aboutsummaryrefslogtreecommitdiffstats
path: root/erts/emulator/beam/erl_lock_count.h
diff options
context:
space:
mode:
Diffstat (limited to 'erts/emulator/beam/erl_lock_count.h')
-rw-r--r--erts/emulator/beam/erl_lock_count.h937
1 files changed, 815 insertions, 122 deletions
diff --git a/erts/emulator/beam/erl_lock_count.h b/erts/emulator/beam/erl_lock_count.h
index 6caffbfe86..c89dfcba47 100644
--- a/erts/emulator/beam/erl_lock_count.h
+++ b/erts/emulator/beam/erl_lock_count.h
@@ -18,60 +18,56 @@
* %CopyrightEnd%
*/
-/*
- * Description: Statistics for locks.
- *
- * Author: Björn-Egil Dahlberg
- * Date: 2008-07-03
- * Abstract:
- * Locks statistics internal representation.
- *
- * Conceptual representation,
- * - set name
- * | - id (the unique lock)
- * | | - lock type
- * | | - statistics
- * | | | - location (file and line number)
- * | | | - tries
- * | | | - 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 aqusition had.
- *
- * Runtime options
- * - suspend, used when internal lock-counting can't be applied. For instance
- * when allocating a term for the outside and halloc needs to be used.
- * Default: off.
- * - location, reserved and not used.
- * - proclock, disable proclock counting. Used when performance might be an
- * issue. Accessible from erts_debug:lock_counters({process_locks, bool()}).
- * Default: off.
- * - copysave, enable saving of destroyed locks (and thereby its statistics).
- * If memory constraints is an issue this need to be disabled.
- * Accessible from erts_debug:lock_counters({copy_save, bool()}).
- * Default: off.
+/**
+ * @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 aqusition had.
+ *
+ * Runtime options:
+ * - location, reserved and not used.
+ * - proclock, disable proclock counting. Used when performance might be an
+ * issue. Accessible from erts_debug:lock_counters({process_locks, bool()}).
+ * Default: off.
+ * - copysave, enable saving of destroyed locks (and thereby its statistics).
+ * If memory constraints is an issue this need to be disabled.
+ * Accessible from erts_debug:lock_counters({copy_save, bool()}).
+ * Default: off.
*/
-#include "sys.h"
-
#ifndef ERTS_LOCK_COUNT_H__
#define ERTS_LOCK_COUNT_H__
#ifdef ERTS_ENABLE_LOCK_COUNT
#ifndef ERTS_ENABLE_LOCK_POSITION
-/* Enable in order for _x variants of mtx functions to be used. */
+/** @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"
#define ERTS_LCNT_MAX_LOCK_LOCATIONS (10)
@@ -106,13 +102,8 @@
| ERTS_LCNT_LT_RWMUTEX \
| ERTS_LCNT_LT_PROCLOCK )
-#define ERTS_LCNT_LOCK_TYPE(lock) ((lock)->flag & ERTS_LCNT_LT_ALL)
-#define ERTS_LCNT_IS_LOCK_INVALID(lock) (!((lock)->flag & ERTS_LCNT_LT_ALL))
-#define ERTS_LCNT_CLEAR_FLAG(lock) ((lock)->flag = 0)
-
-/* runtime options */
+/* Runtime options */
-#define ERTS_LCNT_OPT_SUSPEND (((Uint16) 1) << 0)
#define ERTS_LCNT_OPT_LOCATION (((Uint16) 1) << 1)
#define ERTS_LCNT_OPT_PROCLOCK (((Uint16) 1) << 2)
#define ERTS_LCNT_OPT_PORTLOCK (((Uint16) 1) << 3)
@@ -123,116 +114,818 @@ typedef struct {
unsigned long ns;
} erts_lcnt_time_t;
-extern erts_lcnt_time_t timer_start;
-
typedef struct {
- Uint32 ns[ERTS_LCNT_HISTOGRAM_SLOT_SIZE]; /* log2 array of nano seconds occurences */
+ /* @brief log2 array of nano seconds occurences */
+ Uint32 ns[ERTS_LCNT_HISTOGRAM_SLOT_SIZE];
} erts_lcnt_hist_t;
