59 lines
1.7 KiB
Rust
59 lines
1.7 KiB
Rust
use libc::{c_void, ftruncate, mmap, munmap, shm_open, shm_unlink, MAP_FAILED, MAP_SHARED, O_CREAT, O_EXCL, O_RDWR, PROT_READ};
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#[derive(Clone)]
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pub struct ShmPool {
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pub fd: i32,
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pub id: u32,
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pub addr: *mut c_void,
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pub size: usize,
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}
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impl ShmPool {
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pub fn new(size: usize, id: u32) -> std::io::Result<ShmPool> {
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let shm_path: *const i8 = b"/chlorostart\0".as_ptr() as *const i8;
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let fd = unsafe { shm_open(shm_path, O_RDWR | O_EXCL | O_CREAT, 0o600) };
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if fd == -1 {
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eprint!("shm_open in ShmPool::new() failed: ");
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return Err(std::io::Error::last_os_error())
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}
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if unsafe { shm_unlink(shm_path) } == -1 {
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eprint!("shm_unlink in ShmPool::new() failed: ");
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return Err(std::io::Error::last_os_error())
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}
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if unsafe { ftruncate(fd, size as i64) } == -1 {
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eprint!("ftruncate in ShmPool::new() failed: ");
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return Err(std::io::Error::last_os_error())
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}
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let addr = unsafe {
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mmap(std::ptr::null_mut(), size, PROT_READ | PROT_READ, MAP_SHARED, fd, 0)
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};
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if addr == MAP_FAILED {
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eprint!("mmap in ShmPool::new() failed: ");
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return Err(std::io::Error::last_os_error())
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}
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Ok(ShmPool {
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fd,
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id,
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addr,
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size
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})
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}
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pub fn resize(&mut self, size: usize) -> std::io::Result<()> {
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if unsafe { ftruncate(self.fd, size as i64) } == -1 {
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return Err(std::io::Error::last_os_error())
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};
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self.size = size;
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Ok(())
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}
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}
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impl Drop for ShmPool {
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fn drop(&mut self) {
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unsafe { munmap(self.addr, self.size); }
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}
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}
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