diff options
Diffstat (limited to 'memory/jemalloc/src/src/chunk_dss.c')
| -rw-r--r-- | memory/jemalloc/src/src/chunk_dss.c | 237 |
1 files changed, 0 insertions, 237 deletions
diff --git a/memory/jemalloc/src/src/chunk_dss.c b/memory/jemalloc/src/src/chunk_dss.c deleted file mode 100644 index 85a13548f..000000000 --- a/memory/jemalloc/src/src/chunk_dss.c +++ /dev/null @@ -1,237 +0,0 @@ -#define JEMALLOC_CHUNK_DSS_C_ -#include "jemalloc/internal/jemalloc_internal.h" -/******************************************************************************/ -/* Data. */ - -const char *dss_prec_names[] = { - "disabled", - "primary", - "secondary", - "N/A" -}; - -/* - * Current dss precedence default, used when creating new arenas. NB: This is - * stored as unsigned rather than dss_prec_t because in principle there's no - * guarantee that sizeof(dss_prec_t) is the same as sizeof(unsigned), and we use - * atomic operations to synchronize the setting. - */ -static unsigned dss_prec_default = (unsigned)DSS_PREC_DEFAULT; - -/* Base address of the DSS. */ -static void *dss_base; -/* Atomic boolean indicating whether the DSS is exhausted. */ -static unsigned dss_exhausted; -/* Atomic current upper limit on DSS addresses. */ -static void *dss_max; - -/******************************************************************************/ - -static void * -chunk_dss_sbrk(intptr_t increment) -{ - -#ifdef JEMALLOC_DSS - return (sbrk(increment)); -#else - not_implemented(); - return (NULL); -#endif -} - -dss_prec_t -chunk_dss_prec_get(void) -{ - dss_prec_t ret; - - if (!have_dss) - return (dss_prec_disabled); - ret = (dss_prec_t)atomic_read_u(&dss_prec_default); - return (ret); -} - -bool -chunk_dss_prec_set(dss_prec_t dss_prec) -{ - - if (!have_dss) - return (dss_prec != dss_prec_disabled); - atomic_write_u(&dss_prec_default, (unsigned)dss_prec); - return (false); -} - -static void * -chunk_dss_max_update(void *new_addr) -{ - void *max_cur; - spin_t spinner; - - /* - * Get the current end of the DSS as max_cur and assure that dss_max is - * up to date. - */ - spin_init(&spinner); - while (true) { - void *max_prev = atomic_read_p(&dss_max); - - max_cur = chunk_dss_sbrk(0); - if ((uintptr_t)max_prev > (uintptr_t)max_cur) { - /* - * Another thread optimistically updated dss_max. Wait - * for it to finish. - */ - spin_adaptive(&spinner); - continue; - } - if (!atomic_cas_p(&dss_max, max_prev, max_cur)) - break; - } - /* Fixed new_addr can only be supported if it is at the edge of DSS. */ - if (new_addr != NULL && max_cur != new_addr) - return (NULL); - - return (max_cur); -} - -void * -chunk_alloc_dss(tsdn_t *tsdn, arena_t *arena, void *new_addr, size_t size, - size_t alignment, bool *zero, bool *commit) -{ - cassert(have_dss); - assert(size > 0 && (size & chunksize_mask) == 0); - assert(alignment > 0 && (alignment & chunksize_mask) == 0); - - /* - * sbrk() uses a signed increment argument, so take care not to - * interpret a huge allocation request as a negative increment. - */ - if ((intptr_t)size < 0) - return (NULL); - - if (!atomic_read_u(&dss_exhausted)) { - /* - * The loop is necessary to recover from races with other - * threads that are using the DSS for something other than - * malloc. - */ - while (true) { - void *ret, *cpad, *max_cur, *dss_next, *dss_prev; - size_t gap_size, cpad_size; - intptr_t incr; - - max_cur = chunk_dss_max_update(new_addr); - if (max_cur == NULL) - goto label_oom; - - /* - * Calculate how much padding is necessary to - * chunk-align the end of the DSS. - */ - gap_size = (chunksize - CHUNK_ADDR2OFFSET(dss_max)) & - chunksize_mask; - /* - * Compute how much chunk-aligned pad space (if any) is - * necessary to satisfy alignment. This space can be - * recycled for later use. - */ - cpad = (void *)((uintptr_t)dss_max + gap_size); - ret = (void *)ALIGNMENT_CEILING((uintptr_t)dss_max, - alignment); - cpad_size = (uintptr_t)ret - (uintptr_t)cpad; - dss_next = (void *)((uintptr_t)ret + size); - if ((uintptr_t)ret < (uintptr_t)dss_max || - (uintptr_t)dss_next < (uintptr_t)dss_max) - goto label_oom; /* Wrap-around. */ - incr = gap_size + cpad_size + size; - - /* - * Optimistically update dss_max, and roll back below if - * sbrk() fails. No other thread will try to extend the - * DSS while dss_max is greater than the current DSS - * max reported by sbrk(0). - */ - if (atomic_cas_p(&dss_max, max_cur, dss_next)) - continue; - - /* Try to allocate. */ - dss_prev = chunk_dss_sbrk(incr); - if (dss_prev == max_cur) { - /* Success. */ - if (cpad_size != 0) { - chunk_hooks_t chunk_hooks = - CHUNK_HOOKS_INITIALIZER; - chunk_dalloc_wrapper(tsdn, arena, - &chunk_hooks, cpad, cpad_size, - false, true); - } - if (*zero) { - JEMALLOC_VALGRIND_MAKE_MEM_UNDEFINED( - ret, size); - memset(ret, 0, size); - } - if (!*commit) - *commit = pages_decommit(ret, size); - return (ret); - } - - /* - * Failure, whether due to OOM or a race with a raw - * sbrk() call from outside the allocator. Try to roll - * back optimistic dss_max update; if rollback fails, - * it's due to another caller of this function having - * succeeded since this invocation started, in which - * case rollback is not necessary. - */ - atomic_cas_p(&dss_max, dss_next, max_cur); - if (dss_prev == (void *)-1) { - /* OOM. */ - atomic_write_u(&dss_exhausted, (unsigned)true); - goto label_oom; - } - } - } -label_oom: - return (NULL); -} - -static bool -chunk_in_dss_helper(void *chunk, void *max) -{ - - return ((uintptr_t)chunk >= (uintptr_t)dss_base && (uintptr_t)chunk < - (uintptr_t)max); -} - -bool -chunk_in_dss(void *chunk) -{ - - cassert(have_dss); - - return (chunk_in_dss_helper(chunk, atomic_read_p(&dss_max))); -} - -bool -chunk_dss_mergeable(void *chunk_a, void *chunk_b) -{ - void *max; - - cassert(have_dss); - - max = atomic_read_p(&dss_max); - return (chunk_in_dss_helper(chunk_a, max) == - chunk_in_dss_helper(chunk_b, max)); -} - -void -chunk_dss_boot(void) -{ - - cassert(have_dss); - - dss_base = chunk_dss_sbrk(0); - dss_exhausted = (unsigned)(dss_base == (void *)-1); - dss_max = dss_base; -} - -/******************************************************************************/ |