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authordimitri staessens <dimitri.staessens@ugent.be>2017-04-04 02:43:10 +0200
committerdimitri staessens <dimitri.staessens@ugent.be>2017-04-04 09:27:02 +0200
commitf48008cdd28bf31e6f0646b1bb3786f0dc0aede0 (patch)
treeb68ec1c7f6ed81169cfd42f4cac1af6fe0bb65c6 /src/ipcpd
parent0f30eaa3d4dd573f9af30a9fd0c5d22bad63c560 (diff)
downloadouroboros-f48008cdd28bf31e6f0646b1bb3786f0dc0aede0.tar.gz
ouroboros-f48008cdd28bf31e6f0646b1bb3786f0dc0aede0.zip
lib, irmd, ipcpd: Stabilize flow allocation
Diffstat (limited to 'src/ipcpd')
-rw-r--r--src/ipcpd/local/main.c78
1 files changed, 49 insertions, 29 deletions
diff --git a/src/ipcpd/local/main.c b/src/ipcpd/local/main.c
index 718c8d7e..bb7f8325 100644
--- a/src/ipcpd/local/main.c
+++ b/src/ipcpd/local/main.c
@@ -85,7 +85,7 @@ static void * ipcp_local_sdu_loop(void * o)
(void) o;
- while (flow_event_wait(local_data.flows, local_data.fq, &timeout)) {
+ while (true) {
int fd;
ssize_t idx;
@@ -96,9 +96,14 @@ static void * ipcp_local_sdu_loop(void * o)
return (void *) 1; /* -ENOTENROLLED */
}
- pthread_rwlock_rdlock(&local_data.lock);
+ pthread_rwlock_unlock(&ipcpi.state_lock);
+
+ flow_event_wait(local_data.flows, local_data.fq, &timeout);
while ((fd = fqueue_next(local_data.fq)) >= 0) {
+ pthread_rwlock_rdlock(&ipcpi.state_lock);
+ pthread_rwlock_rdlock(&local_data.lock);
+
idx = local_flow_read(fd);
assert(idx < (SHM_BUFFER_SIZE));
@@ -107,10 +112,11 @@ static void * ipcp_local_sdu_loop(void * o)
if (fd != -1)
local_flow_write(fd, idx);
+
+ pthread_rwlock_unlock(&ipcpi.state_lock);
+ pthread_rwlock_unlock(&local_data.lock);
}
- pthread_rwlock_unlock(&local_data.lock);
- pthread_rwlock_unlock(&ipcpi.state_lock);
}
return (void *) 0;
@@ -229,12 +235,6 @@ static int ipcp_local_flow_alloc(int fd,
assert(dst_name);
- out_fd = ipcp_flow_req_arr(getpid(), dst_name, cube);
- if (out_fd < 0) {
- log_dbg("Flow allocation failed.");
- return -1;
- }
-
pthread_rwlock_rdlock(&ipcpi.state_lock);
if (ipcp_get_state() != IPCP_OPERATIONAL) {
@@ -243,16 +243,37 @@ static int ipcp_local_flow_alloc(int fd,
return -1; /* -ENOTENROLLED */
}
+ /*
+ * This function needs to return completely before
+ * flow_resp. Taking the wrlock on the data is the simplest
+ * way to achieve this.
+ */
+
pthread_rwlock_wrlock(&local_data.lock);
- local_data.in_out[fd] = out_fd;
- local_data.in_out[out_fd] = fd;
+ out_fd = ipcp_flow_req_arr(getpid(), dst_name, cube);
+ if (out_fd < 0) {
+ pthread_rwlock_unlock(&ipcpi.state_lock);
+ log_dbg("Flow allocation failed: %d", out_fd);
+ return -1;
+ }
- flow_set_add(local_data.flows, fd);
+ /*
+ * The idea of the port_wait_assign in dev.c was to do the
+ * above synchronisation. But if the lock is not taken, the
+ * resp() function may be called before a lock would be taken
+ * here. This shim will be deprecated, but ideally the sync is
+ * fixed in ipcp.c.
+ */
+
+ local_data.in_out[fd] = out_fd;
+ local_data.in_out[out_fd] = fd;
pthread_rwlock_unlock(&local_data.lock);
pthread_rwlock_unlock(&ipcpi.state_lock);
+ flow_set_add(local_data.flows, fd);
+
log_info("Pending local allocation request on fd %d.", fd);
return 0;
@@ -264,24 +285,30 @@ static int ipcp_local_flow_alloc_resp(int fd,
int out_fd = -1;
int ret = -1;
- if (response)
- return 0;
-
pthread_rwlock_rdlock(&ipcpi.state_lock);
- pthread_rwlock_rdlock(&local_data.lock);
+ pthread_rwlock_wrlock(&local_data.lock);
+
+ if (response) {
+ if (local_data.in_out[fd] != -1)
+ local_data.in_out[local_data.in_out[fd]] = fd;
+ local_data.in_out[fd] = -1;
+ pthread_rwlock_unlock(&local_data.lock);
+ pthread_rwlock_unlock(&ipcpi.state_lock);
+ return 0;
+ }
out_fd = local_data.in_out[fd];
- if (out_fd < 0) {
+ if (out_fd == -1) {
pthread_rwlock_unlock(&local_data.lock);
pthread_rwlock_unlock(&ipcpi.state_lock);
return -1;
}
- flow_set_add(local_data.flows, fd);
-
pthread_rwlock_unlock(&local_data.lock);
pthread_rwlock_unlock(&ipcpi.state_lock);
+ flow_set_add(local_data.flows, fd);
+
if ((ret = ipcp_flow_alloc_reply(out_fd, response)) < 0)
return -1;
@@ -297,24 +324,17 @@ static int ipcp_local_flow_dealloc(int fd)
ipcp_flow_fini(fd);
pthread_rwlock_rdlock(&ipcpi.state_lock);
-
- if (ipcp_get_state() != IPCP_OPERATIONAL) {
- pthread_rwlock_unlock(&ipcpi.state_lock);
- log_dbg("Won't register with non-enrolled IPCP.");
- return -1; /* -ENOTENROLLED */
- }
-
pthread_rwlock_wrlock(&local_data.lock);
flow_set_del(local_data.flows, fd);
local_data.in_out[fd] = -1;
- flow_dealloc(fd);
-
pthread_rwlock_unlock(&local_data.lock);
pthread_rwlock_unlock(&ipcpi.state_lock);
+ flow_dealloc(fd);
+
log_info("Flow with fd %d deallocated.", fd);
return 0;