core:mutex: allow idle thread to use mutexes#859
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Kijewski merged 1 commit intoRIOT-OS:masterfrom Mar 19, 2014
Kijewski:mutex-trylock-error
Merged
core:mutex: allow idle thread to use mutexes#859Kijewski merged 1 commit intoRIOT-OS:masterfrom Kijewski:mutex-trylock-error
Kijewski merged 1 commit intoRIOT-OS:masterfrom
Kijewski:mutex-trylock-error
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Contributor
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ACK. nice one. I used the pid to make sure the same thread doesn't lock a mutex twice in a very early version... |
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Oops, that line too, of course. |
Contributor
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Ping. |
Contributor
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@Kijewski is there any reason to have the thread pid as value for the mutex? its not use in any way? idle thread has the pid zero, right? |
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@mehlis there is no need to store the pid in there. Currently any thread that wants to claim the mutex by means of trylock writes its pid into the mutex. That means Yes, the idle thread has pid 0. |
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ACK |
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core:mutex: allow idle thread to use mutexes
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mutex_t::valis an integral value where 0 means unlocked, and any other value means locked.mutex_trylockwrites the current thread id into this member to denote that it is locked.The problem is that the
idlethread has the PID 0, and is therefore not able to sanely use this function.The reason why the idle thread might need to use mutexes is because it changes the low-power state of the board, and I see reasons why it might be useful to use a mutex in this circumstance.