aboutsummaryrefslogtreecommitdiffstats
path: root/core/nonblocking.go
blob: a73331fae117b4bba479c50a8b81d5c4a4816bc8 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
// Copyright 2018 The dexon-consensus Authors
// This file is part of the dexon-consensus library.
//
// The dexon-consensus library is free software: you can redistribute it
// and/or modify it under the terms of the GNU Lesser General Public License as
// published by the Free Software Foundation, either version 3 of the License,
// or (at your option) any later version.
//
// The dexon-consensus library is distributed in the hope that it will be
// useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
// General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the dexon-consensus library. If not, see
// <http://www.gnu.org/licenses/>.

package core

import (
    "fmt"
    "sync"

    "github.com/dexon-foundation/dexon-consensus/common"
    "github.com/dexon-foundation/dexon-consensus/core/types"
)

type blockConfirmedEvent struct {
    block *types.Block
}

type stronglyAckedEvent struct {
    blockHash common.Hash
}

type totalOrderingDeliveredEvent struct {
    blockHashes common.Hashes
    mode        uint32
}

type blockDeliveredEvent struct {
    blockHash     common.Hash
    blockPosition types.Position
    result        *types.FinalizationResult
}

// nonBlocking implements these interfaces and is a decorator for
// them that makes the methods to be non-blocking.
//  - Application
//  - Debug
//  - It also provides nonblockig for blockdb update.
type nonBlocking struct {
    app          Application
    debug        Debug
    eventChan    chan interface{}
    events       []interface{}
    eventsChange *sync.Cond
    running      sync.WaitGroup
}

func newNonBlocking(app Application, debug Debug) *nonBlocking {
    nonBlockingModule := &nonBlocking{
        app:          app,
        debug:        debug,
        eventChan:    make(chan interface{}, 6),
        events:       make([]interface{}, 0, 100),
        eventsChange: sync.NewCond(&sync.Mutex{}),
    }
    go nonBlockingModule.run()
    return nonBlockingModule
}

func (nb *nonBlocking) addEvent(event interface{}) {
    nb.eventsChange.L.Lock()
    defer nb.eventsChange.L.Unlock()
    nb.events = append(nb.events, event)
    nb.eventsChange.Broadcast()
}

func (nb *nonBlocking) run() {
    // This go routine consume the first event from events and call the
    // corresponding methods of Application/Debug/blockdb.
    for {
        var event interface{}
        func() {
            nb.eventsChange.L.Lock()
            defer nb.eventsChange.L.Unlock()
            for len(nb.events) == 0 {
                nb.eventsChange.Wait()
            }
            event = nb.events[0]
            nb.events = nb.events[1:]
            nb.running.Add(1)
        }()
        switch e := event.(type) {
        case stronglyAckedEvent:
            nb.debug.StronglyAcked(e.blockHash)
        case blockConfirmedEvent:
            nb.app.BlockConfirmed(*e.block)
        case totalOrderingDeliveredEvent:
            nb.debug.TotalOrderingDelivered(e.blockHashes, e.mode)
        case blockDeliveredEvent:
            nb.app.BlockDelivered(e.blockHash, e.blockPosition, *e.result)
        default:
            fmt.Printf("Unknown event %v.", e)
        }
        nb.running.Done()
        nb.eventsChange.Broadcast()
    }
}

// wait will wait for all event in events finishes.
func (nb *nonBlocking) wait() {
    nb.eventsChange.L.Lock()
    defer nb.eventsChange.L.Unlock()
    for len(nb.events) > 0 {
        nb.eventsChange.Wait()
    }
    nb.running.Wait()
}

// PreparePayload cannot be non-blocking.
func (nb *nonBlocking) PreparePayload(position types.Position) ([]byte, error) {
    return nb.app.PreparePayload(position)
}

// PrepareWitness cannot be non-blocking.
func (nb *nonBlocking) PrepareWitness(height uint64) (types.Witness, error) {
    return nb.app.PrepareWitness(height)
}

// VerifyBlock cannot be non-blocking.
func (nb *nonBlocking) VerifyBlock(block *types.Block) types.BlockVerifyStatus {
    return nb.app.VerifyBlock(block)
}

// BlockConfirmed is called when a block is confirmed and added to lattice.
func (nb *nonBlocking) BlockConfirmed(block types.Block) {
    nb.addEvent(blockConfirmedEvent{&block})
}

// StronglyAcked is called when a block is strongly acked.
func (nb *nonBlocking) StronglyAcked(blockHash common.Hash) {
    if nb.debug != nil {
        nb.addEvent(stronglyAckedEvent{blockHash})
    }
}

// TotalOrderingDelivered is called when the total ordering algorithm deliver
// a set of block.
func (nb *nonBlocking) TotalOrderingDelivered(
    blockHashes common.Hashes, mode uint32) {
    if nb.debug != nil {
        nb.addEvent(totalOrderingDeliveredEvent{blockHashes, mode})
    }
}

// BlockDelivered is called when a block is add to the compaction chain.
func (nb *nonBlocking) BlockDelivered(blockHash common.Hash,
    blockPosition types.Position, result types.FinalizationResult) {
    nb.addEvent(blockDeliveredEvent{
        blockHash:     blockHash,
        blockPosition: blockPosition,
        result:        &result,
    })
}