Replace rand() with realtime-safe pcg-rand #28 #31
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On unices (Linux and macOS) the call to rand() takes a lock (preserve global random seed) and is hence not realtime-safe. On Windows this is less of an issue since rand() uses a thread-local variable by default. However PCG-rand is still a preferable alternative.
The motivation for 6 calls was likely because default Windows rand() provides only 15 bits (RAND_MAX = 32768), which is is insufficient for float (23 bit mantissa). This is no longer needed with the given pcg-random.org implementation.
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I do not know how you manage the replicated source code (LinuxVST, WinVST, MacVST, MacAU etc). This is just an proof-of-concept to hopefully get the ball rolling. Note: before replicating this to all other plugins, consider a shared include, in a dedicated namespace (so it does not interfere with symbols of other plugins). on macOS and Linux (really gcc, clang), override the default visibility. e.g namespace AirWindows {
class __attribute__ ((visibility ("hidden")) PCGRand
{
/* ... */
};
} // namespaceAlternatively you could |
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On unices (Linux and macOS) the call to rand() takes a
lock (preserve global random seed) and is hence not realtime-safe.
On Windows this is less of an issue since rand() uses a thread-local
variable by default. However PCG-rand is still a preferable alternative.
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NOTE: THIS CODE IS UNTESTED!
Other plugins using rand() should be updated likewise.