of this exercise is to detect the case where a prior postmaster |
||||
* crashed, but it left child backends that are still running. Therefore |
||||
* we only care about shmem segments that are associated with the intended |
||||
* DataDir. This is an important consideration since accidental matches of |
||||
* shmem segment IDs are reasonably common. |
||||
* |
||||
*/ |
||||
bool |
||||
PGSharedMemoryIsInUse(unsigned long id1, unsigned long id2) |
||||
{ |
||||
char *szShareMem; |
||||
HANDLE hmap; |
||||
|
||||
szShareMem = GetSharedMemName(); |
||||
|
||||
hmap = OpenFileMapping(FILE_MAP_READ, FALSE, szShareMem); |
||||
|
||||
free(szShareMem); |
||||
|
||||
if (hmap == NULL) |
||||
return false; |
||||
|
||||
CloseHandle(hmap); |
||||
return true; |
||||
} |
||||
|
||||
|
||||
/*
|
||||
* PGSharedMemoryCreate |
||||
* |
||||
* Create a shared memory segment of the given size and initialize its |
||||
* standard header. |
||||
* |
||||
* makePrivate means to always create a new segment, rather than attach to |
||||
* or recycle any existing segment. On win32, we always create a new segment, |
||||
* since there is no need for recycling (segments go away automatically |
||||
* when the last backend exits) |
||||
* |
||||
*/ |
||||
PGShmemHeader * |
||||
PGSharedMemoryCreate(Size size, bool makePrivate, int port) |
||||
{ |
||||
void *memAddress; |
||||
PGShmemHeader *hdr; |
||||
HANDLE hmap, |
||||
hmap2; |
||||
char *szShareMem; |
||||
|
||||
/* Room for a header? */ |
||||
Assert(size > MAXALIGN(sizeof(PGShmemHeader))); |
||||
|
||||
szShareMem = GetSharedMemName(); |
||||
|
||||
UsedShmemSegAddr = NULL; |
||||
|
||||
hmap = CreateFileMapping((HANDLE) 0xFFFFFFFF, /* Use the pagefile */ |
||||
NULL, /* Default security attrs */ |
||||
PAGE_READWRITE, /* Memory is Read/Write */ |
||||
0L, /* Size Upper 32 Bits */ |
||||
(DWORD) size, /* Size Lower 32 bits */ |
||||
szShareMem); |
||||
|
||||
if (!hmap) |
||||
ereport(FATAL, |
||||
(errmsg("could not create shared memory segment: %lu", GetLastError()), |
||||
errdetail("Failed system call was CreateFileMapping(size=%lu, name=%s)", size, szShareMem))); |
||||
|
||||
/*
|
||||
* If the segment already existed, CreateFileMapping() will return a |
||||
* handle to the existing one. |
||||
*/ |
||||
if (GetLastError() == ERROR_ALREADY_EXISTS) |
||||
{ |
||||
/*
|
||||
* When recycling a shared memory segment, it may take a short while |
||||
* before it gets dropped from the global namespace. So re-try after |
||||
* sleeping for a second. |
||||
*/ |
||||
CloseHandle(hmap); /* Close the old handle, since we got a valid
|
||||
* one to the previous segment. */ |
||||
|
||||
Sleep(1000); |
||||
|
||||
hmap = CreateFileMapping((HANDLE) 0xFFFFFFFF, NULL, PAGE_READWRITE, 0L, (DWORD) size, szShareMem); |
||||
if (!hmap) |
||||
ereport(FATAL, |
||||
(errmsg("could not create shared memory segment: %lu", GetLastError()), |
||||
errdetail("Failed system call was CreateFileMapping(size=%lu, name=%s)", size, szShareMem))); |
||||
|
||||
if (GetLastError() == ERROR_ALREADY_EXISTS) |
||||
ereport(FATAL, |
||||
(errmsg("pre-existing shared memory block is still in use"), |
||||
errhint("Check if there are any old server processes still running, and terminate them."))); |
||||
} |
||||
|
||||
free(szShareMem); |
||||
|
||||
/*
|
||||
* Make the handle inheritable |
||||
*/ |
||||
if (!DuplicateHandle(GetCurrentProcess(), hmap, GetCurrentProcess(), &hmap2, 0, TRUE, DUPLICATE_SAME_ACCESS)) |
||||
ereport(FATAL, |
||||
(errmsg("could not create shared memory segment: %lu", GetLastError()), |
||||
errdetail("Failed system call was DuplicateHandle"))); |
||||
|
||||
/*
|
||||
* Close the old, non-inheritable handle. If this fails we don't really |
||||
* care. |
||||
*/ |
||||
if (!CloseHandle(hmap)) |
