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/*
* %CopyrightBegin%
*
* Copyright Ericsson AB 2008-2017. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* %CopyrightEnd%
*/
/**
* @description Statistics for locks.
* @file erl_lock_count.h
*
* @author Björn-Egil Dahlberg
* @author John Högberg
*
* Conceptual representation:
*
* - set name
* | - id (the unique lock)
* | | - lock type
* | | - statistics
* | | | - location (file and line number)
* | | | - attempts
* | | | - collisions (including trylock busy)
* | | | - timer (time spent in waiting for lock)
* | | | - n_timer (collisions excluding trylock busy)
* | | | - histogram
* | | | | - # 0 = log2(lock wait_time ns)
* | | | | - ...
* | | | | - # n = log2(lock wait_time ns)
*
* Each instance of a lock is the unique lock, i.e. set and id in that set.
* For each lock there is a set of statistics with where and what impact
* the lock acquisition had.
*/
#ifndef ERTS_LOCK_COUNT_H__
#define ERTS_LOCK_COUNT_H__
#ifdef ERTS_ENABLE_LOCK_COUNT
#ifndef ERTS_ENABLE_LOCK_POSITION
/** @brief Controls whether _x variants of mtx functions are used. */
#define ERTS_ENABLE_LOCK_POSITION 1
#endif
#include "sys.h"
#include "ethread.h"
#include "erl_term.h"
#include "erl_lock_flags.h"
#define ERTS_LCNT_MAX_LOCK_LOCATIONS (5)
#define ERTS_LCNT_HISTOGRAM_MAX_NS (((unsigned long)1LL << 28) - 1)
#if 0 || defined(ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT)
#define ERTS_LCNT_HISTOGRAM_SLOT_SIZE (30)
#define ERTS_LCNT_HISTOGRAM_RSHIFT (0)
#else
#define ERTS_LCNT_HISTOGRAM_SLOT_SIZE (20)
#define ERTS_LCNT_HISTOGRAM_RSHIFT (10)
#endif
typedef struct {
unsigned long s;
unsigned long ns;
} erts_lcnt_time_t;
typedef struct {
/* @brief log2 array of nano seconds occurences */
Uint32 ns[ERTS_LCNT_HISTOGRAM_SLOT_SIZE];
} erts_lcnt_hist_t;
typedef struct {
/** @brief In which file the lock was taken. May be NULL. */
const char *file;
/** @brief Line number in \c file */
unsigned int line;
/* "attempts" and "collisions" need to be atomic since try_lock busy does
* not acquire a lock and there is no post action to rectify the
* situation. */
ethr_atomic_t attempts;
ethr_atomic_t collisions;
erts_lcnt_time_t total_time_waited;
Uint64 times_waited;
erts_lcnt_hist_t wait_time_histogram;
} erts_lcnt_lock_stats_t;
typedef struct lcnt_lock_info_t_ {
erts_lock_flags_t flags;
const char *name;
/** @brief Id if possible, must be an immediate */
Eterm id;
/* The first entry is reserved as a fallback for when location information
* is missing, and when the lock is used in more than (MAX_LOCK_LOCATIONS
* - 1) different places. */
erts_lcnt_lock_stats_t location_stats[ERTS_LCNT_MAX_LOCK_LOCATIONS];
unsigned int location_count;
/* -- Everything below is internal to this module ---------------------- */
/* Lock states; rw locks uses both states, other locks only uses w_state */
/** @brief Write state. 0 = not taken, otherwise n threads waiting */
ethr_atomic_t w_state;
/** @brief Read state. 0 = not taken, > 0 -> writes will wait */
ethr_atomic_t r_state;
struct lcnt_lock_info_t_ *prev;
struct lcnt_lock_info_t_ *next;
/** @brief Used in place of erts_refc_t to avoid a circular dependency. */
ethr_atomic_t ref_count;
ethr_atomic32_t lock;
/** @brief Deletion hook called once \c ref_count reaches 0; may defer
* deletion by modifying \c ref_count. */
void (*dispose)(struct lcnt_lock_info_t_ *);
struct lcnt_lock_info_carrier_ *carrier;
} erts_lcnt_lock_info_t;
typedef struct lcnt_lock_info_list_ {
erts_lcnt_lock_info_t head;
erts_lcnt_lock_info_t tail;
} erts_lcnt_lock_info_list_t;
typedef struct {
erts_lcnt_time_t timer_start; /**< Time of last clear */
erts_lcnt_time_t duration; /**< Time since last clear */
erts_lcnt_lock_info_list_t *current_locks;
erts_lcnt_lock_info_list_t *deleted_locks;
} erts_lcnt_data_t;
