server-skynet-source-3rd-je.../include/jemalloc/internal/prof_structs.h
Yinan Zhang b55419f9b9 Restructure profiling
Develop new data structure and code logic for holding profiling
related information stored in the extent that may be needed after the
extent is released, which in particular is the case for the
reallocation code path (e.g. in `rallocx()` and `xallocx()`).  The
data structure is a generalization of `prof_tctx_t`: we previously
only copy out the `prof_tctx` before the extent is released, but we
may be in need of additional fields. Currently the only additional
field is the allocation time field, but there may be more fields in
the future.

The restructuring also resolved a bug: `prof_realloc()` mistakenly
passed the new `ptr` to `prof_free_sampled_object()`, but passing in
the `old_ptr` would crash because it's already been released.  Now
the essential profiling information is collectively copied out early
and safely passed to `prof_free_sampled_object()` after the extent is
released.
2019-11-22 16:31:56 -08:00

205 lines
5.2 KiB
C

#ifndef JEMALLOC_INTERNAL_PROF_STRUCTS_H
#define JEMALLOC_INTERNAL_PROF_STRUCTS_H
#include "jemalloc/internal/ckh.h"
#include "jemalloc/internal/mutex.h"
#include "jemalloc/internal/prng.h"
#include "jemalloc/internal/rb.h"
struct prof_bt_s {
/* Backtrace, stored as len program counters. */
void **vec;
unsigned len;
};
#ifdef JEMALLOC_PROF_LIBGCC
/* Data structure passed to libgcc _Unwind_Backtrace() callback functions. */
typedef struct {
prof_bt_t *bt;
unsigned max;
} prof_unwind_data_t;
#endif
struct prof_accum_s {
#ifndef JEMALLOC_ATOMIC_U64
malloc_mutex_t mtx;
uint64_t accumbytes;
#else
atomic_u64_t accumbytes;
#endif
};
struct prof_cnt_s {
/* Profiling counters. */
uint64_t curobjs;
uint64_t curbytes;
uint64_t accumobjs;
uint64_t accumbytes;
};
typedef enum {
prof_tctx_state_initializing,
prof_tctx_state_nominal,
prof_tctx_state_dumping,
prof_tctx_state_purgatory /* Dumper must finish destroying. */
} prof_tctx_state_t;
struct prof_tctx_s {
/* Thread data for thread that performed the allocation. */
prof_tdata_t *tdata;
/*
* Copy of tdata->thr_{uid,discrim}, necessary because tdata may be
* defunct during teardown.
*/
uint64_t thr_uid;
uint64_t thr_discrim;
/* Profiling counters, protected by tdata->lock. */
prof_cnt_t cnts;
/* Associated global context. */
prof_gctx_t *gctx;
/*
* UID that distinguishes multiple tctx's created by the same thread,
* but coexisting in gctx->tctxs. There are two ways that such
* coexistence can occur:
* - A dumper thread can cause a tctx to be retained in the purgatory
* state.
* - Although a single "producer" thread must create all tctx's which
* share the same thr_uid, multiple "consumers" can each concurrently
* execute portions of prof_tctx_destroy(). prof_tctx_destroy() only
* gets called once each time cnts.cur{objs,bytes} drop to 0, but this
* threshold can be hit again before the first consumer finishes
* executing prof_tctx_destroy().
*/
uint64_t tctx_uid;
/* Linkage into gctx's tctxs. */
rb_node(prof_tctx_t) tctx_link;
/*
* True during prof_alloc_prep()..prof_malloc_sample_object(), prevents
* sample vs destroy race.
*/
bool prepared;
/* Current dump-related state, protected by gctx->lock. */
prof_tctx_state_t state;
/*
* Copy of cnts snapshotted during early dump phase, protected by
* dump_mtx.
*/
prof_cnt_t dump_cnts;
};
typedef rb_tree(prof_tctx_t) prof_tctx_tree_t;
struct prof_info_s {
/* Points to the prof_tctx_t corresponding to the allocation. */
prof_tctx_t *prof_tctx;
/* Time when the allocation was made. */
nstime_t alloc_time;
};
struct prof_gctx_s {
/* Protects nlimbo, cnt_summed, and tctxs. */
malloc_mutex_t *lock;
/*
* Number of threads that currently cause this gctx to be in a state of
* limbo due to one of:
* - Initializing this gctx.
* - Initializing per thread counters associated with this gctx.
* - Preparing to destroy this gctx.
* - Dumping a heap profile that includes this gctx.
* nlimbo must be 1 (single destroyer) in order to safely destroy the
* gctx.
*/
unsigned nlimbo;
/*
* Tree of profile counters, one for each thread that has allocated in
* this context.
*/
prof_tctx_tree_t tctxs;
/* Linkage for tree of contexts to be dumped. */
rb_node(prof_gctx_t) dump_link;
/* Temporary storage for summation during dump. */
prof_cnt_t cnt_summed;
/* Associated backtrace. */
prof_bt_t bt;
/* Backtrace vector, variable size, referred to by bt. */
void *vec[1];
};
typedef rb_tree(prof_gctx_t) prof_gctx_tree_t;
struct prof_tdata_s {
malloc_mutex_t *lock;
/* Monotonically increasing unique thread identifier. */
uint64_t thr_uid;
/*
* Monotonically increasing discriminator among tdata structures
* associated with the same thr_uid.
*/
uint64_t thr_discrim;
/* Included in heap profile dumps if non-NULL. */
char *thread_name;
bool attached;
bool expired;
rb_node(prof_tdata_t) tdata_link;
/*
* Counter used to initialize prof_tctx_t's tctx_uid. No locking is
* necessary when incrementing this field, because only one thread ever
* does so.
*/
uint64_t tctx_uid_next;
/*
* Hash of (prof_bt_t *)-->(prof_tctx_t *). Each thread tracks
* backtraces for which it has non-zero allocation/deallocation counters
* associated with thread-specific prof_tctx_t objects. Other threads
* may write to prof_tctx_t contents when freeing associated objects.
*/
ckh_t bt2tctx;
/* State used to avoid dumping while operating on prof internals. */
bool enq;
bool enq_idump;
bool enq_gdump;
/*
* Set to true during an early dump phase for tdata's which are
* currently being dumped. New threads' tdata's have this initialized
* to false so that they aren't accidentally included in later dump
* phases.
*/
bool dumping;
/*
* True if profiling is active for this tdata's thread
* (thread.prof.active mallctl).
*/
bool active;
/* Temporary storage for summation during dump. */
prof_cnt_t cnt_summed;
/* Backtrace vector, used for calls to prof_backtrace(). */
void *vec[PROF_BT_MAX];
};
typedef rb_tree(prof_tdata_t) prof_tdata_tree_t;
#endif /* JEMALLOC_INTERNAL_PROF_STRUCTS_H */