snapshot v4/p13; more juggling

This commit is contained in:
Gregory Burd 2024-03-30 12:28:57 -04:00
parent 06e0b3bcd7
commit 0079415c34
2 changed files with 72 additions and 121 deletions

View file

@ -1,14 +1,4 @@
#include <assert.h>
#include <errno.h>
#include <stddef.h>
#include <stdio.h>
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
// OPTIONS to set before including sl.h
// ---------------------------------------------------------------------------
#define DEBUG
@ -370,9 +360,8 @@ main()
#endif
#ifdef SNAPSHOTS
sample_t *restored = api_skip_restore_snapshot_sample(list, snaps[snap_i - 1] );
api_skip_release_snapshot_sample(list);
api_skip_free_sample(restored);
api_skip_restore_snapshot_sample(list, snaps[snap_i - 1] );
api_skip_release_snapshots_sample(list);
#endif
assert(strcmp(api_skip_pos_sample(list, SKIP_GTE, -(TEST_ARRAY_SIZE)-1)->value, int_to_roman_numeral(-(TEST_ARRAY_SIZE))) == 0);

View file

@ -31,6 +31,17 @@
* Zhipeng Li <zhpeng.is@gmail.com>
*/
#include <assert.h>
#include <errno.h>
#include <stdarg.h>
#include <stddef.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#ifndef _SKIPLIST_H_
#define _SKIPLIST_H_
@ -168,59 +179,6 @@ void __attribute__((format(printf, 4, 5))) __skip_diag_(const char *file, int li
#endif
#endif
#ifndef SKIPLIST_READ_RDTSC
#define SKIPLIST_READ_RDTSC
#if defined(__linux__)
#if defined(__x86_64__) || defined(__i386__)
#include <stdint.h>
#include <stdio.h>
static inline uint64_t
__skip_read_rdtsc(void)
{
unsigned int hi, lo;
__asm__ volatile("rdtsc" : "=a"(lo), "=d"(hi));
return ((uint64_t)lo) | (((uint64_t)hi) << 32);
}
#elif defined(__arm__) && defined(__aarch64__)
uint64_t
__skip_read_rdtsc()
{
uint64_t value;
asm volatile("MRS %0, PMCCNTR_EL0" : "=r"(value));
return value;
}
#else
#warning Unsupported arch, unable to read the TSC or MRS register on this platform.
#endif
#elif defined(__unix__) || defined(__APPLE__)
#include <sys/time.h>
#include <stdint.h>
#include <stdio.h>
static inline uint64_t
__skip_read_rdtsc(void)
{
struct timeval tv;
gettimeofday(&tv, NULL);
return (uint64_t)tv.tv_sec * 1000000 + tv.tv_usec;
}
#elif defined(_WIN32)
#include <intrin.h>
#include <stdint.h>
#include <stdio.h>
static inline uint64_t
__skip_read_rdtsc(void)
{
return __rdtsc();
}
#endif
#else
#warning Unable to read the Time Stamp Counter (TSC) register on this platform.
#endif
/*
* Skip List declarations.
*/
@ -232,7 +190,7 @@ __skip_read_rdtsc(void)
/*
* A Skip List contains elements, a portion of which is used to manage those
* elements while the rest is defined by the use case for this declaration. The
* house keeping portion is the SKIPLIST_ENTRY below. It maintains the array of
* housekeeping portion is the SKIPLIST_ENTRY below. It maintains the array of
* forward pointers to nodes and has a height (a zero-based count of levels, so
* a height of `0` means one (1) level and a height of `4` means five (5)
* levels).
@ -241,7 +199,7 @@ __skip_read_rdtsc(void)
struct __skiplist_##decl_entry { \
struct type *sle_prev, **sle_next; \
size_t sle_height; \
uint64_t sle_gen; \
size_t sle_gen; \
}
#define SKIPLIST_FOREACH_H2T(decl, prefix, list, elm, iter) \
@ -284,12 +242,15 @@ __skip_read_rdtsc(void)
size_t (*sizeof_entry)(decl##_node_t *); \
int (*compare_entries)(struct decl *, decl##_node_t *, decl##_node_t *, void *); \
int (*preserve_node)(struct decl * slist, const decl##_node_t *src, decl##_node_t **preserved); \