typedef struct lcnt_lock_info_carrier_ erts_lcnt_lock_info_carrier_t;
typedef ethr_atomic_t erts_lcnt_ref_t;
/* -- Globals -------------------------------------------------------------- */
/** @brief Checks whether counting is enabled for any of the given
* categories. */
#define erts_lcnt_check_enabled(flags) \
(lcnt_category_mask__ & flags)
/* -- Lock operations ------------------------------------------------------
*
* All of these will nop if there's nothing "installed" on the given reference,
* in order to transparently support enable/disable at runtime. */
/** @brief Records that a lock is being acquired. */
ERTS_GLB_FORCE_INLINE
void erts_lcnt_lock(erts_lcnt_ref_t *ref);
/** @copydoc erts_lcnt_lock
* @param option Notes whether the lock is a read or write lock. */
ERTS_GLB_FORCE_INLINE
void erts_lcnt_lock_opt(erts_lcnt_ref_t *ref, Uint16 option);
/** @brief Records that a lock has been acquired. */
ERTS_GLB_FORCE_INLINE
void erts_lcnt_lock_post(erts_lcnt_ref_t *ref);
/** @copydoc erts_lcnt_lock_post.
* @param file The name of the file where the lock was acquired.
* @param line The line at which the lock was acquired. */
ERTS_GLB_FORCE_INLINE
void erts_lcnt_lock_post_x(erts_lcnt_ref_t *ref, char *file, unsigned int line);
/** @brief Records that a lock has been released. */
ERTS_GLB_FORCE_INLINE
void erts_lcnt_unlock(erts_lcnt_ref_t *ref);
/** @copydoc erts_lcnt_unlock_opt
* @param option Whether the lock is a read or write lock. */
ERTS_GLB_FORCE_INLINE
void erts_lcnt_unlock_opt(erts_lcnt_ref_t *ref, Uint16 option);
/** @brief Rectifies the case where a lock wasn't actually a lock operation.
*
* Only used for process locks at the moment. */
ERTS_GLB_FORCE_INLINE
void erts_lcnt_lock_unacquire(erts_lcnt_ref_t *ref);
/** @brief Records the result of a trylock, placing the queried lock status in
* \c result. */
ERTS_GLB_FORCE_INLINE
void erts_lcnt_trylock(erts_lcnt_ref_t *ref, int result);
/** @copydoc erts_lcnt_trylock
* @param option Whether the lock is a read or write lock. */
ERTS_GLB_FORCE_INLINE
void erts_lcnt_trylock_opt(erts_lcnt_ref_t *ref, int result, Uint16 option);
/* Indexed variants of the standard lock operations, for use when a single
* reference contains many counters (eg. process locks).
*
* erts_lcnt_open_ref must be used to safely extract the installed carrier,
* which must released with erts_lcnt_close_reference on success.
*
* Refer to \c erts_lcnt_lock for example usage. */
ERTS_GLB_INLINE
void erts_lcnt_lock_idx(erts_lcnt_lock_info_carrier_t *carrier, int index);
ERTS_GLB_INLINE
void erts_lcnt_lock_opt_idx(erts_lcnt_lock_info_carrier_t *carrier, int index, Uint16 option);
ERTS_GLB_INLINE
void erts_lcnt_lock_post_idx(erts_lcnt_lock_info_carrier_t *carrier, int index);
ERTS_GLB_INLINE
void erts_lcnt_lock_post_x_idx(erts_lcnt_lock_info_carrier_t *carrier, int index, char *file, unsigned int line);
ERTS_GLB_INLINE
void erts_lcnt_lock_unacquire_idx(erts_lcnt_lock_info_carrier_t *carrier, int index);
ERTS_GLB_INLINE
void erts_lcnt_unlock_idx(erts_lcnt_lock_info_carrier_t *carrier, int index);
ERTS_GLB_INLINE
void erts_lcnt_unlock_opt_idx(erts_lcnt_lock_info_carrier_t *carrier, int index, Uint16 option);
ERTS_GLB_INLINE
void erts_lcnt_trylock_idx(erts_lcnt_lock_info_carrier_t *carrier, int index, int result);
ERTS_GLB_INLINE
void erts_lcnt_trylock_opt_idx(erts_lcnt_lock_info_carrier_t *carrier, int index, int result, Uint16 option);
/* -- Reference operations ------------------------------------------------- */
/** @brief Registers a lock counter reference; this must be called prior to
* using any other functions in this module. */
ERTS_GLB_INLINE
void erts_lcnt_init_ref(erts_lcnt_ref_t *ref);
/** @brief As \c erts_lcnt_init_ref, but also enables lock counting right
* away if appropriate to reduce noise.
