/* -----------------------------------------------------------------------------
- * $Id: MBlock.c,v 1.5 1999/01/18 09:20:08 sof Exp $
+ *
+ * (c) The GHC Team 1998-1999
*
* MegaBlock Allocator Interface. This file contains all the dirty
* architecture-dependent hackery required to get a chunk of aligned
*
* ---------------------------------------------------------------------------*/
-#define NON_POSIX_SOURCE
+/* This is non-posix compliant. */
+/* #include "PosixSource.h" */
#include "Rts.h"
#include "RtsUtils.h"
#include "MBlock.h"
#include "BlockAlloc.h"
+#ifdef HAVE_STDLIB_H
+#include <stdlib.h>
+#endif
+#ifdef HAVE_STRING_H
+#include <string.h>
+#endif
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
-
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
-
-#ifdef HAVE_SYS_MMAN_H
-#include <sys/mman.h>
+#ifndef mingw32_HOST_OS
+# ifdef HAVE_SYS_MMAN_H
+# include <sys/mman.h>
+# endif
#endif
-
#ifdef HAVE_FCNTL_H
#include <fcntl.h>
#endif
-
-#if cygwin32_TARGET_OS
+#if HAVE_WINDOWS_H
#include <windows.h>
#endif
+#if darwin_HOST_OS
+#include <mach/vm_map.h>
+#endif
-#if freebsd2_TARGET_OS || freebsd3_TARGET_OS
-/* Executable is loaded from 0x0
- * Shared libraries are loaded at 0x2000000
- * Stack is at the top of the address space. The kernel probably owns
- * 0x8000000 onwards, so we'll pick 0x5000000.
- */
-#define ASK_FOR_MEM_AT 0x50000000
+#include <errno.h>
-#elif linux_TARGET_OS
-/* Any ideas?
- */
-#define ASK_FOR_MEM_AT 0x50000000
+lnat mblocks_allocated = 0;
-#elif solaris2_TARGET_OS
-/* guess */
-#define ASK_FOR_MEM_AT 0x50000000
+/* -----------------------------------------------------------------------------
+ The MBlock Map: provides our implementation of HEAP_ALLOCED()
+ -------------------------------------------------------------------------- */
+
+#if SIZEOF_VOID_P == 4
+StgWord8 mblock_map[MBLOCK_MAP_SIZE]; // initially all zeros
+#elif SIZEOF_VOID_P == 8
+static MBlockMap dummy_mblock_map;
+MBlockMap *mblock_cache = &dummy_mblock_map;
+int mblock_map_count = 0;
+MBlockMap **mblock_maps = NULL;
+
+static MBlockMap *
+findMBlockMap(void *p)
+{
+ int i;
+ StgWord32 hi = (StgWord32) (((StgWord)p) >> 32);
+ for( i = 0; i < mblock_map_count; i++ )
+ {
+ if(mblock_maps[i]->addrHigh32 == hi)
+ {
+ return mblock_maps[i];
+ }
+ }
+ return NULL;
+}
-#else
-#error Dont know where to get memory from on this architecture
-/* ToDo: memory locations on other architectures */
+StgBool
+slowIsHeapAlloced(void *p)
+{
+ MBlockMap *map = findMBlockMap(p);
+ if(map)
+ {
+ mblock_cache = map;
+ return map->mblocks[MBLOCK_MAP_ENTRY(p)];
+ }
+ else
+ return 0;
+}
#endif
-lnat mblocks_allocated = 0;
+static void
+markHeapAlloced(void *p)
+{
+#if SIZEOF_VOID_P == 4
+ mblock_map[MBLOCK_MAP_ENTRY(p)] = 1;
+#elif SIZEOF_VOID_P == 8
+ MBlockMap *map = findMBlockMap(p);
+ if(map == NULL)
+ {
+ mblock_map_count++;
+ mblock_maps = realloc(mblock_maps,
+ sizeof(MBlockMap*) * mblock_map_count);
+ map = mblock_maps[mblock_map_count-1] = calloc(1,sizeof(MBlockMap));
+ map->addrHigh32 = (StgWord32) (((StgWord)p) >> 32);
+ }
+ map->mblocks[MBLOCK_MAP_ENTRY(p)] = 1;
+ mblock_cache = map;
+#endif
+}
+
+/* -----------------------------------------------------------------------------
+ Allocate new mblock(s)
+ -------------------------------------------------------------------------- */
void *
getMBlock(void)
return getMBlocks(1);
}
-#ifndef _WIN32
+/* -----------------------------------------------------------------------------
+ The mmap() method
+
+ On Unix-like systems, we use mmap() to allocate our memory. We
+ want memory in chunks of MBLOCK_SIZE, and aligned on an MBLOCK_SIZE
+ boundary. The mmap() interface doesn't give us this level of
+ control, so we have to use some heuristics.
