… | |
… | |
31 | |
31 | |
32 | =cut |
32 | =cut |
33 | |
33 | |
34 | package Coro::Semaphore; |
34 | package Coro::Semaphore; |
35 | |
35 | |
36 | no warnings; |
36 | BEGIN { eval { require warnings } && warnings->unimport ("uninitialized") } |
37 | |
37 | |
38 | use Coro (); |
38 | use Coro (); |
39 | |
39 | |
40 | $VERSION = 0.5; |
40 | $VERSION = 1.0; |
41 | |
41 | |
42 | =item new [inital count] |
42 | =item new [inital count] |
43 | |
43 | |
44 | Creates a new sempahore object with the given initial lock count. The |
44 | Creates a new sempahore object with the given initial lock count. The |
45 | default lock count is 1, which means it is unlocked by default. Zero (or |
45 | default lock count is 1, which means it is unlocked by default. Zero (or |
… | |
… | |
55 | =item $sem->down |
55 | =item $sem->down |
56 | |
56 | |
57 | Decrement the counter, therefore "locking" the semaphore. This method |
57 | Decrement the counter, therefore "locking" the semaphore. This method |
58 | waits until the semaphore is available if the counter is zero. |
58 | waits until the semaphore is available if the counter is zero. |
59 | |
59 | |
|
|
60 | =item $status = $sem->timed_down($timeout) |
|
|
61 | |
|
|
62 | Like C<down>, but returns false if semaphore couldn't be acquired within |
|
|
63 | $timeout seconds, otherwise true. |
|
|
64 | |
60 | =cut |
65 | =cut |
61 | |
66 | |
62 | sub down { |
67 | sub down { |
63 | while ($_[0][0] <= 0) { |
68 | while ($_[0][0] <= 0) { |
64 | push @{$_[0][1]}, $Coro::current; |
69 | push @{$_[0][1]}, $Coro::current; |
65 | Coro::schedule; |
70 | Coro::schedule; |
66 | } |
71 | } |
67 | --$_[0][0]; |
72 | --$_[0][0]; |
|
|
73 | } |
|
|
74 | |
|
|
75 | sub timed_down { |
|
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76 | require Coro::Timer; |
|
|
77 | my $timeout = Coro::Timer::timeout($_[1]); |
|
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78 | |
|
|
79 | while ($_[0][0] <= 0) { |
|
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80 | push @{$_[0][1]}, $Coro::current; |
|
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81 | Coro::schedule; |
|
|
82 | if ($timeout) { |
|
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83 | # ugly as hell. slow, too, btw! |
|
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84 | for (0..$#{$_[0][1]}) { |
|
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85 | if ($_[0][1][$_] == $Coro::current) { |
|
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86 | splice @{$_[0][1]}, $_, 1; |
|
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87 | return; |
|
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88 | } |
|
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89 | } |
|
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90 | die; |
|
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91 | } |
|
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92 | } |
|
|
93 | |
|
|
94 | --$_[0][0]; |
|
|
95 | return 1; |
68 | } |
96 | } |
69 | |
97 | |
70 | =item $sem->up |
98 | =item $sem->up |
71 | |
99 | |
72 | Unlock the semaphore again. |
100 | Unlock the semaphore again. |
… | |
… | |
109 | =item $guard = $sem->guard |
137 | =item $guard = $sem->guard |
110 | |
138 | |
111 | This method calls C<down> and then creates a guard object. When the guard |
139 | This method calls C<down> and then creates a guard object. When the guard |
112 | object is destroyed it automatically calls C<up>. |
140 | object is destroyed it automatically calls C<up>. |
113 | |
141 | |
|
|
142 | =item $guard = $sem->timed_guard($timeout) |
|
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143 | |
|
|
144 | Like C<guard>, but returns undef if semaphore couldn't be acquired within |
|
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145 | $timeout seconds, otherwise the guard object. |
|
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146 | |
114 | =cut |
147 | =cut |
115 | |
148 | |
116 | sub guard { |
149 | sub guard { |
117 | &down; |
150 | &down; |
118 | # double indirection because bless works on the referenced |
151 | # double indirection because bless works on the referenced |
119 | # object, not (only) on the reference itself. |
152 | # object, not (only) on the reference itself. |
120 | bless \\$_[0], Coro::Semaphore::Guard::; |
153 | bless \\$_[0], Coro::Semaphore::guard::; |
121 | } |
154 | } |
122 | |
155 | |
|
|
156 | sub timed_guard { |
|
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157 | &timed_down |
|
|
158 | ? bless \\$_[0], Coro::Semaphore::guard:: |
|
|
159 | : (); |
|
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160 | } |
|
|
161 | |
123 | sub Coro::Semaphore::Guard::DESTROY { |
162 | sub Coro::Semaphore::guard::DESTROY { |
124 | &up(${${$_[0]}}); |
163 | &up(${${$_[0]}}); |
125 | } |
164 | } |
126 | |
165 | |
127 | 1; |
166 | 1; |
128 | |
167 | |