void (*release_snapshots)(struct decl *); \
size_t (*snapshot_current_era)(struct decl *); \
size_t (*snapshot_incr_era)(struct decl *); \
} slh_fns; \
void *slh_aux; \
decl##_node_t *slh_head; \
decl##_node_t *slh_tail; \
struct { \
uint64_t gen; \
size_t gen; \
decl##_node_t *pres; \
} slh_snap; \
} decl##_t; \
@ -350,16 +311,6 @@ __skip_read_rdtsc(void)
return bytes; \
} \
\
/** \
* -- __skip_preserve_node_fn_ TODO \
* \
* Optional: (Snapshot) calls `slh_fns.preserve_node`. \
*/ \
static int __skip_preserve_node_fn_##decl(decl##_t *slist, const decl##_node_t *src, decl##_node_t **preserved) \
{ \
return slist->slh_fns.preserve_node(slist, src, preserved); \
} \
\
/** \
* -- __skip_compare_nodes_ \
* \
@ -407,27 +358,6 @@ __skip_read_rdtsc(void)
return level; \
} \
\
/** \
* -- __skip_snapshot_gen \
* \
* Returns the current generation for snapshot purposes. \
* We use the TSC register on x86_64 for this which, on a 4 GHz processor, \
* would take over 146,000 years for the TSC to wrap around, starting from \
* zero. In practice it won't generally be starting from zero, so if it \
* is within ~5 years of wrapping we'll adjust it a bit. \
*/ \
static inline uint64_t __skip_snapshot_gen_##decl() \
{ \
static uint64_t cycles_5yr_before_a_wrap = 18444725120000000000ULL; \
static uint64_t adjustment = 0; \
uint64_t tsc = __skip_read_rdtsc(); \
if (adjustment == 0) { \
if (tsc > cycles_5yr_before_a_wrap) \
adjustment = tsc - 1; \
} \
return tsc - adjustment; \
} \
\
/** \
* -- skip_alloc_node_ \
* \
@ -613,6 +543,8 @@ __skip_read_rdtsc(void)
slist->slh_fns.free_entry(node); \
free(node); \
} \
if (slist->slh_fns.snapshot_incr_era) \
slist->slh_fns.snapshot_incr_era(slist); \
return; \
} \
\
@ -672,15 +604,6 @@ __skip_read_rdtsc(void)
return len; \
} \
\
/** \
* -- skip_release_snapshot_ TODO/WIP \
* \
*/ \
void prefix##skip_release_snapshot_##decl(decl##_t *slist) \
{ \
if (slist == NULL) \
return; \
} \
/** \
* -- __skip_insert_ \
* \
@ -715,7 +638,7 @@ __skip_read_rdtsc(void)
return -1; \
} \
/* Record the generation for this node to enable snapshots. */ \
new->field.sle_gen = __skip_snapshot_gen_##decl(); \
new->field.sle_gen = slist->slh_fns.snapshot_current_era ? slist->slh_fns.snapshot_current_era(slist) : 0; \
/* Coin toss to determine level of this new node [0, max) */ \
cur_height = slist->slh_head->field.sle_height; \
new_height = __skip_toss_##decl(slist->slh_max_height); \
@ -764,7 +687,7 @@ __skip_read_rdtsc(void)
slist->slh_tail->field.sle_height = new_height; \
} \
/* Record this node's generation for snapshots. */ \
new->field.sle_gen = __skip_snapshot_gen_##decl(); \
new->field.sle_gen = slist->slh_fns.snapshot_current_era ? slist->slh_fns.snapshot_current_era(slist) : 0; \
/* Increase our list length (aka. size, count, etc.) by one. */ \
slist->slh_length++; \
\
@ -1004,12 +927,14 @@ __skip_read_rdtsc(void)
{ \
static decl##_node_t apath[SKIPLIST_MAX_HEIGHT + 1]; \
int rc = 0, np; \
uint64_t cur_gen = __skip_snapshot_gen_##decl(); \
size_t cur_gen; \
decl##_node_t *src, **path = (decl##_node_t **)&apath; \
\
if (slist == NULL) \
return -1; \
\
cur_gen = slist->slh_fns.snapshot_current_era ? slist->slh_fns.snapshot_current_era(slist) : 0; \
\
/* Allocate a buffer, or use a static one. */ \
if (SKIPLIST_MAX_HEIGHT == 1) { \
path = malloc(sizeof(decl##_node_t *) * slist->slh_max_height + 1); \
