bytemark/flexnbd-c
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

Move the mirror commit state mbox to struct control

Browse Source 
The mirror_super signals the commit state to the control thread via an
mbox, and this mbox is moved to control.  It was owned by mirror_super,
but the problem with that is that mirror_super can free the mbox before
the control client has been scheduled to receive the message.  If it's
owned by the control object, that can't happen.
This commit is contained in:
Alex Young
2012-07-15 21:57:36 +01:00
parent b20fbc6a66
commit 10625e402b
6 changed files with 81 additions and 35 deletions
Download Patch File Download Diff File Expand all files Collapse all files

45
src/control.c
View File

@@ -44,7 +44,9 @@
#include <unistd.h>
struct control * control_create(struct flexnbd * flexnbd, const char * csn)
struct control * control_create(
struct flexnbd * flexnbd,
const char * csn)
{
struct control * control = xmalloc( sizeof( struct control ) );
@@ -53,6 +55,7 @@ struct control * control_create(struct flexnbd * flexnbd, const char * csn)
control->flexnbd = flexnbd;
control->socket_name = csn;
control->close_signal = self_pipe_create();
control->mirror_state_mbox = mbox_create();
return control;
}
@@ -70,11 +73,15 @@ void control_destroy( struct control * control )
{
NULLCHECK( control );
mbox_destroy( control->mirror_state_mbox );
self_pipe_destroy( control->close_signal );
free( control );
}
struct control_client * control_client_create( struct flexnbd * flexnbd, int client_fd )
struct control_client * control_client_create(
struct flexnbd * flexnbd,
int client_fd ,
struct mbox * state_mbox )
{
NULLCHECK( flexnbd );
@@ -83,6 +90,7 @@ struct control_client * control_client_create( struct flexnbd * flexnbd, int cli
control_client->socket = client_fd;
control_client->flexnbd = flexnbd;
control_client->mirror_state_mbox = state_mbox;
return control_client;
}
@@ -102,7 +110,10 @@ void control_handle_client( struct control * control, int client_fd )
NULLCHECK( control );
NULLCHECK( control->flexnbd );
struct control_client * control_client =
control_client_create( control->flexnbd, client_fd );
control_client_create(
control->flexnbd,
client_fd ,
control->mirror_state_mbox);
/* We intentionally don't spawn a thread for the client here.
* This is to avoid having more than one thread potentially
@@ -260,6 +271,28 @@ void control_write_mirror_response( enum mirror_state mirror_state, int client_f
#undef write_socket
/* Call this in the thread where you want to receive the mirror state */
enum mirror_state control_client_mirror_wait(
struct control_client* client)
{
NULLCHECK( client );
NULLCHECK( client->mirror_state_mbox );
struct mbox * mbox = client->mirror_state_mbox;
enum mirror_state mirror_state;
enum mirror_state * contents;
contents = (enum mirror_state*)mbox_receive( mbox );
NULLCHECK( contents );
mirror_state = *contents;
free( contents );
return mirror_state;
}
#define write_socket(msg) write(client->socket, (msg "\n"), strlen((msg))+1)
/** Command parser to start mirror process from socket input */
int control_mirror(struct control_client* client, int linesc, char** lines)
@@ -333,7 +366,8 @@ int control_mirror(struct control_client* client, int linesc, char** lines)
connect_to,
connect_from,
max_Bps ,
action_at_finish);
action_at_finish,
client->mirror_state_mbox );
serve->mirror = serve->mirror_super->mirror;
FATAL_IF( 0 != pthread_create(
@@ -346,7 +380,8 @@ int control_mirror(struct control_client* client, int linesc, char** lines)
);
debug("Control thread mirror super waiting");
enum mirror_state state = mirror_super_wait( serve->mirror_super );
enum mirror_state state =
control_client_mirror_wait( client );
debug("Control thread writing response");
control_write_mirror_response( state, client->socket );
}