* @param id An immediate erlang term with whatever extra data you want to
* identify this lock with. */
ERTS_GLB_INLINE
void erts_lcnt_init_ref_x(erts_lcnt_ref_t *ref, const char *name,
Eterm id, erts_lock_flags_t flags);
/** @brief Checks whether counting is enabled on the given reference. */
ERTS_GLB_FORCE_INLINE
int erts_lcnt_check_ref_installed(erts_lcnt_ref_t *ref);
/** @brief Convenience macro to re/enable counting on an already initialized
* reference. Don't forget to specify the lock type in \c flags! */
#define erts_lcnt_install_new_lock_info(ref, name, id, flags) \
if(!erts_lcnt_check_ref_installed(ref)) { \
erts_lcnt_lock_info_carrier_t *__carrier; \
__carrier = erts_lcnt_create_lock_info_carrier(1);\
erts_lcnt_init_lock_info_idx(__carrier, 0, name, id, flags); \
erts_lcnt_install(ref, __carrier);\
} while(0)
erts_lcnt_lock_info_carrier_t *erts_lcnt_create_lock_info_carrier(int count);
/* @brief Initializes the lock info at the given index.
* @param id An immediate erlang term with whatever extra data you want to
* identify this lock with.
* @param flags The flags the lock itself was initialized with. Keep in mind
* that all locks in a carrier must share the same category/static property. */
ERTS_GLB_INLINE
void erts_lcnt_init_lock_info_idx(erts_lcnt_lock_info_carrier_t *carrier, int index,
const char *name, Eterm id, erts_lock_flags_t flags);
/** @brief Atomically installs the given lock counters. Nops (and releases the
* provided carrier) if something was already installed. */
void erts_lcnt_install(erts_lcnt_ref_t *ref, erts_lcnt_lock_info_carrier_t *carrier);
/** @brief Atomically removes the currently installed lock counters. Nops if
* nothing was installed. */
void erts_lcnt_uninstall(erts_lcnt_ref_t *ref);
ERTS_GLB_FORCE_INLINE
int erts_lcnt_open_ref(erts_lcnt_ref_t *ref, int *handle, erts_lcnt_lock_info_carrier_t **result);
ERTS_GLB_FORCE_INLINE
void erts_lcnt_close_ref(int handle, erts_lcnt_lock_info_carrier_t *carrier);
/* -- Module initialization ------------------------------------------------ */
void erts_lcnt_pre_thr_init(void);
void erts_lcnt_post_thr_init(void);
void erts_lcnt_late_init(void);
/* @brief Called after everything in the system has been initialized, including
* the schedulers. This is mainly a backwards compatibility shim for matching
* the old lcnt behavior where all lock counting was enabled by default. */
void erts_lcnt_post_startup(void);
void erts_lcnt_thread_setup(void);
void erts_lcnt_thread_exit_handler(void);
/* -- BIF interface -------------------------------------------------------- */
/** @brief Safely iterates through all entries in the given list.
*
* The referenced item will be valid until the next call to
* \c erts_lcnt_iterate_list after which point it may be destroyed; call
* erts_lcnt_retain_lock_info if you wish to hang on to it beyond that point.
*
* Iteration can be cancelled by calling erts_lcnt_release_lock_info on the
* iterator and breaking out of the loop.
*
* @param iterator The iteration variable; set the pointee to NULL to start
* iteration.
* @return 1 while the iterator is valid, 0 at the end of the list. */
int erts_lcnt_iterate_list(erts_lcnt_lock_info_list_t *list, erts_lcnt_lock_info_t **iterator);
/** @brief Clears the counter state of all locks, and releases all locks
* preserved through erts_lcnt_set_preserve_info (if any). */
void erts_lcnt_clear_counters(void);
/** @brief Retrieves the global lock counter state.
*
* Note that the lists may be modified while you're mucking around with them.