+
+ In the general case, if we want a block of n megablocks, then we
+ allocate n+1 and trim off the slop from either side (using
+ munmap()) to get an aligned chunk of size n. However, the next
+ time we'll try to allocate directly after the previously allocated
+ chunk, on the grounds that this is aligned and likely to be free.
+ If it turns out that we were wrong, we have to munmap() and try
+ again using the general method.
+
+ Note on posix_memalign(): this interface is available on recent
+ systems and appears to provide exactly what we want. However, it
+ turns out not to be as good as our mmap() implementation, because
+ it wastes extra space (using double the address space, in a test on
+ x86_64/Linux). The problem seems to be that posix_memalign()
+ returns memory that can be free()'d, so the library must store
+ extra information along with the allocated block, thus messing up
+ the alignment. Hence, we don't use posix_memalign() for now.
+
+ -------------------------------------------------------------------------- */
+
+#if !defined(mingw32_HOST_OS) && !defined(cygwin32_HOST_OS)
+
+// A wrapper around mmap(), to abstract away from OS differences in
+// the mmap() interface.
+
+static void *
+my_mmap (void *addr, lnat size)
+{
+ void *ret;
+
+#if defined(solaris2_HOST_OS) || defined(irix_HOST_OS)
+ {
+ int fd = open("/dev/zero",O_RDONLY);
+ ret = mmap(addr, size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
+ close(fd);
+ }
+#elif hpux_HOST_OS
+ ret = mmap(addr, size, PROT_READ | PROT_WRITE,
+ MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
+#elif darwin_HOST_OS
+ // Without MAP_FIXED, Apple's mmap ignores addr.
+ // With MAP_FIXED, it overwrites already mapped regions, whic
+ // mmap(0, ... MAP_FIXED ...) is worst of all: It unmaps the program text
+ // and replaces it with zeroes, causing instant death.
+ // This behaviour seems to be conformant with IEEE Std 1003.1-2001.
+ // Let's just use the underlying Mach Microkernel calls directly,
+ // they're much nicer.
+
+ kern_return_t err;
+ ret = addr;
+ if(addr) // try to allocate at adress
+ err = vm_allocate(mach_task_self(),(vm_address_t*) &ret, size, FALSE);
+ if(!addr || err) // try to allocate anywhere
+ err = vm_allocate(mach_task_self(),(vm_address_t*) &ret, size, TRUE);
+
+ if(err) {
+ // don't know what the error codes mean exactly, assume it's
+ // not our problem though.
+ errorBelch("memory allocation failed (requested %lu bytes)", size);
+ stg_exit(EXIT_FAILURE);
+ } else {
+ vm_protect(mach_task_self(),ret,size,FALSE,VM_PROT_READ|VM_PROT_WRITE);
+ }
+#else
+ ret = mmap(addr, size, PROT_READ | PROT_WRITE | PROT_EXEC,
+ MAP_ANON | MAP_PRIVATE, -1, 0);
+#endif
+
+ if (ret == (void *)-1) {
+ if (errno == ENOMEM ||
+ (errno == EINVAL && sizeof(void*)==4 && size >= 0xc0000000)) {
+ // If we request more than 3Gig, then we get EINVAL
+ // instead of ENOMEM (at least on Linux).
+ errorBelch("out of memory (requested %lu bytes)", size);
+ stg_exit(EXIT_FAILURE);
+ } else {
+ barf("getMBlock: mmap: %s", strerror(errno));
+ }
+ }
+
+ return ret;
+}
+
+// Implements the general case: allocate a chunk of memory of 'size'
+// mblocks.
+
+static void *
+gen_map_mblocks (lnat size)
+{
+ int slop;
+ void *ret;
+
+ // Try to map a larger block, and take the aligned portion from
+ // it (unmap the rest).
+ size += MBLOCK_SIZE;
+ ret = my_mmap(0, size);
+
+ // unmap the slop bits around the chunk we allocated
+ slop = (W_)ret & MBLOCK_MASK;
+
+ if (munmap(ret, MBLOCK_SIZE - slop) == -1) {
+ barf("gen_map_mblocks: munmap failed");
+ }
+ if (slop > 0 && munmap(ret+size-slop, slop) == -1) {
+ barf("gen_map_mblocks: munmap failed");
+ }
+
+ // ToDo: if we happened to get an aligned block, then don't
+ // unmap the excess, just use it. For this to work, you
+ // need to keep in mind the following:
+ // * Calling my_mmap() with an 'addr' arg pointing to
+ // already my_mmap()ed space is OK and won't fail.
