server-skynet-source-3rd-je.../include/jemalloc/internal/ehooks.h
2019-12-20 10:18:40 -08:00

265 lines
9.1 KiB
C

#ifndef JEMALLOC_INTERNAL_EHOOKS_H
#define JEMALLOC_INTERNAL_EHOOKS_H
/*
* This module is the internal interface to the extent hooks (both
* user-specified and external). Eventually, this will give us the flexibility
* to use multiple different versions of user-visible extent-hook APIs under a
* single user interface.
*/
#include "jemalloc/internal/atomic.h"
extern const extent_hooks_t ehooks_default_extent_hooks;
typedef struct ehooks_s ehooks_t;
struct ehooks_s {
/* Logically an extent_hooks_t *. */
atomic_p_t ptr;
};
extern const extent_hooks_t ehooks_default_extent_hooks;
/*
* These are not really part of the public API. Each hook has a fast-path for
* the default-hooks case that can avoid various small inefficiencies:
* - Forgetting tsd and then calling tsd_get within the hook.
* - Getting more state than necessary out of the extent_t.
* - Doing arena_ind -> arena -> arena_ind lookups.
* By making the calls to these functions visible to the compiler, it can move
* those extra bits of computation down below the fast-paths where they get ignored.
*/
void *ehooks_default_alloc_impl(tsdn_t *tsdn, void *new_addr, size_t size,
size_t alignment, bool *zero, bool *commit, unsigned arena_ind);
bool ehooks_default_dalloc_impl(void *addr, size_t size);
void ehooks_default_destroy_impl(void *addr, size_t size);
bool ehooks_default_commit_impl(void *addr, size_t offset, size_t length);
bool ehooks_default_decommit_impl(void *addr, size_t offset, size_t length);
#ifdef PAGES_CAN_PURGE_LAZY
bool ehooks_default_purge_lazy_impl(void *addr, size_t offset, size_t length);
#endif
#ifdef PAGES_CAN_PURGE_FORCED
bool ehooks_default_purge_forced_impl(void *addr, size_t offset, size_t length);
#endif
bool ehooks_default_split_impl();
bool ehooks_default_merge_impl(void *addr_a, void *addr_b);
/*
* We don't officially support reentrancy from wtihin the extent hooks. But
* various people who sit within throwing distance of the jemalloc team want
* that functionality in certain limited cases. The default reentrancy guards
* assert that we're not reentrant from a0 (since it's the bootstrap arena,
* where reentrant allocations would be redirected), which we would incorrectly
* trigger in cases where a0 has extent hooks (those hooks themselves can't be
* reentrant, then, but there are reasonable uses for such functionality, like
* putting internal metadata on hugepages). Therefore, we use the raw
* reentrancy guards.
*
* Eventually, we need to think more carefully about whether and where we
* support allocating from within extent hooks (and what that means for things
* like profiling, stats collection, etc.), and document what the guarantee is.
*/
static inline void
ehooks_pre_reentrancy(tsdn_t *tsdn) {
tsd_t *tsd = tsdn_null(tsdn) ? tsd_fetch() : tsdn_tsd(tsdn);
tsd_pre_reentrancy_raw(tsd);
}
static inline void
ehooks_post_reentrancy(tsdn_t *tsdn) {
tsd_t *tsd = tsdn_null(tsdn) ? tsd_fetch() : tsdn_tsd(tsdn);
tsd_post_reentrancy_raw(tsd);
}
/* Beginning of the public API. */
void ehooks_init(ehooks_t *ehooks, extent_hooks_t *extent_hooks);
static inline void
ehooks_set_extent_hooks_ptr(ehooks_t *ehooks, extent_hooks_t *extent_hooks) {
atomic_store_p(&ehooks->ptr, extent_hooks, ATOMIC_RELEASE);
}
static inline extent_hooks_t *
ehooks_get_extent_hooks_ptr(ehooks_t *ehooks) {
return (extent_hooks_t *)atomic_load_p(&ehooks->ptr, ATOMIC_ACQUIRE);
}
static inline bool
ehooks_are_default(ehooks_t *ehooks) {
return ehooks_get_extent_hooks_ptr(ehooks) ==
&ehooks_default_extent_hooks;
}
/*
* In some cases, a caller needs to allocate resources before attempting to call
* a hook. If that hook is doomed to fail, this is wasteful. We therefore
* include some checks for such cases.
