[physfs] Mounting files & CD checking

[Ryan C. Gordon]

Ryan C. Gordon wrote:
>> Physfs is not thread-safe.
> 
> Yes it is.

Sorry, hit send too fast there.  :)

To be clear: the API is thread safe (there are mutexes around all static 
data), but you can only use a PHYSFS_file from one thread at a time. You 
can read/write/seek a file from two threads at once, so long as you 
serialize it, since generally this would be at least an extraordinary 
condition in your program, if not a bug.

You could probably race between PHYSFS_quit() and other functions, so 
don't do that.  :)   Shut down the library from any thread you like, 
just make sure everyone else stopped using it first. Once PHYSFS_quit() 
returns, all other calls will fail without a race condition.

Otherwise, calls to any two functions in PhysicsFS (such as working with 
two separate file handles in different threads, or mounting a directory 
while enumerating CD-ROM drives) are thread safe.

--ryan.