+ // * If my_mmap() can't satisfy the request at the
+ // given 'next_request' address in getMBlocks(), that
+ // you unmap the extra mblock mmap()ed here (or simply
+ // satisfy yourself that the slop introduced isn't worth
+ // salvaging.)
+ //
+
+ // next time, try after the block we just got.
+ ret += MBLOCK_SIZE - slop;
+ return ret;
+}
+
+
+// The external interface: allocate 'n' mblocks, and return the
+// address.
void *
getMBlocks(nat n)
{
- static caddr_t next_request = (caddr_t)ASK_FOR_MEM_AT;
+ static caddr_t next_request = (caddr_t)HEAP_BASE;
caddr_t ret;
lnat size = MBLOCK_SIZE * n;
+ nat i;
-#ifdef solaris2_TARGET_OS
- {
- int fd = open("/dev/zero",O_RDONLY);
- ret = mmap(next_request, size, PROT_READ | PROT_WRITE,
- MAP_FIXED | MAP_PRIVATE, fd, 0);
- close(fd);
- }
-#else
- ret = mmap(next_request, size, PROT_READ | PROT_WRITE,
- MAP_ANON | MAP_PRIVATE, -1, 0);
+ if (next_request == 0) {
+ // use gen_map_mblocks the first time.
+ ret = gen_map_mblocks(size);
+ } else {
+ ret = my_mmap(next_request, size);
+
+ if (((W_)ret & MBLOCK_MASK) != 0) {
+ // misaligned block!
+#if 0 // defined(DEBUG)
+ errorBelch("warning: getMBlock: misaligned block %p returned when allocating %d megablock(s) at %p", ret, n, next_request);
#endif
-
- if (ret == (void *)-1) {
- if (errno == ENOMEM) {
- barf("getMBlock: out of memory");
- } else {
- barf("GetMBlock: mmap failed");
- }
- }
- if (((W_)ret & MBLOCK_MASK) != 0) {
- barf("GetMBlock: misaligned block returned");
+ // unmap this block...
+ if (munmap(ret, size) == -1) {
+ barf("getMBlock: munmap failed");
+ }
+ // and do it the hard way
+ ret = gen_map_mblocks(size);
+ }
}
- IF_DEBUG(gc,fprintf(stderr,"Allocated %d megablock(s) at %x\n",n,(nat)ret));
+ // Next time, we'll try to allocate right after the block we just got.
+ // ToDo: check that we haven't already grabbed the memory at next_request
+ next_request = ret + size;
- next_request += size;
+ IF_DEBUG(gc,debugBelch("Allocated %d megablock(s) at %p\n",n,ret));
+
+ // fill in the table
+ for (i = 0; i < n; i++) {
+ markHeapAlloced( ret + i * MBLOCK_SIZE );
+ }
mblocks_allocated += n;
-
+
return ret;
}
-#else /* _WIN32 */
+#else /* defined(mingw32_HOST_OS) || defined(cygwin32_HOST_OS) */
/*
On Win32 platforms we make use of the two-phased virtual memory API
to allocate mega blocks. We proceed as follows:
- Reserve a large chunk of VM (128M at the time), but don't supply a
- base address that's aligned on a MB boundary. Instead we round up to the
- nearest from the chunk of VM we're given back from the OS (at the
- moment we just leave the 'slop' at the beginning of the reserved
- chunk unused - ToDo: reuse it .)
+ Reserve a large chunk of VM (256M at the time, or what the user asked
+ for via the -M option), but don't supply a base address that's aligned on
+ a MB boundary. Instead we round up to the nearest mblock from the chunk of
+ VM we're handed back from the OS (at the moment we just leave the 'slop' at
+ the beginning of the reserved chunk unused - ToDo: reuse it .)
Reserving memory doesn't allocate physical storage (not even in the
- page file), this is done by committing pages (or mega-blocks in
+ page file), this is done later on by committing pages (or mega-blocks in
our case).
-
*/
+char* base_non_committed = (char*)0;
+char* end_non_committed = (char*)0;
+
+/* Default is to reserve 256M of VM to minimise the slop cost. */
+#define SIZE_RESERVED_POOL ( 256 * 1024 * 1024 )
+
+/* Number of bytes reserved */
+static unsigned long size_reserved_pool = SIZE_RESERVED_POOL;
+
void *
getMBlocks(nat n)
{
- static char* base_non_committed = (char*)0;
static char* base_mblocks = (char*)0;
static char* next_request = (char*)0;
void* ret = (void*)0;
+ nat i;
lnat size = MBLOCK_SIZE * n;
-
- /* Reserve VM 128M at the time to try to minimise the slop cost. */
-#define SIZE_RESERVED_POOL ( 128 * 1024 * 1024 )
-
- if ( (base_non_committed == 0) ||
- (next_request + size > base_non_committed + SIZE_RESERVED_POOL) ) {
+
+ if ( (base_non_committed == 0) || (next_request + size > end_non_committed) ) {
+ if (base_non_committed) {
+ /* Tacky, but if no user-provided -M option is in effect,
+ * set it to the default (==256M) in time for the heap overflow PSA.
