diff options
Diffstat (limited to 'deps/jemalloc/src/pages.c')
| -rw-r--r-- | deps/jemalloc/src/pages.c | 173 |
1 files changed, 173 insertions, 0 deletions
diff --git a/deps/jemalloc/src/pages.c b/deps/jemalloc/src/pages.c new file mode 100644 index 000000000..83a167f67 --- /dev/null +++ b/deps/jemalloc/src/pages.c @@ -0,0 +1,173 @@ +#define JEMALLOC_PAGES_C_ +#include "jemalloc/internal/jemalloc_internal.h" + +/******************************************************************************/ + +void * +pages_map(void *addr, size_t size) +{ + void *ret; + + assert(size != 0); + +#ifdef _WIN32 + /* + * If VirtualAlloc can't allocate at the given address when one is + * given, it fails and returns NULL. + */ + ret = VirtualAlloc(addr, size, MEM_COMMIT | MEM_RESERVE, + PAGE_READWRITE); +#else + /* + * We don't use MAP_FIXED here, because it can cause the *replacement* + * of existing mappings, and we only want to create new mappings. + */ + ret = mmap(addr, size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, + -1, 0); + assert(ret != NULL); + + if (ret == MAP_FAILED) + ret = NULL; + else if (addr != NULL && ret != addr) { + /* + * We succeeded in mapping memory, but not in the right place. + */ + pages_unmap(ret, size); + ret = NULL; + } +#endif + assert(ret == NULL || (addr == NULL && ret != addr) + || (addr != NULL && ret == addr)); + return (ret); +} + +void +pages_unmap(void *addr, size_t size) +{ + +#ifdef _WIN32 + if (VirtualFree(addr, 0, MEM_RELEASE) == 0) +#else + if (munmap(addr, size) == -1) +#endif + { + char buf[BUFERROR_BUF]; + + buferror(get_errno(), buf, sizeof(buf)); + malloc_printf("<jemalloc>: Error in " +#ifdef _WIN32 + "VirtualFree" +#else + "munmap" +#endif + "(): %s\n", buf); + if (opt_abort) + abort(); + } +} + +void * +pages_trim(void *addr, size_t alloc_size, size_t leadsize, size_t size) +{ + void *ret = (void *)((uintptr_t)addr + leadsize); + + assert(alloc_size >= leadsize + size); +#ifdef _WIN32 + { + void *new_addr; + + pages_unmap(addr, alloc_size); + new_addr = pages_map(ret, size); + if (new_addr == ret) + return (ret); + if (new_addr) + pages_unmap(new_addr, size); + return (NULL); + } +#else + { + size_t trailsize = alloc_size - leadsize - size; + + if (leadsize != 0) + pages_unmap(addr, leadsize); + if (trailsize != 0) + pages_unmap((void *)((uintptr_t)ret + size), trailsize); + return (ret); + } +#endif +} + +static bool +pages_commit_impl(void *addr, size_t size, bool commit) +{ + +#ifndef _WIN32 + /* + * The following decommit/commit implementation is functional, but + * always disabled because it doesn't add value beyong improved + * debugging (at the cost of extra system calls) on systems that + * overcommit. + */ + if (false) { + int prot = commit ? (PROT_READ | PROT_WRITE) : PROT_NONE; + void *result = mmap(addr, size, prot, MAP_PRIVATE | MAP_ANON | + MAP_FIXED, -1, 0); + if (result == MAP_FAILED) + return (true); + if (result != addr) { + /* + * We succeeded in mapping memory, but not in the right + * place. + */ + pages_unmap(result, size); + return (true); + } + return (false); + } +#endif + return (true); +} + +bool +pages_commit(void *addr, size_t size) +{ + + return (pages_commit_impl(addr, size, true)); +} + +bool +pages_decommit(void *addr, size_t size) +{ + + return (pages_commit_impl(addr, size, false)); +} + +bool +pages_purge(void *addr, size_t size) +{ + bool unzeroed; + +#ifdef _WIN32 + VirtualAlloc(addr, size, MEM_RESET, PAGE_READWRITE); + unzeroed = true; +#elif defined(JEMALLOC_HAVE_MADVISE) +# ifdef JEMALLOC_PURGE_MADVISE_DONTNEED +# define JEMALLOC_MADV_PURGE MADV_DONTNEED +# define JEMALLOC_MADV_ZEROS true +# elif defined(JEMALLOC_PURGE_MADVISE_FREE) +# define JEMALLOC_MADV_PURGE MADV_FREE +# define JEMALLOC_MADV_ZEROS false +# else +# error "No madvise(2) flag defined for purging unused dirty pages." +# endif + int err = madvise(addr, size, JEMALLOC_MADV_PURGE); + unzeroed = (!JEMALLOC_MADV_ZEROS || err != 0); +# undef JEMALLOC_MADV_PURGE +# undef JEMALLOC_MADV_ZEROS +#else + /* Last resort no-op. */ + unzeroed = true; +#endif + return (unzeroed); +} + |