-typedef struct erts_lcnt_lock_stats_s {
- /* "tries" and "colls" needs to be atomic since
- * trylock busy does not acquire a lock and there
- * is no post action to rectify the situation
- */
+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. */
- char *file; /* which file the lock was taken */
- unsigned int line; /* line number in file */
+ ethr_atomic_t attempts;
+ ethr_atomic_t collisions;
- ethr_atomic_t tries; /* n tries to get lock */
- ethr_atomic_t colls; /* n collisions of tries to get lock */
+ erts_lcnt_time_t total_time_waited;
+ Uint64 times_waited;
- unsigned long timer_n; /* #times waited for lock */
- erts_lcnt_time_t timer; /* total wait time for lock */
- erts_lcnt_hist_t hist;
+ erts_lcnt_hist_t wait_time_histogram;
} erts_lcnt_lock_stats_t;
-/* rw locks uses both states, other locks only uses w_state */
-typedef struct erts_lcnt_lock_s {
- char *name; /* lock name */
- Uint16 flag; /* lock type */
- Eterm id; /* id if possible */
+typedef struct lcnt_lock_info_t_ {
+ const char *name; /**< Lock name */
+ Uint16 flag; /**< Lock type */
+ Eterm id; /**< Id if possible, must be an immediate */
-#ifdef DEBUG
+ /* 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;
+
+#ifdef LCNT_DEBUG_LOCK_FLOW
+ /** @brief Tracks lock/unlock operations. This will explode if the lock is
+ * held at the time lock counting is installed.
+ *
+ * Avoid enabling existing locks at runtime while running in this
+ * configuration. */
ethr_atomic_t flowstate;
#endif
- /* lock states */
- ethr_atomic_t w_state; /* 0 not taken, otherwise n threads waiting */
- ethr_atomic_t r_state; /* 0 not taken, > 0 -> writes will wait */
+ struct lcnt_lock_info_t_ *prev;
+ struct lcnt_lock_info_t_ *next;
- /* statistics */
- unsigned int n_stats;
- erts_lcnt_lock_stats_t stats[ERTS_LCNT_MAX_LOCK_LOCATIONS]; /* first entry is "undefined"*/
+ /** @brief Used in place of erts_refc_t to avoid a circular dependency. */
+ ethr_atomic_t ref_count;
+ ethr_atomic32_t lock;
- /* chains for list handling */
- /* data is hold by lcnt_lock */
- struct erts_lcnt_lock_s *prev;
- struct erts_lcnt_lock_s *next;
-} erts_lcnt_lock_t;
+ /** @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_ *);
-typedef struct {
- erts_lcnt_lock_t *head;
- erts_lcnt_lock_t *tail;
- unsigned long n;
-} erts_lcnt_lock_list_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 duration; /* time since last clear */
- erts_lcnt_lock_list_t *current_locks;
- erts_lcnt_lock_list_t *deleted_locks;
+ 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 {
- int id;
+typedef struct lcnt_lock_info_carrier_ erts_lcnt_lock_info_carrier_t;
- erts_lcnt_time_t timer; /* timer */
- int timer_set; /* bool */
- int lock_in_conflict; /* bool */
-} erts_lcnt_thread_data_t;
+typedef ethr_atomic_t erts_lcnt_ref_t;
-/* globals */
+/* -- Globals -------------------------------------------------------------- */
extern Uint16 erts_lcnt_rt_options;
-/* function declerations */
-
-void erts_lcnt_init(void);
+/* -- 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_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);
+
+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 ------------------------------------------------- */
+
+erts_lcnt_lock_info_carrier_t *erts_lcnt_create_lock_info_carrier(int count);
+
