alt Hacker NewsI’m actually thinking of the sheer size of pthread mutexes. They are giant. The issue says that they wanted something small, efficient, and const constructible. Pthread mutexes are too large for most applications doing fine-grained locking.
I’m actually thinking of the sheer size of pthread mutexes. They are giant. The issue says that they wanted something small, efficient, and const constructible. Pthread mutexes are too large for most applications doing fine-grained locking.
On a typical modern 64-bit Linux for example they're 40 bytes ie they are 320 bits. So yeah, unnecessarily bulky.
On my Linux system today Rust's Mutex<Option<CompactString>> is smaller than the pthread mutex type whether it is locked and has the text "pthread_mutex_t is awful" inside it or maybe unlocked with explicitly no text (not an empty string), either would only take like 30-odd bytes, the pthread_mutex_t is 40 bytes.
On Windows the discrepancy is even bigger, their OS native mutex type is this sprawling 80 byte monster while their Mutex<Option<CompactString> is I believe slightly smaller than on Linux even though it has the same features.