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-rw-r--r--src/common/server-mainloop.c424
1 files changed, 424 insertions, 0 deletions
diff --git a/src/common/server-mainloop.c b/src/common/server-mainloop.c
new file mode 100644
index 0000000..07f02b2
--- /dev/null
+++ b/src/common/server-mainloop.c
@@ -0,0 +1,424 @@
+
+#include "usuals.h"
+#include <errno.h>
+#include <sys/time.h>
+
+#include "server-mainloop.h"
+
+typedef struct _socket_callback
+{
+ int fd;
+ server_socket_callback callback;
+ void* arg;
+
+ struct _socket_callback* next;
+}
+socket_callback;
+
+typedef struct _timer_callback
+{
+ struct timeval at;
+ struct timeval interval;
+ server_timer_callback callback;
+ void* arg;
+
+ struct _timer_callback* next;
+}
+timer_callback;
+
+typedef struct _server_context
+{
+ int stopped;
+ fd_set read_fds;
+ fd_set write_fds;
+ int max_fd;
+ socket_callback* callbacks;
+ timer_callback* timers;
+}
+server_context;
+
+/* Global context */
+static server_context ctx;
+
+static void
+timeval_add(struct timeval* t1, struct timeval* t2)
+{
+ ASSERT(t1->tv_usec < 1000000);
+ ASSERT(t2->tv_usec < 1000000);
+
+ t1->tv_sec += t2->tv_sec;
+ t1->tv_usec += t2->tv_usec;
+ if(t1->tv_usec >= 1000000)
+ {
+ t1->tv_usec -= 1000000;
+ t1->tv_sec += 1;
+ }
+}
+
+static void
+timeval_subtract(struct timeval* t1, struct timeval* t2)
+{
+ ASSERT(t1->tv_usec < 1000000);
+ ASSERT(t2->tv_usec < 1000000);
+
+ t1->tv_sec -= t2->tv_sec;
+ if(t1->tv_usec < t2->tv_usec)
+ {
+ t1->tv_usec += 1000000;
+ t1->tv_sec -= 1;
+ }
+ t1->tv_usec -= t2->tv_usec;
+}
+
+static int
+timeval_compare(struct timeval* t1, struct timeval* t2)
+{
+ ASSERT(t1->tv_usec < 1000000);
+ ASSERT(t2->tv_usec < 1000000);
+
+ if(t1->tv_sec > t2->tv_sec)
+ return 1;
+ else if(t1->tv_sec < t2->tv_sec)
+ return -1;
+ else
+ {
+ if(t1->tv_usec > t2->tv_usec)
+ return 1;
+ else if(t1->tv_usec < t2->tv_usec)
+ return -1;
+ else
+ return 0;
+ }
+}
+
+#define timeval_empty(tv) \
+ ((tv)->tv_sec == 0 && (tv)->tv_usec == 0)
+
+#define timeval_to_ms(tv) \
+ ((((uint64_t)(tv).tv_sec) * 1000L) + (((uint64_t)(tv).tv_usec) / 1000L))
+
+static int
+timeval_dump(struct timeval* tv)
+{
+ fprintf(stderr, "{ %d:%d }", tv->tv_sec, tv->tv_usec / 1000);
+}
+
+static int
+add_timer(int ms, int oneshot, server_timer_callback callback, void* arg)
+{
+ struct timeval interval;
+ timer_callback* cb;
+ int i;
+
+ ASSERT(ms > 0);
+ ASSERT(callback != NULL);
+
+ interval.tv_sec = ms / 1000;
+ interval.tv_usec = (ms % 1000) * 1000; /* into micro seconds */
+
+ cb = (timer_callback*)calloc(1, sizeof(*cb));
+ if(!cb)
+ {
+ errno = ENOMEM;
+ return -1;
+ }
+
+ if(gettimeofday(&(cb->at), NULL) == -1)