+/** @brief Fills in the name and lock type of the given index. */
+#define erts_lcnt_init_lock_info_idx(carrier, index, name, flag) \
+ erts_lcnt_init_lock_info_x_idx(carrier, index, name, flag, NIL)
+
+/** @copydoc erts_lcnt_install_new_lock_info
+ * @param id An immediate erlang term with whatever extra data you want to
+ * identify this lock with. */
+ERTS_GLB_INLINE
+void erts_lcnt_init_lock_info_x_idx(erts_lcnt_lock_info_carrier_t *carrier, int index,
+ const char *name, Uint16 flag, Eterm id);
+
+/** @brief Initializes a lock counter reference; this must be called prior to
+ * using any other functions in this module. */
+#define erts_lcnt_init_ref(ref) ethr_atomic_init(ref, (ethr_sint_t)NULL);
+
+/** @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);
+
+/** @brief Convenience macro to install a single lock counter of the given
+ * name and type. */
+#define erts_lcnt_install_new_lock_info(reference, name, flag) \
+ erts_lcnt_install_new_lock_info_x(reference, name, flag, NIL)
+
+/** @copydoc erts_lcnt_install_new_lock_info
+ * @param id An immediate erlang term with whatever extra data you want to
+ * identify this lock with. */
+#define erts_lcnt_install_new_lock_info_x(reference, name, flag, id) \
+ do { \
+ erts_lcnt_lock_info_carrier_t *__carrier; \
+ __carrier = erts_lcnt_create_lock_info_carrier(1); \
+ erts_lcnt_init_lock_info_x_idx(__carrier, 0, name, flag, id); \
+ erts_lcnt_install(reference, __carrier); \
+ } while(0)
+
+/* -- Module initialization ------------------------------------------------ */
+
+void erts_lcnt_pre_thr_init(void);
+void erts_lcnt_post_thr_init(void);
void erts_lcnt_late_init(void);
-/* thread operations */
void erts_lcnt_thread_setup(void);
void erts_lcnt_thread_exit_handler(void);
-/* list operations (local) */
-erts_lcnt_lock_list_t *erts_lcnt_list_init(void);
+/* -- BIF interface -------------------------------------------------------- */
-void erts_lcnt_list_insert(erts_lcnt_lock_list_t *list, erts_lcnt_lock_t *lock);
-void erts_lcnt_list_delete(erts_lcnt_lock_list_t *list, erts_lcnt_lock_t *lock);
-
-/* lock operations (global) */
-void erts_lcnt_init_lock(erts_lcnt_lock_t *lock, char *name, Uint16 flag);
-void erts_lcnt_init_lock_x(erts_lcnt_lock_t *lock, char *name, Uint16 flag, Eterm id);
-void erts_lcnt_init_lock_empty(erts_lcnt_lock_t *lock);
-void erts_lcnt_destroy_lock(erts_lcnt_lock_t *lock);
+/** @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);
-void erts_lcnt_lock(erts_lcnt_lock_t *lock);
-void erts_lcnt_lock_opt(erts_lcnt_lock_t *lock, Uint16 option);
-void erts_lcnt_lock_post(erts_lcnt_lock_t *lock);
-void erts_lcnt_lock_post_x(erts_lcnt_lock_t *lock, char *file, unsigned int line);
-void erts_lcnt_lock_unaquire(erts_lcnt_lock_t *lock);
+/** @brief Clears the counter state of all locks, and releases all locks
+ * preserved through ERTS_LCNT_OPT_COPYSAVE (if any). */
+void erts_lcnt_clear_counters(void);
-void erts_lcnt_unlock(erts_lcnt_lock_t *lock);
-void erts_lcnt_unlock_opt(erts_lcnt_lock_t *lock, Uint16 option);
+/** @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_trylock_opt(erts_lcnt_lock_t *lock, int res, Uint16 option);
-void erts_lcnt_trylock(erts_lcnt_lock_t *lock, int res);
+void erts_lcnt_retain_lock_info(erts_lcnt_lock_info_t *info);
+void erts_lcnt_release_lock_info(erts_lcnt_lock_info_t *info);
