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Diffstat (limited to 'libitm/config/posix/cachepage.cc')
| -rw-r--r-- | libitm/config/posix/cachepage.cc | 183 |
1 files changed, 183 insertions, 0 deletions
diff --git a/libitm/config/posix/cachepage.cc b/libitm/config/posix/cachepage.cc new file mode 100644 index 00000000000..128cd5435ae --- /dev/null +++ b/libitm/config/posix/cachepage.cc @@ -0,0 +1,183 @@ +/* Copyright (C) 2009, 2011 Free Software Foundation, Inc. + Contributed by Richard Henderson <rth@redhat.com>. + + This file is part of the GNU Transactional Memory Library (libitm). + + Libitm is free software; you can redistribute it and/or modify it + under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + Libitm is distributed in the hope that it will be useful, but WITHOUT ANY + WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS + FOR A PARTICULAR PURPOSE. See the GNU General Public License for + more details. + + Under Section 7 of GPL version 3, you are granted additional + permissions described in the GCC Runtime Library Exception, version + 3.1, as published by the Free Software Foundation. + + You should have received a copy of the GNU General Public License and + a copy of the GCC Runtime Library Exception along with this program; + see the files COPYING3 and COPYING.RUNTIME respectively. If not, see + <http://www.gnu.org/licenses/>. */ + +#include "libitm_i.h" +#include <pthread.h> + +// +// We have three possibilities for alloction: mmap, memalign, posix_memalign +// + +#if defined(HAVE_MMAP_ANON) || defined(HAVE_MMAP_DEV_ZERO) +#include <sys/mman.h> +#include <fcntl.h> +#endif +#ifdef HAVE_MALLOC_H +#include <malloc.h> +#endif + +namespace GTM HIDDEN { + +#if defined(HAVE_MMAP_ANON) +# if !defined(MAP_ANONYMOUS) && defined(MAP_ANON) +# define MAP_ANONYMOUS MAP_ANON +# endif +# define dev_zero -1 +#elif defined(HAVE_MMAP_DEV_ZERO) +# ifndef MAP_ANONYMOUS +# define MAP_ANONYMOUS 0 +# endif +static int dev_zero = -1; +#endif + +#if defined(HAVE_MMAP_ANON) || defined(HAVE_MMAP_DEV_ZERO) +/* If we get here, we've already opened /dev/zero and verified that + PAGE_SIZE is valid for the system. */ +static gtm_cacheline_page * alloc_mmap (void) UNUSED; +static gtm_cacheline_page * +alloc_mmap (void) +{ + gtm_cacheline_page *r; + r = (gtm_cacheline_page *) mmap (NULL, PAGE_SIZE, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS, dev_zero, 0); + if (r == (gtm_cacheline_page *) MAP_FAILED) + abort (); + return r; +} +#endif /* MMAP_ANON | MMAP_DEV_ZERO */ + +#ifdef HAVE_MEMALIGN +static gtm_cacheline_page * alloc_memalign (void) UNUSED; +static gtm_cacheline_page * +alloc_memalign (void) +{ + gtm_cacheline_page *r; + r = (gtm_cacheline_page *) memalign (PAGE_SIZE, PAGE_SIZE); + if (r == NULL) + abort (); + return r; +} +#endif /* MEMALIGN */ + +#ifdef HAVE_POSIX_MEMALIGN +static gtm_cacheline_page *alloc_posix_memalign (void) UNUSED; +static gtm_cacheline_page * +alloc_posix_memalign (void) +{ + void *r; + if (posix_memalign (&r, PAGE_SIZE, PAGE_SIZE)) + abort (); + return (gtm_cacheline_page *) r; +} +#endif /* POSIX_MEMALIGN */ + +#if defined(HAVE_MMAP_ANON) && defined(FIXED_PAGE_SIZE) +# define alloc_page alloc_mmap +#elif defined(HAVE_MMAP_DEV_ZERO) && defined(FIXED_PAGE_SIZE) +static gtm_cacheline_page * +alloc_page (void) +{ + if (dev_zero < 0) + { + dev_zero = open ("/dev/zero", O_RDWR); + assert (dev_zero >= 0); + } + return alloc_mmap (); +} +#elif defined(HAVE_MMAP_ANON) || defined(HAVE_MMAP_DEV_ZERO) +static gtm_cacheline_page * (*alloc_page) (void); +static void __attribute__((constructor)) +init_alloc_page (void) +{ + size_t page_size = getpagesize (); + if (page_size <= PAGE_SIZE && PAGE_SIZE % page_size == 0) + { +# ifndef HAVE_MMAP_ANON + dev_zero = open ("/dev/zero", O_RDWR); + assert (dev_zero >= 0); +# endif + alloc_page = alloc_mmap; + return; + } +# ifdef HAVE_MEMALIGN + alloc_page = alloc_memalign; +# elif defined(HAVE_POSIX_MEMALIGN) + alloc_page = alloc_posix_memalign; +# else +# error "No fallback aligned memory allocation method" +# endif +} +#elif defined(HAVE_MEMALIGN) +# define alloc_page alloc_memalign +#elif defined(HAVE_POSIX_MEMALIGN) +# define alloc_page alloc_posix_memalign +#else +# error "No aligned memory allocation method" +#endif + +static gtm_cacheline_page *free_pages; +static pthread_mutex_t free_page_lock = PTHREAD_MUTEX_INITIALIZER; + +void * +gtm_cacheline_page::operator new (size_t size) +{ + assert (size == sizeof (gtm_cacheline_page)); + assert (size <= PAGE_SIZE); + + pthread_mutex_lock(&free_page_lock); + + gtm_cacheline_page *r = free_pages; + free_pages = r ? r->prev : NULL; + + pthread_mutex_unlock(&free_page_lock); + + if (r == NULL) + r = alloc_page (); + + return r; +} + +void +gtm_cacheline_page::operator delete (void *xhead) +{ + gtm_cacheline_page *head = static_cast<gtm_cacheline_page *>(xhead); + gtm_cacheline_page *tail; + + if (head == 0) + return; + + /* ??? We should eventually really free some of these. */ + + for (tail = head; tail->prev != 0; tail = tail->prev) + continue; + + pthread_mutex_lock(&free_page_lock); + + tail->prev = free_pages; + free_pages = head; + + pthread_mutex_unlock(&free_page_lock); +} + +} // namespace GTM |