Line data Source code
1 : #ifndef HEADER_fd_src_flamenco_leaders_fd_leaders_h
2 : #define HEADER_fd_src_flamenco_leaders_fd_leaders_h
3 :
4 : /* fd_leaders provides APIs for the Solana leader schedule.
5 : Logic is compatible with Solana mainnet as of 2023-Jul.
6 :
7 : Every slot is assigned a leader (identified by a "node identity"
8 : public key). The sequence of leaders for all slots in an epoch is
9 : called the "leader schedule". The main responsibility of the leader
10 : is to produce a block for the slot.
11 :
12 : The leader schedule is divided into sched_cnt rotations. Each
13 : rotation spans one or more slots, such that
14 :
15 : slots_per_epoch = sched_cnt * slots_per_rotation
16 :
17 : The leader can only change between rotations. An example leader
18 : schedule looks as follows (where A, B, C are node identities and each
19 : column is a slot, with 4 slots per rotation)
20 :
21 : A A A A B B B B B B B B C C C C A A A A
22 : ^ ^ ^ ^ ^
23 : rotation rotation rotation rotation rotation
24 :
25 : The mainnet epoch duration is quite long (currently 432000 slots, for
26 : more information see fd_sysvar_epoch_schedule.h). To save space, we
27 : dedup pubkeys into a lookup table and only store an index for each
28 : rotation. */
29 :
30 : #include "fd_leaders_base.h"
31 : #include "../../ballet/wsample/fd_wsample.h"
32 :
33 24 : #define FD_ULONG_MAX( a, b ) (__builtin_choose_expr( __builtin_constant_p( a ) & __builtin_constant_p( b ), \
34 24 : ((ulong )(a))>=((ulong )(b)) ? ((ulong )(a)) : ((ulong )(b)), \
35 24 : fd_ulong_max( (a), (b) ) ))
36 :
37 : /* FD_EPOCH_LEADERS_{ALIGN,FOOTPRINT} are compile-time-friendly versions
38 : of the fd_epoch_leaders_{align,footprint} functions. */
39 :
40 0 : #define FD_EPOCH_LEADERS_ALIGN (64UL)
41 : #define FD_EPOCH_LEADERS_FOOTPRINT( pub_cnt, slot_cnt ) \
42 6375 : ( FD_LAYOUT_FINI( FD_LAYOUT_APPEND( FD_LAYOUT_APPEND( \
43 6375 : FD_LAYOUT_INIT, \
44 6375 : alignof(fd_epoch_leaders_t), sizeof(fd_epoch_leaders_t) ), \
45 6375 : alignof(uint), ( \
46 6375 : (slot_cnt+FD_EPOCH_SLOTS_PER_ROTATION-1UL)/FD_EPOCH_SLOTS_PER_ROTATION*sizeof(uint) \
47 6375 : ) ), \
48 6375 : FD_EPOCH_LEADERS_ALIGN ) + \
49 6375 : FD_ULONG_ALIGN_UP( FD_ULONG_MAX( 32UL*((pub_cnt)+1UL), \
50 6375 : FD_WSAMPLE_FOOTPRINT( pub_cnt, 0 ) ), 64UL ) )
51 :
52 6856065 : #define FD_EPOCH_SLOTS_PER_ROTATION (4UL)
53 :
54 : /* FD_EPOCH_LEADERS_MAX_FOOTPRINT is the maximum footprint of a leader
55 : schedule object that the runtime can support given a constant
56 : slots per epoch (432K) and a max number of vote accounts (40200). */
57 :
58 : #define FD_EPOCH_LEADERS_MAX_FOOTPRINT (FD_EPOCH_LEADERS_FOOTPRINT(FD_RUNTIME_MAX_VOTE_ACCOUNTS, FD_RUNTIME_SLOTS_PER_EPOCH))
59 :
60 : /* fd_epoch_leaders_t contains the leader schedule of a Solana epoch. */
61 :
62 : struct fd_epoch_leaders {
63 : /* This struct contains the schedule for epoch `epoch` which spans
64 : slots [slot0, slot0+slot_cnt). */
65 : ulong epoch;
66 : ulong slot0;
67 : ulong slot_cnt;
68 :
69 : /* pub is a lookup table for node public keys with length pub_cnt */
70 : fd_pubkey_t * pub;
71 : ulong pub_cnt;
72 :
73 : /* sched contains the leader schedule in the form of indexes into
74 : the pub array. For sched_cnt, refer to below. */
75 : uint * sched;
76 : ulong sched_cnt;
77 : };
78 : typedef struct fd_epoch_leaders fd_epoch_leaders_t;
79 :
80 : FD_PROTOTYPES_BEGIN
81 :
82 : /* fd_epoch_leaders_{align,footprint} describe the required footprint
83 : and alignment of the leader schedule object. pub_cnt is the number
84 : of unique public keys. slot_cnt is the number of slots in the
85 : epoch. */
86 :
87 : FD_FN_CONST ulong
88 : fd_epoch_leaders_align( void );
89 :
90 : FD_FN_CONST ulong
91 : fd_epoch_leaders_footprint( ulong pub_cnt,
92 : ulong slot_cnt );
93 :
94 : /* fd_epoch_leaders_new formats a memory region for use as a leader
95 : schedule object. shmem points to the first byte of a memory region
96 : with matching alignment and footprint requirements. The leader
97 : schedule object will contain the leader schedule for epoch `epoch`
98 : which spans slots [slot0, slot0+slot_cnt). `slot0` must be the first
99 : slot in the epoch, but slot_cnt can be less than the length of the
100 : epoch to derive only the first portion of the leader schedule.
