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author | Indrajith K L | 2022-12-03 17:00:20 +0530 |
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committer | Indrajith K L | 2022-12-03 17:00:20 +0530 |
commit | f5c4671bfbad96bf346bd7e9a21fc4317b4959df (patch) | |
tree | 2764fc62da58f2ba8da7ed341643fc359873142f /v_windows/v/vlib/os/notify/backend_linux.c.v | |
download | cli-tools-windows-master.tar.gz cli-tools-windows-master.tar.bz2 cli-tools-windows-master.zip |
Diffstat (limited to 'v_windows/v/vlib/os/notify/backend_linux.c.v')
-rw-r--r-- | v_windows/v/vlib/os/notify/backend_linux.c.v | 206 |
1 files changed, 206 insertions, 0 deletions
diff --git a/v_windows/v/vlib/os/notify/backend_linux.c.v b/v_windows/v/vlib/os/notify/backend_linux.c.v new file mode 100644 index 0000000..1913913 --- /dev/null +++ b/v_windows/v/vlib/os/notify/backend_linux.c.v @@ -0,0 +1,206 @@ +module notify + +import time +import os + +#include <sys/epoll.h> + +struct C.epoll_event { + events u32 + data C.epoll_data_t +} + +[typedef] +union C.epoll_data_t { + ptr voidptr + fd int + u32 u32 + u64 u64 +} + +fn C.epoll_create1(int) int + +fn C.epoll_ctl(int, int, int, &C.epoll_event) int + +fn C.epoll_wait(int, &C.epoll_event, int, int) int + +// EpollNotifier provides methods that implement FdNotifier using the +// epoll I/O event notification facility (linux only) +[noinit] +struct EpollNotifier { + epoll_fd int +} + +// EpollEvent describes an event that occurred for a file descriptor in +// the watch list +[noinit] +struct EpollEvent { +pub: + fd int + kind FdEventType +} + +// new creates a new EpollNotifier +// The FdNotifier interface is returned to allow OS specific +// implementations without exposing the concrete type +pub fn new() ?FdNotifier { + fd := C.epoll_create1(0) // 0 indicates default behavior + if fd == -1 { + return error(os.posix_get_error_msg(C.errno)) + } + // Needed to circumvent V limitations + x := &EpollNotifier{ + epoll_fd: fd + } + return x +} + +const ( + epoll_read = u32(C.EPOLLIN) + epoll_write = u32(C.EPOLLOUT) + epoll_peer_hangup = u32(C.EPOLLRDHUP) + epoll_exception = u32(C.EPOLLPRI) + epoll_error = u32(C.EPOLLERR) + epoll_hangup = u32(C.EPOLLHUP) + epoll_edge_trigger = u32(C.EPOLLET) + epoll_one_shot = u32(C.EPOLLONESHOT) + epoll_wake_up = u32(C.EPOLLWAKEUP) + epoll_exclusive = u32(C.EPOLLEXCLUSIVE) +) + +// ctl is a helper method for add, modify, and remove +fn (mut en EpollNotifier) ctl(fd int, op int, mask u32) ? { + event := C.epoll_event{ + events: mask + data: C.epoll_data_t{ + fd: fd + } + } + if C.epoll_ctl(en.epoll_fd, op, fd, &event) == -1 { + return error(os.posix_get_error_msg(C.errno)) + } +} + +// add adds a file descriptor to the watch list +fn (mut en EpollNotifier) add(fd int, events FdEventType, conf ...FdConfigFlags) ? { + mask := flags_to_mask(events, ...conf) + en.ctl(fd, C.EPOLL_CTL_ADD, mask) ? +} + +// modify sets an existing entry in the watch list to the provided events and configuration +fn (mut en EpollNotifier) modify(fd int, events FdEventType, conf ...FdConfigFlags) ? { + mask := flags_to_mask(events, ...conf) + en.ctl(fd, C.EPOLL_CTL_MOD, mask) ? +} + +// remove removes a file descriptor from the watch list +fn (mut en EpollNotifier) remove(fd int) ? { + en.ctl(fd, C.EPOLL_CTL_DEL, 0) ? +} + +// wait waits to be notified of events on the watch list, +// returns at most 512 events +fn (mut en EpollNotifier) wait(timeout time.Duration) []FdEvent { + // arbitrary 512 limit; events will round robin on successive + // waits if the number exceeds this + // NOTE: we use a fixed size array here for stack allocation; this has + // the added bonus of making EpollNotifier thread safe + events := [512]C.epoll_event{} + // populate events with the new events + to := timeout.sys_milliseconds() + count := C.epoll_wait(en.epoll_fd, &events[0], events.len, to) + + if count > 0 { + mut arr := []FdEvent{cap: count} + for i := 0; i < count; i++ { + fd := unsafe { events[i].data.fd } + kind := event_mask_to_flag(events[i].events) + if kind.is_empty() { + // NOTE: tcc only reports the first event for some + // reason, leaving subsequent structs in the array as 0 + // (or possibly garbage) + panic('encountered an empty event kind; this is most likely due to using tcc') + } + arr << &EpollEvent{ + fd: fd + kind: kind + } + } + return arr + } + return [] +} + +// close closes the EpollNotifier, +// any successive calls to add, modify, remove, and wait should fail +fn (mut en EpollNotifier) close() ? { + if C.close(en.epoll_fd) == -1 { + return error(os.posix_get_error_msg(C.errno)) + } +} + +// event_mask_to_flag is a helper function that converts a bitmask +// returned by epoll_wait to FdEventType +fn event_mask_to_flag(mask u32) FdEventType { + mut flags := FdEventType{} + + if mask & notify.epoll_read != 0 { + flags.set(.read) + } + if mask & notify.epoll_write != 0 { + flags.set(.write) + } + if mask & notify.epoll_peer_hangup != 0 { + flags.set(.peer_hangup) + } + if mask & notify.epoll_exception != 0 { + flags.set(.exception) + } + if mask & notify.epoll_error != 0 { + flags.set(.error) + } + if mask & notify.epoll_hangup != 0 { + flags.set(.hangup) + } + + return flags +} + +// flags_to_mask is a helper function that converts FdEventType and +// FdConfigFlags to a bitmask used by the C functions +fn flags_to_mask(events FdEventType, confs ...FdConfigFlags) u32 { + mut mask := u32(0) + if events.has(.read) { + mask |= notify.epoll_read + } + if events.has(.write) { + mask |= notify.epoll_write + } + if events.has(.peer_hangup) { + mask |= notify.epoll_peer_hangup + } + if events.has(.exception) { + mask |= notify.epoll_exception + } + if events.has(.error) { + mask |= notify.epoll_error + } + if events.has(.hangup) { + mask |= notify.epoll_hangup + } + for conf in confs { + if conf.has(.edge_trigger) { + mask |= notify.epoll_edge_trigger + } + if conf.has(.one_shot) { + mask |= notify.epoll_one_shot + } + if conf.has(.wake_up) { + mask |= notify.epoll_wake_up + } + if conf.has(.exclusive) { + mask |= notify.epoll_exclusive + } + } + return mask +} |