+ {
+ free(cb);
+ return -1;
+ }
+
+ timeval_add(&(cb->at), &interval);
+
+ if (oneshot)
+ memset(&(cb->interval), 0, sizeof(cb->interval));
+ else
+ memcpy(&(cb->interval), &interval, sizeof(cb->interval));
+
+ cb->callback = callback;
+ cb->arg = arg;
+
+ cb->next = ctx.timers;
+ ctx.timers = cb;
+
+ return 0;
+}
+
+static timer_callback*
+remove_timer(timer_callback* timcb)
+{
+ timer_callback* cb;
+ timer_callback* next;
+ int i;
+
+ if(!ctx.timers)
+ return;
+
+ /* First in list */;
+ if(ctx.timers == timcb)
+ {
+ cb = ctx.timers;
+ ctx.timers = ctx.timers->next;
+ free(cb);
+ return ctx.timers;
+ }
+
+ /* One ahead processing of rest */
+ for(cb = ctx.timers; cb->next; cb = cb->next)
+ {
+ if(cb->next == timcb)
+ {
+ next = cb->next->next;
+ free(cb->next);
+ cb->next = next;
+ return cb->next;
+ }
+ }
+}
+
+void
+server_init()
+{
+ memset(&ctx, 0, sizeof (ctx));
+ FD_ZERO(&ctx.read_fds);
+ FD_ZERO(&ctx.write_fds);
+
+ ctx.max_fd = -1;
+ ctx.stopped = 1;
+ ctx.callbacks = NULL;
+ ctx.timers = NULL;
+}
+
+void
+server_uninit()
+{
+ timer_callback* timcb;
+ timer_callback* timn;
+ socket_callback* sockcb;
+ socket_callback* sockn;
+
+ for(timcb = ctx.timers; timcb; timcb = timn)
+ {
+ timn = timcb->next;
+ free(timcb);
+ }
+
+ ctx.timers = NULL;
+
+ for(sockcb = ctx.callbacks; sockcb; sockcb = sockn)
+ {
+ sockn = sockcb->next;
+ free(sockcb);
+ }
+
+ ctx.timers = NULL;
+}
+
+uint64_t
+server_get_time()
+{
+ struct timeval tv;
+ if(gettimeofday(&tv, NULL) == -1)
+ return 0L;
+ return timeval_to_ms(tv);
+}
+
+int
+server_run()
+{
+ struct timeval* timeout;
+ struct timeval tv, current;
+ timer_callback* timcb;
+ socket_callback* sockcb;
+ fd_set rfds, wfds;
+ int r, i;
+
+ /* No watches have been set */
+ ASSERT(ctx.max_fd > -1);
+
+ ctx.stopped = 0;
+
+ while(!ctx.stopped)
+ {
+ /* Watch for the various fds */
+ memcpy(&rfds, &ctx.read_fds, sizeof(rfds));
+ memcpy(&wfds, &ctx.write_fds, sizeof(wfds));
+
+ /* Prepare for timers */
+ timeout = NULL;
+ if(gettimeofday(&current, NULL) == -1)
+ return -1;
+
+ /* Cycle through timers */
+ for(timcb = ctx.timers; timcb; )
+ {
+ ASSERT(timcb->callback);
+
+ /* Call any timers that have already passed */
+ if(timeval_compare(&current, &timcb->at) >= 0)
+ {
+ /* Convert to milliseconds, and make the call */
+ r = (timcb->callback)(timeval_to_ms(current), timcb->arg);
+
+ /* Reset timer if so desired */
+ if (r == 1 && !timeval_empty(&timcb->interval))
+ {
+ timeval_add(&timcb->at, &timcb->interval);
+
+ /* If the time has already passed, just use current time */
+ if(timeval_compare(&(timcb->at), &current) <= 0)
+ memcpy(&(timcb->at), &current, sizeof(timcb->at));
+ }
+
