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Diffstat (limited to 'user/include/unistd.h')
| -rw-r--r-- | user/include/unistd.h | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/user/include/unistd.h b/user/include/unistd.h index cad3a81..27b6d31 100644 --- a/user/include/unistd.h +++ b/user/include/unistd.h @@ -187,6 +187,29 @@ extern void *brk(const void *addr); extern void *sbrk(intptr_t increment); /** + * Allocate a number of pages shared with another PID. Does not map the pages + * into the other process's vtable until the other process calls popsharedmem(). + * + * @param num_pages number of pages to allocate + * @param other_pid pid of other process + * @return pointer to the virtual address which will be accessible by both, + * after popsharedmem() is called. + */ +extern void* allocshared(size_t num_pages, int other_pid); + +/** + * Checks if another process has tried to share memory with us, and return it. + * No size information is returned, it is only guaranteed that there is at least + * one page in the shared allocation. To get around this, the sharer can write + * a size number to the start of the first page. + * + * @return page aligned pointer to the start of the shared pages, or NULL if no + * process has tried to share with us, or NULL if we the shared virtual address + * space is already occupied in the caller's pagetable. + */ +extern void* popsharedmem(void); + +/** * Poweroff the system. * * @return 1 on failure |