* Always use \c erts_lcnt_iterate_list to enumerate them. */
erts_lcnt_data_t erts_lcnt_get_data(void);
void erts_lcnt_retain_lock_info(erts_lcnt_lock_info_t *info);
void erts_lcnt_release_lock_info(erts_lcnt_lock_info_t *info);
/** @brief Sets whether to preserve the info of destroyed/uninstalled locks.
*
* This option makes no distinction whether the lock was destroyed or if lock
* counting was simply disabled, so erts_lcnt_set_category_mask must not be
* used while this option is active. */
void erts_lcnt_set_preserve_info(int enable);
int erts_lcnt_get_preserve_info(void);
/** @brief Updates the category mask, enabling or disabling counting on the
* affected locks as necessary.
*
* This is not guaranteed to find all existing locks; only those that are
* flagged as static locks and those reachable through other means can be
* altered. */
void erts_lcnt_set_category_mask(erts_lock_flags_t mask);
erts_lock_flags_t erts_lcnt_get_category_mask(void);
/* -- Inline implementation ------------------------------------------------ */
/* The following is a hack to get the things we need from erl_thr_progress.h,
* which we can't #include without dependency hell breaking loose.
*
* The size of LcntThrPrgrLaterOp and value of the constant are verified at
* compile-time in erts_lcnt_pre_thr_init. */
int lcnt_thr_progress_unmanaged_delay__(void);
void lcnt_thr_progress_unmanaged_continue__(int handle);
typedef struct { Uint64 _[4]; } LcntThrPrgrLaterOp;
#define LCNT_THR_PRGR_DHANDLE_MANAGED -1
struct lcnt_lock_info_carrier_ {
ethr_atomic_t ref_count;
LcntThrPrgrLaterOp release_entries;
unsigned char entry_count;
erts_lcnt_lock_info_t entries[];
};
typedef struct {
erts_lcnt_time_t timer; /* timer */
int timer_set; /* bool */
int lock_in_conflict; /* bool */
} lcnt_thread_data_t__;
extern const int lcnt_log2_tab64__[];
extern ethr_tsd_key lcnt_thr_data_key__;
extern erts_lock_flags_t lcnt_category_mask__;
#ifdef DEBUG
extern int lcnt_initialization_completed__;
#endif
void lcnt_register_static_lock__(erts_lcnt_ref_t *reference, const char *name, Eterm id,
erts_lock_flags_t flags);
void lcnt_deallocate_carrier__(erts_lcnt_lock_info_carrier_t *carrier);
ERTS_GLB_INLINE
int lcnt_log2__(Uint64 v);
ERTS_GLB_INLINE
void lcnt_update_wait_histogram__(erts_lcnt_hist_t *hist, erts_lcnt_time_t *time_waited);
ERTS_GLB_INLINE
void lcnt_update_stats__(erts_lcnt_lock_stats_t *stats, int lock_in_conflict, erts_lcnt_time_t *time_waited);
ERTS_GLB_INLINE
erts_lcnt_lock_stats_t *lcnt_get_lock_stats__(erts_lcnt_lock_info_t *info, char *file, unsigned int line);
ERTS_GLB_INLINE
void lcnt_dec_lock_state__(ethr_atomic_t *l_state);
ERTS_GLB_INLINE
void lcnt_time__(erts_lcnt_time_t *time);
ERTS_GLB_INLINE
void lcnt_time_add__(erts_lcnt_time_t *t, erts_lcnt_time_t *d);
ERTS_GLB_INLINE
void lcnt_time_diff__(erts_lcnt_time_t *d, erts_lcnt_time_t *t1, erts_lcnt_time_t *t0);
ERTS_GLB_INLINE
void lcnt_retain_carrier__(erts_lcnt_lock_info_carrier_t *carrier);
ERTS_GLB_INLINE
void lcnt_release_carrier__(erts_lcnt_lock_info_carrier_t *carrier);
ERTS_GLB_INLINE
lcnt_thread_data_t__ *lcnt_get_thread_data__(void);
#if ERTS_GLB_INLINE_INCL_FUNC_DEF
ERTS_GLB_INLINE
void lcnt_time__(erts_lcnt_time_t *time) {
/*
* erts_sys_hrtime() is the highest resolution
* we could find, it may or may not be monotonic...