+ /* Otherwise remove it. Either one shot, or returned 0 */
+ else
+ {
+ timcb = remove_timer(timcb);
+ continue;
+ }
+ }
+
+ /* Get soonest timer */
+ if (!timeout || timeval_compare(timeout, &timcb->at) < 0)
+ timeout = &timcb->at;
+
+ timcb = timcb->next;
+ }
+
+ /* Convert to an offset */
+ if(timeout)
+ {
+ memcpy(&tv, timeout, sizeof(tv));
+ timeout = &tv;
+ timeval_subtract(timeout, &current);
+ }
+
+ /* fprintf(stderr, "selecting with timeout: ");
+ timeval_dump(timeout);
+ fprintf(stderr, "\n"); */
+
+ r = select(ctx.max_fd, &rfds, &wfds, NULL, timeout);
+ if (r < 0)
+ {
+ /* Interrupted so try again, and possibly exit */
+ if (errno == EINTR)
+ continue;
+
+ /* Programmer errors */
+ ASSERT (errno != EBADF);
+ ASSERT (errno != EINVAL);
+ return r;
+ }
+
+ /* Timeout, just jump to timeout processing */
+ if(r == 0)
+ continue;
+
+ for(sockcb = ctx.callbacks; sockcb; sockcb = sockcb->next)
+ {
+ ASSERT(sockcb->fd != -1);
+
+ /* Call any that are set */
+ if (FD_ISSET(sockcb->fd, &rfds))
+ (sockcb->callback)(sockcb->fd, SERVER_READ, sockcb->arg);
+ if (FD_ISSET(sockcb->fd, &wfds))
+ (sockcb->callback)(sockcb->fd, SERVER_WRITE, sockcb->arg);
+ }
+ }
+
+ return 0;
+}
+
+void
+server_stop()
+{
+ ctx.stopped = 1;
+}
+
+int
+server_stopped()
+{
+ return ctx.stopped;
+}
+
+int
+server_watch(int fd, int type, server_socket_callback callback, void* arg)
+{
+ socket_callback* cb;
+ int i;
+ ASSERT(type != 0);
+ ASSERT(fd != -1);
+ ASSERT(callback != NULL);
+
+ cb = (socket_callback*)calloc(sizeof(*cb), 1);
+ if(!cb)
+ {
+ errno = ENOMEM;
+ return -1;
+ }
+
+ cb->fd = fd;
+ cb->callback = callback;
+ cb->arg = arg;
+
+ cb->next = ctx.callbacks;
+ ctx.callbacks = cb;
+
+ if (type & SERVER_READ)
+ FD_SET(fd, &ctx.read_fds);
+ if (type & SERVER_WRITE)
+ FD_SET(fd, &ctx.write_fds);
+
+ if(fd >= ctx.max_fd)
+ ctx.max_fd = fd + 1;
+
+ return 0;
+}
+
+void
+server_unwatch(int fd)
+{
+ socket_callback* cb;
+ int i;
+
+ ASSERT(fd != -1);
+
+ FD_CLR(fd, &ctx.read_fds);
+ FD_CLR(fd, &ctx.write_fds);
+
+ if(!ctx.callbacks)
+ return;
+
+ /* First in list */;
+ if(ctx.callbacks->fd == fd)
+ {
+ cb = ctx.callbacks;
+ ctx.callbacks = cb->next;
+ free(cb);
+ return;
+ }
+
+ /* One ahead processing of rest */
+ for(cb = ctx.callbacks; cb->next; cb = cb->next)
+ {
+ if(cb->next->fd == fd)
+ {
+ cb->next = cb->next->next;
+ free(cb->next);
+ return;
+ }
+ }
+}
+
+int
+server_timer(int ms, server_timer_callback callback, void* arg)
+{
+ return add_timer(ms, 0, callback, arg);
+}
+
+int
+server_oneshot(int ms, server_timer_callback callback, void* arg)
+{
+ return add_timer(ms, 1, callback, arg);
+}
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