+ */
+ if (RtsFlags.GcFlags.maxHeapSize == 0) {
+ RtsFlags.GcFlags.maxHeapSize = size_reserved_pool / BLOCK_SIZE;
+ }
+ heapOverflow();
+ }
+ if (RtsFlags.GcFlags.maxHeapSize != 0) {
+ size_reserved_pool = BLOCK_SIZE * RtsFlags.GcFlags.maxHeapSize;
+ if (size_reserved_pool < MBLOCK_SIZE) {
+ size_reserved_pool = 2*MBLOCK_SIZE;
+ }
+ }
base_non_committed = VirtualAlloc ( NULL
- , SIZE_RESERVED_POOL
+ , size_reserved_pool
, MEM_RESERVE
, PAGE_READWRITE
);
if ( base_non_committed == 0 ) {
-# ifdef DEBUG
- fprintf(stderr, "getMBlocks: VirtualAlloc failed with: %d\n", GetLastError());
-# endif
+ errorBelch("getMBlocks: VirtualAlloc failed with: %ld\n", GetLastError());
ret=(void*)-1;
} else {
- /* The returned pointer is not aligned on a mega-block boundary. Make it. */
- base_mblocks = (char*)((unsigned)base_non_committed & (unsigned)0xfff00000) + 0x100000;
-# if 0
- fprintf(stderr, "Dropping %d bytes off of 128M chunk\n",
- (unsigned)base_mblocks - (unsigned)base_non_committed);
-# endif
-
- if ( ((char*)base_mblocks + size) > ((char*)base_non_committed + SIZE_RESERVED_POOL) ) {
-# ifdef DEBUG
- fprintf(stderr, "oops, committed too small a region to start with.");
-# endif
+ end_non_committed = (char*)base_non_committed + (unsigned long)size_reserved_pool;
+ /* The returned pointer is not aligned on a mega-block boundary. Make it. */
+ base_mblocks = (char*)((unsigned long)base_non_committed & (unsigned long)~MBLOCK_MASK) + MBLOCK_SIZE;
+# if 0
+ debugBelch("getMBlocks: Dropping %d bytes off of 256M chunk\n",
+ (unsigned)base_mblocks - (unsigned)base_non_committed);
+# endif
+
+ if ( ((char*)base_mblocks + size) > end_non_committed ) {
+ debugBelch("getMBlocks: oops, committed too small a region to start with.");
ret=(void*)-1;
} else {
next_request = base_mblocks;
if ( ret != (void*)-1 ) {
ret = VirtualAlloc(next_request, size, MEM_COMMIT, PAGE_READWRITE);
if (ret == NULL) {
-# ifdef DEBUG
- fprintf(stderr, "getMBlocks: VirtualAlloc failed with: %d\n", GetLastError());
-# endif
+ debugBelch("getMBlocks: VirtualAlloc failed with: %ld\n", GetLastError());
ret=(void*)-1;
}
}
if (((W_)ret & MBLOCK_MASK) != 0) {
- barf("GetMBlock: misaligned block returned");
+ barf("getMBlocks: misaligned block returned");
}
- IF_DEBUG(gc,fprintf(stderr,"Allocated %d megablock(s) at %x\n",n,(nat)ret));
+ if (ret == (void*)-1) {
+ barf("getMBlocks: unknown memory allocation failure on Win32.");
+ }
+ IF_DEBUG(gc,debugBelch("Allocated %d megablock(s) at 0x%x\n",n,(nat)ret));
next_request = (char*)next_request + size;
mblocks_allocated += n;
+ // fill in the table
+ for (i = 0; i < n; i++) {
+ markHeapAlloced( ret + i * MBLOCK_SIZE );
+ }
+
return ret;
}
rc = VirtualFree(p, n * MBLOCK_SIZE , MEM_DECOMMIT );
if (rc == FALSE) {
-# ifdef DEBUG
- fprintf(stderr, "freeMBlocks: VirtualFree failed with: %d\n", GetLastError());
-# endif
+# ifdef DEBUG
+ debugBelch("freeMBlocks: VirtualFree failed with: %d\n", GetLastError());
+# endif
}
}