*/
ErtsMonotonicTime mtime = erts_sys_hrtime();
time->s = (unsigned long) (mtime / 1000000000LL);
time->ns = (unsigned long) (mtime - 1000000000LL*time->s);
}
/* difference d must be non-negative */
ERTS_GLB_INLINE
void lcnt_time_add__(erts_lcnt_time_t *t, erts_lcnt_time_t *d) {
t->s += d->s;
t->ns += d->ns;
t->s += t->ns / 1000000000LL;
t->ns = t->ns % 1000000000LL;
}
ERTS_GLB_INLINE
void lcnt_time_diff__(erts_lcnt_time_t *d, erts_lcnt_time_t *t1, erts_lcnt_time_t *t0) {
long ds;
long dns;
ds = t1->s - t0->s;
dns = t1->ns - t0->ns;
/* the difference should not be able to get bigger than 1 sec in ns*/
if (dns < 0) {
ds -= 1;
dns += 1000000000LL;
}
ASSERT(ds >= 0);
d->s = ds;
d->ns = dns;
}
ERTS_GLB_INLINE
int lcnt_log2__(Uint64 v) {
v |= v >> 1;
v |= v >> 2;
v |= v >> 4;
v |= v >> 8;
v |= v >> 16;
v |= v >> 32;
return lcnt_log2_tab64__[((Uint64)((v - (v >> 1))*0x07EDD5E59A4E28C2)) >> 58];
}
ERTS_GLB_INLINE
void lcnt_update_wait_histogram__(erts_lcnt_hist_t *hist, erts_lcnt_time_t *time_waited) {
int idx;
if(time_waited->s > 0 || time_waited->ns > ERTS_LCNT_HISTOGRAM_MAX_NS) {
idx = ERTS_LCNT_HISTOGRAM_SLOT_SIZE - 1;
} else {
unsigned long r = time_waited->ns >> ERTS_LCNT_HISTOGRAM_RSHIFT;
idx = r ? lcnt_log2__(r) : 0;
}
hist->ns[idx]++;
}
ERTS_GLB_INLINE
void lcnt_update_stats__(erts_lcnt_lock_stats_t *stats, int lock_in_conflict, erts_lcnt_time_t *time_waited) {
ethr_atomic_inc(&stats->attempts);
if(lock_in_conflict) {
ethr_atomic_inc(&stats->collisions);
}
if(time_waited) {
stats->times_waited++;
lcnt_time_add__(&stats->total_time_waited, time_waited);
lcnt_update_wait_histogram__(&stats->wait_time_histogram, time_waited);
}
}
/* If we were installed while the lock was held, r/w_state will be 0 and we
* can't tell which unlock or unacquire operation was the last. To get around
* this we assume that all excess operations go *towards* zero rather than down
* to zero, eventually becoming consistent with the actual state once the lock
* is fully released.
*
* Conflicts might not be counted until the recorded state is fully consistent
* with the actual state, but there should be no other ill effects. */
ERTS_GLB_INLINE
void lcnt_dec_lock_state__(ethr_atomic_t *l_state) {
ethr_sint_t state = ethr_atomic_dec_read_acqb(l_state);
/* We can not assume that state is >= -1 here; unlock and unacquire might
* bring it below -1 and race to increment it back. */
if(state < 0) {
ethr_atomic_inc_acqb(l_state);
}
}
ERTS_GLB_INLINE
erts_lcnt_lock_stats_t *lcnt_get_lock_stats__(erts_lcnt_lock_info_t *info, char *file, unsigned int line) {
unsigned int i;
ASSERT(info->location_count >= 1 && info->location_count <= ERTS_LCNT_MAX_LOCK_LOCATIONS);
for(i = 0; i < info->location_count; i++) {
erts_lcnt_lock_stats_t *stats = &info->location_stats[i];
if(stats->file == file && stats->line == line) {
return stats;
}
}
if(info->location_count < ERTS_LCNT_MAX_LOCK_LOCATIONS) {
erts_lcnt_lock_stats_t *stats = &info->location_stats[info->location_count];
stats->file = file;
stats->line = line;
info->location_count++;
