1 #define JEMALLOC_PAGES_C_
2 #include "jemalloc/internal/jemalloc_internal.h"
4 /******************************************************************************/
7 pages_map(void *addr, size_t size)
15 * If VirtualAlloc can't allocate at the given address when one is
16 * given, it fails and returns NULL.
18 ret = VirtualAlloc(addr, size, MEM_COMMIT | MEM_RESERVE,
22 * We don't use MAP_FIXED here, because it can cause the *replacement*
23 * of existing mappings, and we only want to create new mappings.
25 ret = mmap(addr, size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON,
29 if (ret == MAP_FAILED)
31 else if (addr != NULL && ret != addr) {
33 * We succeeded in mapping memory, but not in the right place.
35 pages_unmap(ret, size);
39 assert(ret == NULL || (addr == NULL && ret != addr)
40 || (addr != NULL && ret == addr));
45 pages_unmap(void *addr, size_t size)
49 if (VirtualFree(addr, 0, MEM_RELEASE) == 0)
51 if (munmap(addr, size) == -1)
54 char buf[BUFERROR_BUF];
56 buferror(get_errno(), buf, sizeof(buf));
57 malloc_printf("<jemalloc>: Error in "
70 pages_trim(void *addr, size_t alloc_size, size_t leadsize, size_t size)
72 void *ret = (void *)((uintptr_t)addr + leadsize);
74 assert(alloc_size >= leadsize + size);
79 pages_unmap(addr, alloc_size);
80 new_addr = pages_map(ret, size);
84 pages_unmap(new_addr, size);
89 size_t trailsize = alloc_size - leadsize - size;
92 pages_unmap(addr, leadsize);
94 pages_unmap((void *)((uintptr_t)ret + size), trailsize);
101 pages_commit_impl(void *addr, size_t size, bool commit)
106 * The following decommit/commit implementation is functional, but
107 * always disabled because it doesn't add value beyong improved
108 * debugging (at the cost of extra system calls) on systems that
112 int prot = commit ? (PROT_READ | PROT_WRITE) : PROT_NONE;
113 void *result = mmap(addr, size, prot, MAP_PRIVATE | MAP_ANON |
115 if (result == MAP_FAILED)
117 if (result != addr) {
119 * We succeeded in mapping memory, but not in the right
122 pages_unmap(result, size);
132 pages_commit(void *addr, size_t size)
135 return (pages_commit_impl(addr, size, true));
139 pages_decommit(void *addr, size_t size)
142 return (pages_commit_impl(addr, size, false));
146 pages_purge(void *addr, size_t size)
151 VirtualAlloc(addr, size, MEM_RESET, PAGE_READWRITE);
153 #elif defined(JEMALLOC_HAVE_MADVISE)
154 # ifdef JEMALLOC_PURGE_MADVISE_DONTNEED
155 # define JEMALLOC_MADV_PURGE MADV_DONTNEED
156 # define JEMALLOC_MADV_ZEROS true
157 # elif defined(JEMALLOC_PURGE_MADVISE_FREE)
158 # define JEMALLOC_MADV_PURGE MADV_FREE
159 # define JEMALLOC_MADV_ZEROS false
161 # error "No madvise(2) flag defined for purging unused dirty pages."
163 int err = madvise(addr, size, JEMALLOC_MADV_PURGE);
164 unzeroed = (!JEMALLOC_MADV_ZEROS || err != 0);
165 # undef JEMALLOC_MADV_PURGE
166 # undef JEMALLOC_MADV_ZEROS
168 /* Last resort no-op. */