area is a better field name for sharedarea

1 files changed, 118 insertions, 0 deletions

diff --git a/core/sharedarea.c b/core/sharedarea.c
new file mode 100644
index 00000000..ca75bf3a
--- /dev/null
+++ b/core/sharedarea.c
@@ -0,0 +1,118 @@
+#include <uwsgi.h>
+
+extern struct uwsgi_server uwsgi;
+
+/*
+
+This is an high-performance memory area shared by all workers/cores/threads
+
+Contrary to the caching subsystem it is 1-copy (caching for non-c apps is 2-copy)
+
+Languages not allowing that kind of access should emulate it calling uwsgi_malloc and then copying it back to
+the language object.
+
+The memory areas could be monitored for changes (read: cores can be suspended while waiting for values)
+
+You can configure multiple areas specifying multiple --sharedarea options
+
+This is a very low-level api, try to use it to build higher-level primitives or rely on the caching subsystem
+
+*/
+
+struct uwsgi_sharedarea *uwsgi_sharedarea_get_by_id(int id, uint64_t pos) {
+	if (id > uwsgi.sharedareas_cnt-1) return NULL;
+	struct uwsgi_sharedarea *sa = uwsgi.sharedareas[id];
+	if (pos > sa->max_pos) return NULL;
+	return sa;
+}
+
+int uwsgi_sharedarea_read(int id, uint64_t pos, char *blob, uint64_t len) {
+	return -1;
+} 
+
+int uwsgi_sharedarea_write(int id, uint64_t pos, char *blob, uint64_t len) {
+	return -1;
+} 
+
+int uwsgi_sharedarea_read64(int id, uint64_t pos, int64_t *value) {
+	return -1;
+}
+
+int uwsgi_sharedarea_write64(int id, uint64_t pos, int64_t value) {
+	return -1;
+}
+
+/*
+	returns:
+		0 -> on updates
+		-1 -> on error
+		-2 -> on timeout
+*/
+int uwsgi_sharedarea_wait(int id, int freq, int timeout) {
+	int waiting = 0;
+	struct uwsgi_sharedarea *sa = uwsgi_sharedarea_get_by_id(id, 0);
+	if (!sa) return -1;
+	uwsgi_rlock(sa->lock);
+	uint64_t updates = sa->updates;
+	uwsgi_rwunlock(sa->lock);
+	while(timeout == 0 || (timeout > 0 && (waiting/1000) >= timeout)) {
+		uwsgi.wait_milliseconds_hook(freq);
+		waiting += freq;
+		// lock sa
+		uwsgi_rlock(sa->lock);
+		if (sa->updates != updates) return 0;
+		// unlock sa
+		uwsgi_rwunlock(sa->lock);
+	}
+	return -2;
+}
+
+struct uwsgi_sharedarea *uwsgi_sharedarea_init(int id, int pages) {
+	uwsgi.sharedareas[id] = uwsgi_calloc_shared(uwsgi.page_size * (pages + 1));
+	uwsgi.sharedareas[id]->area = ((char *) uwsgi.sharedareas[id]) + uwsgi.page_size;
+	uwsgi.sharedareas[id]->id = id;
+	uwsgi.sharedareas[id]->fd = -1;
+	uwsgi.sharedareas[id]->pages = pages;
+	uwsgi.sharedareas[id]->max_pos = (uwsgi.page_size * pages) -1;
+	char *id_str = uwsgi_num2str(id);
+	uwsgi.sharedareas[id]->lock = uwsgi_rwlock_init(uwsgi_concat2("sharedarea", id_str));
+	free(id_str);
+	return uwsgi.sharedareas[id];
+}
+
+struct uwsgi_sharedarea *uwsgi_sharedarea_init_keyval(int id, char *arg) {
+	char *s_pages = NULL;
+	char *s_file = NULL;
+	char *s_fd = NULL;
+	char *s_size = NULL;
+	if (uwsgi_kvlist_parse(arg, strlen(arg), ',', '=',
+		"pages", &s_pages,
+		"file", &s_file,
+		"fd", &s_fd,
+		"size", &s_size,
+		NULL)) {
+	}
+
+	return NULL;
+}
+
+
+void uwsgi_sharedareas_init() {
+	struct uwsgi_string_list *usl = NULL;
+	uwsgi_foreach(usl, uwsgi.sharedareas_list) {
+		uwsgi.sharedareas_cnt++;
+	}
+	uwsgi.sharedareas = uwsgi_calloc(sizeof(struct uwsgi_sharedarea *) * uwsgi.sharedareas_cnt);
+	int id = 0;
+	uwsgi_foreach(usl, uwsgi.sharedareas_list) {
+		char *is_keyval = strchr(usl->value, '=');
+		struct uwsgi_sharedarea *sa = NULL;
+		if (!is_keyval) {
+			sa = uwsgi_sharedarea_init(id, atoi(usl->value));
+		}
+		else {
+			sa = uwsgi_sharedarea_init_keyval(id, usl->value);
+		}
+		id++;
+	}
+}