return stats;
}
return &info->location_stats[0];
}
ERTS_GLB_INLINE
lcnt_thread_data_t__ *lcnt_get_thread_data__(void) {
lcnt_thread_data_t__ *eltd = (lcnt_thread_data_t__ *)ethr_tsd_get(lcnt_thr_data_key__);
ASSERT(eltd);
return eltd;
}
ERTS_GLB_FORCE_INLINE
int erts_lcnt_open_ref(erts_lcnt_ref_t *ref, int *handle, erts_lcnt_lock_info_carrier_t **result) {
if(ERTS_LIKELY(!erts_lcnt_check_ref_installed(ref))) {
return 0;
}
ASSERT(lcnt_initialization_completed__);
(*handle) = lcnt_thr_progress_unmanaged_delay__();
(*result) = (erts_lcnt_lock_info_carrier_t*)ethr_atomic_read(ref);
if(*result) {
if(*handle != LCNT_THR_PRGR_DHANDLE_MANAGED) {
lcnt_retain_carrier__(*result);
lcnt_thr_progress_unmanaged_continue__(*handle);
}
return 1;
} else if(*handle != LCNT_THR_PRGR_DHANDLE_MANAGED) {
lcnt_thr_progress_unmanaged_continue__(*handle);
}
return 0;
}
ERTS_GLB_FORCE_INLINE
void erts_lcnt_close_ref(int handle, erts_lcnt_lock_info_carrier_t *carrier) {
if(handle != LCNT_THR_PRGR_DHANDLE_MANAGED) {
lcnt_release_carrier__(carrier);
}
}
ERTS_GLB_INLINE
void erts_lcnt_init_ref(erts_lcnt_ref_t *ref) {
ethr_atomic_init(ref, (ethr_sint_t)NULL);
}
ERTS_GLB_INLINE
void erts_lcnt_init_ref_x(erts_lcnt_ref_t *ref, const char *name,
Eterm id, erts_lock_flags_t flags) {
erts_lcnt_init_ref(ref);
if(flags & ERTS_LOCK_FLAGS_PROPERTY_STATIC) {
lcnt_register_static_lock__(ref, name, id, flags);
}
if(erts_lcnt_check_enabled(flags)) {
erts_lcnt_install_new_lock_info(ref, name, id, flags);
}
}
ERTS_GLB_FORCE_INLINE
int erts_lcnt_check_ref_installed(erts_lcnt_ref_t *ref) {
return (!!*ethr_atomic_addr(ref));
}
ERTS_GLB_FORCE_INLINE
void erts_lcnt_lock(erts_lcnt_ref_t *ref) {
erts_lcnt_lock_info_carrier_t *carrier;
int handle;
if(erts_lcnt_open_ref(ref, &handle, &carrier)) {
erts_lcnt_lock_idx(carrier, 0);
erts_lcnt_close_ref(handle, carrier);
}
}
ERTS_GLB_FORCE_INLINE
void erts_lcnt_lock_opt(erts_lcnt_ref_t *ref, Uint16 option) {
erts_lcnt_lock_info_carrier_t *carrier;
int handle;
if(erts_lcnt_open_ref(ref, &handle, &carrier)) {
erts_lcnt_lock_opt_idx(carrier, 0, option);
erts_lcnt_close_ref(handle, carrier);
}
}
ERTS_GLB_FORCE_INLINE
void erts_lcnt_lock_post(erts_lcnt_ref_t *ref) {
erts_lcnt_lock_info_carrier_t *carrier;
int handle;
if(erts_lcnt_open_ref(ref, &handle, &carrier)) {
erts_lcnt_lock_post_idx(carrier, 0);
erts_lcnt_close_ref(handle, carrier);
}
}
ERTS_GLB_FORCE_INLINE
void erts_lcnt_lock_post_x(erts_lcnt_ref_t *ref, char *file, unsigned int line) {
erts_lcnt_lock_info_carrier_t *carrier;
int handle;
if(erts_lcnt_open_ref(ref, &handle, &carrier)) {
erts_lcnt_lock_post_x_idx(carrier, 0, file, line);
erts_lcnt_close_ref(handle, carrier);
}
}
ERTS_GLB_FORCE_INLINE
void erts_lcnt_lock_unacquire(erts_lcnt_ref_t *ref) {
erts_lcnt_lock_info_carrier_t *carrier;
int handle;
if(erts_lcnt_open_ref(ref, &handle, &carrier)) {
erts_lcnt_lock_unacquire_idx(carrier, 0);
erts_lcnt_close_ref(handle, carrier);
}
}
ERTS_GLB_FORCE_INLINE
void erts_lcnt_unlock(erts_lcnt_ref_t *ref) {
erts_lcnt_lock_info_carrier_t *carrier;
int handle;
