syscalls: poll

src/sys/syscalls/poll.c

@@ -0,0 +1,114 @@
+#include <kernel/syscalls.h>
+#include <kernel/alloc.h>
+#include <kernel/vmm.h>
+#include <arch/cls.h>
+#include <poll.h>
+#include <kernel/sched.h>
+
+#define MAXNFDS 4096
+
+syscallret syscall_poll(pollfd *fds, size_t nfds, int timeoutms){
+	syscallret retv;
+	retv.ret = -1;
+
+	if(fds > USER_SPACE_END){
+		retv.errno = EFAULT;
+		return retv;
+	}
+
+	if(nfds > MAXNFDS){
+		retv.errno = EINVAL;
+		return retv;
+	}
+
+
+	// create the internal list
+
+	pollfd* ilist = alloc(1);
+
+	if(!ilist){
+		retv.errno = ENOMEM;
+		return retv;
+	}
+	
+	for(size_t fd = 0; fd < nfds; ++fd){
+
+		void* tmp = realloc(ilist,(fd+1)*sizeof(pollfd));
+		if(!tmp){
+			retv.errno = ENOMEM;
+			goto ret;
+		}
+		
+		ilist[fd].fd = fds[fd].fd;
+		ilist[fd].events = fds[fd].events;
+	}
+
+	// check for events and stuff
+
+	bool eventhappened = false;
+
+	fdtable_t* fdtable = &arch_getcls()->thread->proc->fdtable;
+
+	while(!eventhappened){
+		for(uintmax_t i = 0; i < nfds; ++i){
+			if(ilist[i].fd < 0 || ilist[i].events == 0)
+				continue;
+			
+			// open fd
+			
+			fd_t* fd;
+
+			int err = fd_access(fdtable, &fd, ilist[i].fd);
+
+			if(err){
+				ilist[i].revents = POLLNVAL;
+				eventhappened = true;
+				continue;
+			}
+			
+			// poll
+			
+			if(fd->node){
+				if(vfs_poll(fd->node, &ilist[i]))
+					ilist[i].revents = POLLERR;
+			}
+
+			if(ilist[i].revents)
+				eventhappened = true;
+
+			// cleanup
+			
+			fd_release(fd);
+			
+		}	
+		
+		// TODO check for signal or timeout
+
+
+	}
+
+	// copy results into each fd
+
+	size_t eventcount = 0;
+
+	for(uintmax_t i = 0; i < nfds; ++i){
+		
+		if(ilist[i].fd < 0 || ilist[i].revents == 0)
+			continue;
+
+		fds[i].revents = ilist[i].revents;
+		
+		++eventcount;
+
+	}
+
+	retv.errno = 0;
+	retv.ret = eventcount;
+
+	ret:
+	
+	if(ilist)
+		free(ilist);
+	
+	return retv;
+}