From 3a4548cfb2fb7e7344618f449ab9bf651ef83e6b Mon Sep 17 00:00:00 2001 From: Ben Pfaff Date: Tue, 24 Apr 2012 10:57:41 -0700 Subject: [PATCH] jsonrpc: Keep jsonrpc_recv() from taking over the CPU. jsonrpc_recv() could take an unbounded amount of CPU time as long as data kept arriving, preventing other work from taking place. This limits the amount of work to processing at most 25 kB of received data and then yielding to the caller. Signed-off-by: Ben Pfaff --- lib/jsonrpc.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) diff --git a/lib/jsonrpc.c b/lib/jsonrpc.c index fc8a75b0..4ebff104 100644 --- a/lib/jsonrpc.c +++ b/lib/jsonrpc.c @@ -277,13 +277,19 @@ jsonrpc_send(struct jsonrpc *rpc, struct jsonrpc_msg *msg) int jsonrpc_recv(struct jsonrpc *rpc, struct jsonrpc_msg **msgp) { + int i; + *msgp = NULL; if (rpc->status) { return rpc->status; } - while (!rpc->received) { - if (byteq_is_empty(&rpc->input)) { + for (i = 0; i < 50; i++) { + if (rpc->received) { + *msgp = rpc->received; + rpc->received = NULL; + return 0; + } else if (byteq_is_empty(&rpc->input)) { size_t chunk; int retval; @@ -328,9 +334,7 @@ jsonrpc_recv(struct jsonrpc *rpc, struct jsonrpc_msg **msgp) } } - *msgp = rpc->received; - rpc->received = NULL; - return 0; + return EAGAIN; } /* Causes the poll loop to wake up when jsonrpc_recv() may return a value other -- 2.30.2