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Diffstat (limited to 'rts/sm/MBlock.c')
| -rw-r--r-- | rts/sm/MBlock.c | 527 |
1 files changed, 527 insertions, 0 deletions
diff --git a/rts/sm/MBlock.c b/rts/sm/MBlock.c new file mode 100644 index 0000000000..85fe02da6e --- /dev/null +++ b/rts/sm/MBlock.c @@ -0,0 +1,527 @@ +/* ----------------------------------------------------------------------------- + * + * (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 + * memory from the operating system. + * + * ---------------------------------------------------------------------------*/ + +/* This is non-posix compliant. */ +/* #include "PosixSource.h" */ + +#include "Rts.h" +#include "RtsUtils.h" +#include "RtsFlags.h" +#include "MBlock.h" +#include "BlockAlloc.h" +#include "Trace.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 +#ifndef mingw32_HOST_OS +# ifdef HAVE_SYS_MMAN_H +# include <sys/mman.h> +# endif +#endif +#ifdef HAVE_FCNTL_H +#include <fcntl.h> +#endif +#if HAVE_WINDOWS_H +#include <windows.h> +#endif +#if darwin_HOST_OS +#include <mach/vm_map.h> +#endif + +#include <errno.h> + +lnat mblocks_allocated = 0; + +/* ----------------------------------------------------------------------------- + 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; +} + +StgBool +slowIsHeapAlloced(void *p) +{ + MBlockMap *map = findMBlockMap(p); + if(map) + { + mblock_cache = map; + return map->mblocks[MBLOCK_MAP_ENTRY(p)]; + } + else + return 0; +} +#endif + +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); +} + +/* ----------------------------------------------------------------------------- + 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)HEAP_BASE; + caddr_t ret; + lnat size = MBLOCK_SIZE * n; + nat i; + + 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 + + // unmap this block... + if (munmap(ret, size) == -1) { + barf("getMBlock: munmap failed"); + } + // and do it the hard way + ret = gen_map_mblocks(size); + } + } + + // 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; + + debugTrace(DEBUG_gc, "allocated %d megablock(s) at %p",n,ret); + + // fill in the table + for (i = 0; i < n; i++) { + markHeapAlloced( ret + i * MBLOCK_SIZE ); + } + + mblocks_allocated += n; + + return ret; +} + +void +freeAllMBlocks(void) +{ + /* XXX Do something here */ +} + +#else /* defined(mingw32_HOST_OS) || defined(cygwin32_HOST_OS) */ + +/* alloc_rec keeps the info we need to have matching VirtualAlloc and + VirtualFree calls. +*/ +typedef struct alloc_rec_ { + char* base; /* non-aligned base address, directly from VirtualAlloc */ + int size; /* Size in bytes */ + struct alloc_rec_* next; +} alloc_rec; + +typedef struct block_rec_ { + char* base; /* base address, non-MBLOCK-aligned */ + int size; /* size in bytes */ + struct block_rec_* next; +} block_rec; + +static alloc_rec* allocs = 0; +static block_rec* free_blocks = 0; + +static +alloc_rec* +allocNew(nat n) { + alloc_rec* rec; + rec = (alloc_rec*)stgMallocBytes(sizeof(alloc_rec),"getMBlocks: allocNew"); + rec->size = (n+1)*MBLOCK_SIZE; + rec->base = + VirtualAlloc(NULL, rec->size, MEM_RESERVE, PAGE_READWRITE); + if(rec->base==0) { + stgFree((void*)rec); + rec=0; + sysErrorBelch( + "getMBlocks: VirtualAlloc MEM_RESERVE %d blocks failed", n); + } else { + alloc_rec temp; + temp.base=0; temp.size=0; temp.next=allocs; + + alloc_rec* it; + it=&temp; + for(; it->next!=0 && it->next->base<rec->base; it=it->next) ; + rec->next=it->next; + it->next=rec; + + allocs=temp.next; + debugTrace(DEBUG_gc, "allocated %d megablock(s) at 0x%x",n,(nat)rec->base); + } + return rec; +} + +static +void +insertFree(char* alloc_base, int alloc_size) { + block_rec temp; + block_rec* it; + block_rec* prev; + + temp.base=0; temp.size=0; temp.next=free_blocks; + it = free_blocks; + prev = &temp; + for( ; it!