On Sun, 2003-02-16 at 16:07, Frank A. Uepping wrote: > can I assume that the access (read/write) to an int is atomic > on all supported platforms? > Does the kernel define some type like the C sig_atomic_t > for kernel space? Well, yes - on all architectures Linux supports, word-size stores and loads are atomic. There is code in the kernel today that makes use of this assumption, so it is a safe one. For example, you can always store a pointer value and rest assured the store will not interleave with another. Likewise, a concurrent read will always see the previous value or the new value, but never a mix. Nonetheless, if you need to do anything more complicated, I suggest using the atomic operators. See include/asm/atomic.c There is atomic read and write, atomic add-and-store, sub-and-store, swap, etc. Robert Love -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