101 : pub_cnt is the number of unique public keys in this schedule.
102 : `stakes` points to the first entry of pub_cnt entries of stake
103 : weights sorted by tuple (stake, pubkey) in descending order.
104 : `vote_keyed_lsched` is either 0 or 1, when 1 the leader schedule
105 : is computed by vote accounts (see SIMD-0180).
106 :
107 : If `stakes` does not include all staked nodes, e.g. in the case of an
108 : attack that swamps the network with fake validators, `stakes` should
109 : contain the first `pub_cnt` of them in the normal sort order, and the
110 : sum of the remaining stake must be provided in excluded_stake,
111 : measured in lamports.
112 :
113 : Does NOT retain a read interest in stakes upon return.
114 : The caller is not joined to the object on return. */
115 : void *
116 : fd_epoch_leaders_new( void * shmem,
117 : ulong epoch,
118 : ulong slot0,
119 : ulong slot_cnt,
120 : ulong pub_cnt,
121 : fd_vote_stake_weight_t * stakes, /* indexed [0, pub_cnt) */
122 : ulong excluded_stake,
123 : ulong vote_keyed_lsched );
124 :
125 : /* fd_epoch_leaders_join joins the caller to the leader schedule object.
126 : fd_epoch_leaders_leave undoes an existing join. */
127 :
128 : fd_epoch_leaders_t *
129 : fd_epoch_leaders_join( void * shleaders );
130 :
131 : void *
132 : fd_epoch_leaders_leave( fd_epoch_leaders_t * leaders );
133 :
134 : /* fd_epoch_leaders_delete unformats a memory region and returns owner-
135 : ship back to the caller. */
136 :
137 : void *
138 : fd_epoch_leaders_delete( void * shleaders );
139 :
140 : /* FD_INDETERMINATE_LEADER has base58 encoding
141 : 1111111111indeterminateLeader9QSxFYNqsXA. In hex, this pubkey ends
142 : with 0x0badf00d0badf00d. */
143 6363 : #define FD_INDETERMINATE_LEADER 0x00U,0x00U,0x00U,0x00U,0x00U,0x00U,0x00U,0x00U,0x00U,0x00U,0x99U,0xf6U,0x0fU,0x96U,0x2cU,0xddU,\
144 6363 : 0x38U,0x21U,0xf3U,0x0cU,0x16U,0x1dU,0xe3U,0x0aU,0x0bU,0xadU,0xf0U,0x0dU,0x0bU,0xadU,0xf0U,0x0dU
145 :
146 : /* fd_epoch_leaders_get returns a pointer to the selected public key
147 : given a slot. Returns NULL if slot is not in [slot0, slot0+slot_cnt)
148 : given the values supplied in fd_epoch_leaders_new.
149 :
150 : If a non-zero value was provided for excluded_stake in
151 : fd_epoch_leaders_new and a validator included in the excluded_stake
152 : is the leader for the requested slot, instead of returning the
153 : correct value (which is not known), fd_epoch_leaders_get will return
154 : a pointer to a pubkey with value FD_INDETERMINATE_LEADER. */
155 :
156 : FD_FN_PURE static inline fd_pubkey_t const *
157 : fd_epoch_leaders_get( fd_epoch_leaders_t const * leaders,
158 6843939 : ulong slot ) {
159 6843939 : if( FD_UNLIKELY( leaders==NULL ) ) return NULL;
160 6843939 : ulong slot_delta = slot - leaders->slot0;
161 6843939 : if( FD_UNLIKELY( slot < leaders->slot0 ) ) return NULL;
162 6843795 : if( FD_UNLIKELY( slot_delta>=leaders->slot_cnt ) ) return NULL;
163 6843345 : return (fd_pubkey_t const *)( leaders->pub + leaders->sched[ slot_delta/FD_EPOCH_SLOTS_PER_ROTATION ] );
164 6843795 : }
165 :
166 : FD_PROTOTYPES_END
167 :
168 : #endif /* HEADER_fd_src_flamenco_leaders_fd_leaders_h */
|