||||
elog(LOG, "could not close handle to shared memory: %lu", GetLastError()); |
||||
|
||||
|
||||
/* Register on-exit routine to delete the new segment */ |
||||
on_shmem_exit(pgwin32_SharedMemoryDelete, Int32GetDatum((unsigned long) hmap2)); |
||||
|
||||
/*
|
||||
* Get a pointer to the new shared memory segment. Map the whole segment |
||||
* at once, and let the system decide on the initial address. |
||||
*/ |
||||
memAddress = MapViewOfFileEx(hmap2, FILE_MAP_WRITE | FILE_MAP_READ, 0, 0, 0, NULL); |
||||
if (!memAddress) |
||||
ereport(FATAL, |
||||
(errmsg("could not create shared memory segment: %lu", GetLastError()), |
||||
errdetail("Failed system call was MapViewOfFileEx"))); |
||||
|
||||
|
||||
|
||||
/*
|
||||
* OK, we created a new segment. Mark it as created by this process. The |
||||
* order of assignments here is critical so that another Postgres process |
||||
* can't see the header as valid but belonging to an invalid PID! |
||||
*/ |
||||
hdr = (PGShmemHeader *) memAddress; |
||||
hdr->creatorPID = getpid(); |
||||
hdr->magic = PGShmemMagic; |
||||
|
||||
/*
|
||||
* Initialize space allocation status for segment. |
||||
*/ |
||||
hdr->totalsize = size; |
||||
hdr->freeoffset = MAXALIGN(sizeof(PGShmemHeader)); |
||||
|
||||
/* Save info for possible future use */ |
||||
UsedShmemSegAddr = memAddress; |
||||
UsedShmemSegID = (unsigned long) hmap2; |
||||
|
||||
return hdr; |
||||
} |
||||
|
||||
/*
|
||||
* PGSharedMemoryReAttach |
||||
* |
||||
* Re-attach to an already existing shared memory segment. Use the |
||||
* handle inherited from the postmaster. |
||||
* |
||||
* UsedShmemSegID and UsedShmemSegAddr are implicit parameters to this |
||||
* routine. The caller must have already restored them to the postmaster's |
||||
* values. |
||||
*/ |
||||
void |
||||
PGSharedMemoryReAttach(void) |
||||
{ |
||||
PGShmemHeader *hdr; |
||||
void *origUsedShmemSegAddr = UsedShmemSegAddr; |
||||
|
||||
Assert(UsedShmemSegAddr != NULL); |
||||
Assert(IsUnderPostmaster); |
||||
|
||||
hdr = (PGShmemHeader *) MapViewOfFileEx((HANDLE) UsedShmemSegID, FILE_MAP_READ | FILE_MAP_WRITE, 0, 0, 0, UsedShmemSegAddr); |
||||
if (!hdr) |
||||
elog(FATAL, "could not reattach to shared memory (key=%d, addr=%p): %lu", |
||||
(int) UsedShmemSegID, UsedShmemSegAddr, GetLastError()); |
||||
if (hdr != origUsedShmemSegAddr) |
||||
elog(FATAL, "reattaching to shared memory returned unexpected address (got %p, expected %p)", |
||||
hdr, origUsedShmemSegAddr); |
||||
if (hdr->magic != PGShmemMagic) |
||||
elog(FATAL, "reattaching to shared memory returned non-PostgreSQL memory"); |
||||
|
||||
UsedShmemSegAddr = hdr; /* probably redundant */ |
||||
} |
||||
|
||||
/*
|
||||
* PGSharedMemoryDetach |
||||
* |
||||
* Detach from the shared memory segment, if still attached. This is not |
||||
* intended for use by the process that originally created the segment. Rather, |
||||
* this is for subprocesses that have inherited an attachment and want to |
||||
* get rid of it. |
||||
*/ |
||||
void |
||||
PGSharedMemoryDetach(void) |
||||
{ |
||||
if (UsedShmemSegAddr != NULL) |
||||
{ |
||||
if (!UnmapViewOfFile(UsedShmemSegAddr)) |
||||
elog(LOG, "could not unmap view of shared memory: %lu", GetLastError()); |
||||
|
||||
UsedShmemSegAddr = NULL; |
||||
} |
||||
} |
||||
|
||||
|
||||
/*
|
||||
* pgwin32_SharedMemoryDelete(status, shmId) deletes a shared memory segment |
||||
* (called as an on_shmem_exit callback, hence funny argument list) |
||||
*/ |
||||
static void |
||||
pgwin32_SharedMemoryDelete(int status, Datum shmId) |
||||
{ |
||||
PGSharedMemoryDetach(); |
||||
if (!CloseHandle((HANDLE) DatumGetInt32(shmId))) |
||||
elog(LOG, "could not close handle to shared memory: %lu", GetLastError()); |
||||
} |
||||
Loading…
Reference in new issue