1MCE::Shared::Sequence(3U)ser Contributed Perl DocumentatiMoCnE::Shared::Sequence(3)
2
6 MCE::Shared::Sequence - Sequence helper class
7
9 This document describes MCE::Shared::Sequence version 1.873
10
12 A number sequence class for use as a standalone or managed by
13 MCE::Shared.
14
16 # non-shared or local construction for use by a single process
17 use MCE::Shared::Sequence;
19 my $seq_a = MCE::Shared::Sequence->new( $begin, $end, $step, $fmt );
21 my $seq_b = MCE::Shared::Sequence->new(
23 { chunk_size => 10, bounds_only => 1 },
24 $begin, $end, $step, $fmt
25 );
26 # construction for sharing with other threads and processes
28 use MCE::Shared;
30 my $seq_a = MCE::Shared->sequence( 1, 100 );
32 my $seq_b = MCE::Shared->sequence(
34 { chunk_size => 10, bounds_only => 1 },
35 1, 100
36 );
37 # example
39 use MCE::Hobo;
41 sub parallel_a {
43 my ( $id ) = @_;
44 while ( defined ( my $num = $seq_a->next ) ) {
45 print "$id: $num\n";
46 }
47 }
48 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 MCE::Hobo->new( \¶llel_a, $_ ) for 1 .. 2;
59 MCE::Hobo->new( \¶llel_b, $_ ) for 3 .. 4;
60 # ... do other work ...
62 MCE::Hobo->waitall();
64
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 $seq_n_formatted = sprintf( "%4.1f", $seq_n );
76 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 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 use MCE::Shared;
86 # demo 1
88 $seq1 = MCE::Shared->sequence(
90 { chunk_size => 10, bounds_only => 0 }, 1, 20
91 );
92 # @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 while ( my @chunk = $seq1->next ) {
97 ...
98 }
99 # demo 2
101 $seq2 = MCE::Shared->sequence(
103 { chunk_size => 10, bounds_only => 1 }, 1, 100
104 );
105 # ( $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 # 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 while ( my ( $beg, $end, $chunk_id ) = $seq2->next ) {
118 for my $i ( $beg .. $end ) {
119 ...
120 }
121 }
122 Parameters may be given later with "rewind" before calling "next".
124 # non-shared or local construction for use by a single process
126 use MCE::Shared::Sequence;
128 $seq = MCE::Shared::Sequence->new;
130 $seq->rewind( -1, 1, 0.1, "%4.1f" );
131 $seq = MCE::Shared::Sequence->new(
133 { chunk_size => 10, bounds_only => 1 }, 1, 100
134 );
135 # construction for sharing with other threads and processes
137 use MCE::Shared;
139 $seq = MCE::Shared->sequence;
141 $seq->rewind( 1, 100 );
142 $seq = MCE::Shared->sequence(
144 { chunk_size => 10, bounds_only => 1 }, 1, 100
145 );
146 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 # default: { chunk_size => 1, bounds_only => 0 }
152 $seq = MCE::Shared->sequence( 1, 100 );
153 while ( defined ( my $num = $seq->next ) ) {
155 ...
156 }
157 # chunking
159 $seq = MCE::Shared->sequence(
161 { chunk_size => 10 }, 1, 100
162 );
163 while ( my @chunk = $seq->next ) {
165 ...
166 }
167 # chunking, boundaries only
169 $seq = MCE::Shared->sequence(
171 { chunk_size => 10, bounds_only => 1 }, 1, 100
172 );
173 while ( my ( $beg, $end, $chunk_id ) = $seq->next ) {
175 for my $i ( $beg .. $end ) {
176 ...
177 }
178 }
179 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 $seq->rewind;
187 $seq->rewind( { chunk_size => 10, bounds_only => 1 }, 1, 100 );
189 while ( my ( $beg, $end ) = $seq->next ) {
191 for my $i ( $beg .. $end ) {
192 ...
193 }
194 }
195 $seq->rewind( 1, 100 );
197 while ( defined ( my $num = $seq->next ) ) {
199 ...
200 }
201
203 MCE, MCE::Hobo, MCE::Shared
204
206 Mario E. Roy, <marioeroy AT gmail DOT com>
207perl v5.32.1 2021-01-27 MCE::Shared::Sequence(3)