if(erts_lcnt_open_ref(ref, &handle, &carrier)) {
erts_lcnt_unlock_idx(carrier, 0);
erts_lcnt_close_ref(handle, carrier);
}
}
ERTS_GLB_FORCE_INLINE
void erts_lcnt_unlock_opt(erts_lcnt_ref_t *ref, Uint16 option) {
erts_lcnt_lock_info_carrier_t *carrier;
int handle;
if(erts_lcnt_open_ref(ref, &handle, &carrier)) {
erts_lcnt_unlock_opt_idx(carrier, 0, option);
erts_lcnt_close_ref(handle, carrier);
}
}
ERTS_GLB_FORCE_INLINE
void erts_lcnt_trylock(erts_lcnt_ref_t *ref, int result) {
erts_lcnt_lock_info_carrier_t *carrier;
int handle;
if(erts_lcnt_open_ref(ref, &handle, &carrier)) {
erts_lcnt_trylock_idx(carrier, 0, result);
erts_lcnt_close_ref(handle, carrier);
}
}
ERTS_GLB_FORCE_INLINE
void erts_lcnt_trylock_opt(erts_lcnt_ref_t *ref, int result, Uint16 option) {
erts_lcnt_lock_info_carrier_t *carrier;
int handle;
if(erts_lcnt_open_ref(ref, &handle, &carrier)) {
erts_lcnt_trylock_opt_idx(carrier, 0, result, option);
erts_lcnt_close_ref(handle, carrier);
}
}
ERTS_GLB_INLINE
void erts_lcnt_lock_idx(erts_lcnt_lock_info_carrier_t *carrier, int index) {
erts_lcnt_lock_opt_idx(carrier, index, ERTS_LOCK_OPTION_WRITE);
}
ERTS_GLB_INLINE
void erts_lcnt_lock_opt_idx(erts_lcnt_lock_info_carrier_t *carrier, int index, Uint16 option) {
erts_lcnt_lock_info_t *info = &carrier->entries[index];
lcnt_thread_data_t__ *eltd = lcnt_get_thread_data__();
ASSERT(index < carrier->entry_count);
ASSERT((option & ERTS_LOCK_OPTION_READ) || (option & ERTS_LOCK_OPTION_WRITE));
if(option & ERTS_LOCK_OPTION_WRITE) {
ethr_sint_t w_state, r_state;
w_state = ethr_atomic_inc_read(&info->w_state) - 1;
r_state = ethr_atomic_read(&info->r_state);
/* We cannot acquire w_lock if either w or r are taken */
eltd->lock_in_conflict = (w_state > 0) || (r_state > 0);
} else {
ethr_sint_t w_state = ethr_atomic_read(&info->w_state);
/* We cannot acquire r_lock if w_lock is taken */
eltd->lock_in_conflict = (w_state > 0);
}
if(option & ERTS_LOCK_OPTION_READ) {
ASSERT(info->flags & ERTS_LOCK_FLAGS_PROPERTY_READ_WRITE);
ethr_atomic_inc(&info->r_state);
}
if(eltd->lock_in_conflict) {
/* Only set the timer if nobody else has it. This should only happen
* when proc_locks acquires several locks "atomically." All other locks
* will block the thread when locked (w_state > 0) */
if(eltd->timer_set == 0) {
lcnt_time__(&eltd->timer);
}
eltd->timer_set++;
}
}
ERTS_GLB_INLINE
void erts_lcnt_lock_post_idx(erts_lcnt_lock_info_carrier_t *carrier, int index) {
erts_lcnt_lock_post_x_idx(carrier, index, NULL, 0);
}
ERTS_GLB_INLINE
void erts_lcnt_lock_post_x_idx(erts_lcnt_lock_info_carrier_t *carrier, int index, char *file, unsigned int line) {
erts_lcnt_lock_info_t *info = &carrier->entries[index];
lcnt_thread_data_t__ *eltd = lcnt_get_thread_data__();
erts_lcnt_lock_stats_t *stats;
ASSERT(index < carrier->entry_count);
/* If the lock was in conflict, update the time spent waiting. */
stats = lcnt_get_lock_stats__(info, file, line);
if(eltd->timer_set) {
erts_lcnt_time_t time_wait;
erts_lcnt_time_t timer;
lcnt_time__(&timer);
lcnt_time_diff__(&time_wait, &timer, &eltd->timer);
