poll.c

commit d7dc055bae2ed8019831df3a6bbe2d7f5ac3a7b6
parent 7c01a7e82b69d9e45eeb76573c688d07df45be83
Author: Yersa Nordman <yersa@finwo.nl>
Date:   Wed, 27 Dec 2023 23:48:31 +0100

work-in-progress implementation

Diffstat:
A
README.md
 | 
31
+++++++++++++++++++++++++++++++
A
config.mk
 | 
1
+
A
package.ini
 | 
9
+++++++++
A
src/fpoll.c
 | 
68
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
A
src/fpoll.h
 | 
40
++++++++++++++++++++++++++++++++++++++++

5 files changed, 149 insertions(+), 0 deletions(-)
diff --git a/README.md b/README.md
@@ -0,0 +1,31 @@
+finwo/poll
+==========
+
+Basic cross-platform io multiplexing library, focussing on polling
+
+## Why
+
+Yes, there's already modern replacements for [poll(2)][poll2] and
+[select(2)][select2], and things like libevent, that handle io multiplexing
+properly, but none that I could find that were easily embeddable without having
+the resulting binary depend on those libraries.
+
+While initially an easy-to-use wrapper around poll(2), platform-specific
+optimizations (like using epoll/kqueue) will be implemented here without the
+external api changing to allow all my projects to benefit from the work here.
+
+## Installation
+
+This library is intended to be installed through
+[dep](https://github.com/finwo/dep), but can be embedded by dropping in the
+[fpoll.c](src/fpoll.c) and [fpoll.h](src/fpoll.h) files into your project and
+including them during compilation.
+
+```
+dep add finwo/poll
+```
+
+## API
+
+[poll2]: https://man7.org/linux/man-pages/man2/poll.2.html
+[select2]: https://man7.org/linux/man-pages/man2/select.2.html
diff --git a/config.mk b/config.mk
@@ -0,0 +1 @@
+SRC+=__DIRNAME/src/fpoll.c
diff --git a/package.ini b/package.ini
@@ -0,0 +1,9 @@
+[dependencies]
+
+[export]
+config.mk=config.mk
+include/finwo/poll.h=src/fpoll.h
+
+[package]
+deps=lib
+name=finwo/poll
diff --git a/src/fpoll.c b/src/fpoll.c
@@ -0,0 +1,68 @@
+#include <poll.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "fpoll.h"
+
+/* struct fpoll { */
+/*   struct pollfd *fds; */
+/*   int size; */
+/*   int limit; */
+/* }; */
+
+struct fpoll * fpoll_create() {
+  struct fpoll *output = calloc(1, sizeof(struct fpoll));
+  return output;
+}
+
+FPOLL_STATUS fpoll_close(struct fpoll *descriptor) {
+  if (descriptor->fds) free(descriptor->fds);
+  free(descriptor);
+  return FPOLL_STATUS_OK;
+}
+
+int fpoll_wait(struct fpoll *descriptor, struct fpoll_ev *evs, int max_evs, int timeout) {
+  return 0;
+}
+
+FPOLL_STATUS fpoll_add(struct fpoll *descriptor, FPOLL_EVENT events, FPOLL_FD filedescriptor) {
+
+  // Initial alloc
+  if (!descriptor->fds) {
+    descriptor->limit = 4;
+    descriptor->fds   = calloc(descriptor->limit, sizeof(struct pollfd));
+  }
+
+  // Grow alloc
+  if (descriptor->limit < (descriptor->size + 1)) {
+    descriptor->limit = descriptor->limit * 2;
+    descriptor->fds   = realloc(descriptor->fds, descriptor->limit);
+  }
+
+  // Find the filedescriptor in the list
+  struct pollfd *pfd = NULL;
+  int i;
+  for(i = 0 ; i < descriptor->size; i++) {
+    if (filedescriptor != descriptor->fds[i].fd) continue;
+    pfd = &(descriptor->fds[i]);
+  }
+
+  // Assign a new pollfd if needed
+  if (!pfd) {
+    pfd              = &(descriptor->fds[descriptor->size]);
+    descriptor->size = descriptor->size + 1;
+    pfd->fd          = filedescriptor;
+    pfd->events      = 0;
+  }
+
+  // Assign the correct events
+  if (events & FPOLL_IN) pfd->events |= POLLIN;
+  if (events & FPOLL_OUT) pfd->events |= POLLOUT;
+
+  return FPOLL_STATUS_OK;
+}
+
+FPOLL_STATUS fpoll_del(struct fpoll *descriptor, FPOLL_EVENT events, FPOLL_FD filedescriptor) {
+  return FPOLL_STATUS_OK;
+}
diff --git a/src/fpoll.h b/src/fpoll.h
@@ -0,0 +1,40 @@
+#ifndef __FINWO_POLL_H__
+#define __FINWO_POLL_H__
+
+#include <poll.h>
+
+#ifndef FPOLL_STATUS
+#define FPOLL_STATUS        int
+#endif
+#define FPOLL_STATUS_OK     0
+#define FPOLL_STATUS_ERROR  1
+
+#ifndef FPOLL_EVENT
+#define FPOLL_EVENT         int
+#endif
+#define FPOLL_IN            1
+#define FPOLL_OUT           2
+#define FPOLL_HUP           4
+
+#ifndef FPOLL_FD
+#define FPOLL_FD            int
+#endif
+
+struct fpoll {
+  struct pollfd *fds;
+  int size;
+  int limit;
+};
+
+struct fpoll_ev {
+  FPOLL_FD    fd;
+  FPOLL_EVENT ev;
+};
+
+struct fpoll * fpoll_create();
+FPOLL_STATUS   fpoll_close(struct fpoll *);
+int            fpoll_wait(struct fpoll *, struct fpoll_ev *, int max_evs, int timeout);
+FPOLL_STATUS   fpoll_add(struct fpoll *, FPOLL_EVENT, FPOLL_FD);
+FPOLL_STATUS   fpoll_del(struct fpoll *, FPOLL_EVENT, FPOLL_FD);
+
+#endif // __FINWO_POLL_H__