-/* bif interface */
Uint16 erts_lcnt_set_rt_opt(Uint16 opt);
Uint16 erts_lcnt_clear_rt_opt(Uint16 opt);
-void erts_lcnt_clear_counters(void);
-char *erts_lcnt_lock_type(Uint16 type);
-erts_lcnt_data_t *erts_lcnt_get_data(void);
+
+const char *erts_lcnt_lock_type(Uint16 type);
+
+/* -- 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;
+
+ void (*deallocate)(struct lcnt_lock_info_carrier_ *);
+
+ 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 ethr_tsd_key lcnt_thr_data_key__;
+
+/** @brief Some operations (eg erts_alloc or erts_thr_progress_unmanaged_delay)
+ * are unsafe in the early stages of initialization, so we're using this flag
+ * to know when we can move over to normal operation. */
+extern int lcnt_initialization_completed__;
+
+extern const int lcnt_log2_tab64__[];
+
+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) {
+ ASSERT(info->location_count >= 1 && info->location_count <= ERTS_LCNT_MAX_LOCK_LOCATIONS);
+
+ if(erts_lcnt_rt_options & ERTS_LCNT_OPT_LOCATION) {
+ unsigned int i;
+
+ 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(!*ethr_atomic_addr(ref) || !lcnt_initialization_completed__) {
+ return 0;
+ }
+
+ (*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_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_LCNT_LO_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_LCNT_LO_READ) || (option & ERTS_LCNT_LO_WRITE));
+
+ if(option & ERTS_LCNT_LO_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_LCNT_LO_READ) {
+ 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);
+
+#ifdef LCNT_DEBUG_LOCK_FLOW
+ if(!(info->flag & (ERTS_LCNT_LT_RWMUTEX | ERTS_LCNT_LT_RWSPINLOCK))) {
+ ASSERT(ethr_atomic_inc_read(&info->flowstate) == 1);
+ }
+#endif
+
+ /* 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) {
+#ifdef LCNT_DEBUG_LOCK_FLOW
+ erts_lcnt_lock_info_t *info = &carrier->entries[index];
+
+ ASSERT(ethr_atomic_dec_read(&info->flowstate) == 0);
+#endif
+
+ ASSERT(index < carrier->entry_count);
+
+ erts_lcnt_unlock_opt_idx(carrier, index, ERTS_LCNT_LO_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_LCNT_LO_READ) || (option & ERTS_LCNT_LO_WRITE));
+
+ if(option & ERTS_LCNT_LO_WRITE) {
+ lcnt_dec_lock_state__(&info->w_state);
+ }
+
+ if(option & ERTS_LCNT_LO_READ) {
+ 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) {
+#ifdef LCNT_DEBUG_LOCK_FLOW
+ erts_lcnt_lock_info_t *info = &carrier->entries[index];
+
+ ASSERT(result == EBUSY || ethr_atomic_inc_read(&info->flowstate) == 1);
+#endif
+
+ ASSERT(index < carrier->entry_count);
+
+ erts_lcnt_trylock_opt_idx(carrier, index, result, ERTS_LCNT_LO_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_LCNT_LO_READ) || (option & ERTS_LCNT_LO_WRITE));
+
+ if(result != EBUSY) {
+ if(option & ERTS_LCNT_LO_WRITE) {
+ ethr_atomic_inc(&info->w_state);
+ }
+
+ if(option & ERTS_LCNT_LO_READ) {
+ 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_x_idx(erts_lcnt_lock_info_carrier_t *carrier, int index,
+ const char *name, Uint16 flag, Eterm id) {
+ erts_lcnt_lock_info_t *info = &carrier->entries[index];
+
+ ASSERT(is_immed(id));
+
+ info->flag = flag;
+ 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) {
+ carrier->deallocate(carrier);
+ }
+}
+
+#endif
#endif /* ifdef ERTS_ENABLE_LOCK_COUNT */
#endif /* ifndef ERTS_LOCK_COUNT_H__ */