From 016bac72c041e8589ece82fe86906fc9cf8f950c Mon Sep 17 00:00:00 2001 From: Simon Marlow Date: Wed, 17 Oct 2007 13:41:45 +0000 Subject: [PATCH] Refactoring: extract platform-specific code from sm/MBlock.c Also common-up some duplicate bits in the platform-specific code --- rts/posix/OSMem.c | 197 ++++++++++++++++++++++- rts/sm/MBlock.c | 448 ++--------------------------------------------------- rts/sm/OSMem.h | 5 +- rts/win32/OSMem.c | 229 ++++++++++++++++++++++++++- 4 files changed, 442 insertions(+), 437 deletions(-) diff --git a/rts/posix/OSMem.c b/rts/posix/OSMem.c index 12cb43d..9e6e62b 100644 --- a/rts/posix/OSMem.c +++ b/rts/posix/OSMem.c @@ -1,17 +1,212 @@ /* ----------------------------------------------------------------------------- * - * (c) The University of Glasgow 2006 + * (c) The University of Glasgow 2006-2007 * * OS-specific memory management * * ---------------------------------------------------------------------------*/ +/* This is non-posix compliant. */ +/* #include "PosixSource.h" */ + #include "Rts.h" #include "OSMem.h" +#include "RtsFlags.h" +#ifdef HAVE_UNISTD_H #include +#endif +#ifdef HAVE_SYS_TYPES_H #include +#endif +#ifdef HAVE_SYS_MMAN_H #include +#endif +#ifdef HAVE_STRING_H +#include +#endif + +#include + +#if darwin_HOST_OS +#include +#include +#endif + +static caddr_t next_request = 0; + +void osMemInit(void) +{ + next_request = (caddr_t)RtsFlags.GcFlags.heapBase; +} + +/* ----------------------------------------------------------------------------- + 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. + + -------------------------------------------------------------------------- */ + +// 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(),(vm_address_t)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; +} + +void * +osGetMBlocks(nat n) +{ + caddr_t ret; + lnat size = MBLOCK_SIZE * n; + + 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; + + return ret; +} + +void osFreeAllMBlocks(void) +{ + /* XXX Do something here (bug #711) */ +} lnat getPageSize (void) { diff --git a/rts/sm/MBlock.c b/rts/sm/MBlock.c index 1b98734..901ad69 100644 --- a/rts/sm/MBlock.c +++ b/rts/sm/MBlock.c @@ -1,6 +1,6 @@ /* ----------------------------------------------------------------------------- * - * (c) The GHC Team 1998-1999 + * (c) The GHC Team 1998-2007 * * MegaBlock Allocator Interface. This file contains all the dirty * architecture-dependent hackery required to get a chunk of aligned @@ -8,58 +8,21 @@ * * ---------------------------------------------------------------------------*/ -/* This is non-posix compliant. */ -/* #include "PosixSource.h" */ +#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 -#endif -#ifdef HAVE_STRING_H -#include -#endif -#ifdef HAVE_UNISTD_H -#include -#endif -#ifdef HAVE_SYS_TYPES_H -#include -#endif -#ifndef mingw32_HOST_OS -# ifdef HAVE_SYS_MMAN_H -# include -# endif -#endif -#ifdef HAVE_FCNTL_H -#include -#endif -#if HAVE_WINDOWS_H -#include -#endif -#if darwin_HOST_OS -#include -#include -#endif - -#include +#include "OSMem.h" lnat mblocks_allocated = 0; -#if !defined(mingw32_HOST_OS) && !defined(cygwin32_HOST_OS) -static caddr_t next_request = 0; -#endif - void initMBlocks(void) { -#if !defined(mingw32_HOST_OS) && !defined(cygwin32_HOST_OS) - next_request = (caddr_t)RtsFlags.GcFlags.heapBase; -#endif + osMemInit(); } /* ----------------------------------------------------------------------------- @@ -133,379 +96,25 @@ 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(),(vm_address_t)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) { - 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; - if (GetLastError() == ERROR_NOT_ENOUGH_MEMORY) { - - errorBelch("out of memory"); - } else { - 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->basebase; 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->basenext) {} - - 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->sizenext ) {} - 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"); - } + nat i; + void *ret; - commitBlocks(ret, MBLOCK_SIZE*n); + ret = osGetMBlocks(n); - /* Global bookkeeping */ - mblocks_allocated += n; - int i; - for(i=0; i<(int)n; ++i) { - markHeapAlloced( ret + i * MBLOCK_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; } @@ -513,32 +122,5 @@ getMBlocks(nat n) { 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; - } - } + osFreeAllMBlocks(); } - -#endif diff --git a/rts/sm/OSMem.h b/rts/sm/OSMem.h index 417f106..d5b09a1 100644 --- a/rts/sm/OSMem.h +++ b/rts/sm/OSMem.h @@ -1,10 +1,13 @@ /* ----------------------------------------------------------------------------- * - * (c) The University of Glasgow 2006 + * (c) The University of Glasgow 2006-2007 * * OS-specific memory management * * ---------------------------------------------------------------------------*/ +void osMemInit(void); +void *osGetMBlocks(nat n); +void osFreeAllMBlocks(void); lnat getPageSize (void); void setExecutable (void *p, lnat len, rtsBool exec); diff --git a/rts/win32/OSMem.c b/rts/win32/OSMem.c index cdecf02..f4c1264 100644 --- a/rts/win32/OSMem.c +++ b/rts/win32/OSMem.c @@ -1,14 +1,239 @@ /* ----------------------------------------------------------------------------- * - * (c) The University of Glasgow 2006 + * (c) The University of Glasgow 2006-2007 * * OS-specific memory management * * ---------------------------------------------------------------------------*/ -#include #include "Rts.h" #include "OSMem.h" +#include "RtsUtils.h" +#include "RtsMessages.h" + +#if HAVE_WINDOWS_H +#include +#endif + +/* 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 = NULL; +static block_rec* free_blocks = NULL; + +void +osMemInit(void) +{ + allocs = NULL; + free_blocks = NULL; +} + +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; + if (GetLastError() == ERROR_NOT_ENOUGH_MEMORY) { + + errorBelch("out of memory"); + } else { + 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->basebase; it=it->next) ; + rec->next=it->next; + it->next=rec; + + allocs=temp.next; + } + 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->basenext) {} + + 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->sizenext ) {} + 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 * +osGetMBlocks(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); + } + + return ret; +} + +void +osFreeAllMBlocks(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; + } + } +} lnat getPageSize (void) { -- 1.7.10.4