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Comparing Coro/Coro/Semaphore.pm (file contents):
Revision 1.53 by root, Wed Feb 1 23:59:41 2006 UTC vs.
Revision 1.80 by root, Sat Nov 15 06:26:52 2008 UTC

… …
31 31
32=cut 32=cut
33 33
34package Coro::Semaphore; 34package Coro::Semaphore;
35 35
36BEGIN { eval { require warnings } && warnings->unimport ("uninitialized") } 36no warnings;
37 37
38use Coro (); 38use Coro ();
39 39
40$VERSION = 1.9; 40$VERSION = 5.0;
41 41
42=item new [inital count] 42=item new [inital count]
43 43
44Creates a new sempahore object with the given initial lock count. The 44Creates a new sempahore object with the given initial lock count. The
45default lock count is 1, which means it is unlocked by default. Zero (or 45default lock count is 1, which means it is unlocked by default. Zero (or
46negative values) are also allowed, in which case the semaphore is locked 46negative values) are also allowed, in which case the semaphore is locked
47by default. 47by default.
48 48
49=cut 49=item $sem->count
50 50
51sub new { 51Returns the current semaphore count.
52 bless [defined $_[1] ? $_[1] : 1], $_[0]; 52
53} 53=item $sem->adjust ($diff)
54
55Atomically adds the amount given to the current semaphore count. If the
56count becomes positive, wakes up any waiters. Does not block if the count
57becomes negative, however.
54 58
55=item $sem->down 59=item $sem->down
56 60
57Decrement the counter, therefore "locking" the semaphore. This method 61Decrement the counter, therefore "locking" the semaphore. This method
58waits until the semaphore is available if the counter is zero. 62waits until the semaphore is available if the counter is zero.
59 63
60=item $status = $sem->timed_down($timeout)
61
62Like C<down>, but returns false if semaphore couldn't be acquired within
63$timeout seconds, otherwise true.
64
65=cut 64=cut
66 65
67sub down { 66#=item $status = $sem->timed_down ($timeout)
68 while ($_[0][0] <= 0) { 67#
69 push @{$_[0][1]}, $Coro::current; 68#Like C<down>, but returns false if semaphore couldn't be acquired within
70 Coro::schedule; 69#$timeout seconds, otherwise true.
71 }
72 --$_[0][0];
73}
74 70
75sub timed_down { 71#sub timed_down {
76 require Coro::Timer; 72# require Coro::Timer;
77 my $timeout = Coro::Timer::timeout($_[1]); 73# my $timeout = Coro::Timer::timeout ($_[1]);
78 74#
79 while ($_[0][0] <= 0) { 75# while ($_[0][0] <= 0) {
80 push @{$_[0][1]}, $Coro::current; 76# push @{$_[0][1]}, $Coro::current;
81 Coro::schedule; 77# &Coro::schedule;
82 if ($timeout) { 78# if ($timeout) {
83 # ugly as hell. slow, too, btw! 79# # ugly as hell. slow, too, btw!
84 for (0..$#{$_[0][1]}) { 80# for (0..$#{$_[0][1]}) {
85 if ($_[0][1][$_] == $Coro::current) { 81# if ($_[0][1][$_] == $Coro::current) {
86 splice @{$_[0][1]}, $_, 1; 82# splice @{$_[0][1]}, $_, 1;
87 return; 83# return;
88 } 84# }
89 } 85# }
90 die; 86# die;
91 } 87# }
92 } 88# }
93 89#
94 --$_[0][0]; 90# --$_[0][0];
95 return 1; 91# return 1;
96} 92#}
97 93
98=item $sem->up 94=item $sem->up
99 95
100Unlock the semaphore again. 96Unlock the semaphore again.
101
102=cut
103
104sub up {
105 if (++$_[0][0] > 0) {
106 (shift @{$_[0][1]})->ready if @{$_[0][1]};
107 }
108}
109 97
110=item $sem->try 98=item $sem->try
111 99
112Try to C<down> the semaphore. Returns true when this was possible, 100Try to C<down> the semaphore. Returns true when this was possible,
113otherwise return false and leave the semaphore unchanged. 101otherwise return false and leave the semaphore unchanged.
114 102
115=cut
116
117sub try {
118 if ($_[0][0] > 0) {
119 --$_[0][0];
120 return 1;
121 } else {
122 return 0;
123 }
124}
125
126=item $sem->waiters 103=item $sem->waiters
127 104
128In scalar context, returns the number of coroutines waiting for this 105In scalar context, returns the number of coroutines waiting for this
129semaphore. 106semaphore.
130 107
131=cut
132
133sub waiters {
134 @{$_[0][1]};
135}
136
137=item $guard = $sem->guard 108=item $guard = $sem->guard
138 109
139This method calls C<down> and then creates a guard object. When the guard 110This method calls C<down> and then creates a guard object. When the guard
140object is destroyed it automatically calls C<up>. 111object is destroyed it automatically calls C<up>.
141
142=item $guard = $sem->timed_guard($timeout)
143
144Like C<guard>, but returns undef if semaphore couldn't be acquired within
145$timeout seconds, otherwise the guard object.
146 112
147=cut 113=cut
148 114
149sub guard { 115sub guard {
150 &down; 116 &down;
151 # double indirection because bless works on the referenced 117 # double indirection because bless works on the referenced
152 # object, not (only) on the reference itself. 118 # object, not (only) on the reference itself.
153 bless \\$_[0], Coro::Semaphore::guard::; 119 bless \\$_[0], Coro::Semaphore::guard::;
154} 120}
155 121
122#=item $guard = $sem->timed_guard ($timeout)
123#
124#Like C<guard>, but returns undef if semaphore couldn't be acquired within
125#$timeout seconds, otherwise the guard object.
126
156sub timed_guard { 127#sub timed_guard {
157 &timed_down 128# &timed_down
158 ? bless \\$_[0], Coro::Semaphore::guard:: 129# ? bless \\$_[0], Coro::Semaphore::guard::
159 : (); 130# : ();
160} 131#}
161 132
162sub Coro::Semaphore::guard::DESTROY { 133sub Coro::Semaphore::guard::DESTROY {
163 &up(${${$_[0]}}); 134 &up(${${$_[0]}});
164} 135}
165 136

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