=0 && it->base<alloc_base; prev=it, it=it->next) {} + + if(it!=0 && alloc_base+alloc_size == it->base) { + if(prev->base + prev->size == alloc_base) { /* Merge it, alloc, prev */ + prev->size += alloc_size + it->size; + prev->next = it->next; + stgFree(it); + } else { /* Merge it, alloc */ + it->base = alloc_base; + it->size += alloc_size; + } + } else if(prev->base + prev->size == alloc_base) { /* Merge alloc, prev */ + prev->size += alloc_size; + } else { /* Merge none */ + block_rec* rec; + rec = (block_rec*)stgMallocBytes(sizeof(block_rec),"getMBlocks: insertFree"); + rec->base=alloc_base; + rec->size=alloc_size; + rec->next = it; + prev->next=rec; + } + free_blocks=temp.next; +} + +static +void* +findFreeBlocks(nat n) { + void* ret=0; + block_rec* it; + block_rec temp; + block_rec* prev; + + int required_size; + it=free_blocks; + required_size = n*MBLOCK_SIZE; + temp.next=free_blocks; temp.base=0; temp.size=0; + prev=&temp; + /* TODO: Don't just take first block, find smallest sufficient block */ + for( ; it!=0 && it->size<required_size; prev=it, it=it->next ) {} + if(it!=0) { + if( (((unsigned long)it->base) & MBLOCK_MASK) == 0) { /* MBlock aligned */ + ret = (void*)it->base; + if(it->size==required_size) { + prev->next=it->next; + stgFree(it); + } else { + it->base += required_size; + it->size -=required_size; + } + } else { + char* need_base; + block_rec* next; + int new_size; + need_base = (char*)(((unsigned long)it->base) & ((unsigned long)~MBLOCK_MASK)) + MBLOCK_SIZE; + next = (block_rec*)stgMallocBytes( + sizeof(block_rec) + , "getMBlocks: findFreeBlocks: splitting"); + new_size = need_base - it->base; + next->base = need_base +required_size; + next->size = it->size - (new_size+required_size); + it->size = new_size; + next->next = it->next; + it->next = next; + ret=(void*)need_base; + } + } + free_blocks=temp.next; + return ret; +} + +/* VirtualAlloc MEM_COMMIT can't cross boundaries of VirtualAlloc MEM_RESERVE, + so we might need to do many VirtualAlloc MEM_COMMITs. We simply walk the + (ordered) allocated blocks. */ +static void +commitBlocks(char* base, int size) { + alloc_rec* it; + it=allocs; + for( ; it!=0 && (it->base+it->size)<=base; it=it->next ) {} + for( ; it!=0 && size>0; it=it->next ) { + int size_delta; + void* temp; + size_delta = it->size - (base-it->base); + if(size_delta>size) size_delta=size; + temp = VirtualAlloc(base, size_delta, MEM_COMMIT, PAGE_READWRITE); + if(temp==0) { + sysErrorBelch("getMBlocks: VirtualAlloc MEM_COMMIT failed"); + stg_exit(EXIT_FAILURE); + } + size-=size_delta; + base+=size_delta; + } +} + +void * +getMBlocks(nat n) { + void* ret; + ret = findFreeBlocks(n); + if(ret==0) { + alloc_rec* alloc; + alloc = allocNew(n); + /* We already belch in allocNew if it fails */ + if (alloc == 0) { + stg_exit(EXIT_FAILURE); + } else { + insertFree(alloc->base, alloc->size); + ret = findFreeBlocks(n); + } + } + + if(ret!=0) { + /* (In)sanity tests */ + if (((W_)ret & MBLOCK_MASK) != 0) { + barf("getMBlocks: misaligned block returned"); + } + + commitBlocks(ret, MBLOCK_SIZE*n); + + /* Global bookkeeping */ + mblocks_allocated += n; + int i; + for(i=0; i<(int)n; ++i) { + markHeapAlloced( ret + i * MBLOCK_SIZE ); + } + } + + return ret; +} + +void +freeAllMBlocks(void) +{ + { + block_rec* next; + block_rec* it; + next=0; + it = free_blocks; + for(; it!=0; ) { + next = it->next; + stgFree(it); + it=next; + } + } + { + alloc_rec* next; + alloc_rec* it; + next=0; + it=allocs; + for(; it!=0; ) { + if(!VirtualFree((void*)it->base, 0, MEM_RELEASE)) { + sysErrorBelch("freeAllMBlocks: VirtualFree MEM_RELEASE failed"); + stg_exit(EXIT_FAILURE); + } + next = it->next; + stgFree(it); + it=next; + } + } +} + +#endif |