@ -1031,9 +956,11 @@ __skip_read_rdtsc(void)
Snapshots preserve the node if it is younger than our snapshot \
moment. */ \
if (slist->slh_fns.preserve_node) { \
np = __skip_preserve_node_fn_##decl(slist, src, NULL); \
np = slist->slh_fns.preserve_node(slist, src, NULL); \
if (np > 0) \
return np; \
if (slist->slh_fns.snapshot_incr_era) \
slist->slh_fns.snapshot_incr_era(slist); \
} \
\
slist->slh_fns.update_entry(src); \
@ -1073,9 +1000,11 @@ __skip_read_rdtsc(void)
Snapshots preserve the node if it is younger than our snapshot \
moment, this node is about to be removed. */ \
if (slist->slh_fns.preserve_node) { \
np = __skip_preserve_node_fn_##decl(slist, node, NULL); \
np = slist->slh_fns.preserve_node(slist, node, NULL); \
if (np > 0) \
return np; \
if (slist->slh_fns.snapshot_incr_era) \
slist->slh_fns.snapshot_incr_era(slist); \
} \
/* We found it, set the next->prev to the node->prev keeping in mind \
that the next node might be the tail). */ \
@ -1129,13 +1058,23 @@ __skip_read_rdtsc(void)
if (slist == NULL) \
return; \
\
prefix##skip_release_##decl(slist); /* TODO snaps free? */ \
prefix##skip_release_##decl(slist); \
\
free(slist->slh_head); \
free(slist->slh_tail); \
}
#define SKIPLIST_DECL_SNAPSHOTS(decl, prefix, field) \
/** \
* -- _skip_release_snapshots_ TODO \
* \
*/ \
void prefix##skip_release_snapshots_##decl(decl##_t *slist) \
{ \
if (slist == NULL) \
return; \
} \
\
/** \
* -- __skip_preserve_node_ \
* \
@ -1228,7 +1167,7 @@ __skip_read_rdtsc(void)
{ \
if (slist == NULL) \
return 0; \
slist->slh_snap.gen = __skip_snapshot_gen_##decl(); \
slist->slh_snap.gen = slist->slh_fns.snapshot_current_era(slist); \
return slist->slh_snap.gen; \
} \
\
@ -1252,10 +1191,9 @@ __skip_read_rdtsc(void)
* - Starting with slh_pres, the `node->field.sle_next[0]` form a \
* singly-linked list. \
*/ \
decl##_t *prefix##skip_restore_snapshot_##decl(decl##_t *slist, uint64_t gen) \
decl##_t *prefix##skip_restore_snapshot_##decl(decl##_t *slist, size_t gen) \
{ \
size_t i; \
uint64_t cur_gen; \
size_t i, cur_gen; \
decl##_node_t *node, *prev; \
\
if (slist == NULL) \
@ -1264,7 +1202,7 @@ __skip_read_rdtsc(void)
if (gen >= slist->slh_snap.gen || slist->slh_snap.pres == NULL) \
return slist; \
\
cur_gen = __skip_snapshot_gen_##decl(); \
cur_gen = slist->slh_fns.snapshot_current_era(slist); \
\
/* (a) */ \
SKIPLIST_FOREACH_H2T(decl, prefix, slist, node, i) \
@ -1323,6 +1261,26 @@ __skip_read_rdtsc(void)
return slist; \
} \
\
/** \
* -- __skip_snapshot_current_era \
* \
* Returns the current generation for snapshot purposes. \
*/ \
static size_t __skip_snapshot_current_era_##decl(decl##_t *slist) \
{ \
return slist->slh_snap.gen; \
} \
\
/** \
* -- __skip_snapshot_incr_era \
* \
* Increments the snapshot generation. \
*/ \
static size_t __skip_snapshot_incr_era_##decl(decl##_t *slist) \
{ \
return ++slist->slh_snap.gen; \
} \
\
/** \
* -- skip_snapshots_init_ \
* \
@ -1330,8 +1288,12 @@ __skip_read_rdtsc(void)
*/ \
void prefix##skip_snapshots_init_##decl(decl##_t *slist) \
{ \
if (slist != NULL) \
if (slist != NULL) { \
slist->slh_fns.preserve_node = __skip_preserve_node_##decl; \
slist->slh_fns.release_snapshots = prefix##skip_release_snapshots_##decl; \
slist->slh_fns.snapshot_current_era = __skip_snapshot_current_era_##decl; \
slist->slh_fns.snapshot_incr_era = __skip_snapshot_incr_era_##decl; \
} \
}
#define SKIPLIST_DECL_ARCHIVE(decl, prefix, field) \