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| 16 | |
16 | |
| 17 | cede; |
17 | cede; |
| 18 | |
18 | |
| 19 | DESCRIPTION |
19 | DESCRIPTION |
| 20 | This module collection manages coroutines. Coroutines are similar to |
20 | This module collection manages coroutines. Coroutines are similar to |
| 21 | threads but don't run in parallel. |
21 | threads but don't run in parallel at the same time even on SMP machines. |
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22 | The specific flavor of coroutine use din this module also guarentees you |
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23 | that it will not switch between coroutines unless necessary, at |
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24 | easily-identified points in your program, so locking and parallel access |
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25 | are rarely an issue, making coroutine programming much safer than |
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26 | threads programming. |
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27 | |
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28 | (Perl, however, does not natively support real threads but instead does |
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29 | a very slow and memory-intensive emulation of processes using threads. |
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30 | This is a performance win on Windows machines, and a loss everywhere |
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31 | else). |
| 22 | |
32 | |
| 23 | In this module, coroutines are defined as "callchain + lexical variables |
33 | In this module, coroutines are defined as "callchain + lexical variables |
| 24 | + @_ + $_ + $@ + $^W + C stack), that is, a coroutine has it's own |
34 | + @_ + $_ + $@ + $/ + C stack), that is, a coroutine has its own |
| 25 | callchain, it's own set of lexicals and it's own set of perl's most |
35 | callchain, its own set of lexicals and its own set of perls most |
| 26 | important global variables. |
36 | important global variables. |
| 27 | |
37 | |
| 28 | $main |
38 | $main |
| 29 | This coroutine represents the main program. |
39 | This coroutine represents the main program. |
| 30 | |
40 | |
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| 164 | $olddesc = $coroutine->desc ($newdesc) |
174 | $olddesc = $coroutine->desc ($newdesc) |
| 165 | Sets (or gets in case the argument is missing) the description for |
175 | Sets (or gets in case the argument is missing) the description for |
| 166 | this coroutine. This is just a free-form string you can associate |
176 | this coroutine. This is just a free-form string you can associate |
| 167 | with a coroutine. |
177 | with a coroutine. |
| 168 | |
178 | |
| 169 | UTILITY FUNCTIONS |
179 | GLOBAL FUNCTIONS |
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180 | Coro::nready |
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181 | Returns the number of coroutines that are currently in the ready |
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182 | state, i.e. that can be swicthed to. The value 0 means that the only |
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183 | runnable coroutine is the currently running one, so "cede" would |
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184 | have no effect, and "schedule" would cause a deadlock unless there |
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185 | is an idle handler that wakes up some coroutines. |
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186 | |
| 170 | unblock_sub { ... } |
187 | unblock_sub { ... } |
| 171 | This utility function takes a BLOCK or code reference and "unblocks" |
188 | This utility function takes a BLOCK or code reference and "unblocks" |
| 172 | it, returning the new coderef. This means that the new coderef will |
189 | it, returning the new coderef. This means that the new coderef will |
| 173 | return immediately without blocking, returning nothing, while the |
190 | return immediately without blocking, returning nothing, while the |
| 174 | original code ref will be called (with parameters) from within its |
191 | original code ref will be called (with parameters) from within its |