lcnt_update_stats__(stats, eltd->lock_in_conflict, &time_wait);
eltd->timer_set--;
ASSERT(eltd->timer_set >= 0);
} else {
lcnt_update_stats__(stats, eltd->lock_in_conflict, NULL);
}
}
ERTS_GLB_INLINE
void erts_lcnt_unlock_idx(erts_lcnt_lock_info_carrier_t *carrier, int index) {
ASSERT(index < carrier->entry_count);
erts_lcnt_unlock_opt_idx(carrier, index, ERTS_LOCK_OPTION_WRITE);
}
ERTS_GLB_INLINE
void erts_lcnt_unlock_opt_idx(erts_lcnt_lock_info_carrier_t *carrier, int index, Uint16 option) {
erts_lcnt_lock_info_t *info = &carrier->entries[index];
ASSERT(index < carrier->entry_count);
ASSERT((option & ERTS_LOCK_OPTION_READ) || (option & ERTS_LOCK_OPTION_WRITE));
if(option & ERTS_LOCK_OPTION_WRITE) {
lcnt_dec_lock_state__(&info->w_state);
}
if(option & ERTS_LOCK_OPTION_READ) {
ASSERT(info->flags & ERTS_LOCK_FLAGS_PROPERTY_READ_WRITE);
lcnt_dec_lock_state__(&info->r_state);
}
}
ERTS_GLB_INLINE
void erts_lcnt_lock_unacquire_idx(erts_lcnt_lock_info_carrier_t *carrier, int index) {
erts_lcnt_lock_info_t *info = &carrier->entries[index];
ASSERT(index < carrier->entry_count);
lcnt_dec_lock_state__(&info->w_state);
}
ERTS_GLB_INLINE
void erts_lcnt_trylock_idx(erts_lcnt_lock_info_carrier_t *carrier, int index, int result) {
ASSERT(index < carrier->entry_count);
erts_lcnt_trylock_opt_idx(carrier, index, result, ERTS_LOCK_OPTION_WRITE);
}
ERTS_GLB_INLINE
void erts_lcnt_trylock_opt_idx(erts_lcnt_lock_info_carrier_t *carrier, int index, int result, Uint16 option) {
erts_lcnt_lock_info_t *info = &carrier->entries[index];
ASSERT(index < carrier->entry_count);
ASSERT((option & ERTS_LOCK_OPTION_READ) || (option & ERTS_LOCK_OPTION_WRITE));
if(result != EBUSY) {
if(option & ERTS_LOCK_OPTION_WRITE) {
ethr_atomic_inc(&info->w_state);
}
if(option & ERTS_LOCK_OPTION_READ) {
ASSERT(info->flags & ERTS_LOCK_FLAGS_PROPERTY_READ_WRITE);
ethr_atomic_inc(&info->r_state);
}
lcnt_update_stats__(&info->location_stats[0], 0, NULL);
} else {
ethr_atomic_inc(&info->location_stats[0].attempts);
ethr_atomic_inc(&info->location_stats[0].collisions);
}
}
ERTS_GLB_INLINE
void erts_lcnt_init_lock_info_idx(erts_lcnt_lock_info_carrier_t *carrier, int index,
const char *name, Eterm id, erts_lock_flags_t flags) {
erts_lcnt_lock_info_t *info = &carrier->entries[index];
ASSERT(is_immed(id));
ASSERT(flags & ERTS_LOCK_FLAGS_MASK_TYPE);
ASSERT(flags & ERTS_LOCK_FLAGS_MASK_CATEGORY);
info->flags = flags;
info->name = name;
info->id = id;
}
ERTS_GLB_INLINE
void lcnt_retain_carrier__(erts_lcnt_lock_info_carrier_t *carrier) {
#ifdef DEBUG
ASSERT(ethr_atomic_inc_read_acqb(&carrier->ref_count) >= 2);
#else
ethr_atomic_inc_acqb(&carrier->ref_count);
#endif
}
ERTS_GLB_INLINE
void lcnt_release_carrier__(erts_lcnt_lock_info_carrier_t *carrier) {
ethr_sint_t count = ethr_atomic_dec_read_relb(&carrier->ref_count);
ASSERT(count >= 0);
if(count == 0) {
lcnt_deallocate_carrier__(carrier);
}
}
#endif
#endif /* ifdef ERTS_ENABLE_LOCK_COUNT */
#endif /* ifndef ERTS_LOCK_COUNT_H__ */
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