Re: Is socket.send thread safe?
On Monday, 26 March 2018 at 16:14:31 UTC, Jonathan wrote: Can I send data over an std.socket on multiple threads without manual mutexing? If not, can I send data on a separate thread than receive? The docs for std.socket say nothing of it (which I guess means I should assume it is not thread safe but...). It’s thin-wrapper over system interface. It’s thread-safe in that system will not topple over, you will likely get some interleaving of data. HOWEVER: there is such a thing as short-writes, which means that since OS buffer may fill up it could write less then you intended to and return that amount. It certainly happens with O_NONBLOCK. In normal blocking mode it might work, but in general it’s a bad idea to do writes to a single socket from multiple threads w/o some coordination s.t. only can do it at any given time. Lastly as far as guarantees go, POSIX doesn’t state that 2 writes will be interleaved “exactly”, it may for instance splice them zebra-style by some chunk size and I could imagine why (on long buffers). My suggestion is to have a queue of messages and a thread to send them. You might also want to check and see if there is a better protocol then TCP to take advantage of unordered messages. I think there is at least RDP (reliable datagram protocol) on Linux that might fit the bill. Thanks!
Re: Is socket.send thread safe?
On Monday, 26 March 2018 at 17:55:10 UTC, bauss wrote: On Monday, 26 March 2018 at 16:14:31 UTC, Jonathan wrote: Can I send data over an std.socket on multiple threads without manual mutexing? If not, can I send data on a separate thread than receive? The docs for std.socket say nothing of it (which I guess means I should assume it is not thread safe but...). Thanks! Define thread safe. It's safe in the way that the buffers each call to send will have will be what you expect. Ex. thread1 sends [1,2,3] and thread2 sends [4,5,6] then you're guaranteed that what you receive would be [1,2,3] and [4,5,6]. What it isn't safe from would be race conditions. So you don't know if you get it like [1,2,3,4,5,6] or [4,5,6,1,2,3]. So if the order of the buffer matters then you should use a mutex, but if the order doesn't matter then you don't need to. You answered what I needed. The order of receiving the messages is not a problem, merely that a message its self is not broken, ie: [4,1,2,5,3,6](This would not work!) Thanks!
Re: Is socket.send thread safe?
On Monday, 26 March 2018 at 16:14:31 UTC, Jonathan wrote: Can I send data over an std.socket on multiple threads without manual mutexing? If not, can I send data on a separate thread than receive? The docs for std.socket say nothing of it (which I guess means I should assume it is not thread safe but...). Thanks! Define thread safe. It's safe in the way that the buffers each call to send will have will be what you expect. Ex. thread1 sends [1,2,3] and thread2 sends [4,5,6] then you're guaranteed that what you receive would be [1,2,3] and [4,5,6]. What it isn't safe from would be race conditions. So you don't know if you get it like [1,2,3,4,5,6] or [4,5,6,1,2,3]. So if the order of the buffer matters then you should use a mutex, but if the order doesn't matter then you don't need to.
Is socket.send thread safe?
Can I send data over an std.socket on multiple threads without manual mutexing? If not, can I send data on a separate thread than receive? The docs for std.socket say nothing of it (which I guess means I should assume it is not thread safe but...). Thanks!
