/* -----------------------------------------------------------------------------
*
- * (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 "sm/OSMem.h"
+
+#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>
+#endif
+#ifdef HAVE_STRING_H
+#include <string.h>
+#endif
+#ifdef HAVE_FCNTL_H
+#include <fcntl.h>
+#endif
+
+#include <errno.h>
+
+#if darwin_HOST_OS
+#include <mach/mach.h>
+#include <mach/vm_map.h>
+#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 = 0;
+ 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,
+ 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;
+ StgWord8 *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 * (lnat)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)
{
StgWord size = startOfLastPage - startOfFirstPage + pageSize;
if (mprotect((void*)startOfFirstPage, (size_t)size,
(exec ? PROT_EXEC : 0) | PROT_READ | PROT_WRITE) != 0) {
- barf("makeExecutable: failed to protect 0x%p\n", p);
+ barf("setExecutable: failed to protect 0x%p\n", p);
}
}
projects / ghc-hetmet.git / blobdiff