Remove libevent.

Fixed any exposed bugs across the stack.

Add a poll() based implementation. Heavily leverages pollset infrastructure to allow small polls to be the norm. Exposes a mechanism to plug in epoll/kqueue for platforms where we have them.

Simplify iomgr callbacks to return one bit of success or failure (instead of the multi valued result that was mostly unused previously). This will ease the burden on new implementations, and the previous system provided no real value anyway.

Removed timeouts on endpoint read/write routines. This simplifies porting burden by providing a more orthogonal interface, and the functionality can always be replicated when desired by using an alarm combined with endpoint_shutdown. I'm fairly certain we ended up with this interface because it was convenient to do from libevent.

Things that need attention still:
- adding an fd to a pollset is O(n^2) - but this is probably ok given that we'll not
use this for multipolling once platform specific implementations are added.
- we rely on the backup poller too often - especially for SSL handshakes and for client
connection establishment we should have a better mechanism ([] []
- Linux needs to use epoll for multiple fds, FreeBSD variants (including
Darwin) need to use kqueue. ([] []
- Linux needs to use eventfd for poll kicking. ([]
	Change on 2015/01/07 by ctiller <ctiller@google.com>
-------------
Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=83461069

1 files changed, 17 insertions, 4 deletions

diff --git a/src/core/iomgr/pollset.h b/src/core/iomgr/pollset.h
index ba1a9d5429..7374a4ec13 100644
--- a/src/core/iomgr/pollset.h
+++ b/src/core/iomgr/pollset.h
@@ -34,18 +34,31 @@
 #ifndef __GRPC_INTERNAL_IOMGR_POLLSET_H_
 #define __GRPC_INTERNAL_IOMGR_POLLSET_H_
 
+#include <grpc/support/port_platform.h>
+
 /* A grpc_pollset is a set of file descriptors that a higher level item is
    interested in. For example:
     - a server will typically keep a pollset containing all connected channels,
       so that it can find new calls to service
     - a completion queue might keep a pollset with an entry for each transport
       that is servicing a call that it's tracking */
-/* Eventually different implementations of iomgr will provide their own
-   grpc_pollset structs. As this is just a dummy wrapper to get the API in,
-   we just define a simple type here. */
-typedef struct { char unused; } grpc_pollset;
+
+#ifdef GPR_POSIX_SOCKET
+#include "src/core/iomgr/pollset_posix.h"
+#endif
 
 void grpc_pollset_init(grpc_pollset *pollset);
 void grpc_pollset_destroy(grpc_pollset *pollset);
 
+/* Do some work on a pollset.
+   May involve invoking asynchronous callbacks, or actually polling file
+   descriptors.
+   Requires GRPC_POLLSET_MU(pollset) locked.
+   May unlock GRPC_POLLSET_MU(pollset) during its execution. */
+int grpc_pollset_work(grpc_pollset *pollset, gpr_timespec deadline);
+
+/* Break a pollset out of polling work
+   Requires GRPC_POLLSET_MU(pollset) locked. */
+void grpc_pollset_kick(grpc_pollset *pollset);
+
 #endif /* __GRPC_INTERNAL_IOMGR_POLLSET_H_ */