*/
static inline bool
ehooks_split_will_fail(ehooks_t *ehooks) {
return ehooks_get_extent_hooks_ptr(ehooks)->split == NULL;
}
static inline bool
ehooks_merge_will_fail(ehooks_t *ehooks) {
return ehooks_get_extent_hooks_ptr(ehooks)->merge == NULL;
}
static inline void *
ehooks_alloc(tsdn_t *tsdn, ehooks_t *ehooks, void *new_addr, size_t size,
size_t alignment, bool *zero, bool *commit, unsigned arena_ind) {
extent_hooks_t *extent_hooks = ehooks_get_extent_hooks_ptr(ehooks);
if (extent_hooks == &ehooks_default_extent_hooks) {
return ehooks_default_alloc_impl(tsdn, new_addr, size,
alignment, zero, commit, arena_ind);
}
ehooks_pre_reentrancy(tsdn);
void *ret = extent_hooks->alloc(extent_hooks, new_addr, size, alignment,
zero, commit, arena_ind);
ehooks_post_reentrancy(tsdn);
return ret;
}
static inline bool
ehooks_dalloc(tsdn_t *tsdn, ehooks_t *ehooks, void *addr, size_t size,
bool committed, unsigned arena_ind) {
extent_hooks_t *extent_hooks = ehooks_get_extent_hooks_ptr(ehooks);
if (extent_hooks == &ehooks_default_extent_hooks) {
return ehooks_default_dalloc_impl(addr, size);
} else if (extent_hooks->dalloc == NULL) {
return true;
} else {
ehooks_pre_reentrancy(tsdn);
bool err = extent_hooks->dalloc(extent_hooks, addr, size,
committed, arena_ind);
ehooks_post_reentrancy(tsdn);
return err;
}
}
static inline void
ehooks_destroy(tsdn_t *tsdn, ehooks_t *ehooks, void *addr, size_t size,
bool committed, unsigned arena_ind) {
extent_hooks_t *extent_hooks = ehooks_get_extent_hooks_ptr(ehooks);
if (extent_hooks == &ehooks_default_extent_hooks) {
return ehooks_default_destroy_impl(addr, size);
} else if (extent_hooks->destroy == NULL) {
return;
} else {
ehooks_pre_reentrancy(tsdn);
extent_hooks->destroy(extent_hooks, addr, size, committed,
arena_ind);
ehooks_post_reentrancy(tsdn);
}
}
static inline bool
ehooks_commit(tsdn_t *tsdn, ehooks_t *ehooks, void *addr, size_t size,
size_t offset, size_t length, unsigned arena_ind) {
extent_hooks_t *extent_hooks = ehooks_get_extent_hooks_ptr(ehooks);
if (extent_hooks == &ehooks_default_extent_hooks) {
return ehooks_default_commit_impl(addr, offset, length);
} else if (extent_hooks->commit == NULL) {
return true;
} else {
ehooks_pre_reentrancy(tsdn);
bool err = extent_hooks->commit(extent_hooks, addr, size,
offset, length, arena_ind);
ehooks_post_reentrancy(tsdn);
return err;
}
}
static inline bool
ehooks_decommit(tsdn_t *tsdn, ehooks_t *ehooks, void *addr, size_t size,
size_t offset, size_t length, unsigned arena_ind) {
extent_hooks_t *extent_hooks = ehooks_get_extent_hooks_ptr(ehooks);
if (extent_hooks == &ehooks_default_extent_hooks) {
return ehooks_default_decommit_impl(addr, offset, length);
} else if (extent_hooks->decommit == NULL) {
return true;
} else {
ehooks_pre_reentrancy(tsdn);
bool err = extent_hooks->decommit(extent_hooks, addr, size,
offset, length, arena_ind);
ehooks_post_reentrancy(tsdn);
return err;
}
}
static inline bool
ehooks_purge_lazy(tsdn_t *tsdn, ehooks_t *ehooks, void *addr, size_t size,
size_t offset, size_t length, unsigned arena_ind) {
extent_hooks_t *extent_hooks = ehooks_get_extent_hooks_ptr(ehooks);
#ifdef PAGES_CAN_PURGE_LAZY
if (extent_hooks == &ehooks_default_extent_hooks) {
return ehooks_default_purge_lazy_impl(addr, offset, length);
}
#endif
if (extent_hooks->purge_lazy == NULL) {
return true;
} else {
ehooks_pre_reentrancy(tsdn);
bool err = extent_hooks->purge_lazy(extent_hooks, addr, size,
offset, length, arena_ind);
ehooks_post_reentrancy(tsdn);
return err;
}
}
static inline bool
ehooks_purge_forced(tsdn_t *tsdn, ehooks_t *ehooks, void *addr, size_t size,
size_t offset, size_t length, unsigned arena_ind) {
extent_hooks_t *extent_hooks = ehooks_get_extent_hooks_ptr(ehooks);
#ifdef PAGES_CAN_PURGE_FORCED
if (extent_hooks == &ehooks_default_extent_hooks) {
return ehooks_default_purge_forced_impl(addr, offset, length);
}
#endif
if (extent_hooks->purge_forced == NULL) {
return true;
} else {
ehooks_pre_reentrancy(tsdn);
bool err = extent_hooks->purge_forced(extent_hooks, addr, size,
offset, length, arena_ind);
ehooks_post_reentrancy(tsdn);
return err;
}
}
static inline bool
ehooks_split(tsdn_t *tsdn, ehooks_t *ehooks, void *addr, size_t size,
size_t size_a, size_t size_b, bool committed, unsigned arena_ind) {
extent_hooks_t *extent_hooks = ehooks_get_extent_hooks_ptr(ehooks);
if (ehooks_are_default(ehooks)) {
return ehooks_default_split_impl();
} else if (extent_hooks->split == NULL) {
return true;
} else {
ehooks_pre_reentrancy(tsdn);
bool err = extent_hooks->split(extent_hooks, addr, size, size_a,
size_b, committed, arena_ind);
ehooks_post_reentrancy(tsdn);
return err;
}
}
static inline bool
ehooks_merge(tsdn_t *tsdn, ehooks_t *ehooks, void *addr_a, size_t size_a,
void *addr_b, size_t size_b, bool committed, unsigned arena_ind) {
extent_hooks_t *extent_hooks = ehooks_get_extent_hooks_ptr(ehooks);
if (extent_hooks == &ehooks_default_extent_hooks) {
return ehooks_default_merge_impl(addr_a, addr_b);
} else if (extent_hooks->merge == NULL) {
return true;
} else {
ehooks_pre_reentrancy(tsdn);
bool err = extent_hooks->merge(extent_hooks, addr_a, size_a,
addr_b, size_b, committed, arena_ind);
ehooks_post_reentrancy(tsdn);
return err;
}
}
#endif /* JEMALLOC_INTERNAL_EHOOKS_H */