1MCE::Shared::Sequence(3U)ser Contributed Perl DocumentatiMoCnE::Shared::Sequence(3)
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NAME

6       MCE::Shared::Sequence - Sequence helper class
7

VERSION

9       This document describes MCE::Shared::Sequence version 1.873
10

DESCRIPTION

12       A number sequence class for use as a standalone or managed by
13       MCE::Shared.
14

SYNOPSIS

16        # non-shared or local construction for use by a single process
17
18        use MCE::Shared::Sequence;
19
20        my $seq_a = MCE::Shared::Sequence->new( $begin, $end, $step, $fmt );
21
22        my $seq_b = MCE::Shared::Sequence->new(
23           { chunk_size => 10, bounds_only => 1 },
24           $begin, $end, $step, $fmt
25        );
26
27        # construction for sharing with other threads and processes
28
29        use MCE::Shared;
30
31        my $seq_a = MCE::Shared->sequence( 1, 100 );
32
33        my $seq_b = MCE::Shared->sequence(
34           { chunk_size => 10, bounds_only => 1 },
35           1, 100
36        );
37
38        # example
39
40        use MCE::Hobo;
41
42        sub parallel_a {
43           my ( $id ) = @_;
44           while ( defined ( my $num = $seq_a->next ) ) {
45              print "$id: $num\n";
46           }
47        }
48
49        sub parallel_b {
50           my ( $id ) = @_;
51           while ( my ( $beg, $end ) = $seq_b->next ) {
52              for my $num ( $beg .. $end ) {
53                 print "$id: $num\n";
54              }
55           }
56        }
57
58        MCE::Hobo->new( \&parallel_a, $_ ) for 1 .. 2;
59        MCE::Hobo->new( \&parallel_b, $_ ) for 3 .. 4;
60
61        # ... do other work ...
62
63        MCE::Hobo->waitall();
64

API DOCUMENTATION

66   MCE::Shared::Sequence->new ( { options }, begin, end [, step, format ] )
67   MCE::Shared::Sequence->new ( begin, end [, step, format ] )
68   MCE::Shared->sequence ( { options }, begin, end [, step, format ] )
69   MCE::Shared->sequence ( begin, end [, step, format ] )
70       Constructs a new object. "step", if omitted, defaults to 1 if "begin"
71       is smaller than "end" or "-1" if "begin" is greater than "end". The
72       "format" string is passed to "sprintf" behind the scene (% may be
73       omitted).
74
75        $seq_n_formatted = sprintf( "%4.1f", $seq_n );
76
77       Two options "chunk_size" and "bounds_only" are supported, which default
78       to 1 and 0 respectively. Chunking reduces the number of IPC calls to
79       and from the shared-manager process for large sequences.
80
81       If "bounds_only => 1" is specified, the "next" method computes the
82       "begin" and "end" values only for the chunk and not the numbers in
83       between (hence boundaries only).
84
85        use MCE::Shared;
86
87        # demo 1
88
89        $seq1 = MCE::Shared->sequence(
90           { chunk_size => 10, bounds_only => 0 }, 1, 20
91        );
92
93        # @chunk = $seq1->next;  # ( qw/  1  2  3  4  5  6  7  8  9 10 / )
94        # @chunk = $seq1->next;  # ( qw/ 11 12 13 14 15 16 17 18 19 20 / )
95
96        while ( my @chunk = $seq1->next ) {
97           ...
98        }
99
100        # demo 2
101
102        $seq2 = MCE::Shared->sequence(
103           { chunk_size => 10, bounds_only => 1 }, 1, 100
104        );
105
106        # ( $beg, $end ) = $seq2->next;  # (  1,  10 )
107        # ( $beg, $end ) = $seq2->next;  # ( 11,  20 )
108        # ( $beg, $end ) = $seq2->next;  # ( 21,  30 )
109        #    ...
110        # ( $beg, $end ) = $seq2->next;  # ( 81,  90 )
111        # ( $beg, $end ) = $seq2->next;  # ( 91, 100 )
112
113        # The optional chunk_id value, starting at 1, applies to sequence
114        # objects configured with the bounds_only option set to a true
115        # value. API available since 1.834.
116
117        while ( my ( $beg, $end, $chunk_id ) = $seq2->next ) {
118           for my $i ( $beg .. $end ) {
119              ...
120           }
121        }
122
123       Parameters may be given later with "rewind" before calling "next".
124
125        # non-shared or local construction for use by a single process
126
127        use MCE::Shared::Sequence;
128
129        $seq = MCE::Shared::Sequence->new;
130        $seq->rewind( -1, 1, 0.1, "%4.1f" );
131
132        $seq = MCE::Shared::Sequence->new(
133           { chunk_size => 10, bounds_only => 1 }, 1, 100
134        );
135
136        # construction for sharing with other threads and processes
137
138        use MCE::Shared;
139
140        $seq = MCE::Shared->sequence;
141        $seq->rewind( 1, 100 );
142
143        $seq = MCE::Shared->sequence(
144           { chunk_size => 10, bounds_only => 1 }, 1, 100
145        );
146
147   next
148       Returns the next computed sequence(s). An undefined value is returned
149       when the computed "begin" value exceeds the value held by "end".
150
151        # default: { chunk_size => 1, bounds_only => 0 }
152        $seq = MCE::Shared->sequence( 1, 100 );
153
154        while ( defined ( my $num = $seq->next ) ) {
155           ...
156        }
157
158        # chunking
159
160        $seq = MCE::Shared->sequence(
161           { chunk_size => 10 }, 1, 100
162        );
163
164        while ( my @chunk = $seq->next ) {
165           ...
166        }
167
168        # chunking, boundaries only
169
170        $seq = MCE::Shared->sequence(
171           { chunk_size => 10, bounds_only => 1 }, 1, 100
172        );
173
174        while ( my ( $beg, $end, $chunk_id ) = $seq->next ) {
175           for my $i ( $beg .. $end ) {
176              ...
177           }
178        }
179
180   rewind ( { options }, begin, end [, step, format ] )
181   rewind ( begin, end [, step, format ] )
182       Sets the initial value back to the value held by "begin" when no
183       arguments are given. Otherwise, resets the sequence with given
184       criteria.
185
186        $seq->rewind;
187
188        $seq->rewind( { chunk_size => 10, bounds_only => 1 }, 1, 100 );
189
190        while ( my ( $beg, $end ) = $seq->next ) {
191           for my $i ( $beg .. $end ) {
192              ...
193           }
194        }
195
196        $seq->rewind( 1, 100 );
197
198        while ( defined ( my $num = $seq->next ) ) {
199           ...
200        }
201

INDEX

203       MCE, MCE::Hobo, MCE::Shared
204

AUTHOR

206       Mario E. Roy, <marioeroy AT gmail DOT com>
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210perl v5.32.1                      2021-01-27          MCE::Shared::Sequence(3)
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