5 commits

Author	SHA1	Message	Date
ridiculousfish	b79ec0122a	Use pipe2 when creating pipes if avaialble ... This allows us to avoid marking the pipe as CLOEXEC in some cases, saving a system call.	2021-02-05 17:58:08 -08:00
ridiculousfish	97f29b1f4d	Pipe fds to move to the "high range" ... This concerns how fish prevents its own fds from interfering with user-defined fd redirections, like `echo hi >&5`. fish has historically done this by tracking all user defined redirections when running a job, and ensuring that pipes are not assigned the same fds. However this is annoying to pass around - it means that we have to thread user-defined redirections into pipe creation. Take a page from zsh and just ensure that all pipes we create have fds in the "high range," which here means at least 10. The primary way to do this is via the F_DUPFD_CLOEXEC syscall, which also sets CLOEXEC, so we aren't invoking additional syscalls in the common case. This will free us from having to track which fds are in user-defined redirections.	2021-02-05 17:58:08 -08:00
ridiculousfish	4b4bf541d1	Migrate more fd-concerned functions from wutil into fds ... Functions like wopen_cloexec have a new home in fds.cpp. This is in preparation for reworking how internal fds avoid conflict with user fds.	2021-02-05 17:58:08 -08:00
ridiculousfish	6588cf35f4	Move autoclose_pipes_t from io.h to fds.h	2021-02-05 17:58:08 -08:00
ridiculousfish	be9375e914	Migrate autoclose_fd_t to new file fds.h ... fds.h will centralize logic around working with file descriptors. In particular it will be the new home for logic around moving fds to high unused values, replacing the "avoid conflicts" logic.	2021-02-05 17:58:08 -08:00