bytemark/flexnbd-c
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Use client stop signals for thread stopping

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This commit is contained in:
Alex Young
2012-06-07 14:25:30 +01:00
parent a90f84972b
commit 5930f25034
6 changed files with 121 additions and 47 deletions
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19
Rakefile
View File

@@ -25,18 +25,29 @@ task :flexnbd => 'build/flexnbd'
task :build => :flexnbd
task :default => :flexnbd
def check(m)
"build/tests/check_#{m}"
end
namespace "test" do
desc "Run all tests"
task 'run' => ["unit", "scenarios"]
desc "Build C tests"
task 'build' => TEST_MODULES.map { |n| "build/tests/check_#{n}" }
task 'build' => TEST_MODULES.map { |n| check n}
TEST_MODULES.each do |m|
desc "Run tests for #{m}"
task "check_#{m}" => check(m) do
sh check m
end
end
desc "Run C tests"
task 'unit' => 'build' do
TEST_MODULES.each do |n|
ENV['EF_DISABLE_BANNER'] = '1'
sh "build/tests/check_#{n}"
sh check n
end
end
@@ -62,7 +73,7 @@ rule 'build/flexnbd' => OBJECTS do |t|
end
file "build/tests/check_client" =>
file check("client") =>
%w{tests/check_client.c
build/self_pipe.o
build/nbdtypes.o
@@ -83,7 +94,7 @@ end
deps << maybe_obj_name if OBJECTS.include?( maybe_obj_name )
file "build/tests/check_#{m}" => deps do |t|
file check( m ) => deps do |t|
gcc_link(t.name, deps + [LIBCHECK])
end
end

7
src/client.c
View File

@@ -150,16 +150,19 @@ void write_not_zeroes(struct client* client, off64_t from, int len)
* try to honour. 0 otherwise. */
int client_read_request( struct client * client , struct nbd_request *out_request )
{
NULLCHECK( client );
NULLCHECK( out_request );
struct nbd_request_raw request_raw;
fd_set fds;
FD_ZERO(&fds);
FD_SET(client->socket, &fds);
self_pipe_fd_set( client->serve->close_signal, &fds );
self_pipe_fd_set( client->stop_signal, &fds );
CLIENT_ERROR_ON_FAILURE(select(FD_SETSIZE, &fds, NULL, NULL, NULL),
"select() failed");
if ( self_pipe_fd_isset( client->serve->close_signal, &fds ) )
if ( self_pipe_fd_isset( client->stop_signal, &fds ) )
return 0;
if (readloop(client->socket, &request_raw, sizeof(request_raw)) == -1) {

82
src/serve.c
View File

@@ -159,22 +159,11 @@ void serve_open_server_socket(struct server* params)
);
}
/**
* Check to see if a client thread has finished, and if so, tidy up
* after it.
* Returns 1 if the thread was cleaned up and the slot freed, 0
* otherwise.
*
* It's important that client_destroy gets called in the same thread
* which signals the client threads to stop. This avoids the
* possibility of sending a stop signal via a signal which has already
* been destroyed. However, it means that stopped client threads,
* including their signal pipes, won't be cleaned up until the next new
* client connection attempt.
*/
int cleanup_client_thread( struct client_tbl_entry * entry )
int tryjoin_client_thread( struct client_tbl_entry *entry, int (*joinfunc)(pthread_t, void **) )
{
NULLCHECK( entry );
NULLCHECK( joinfunc );
int was_closed = 0;
void * status;
@@ -189,7 +178,7 @@ int cleanup_client_thread( struct client_tbl_entry * entry )
s_client_address,
64 );
if (pthread_tryjoin_np(entry->thread, &status) < 0) {
if (joinfunc(entry->thread, &status) != 0) {
if (errno != EBUSY)
SERVER_ERROR_ON_FAILURE(-1, "Problem with joining thread");
}
@@ -208,6 +197,35 @@ int cleanup_client_thread( struct client_tbl_entry * entry )
}
/**
* Check to see if a client thread has finished, and if so, tidy up
* after it.
* Returns 1 if the thread was cleaned up and the slot freed, 0
* otherwise.
*
* It's important that client_destroy gets called in the same thread
* which signals the client threads to stop. This avoids the
* possibility of sending a stop signal via a signal which has already
* been destroyed. However, it means that stopped client threads,
* including their signal pipes, won't be cleaned up until the next new
* client connection attempt.
*/
int cleanup_client_thread( struct client_tbl_entry * entry )
{
return tryjoin_client_thread( entry, pthread_tryjoin_np );
}
/**
* Join a client thread after having sent a stop signal to it.
* This function will not return until pthread_join has returned, so
* ensures that the client thread is dead.
*/
int join_client_thread( struct client_tbl_entry *entry )
{
return tryjoin_client_thread( entry, pthread_join );
}
/** We can only accommodate MAX_NBD_CLIENTS connections at once. This function
* goes through the current list, waits for any threads that have finished
* and returns the next slot free (or -1 if there are none).
@@ -296,7 +314,7 @@ void accept_nbd_client(
NULLCHECK(client_address);
struct client* client_params;
int slot = cleanup_and_find_client_slot(params);
int slot;
char s_client_address[64] = {0};
@@ -305,6 +323,7 @@ void accept_nbd_client(
return;
}
slot = cleanup_and_find_client_slot(params);
if (slot < 0) {
write(client_fd, "Too many clients", 16);
close(client_fd);
@@ -313,7 +332,10 @@ void accept_nbd_client(
debug( "Client %s accepted.", s_client_address );
client_params = client_create( params, client_fd );
params->nbd_client[slot].client = client_params;
memcpy(&params->nbd_client[slot].address, client_address,
sizeof(union mysockaddr));
if (pthread_create(&params->nbd_client[slot].thread, NULL, client_serve, client_params) < 0) {
debug( "Thread creation problem." );
@@ -323,9 +345,6 @@ void accept_nbd_client(
return;
}
memcpy(&params->nbd_client[slot].address, client_address,
sizeof(union mysockaddr));
debug("nbd thread %d started (%s)", (int) params->nbd_client[slot].thread, s_client_address);
}
@@ -337,6 +356,26 @@ int server_is_closed(struct server* serve)
}
void server_close_clients( struct server *params )
{
NULLCHECK(params);
int i, j;
struct client_tbl_entry *entry;
for( i = 0; i < MAX_NBD_CLIENTS; i++ ) {
entry = &params->nbd_client[i];
if ( entry->thread != 0 ) {
client_signal_stop( entry->client );
}
}
for( j = 0; j < MAX_NBD_CLIENTS; j++ ) {
join_client_thread( &params->nbd_client[i] );
}
}
/** Accept either an NBD or control socket connection, dispatch appropriately */
void serve_accept_loop(struct server* params)
{
@@ -356,14 +395,15 @@ void serve_accept_loop(struct server* params)
SERVER_ERROR_ON_FAILURE(select(FD_SETSIZE, &fds,
NULL, NULL, NULL), "select() failed");
if ( self_pipe_fd_isset( params->close_signal, &fds) )
if ( self_pipe_fd_isset( params->close_signal, &fds ) ){
server_close_clients( params );
return;
}
activity_fd = FD_ISSET(params->server_fd, &fds) ? params->server_fd:
params->control_fd;
client_fd = accept(activity_fd, &client_address.generic, &socklen);
if (activity_fd == params->server_fd) {
debug("Accepted nbd client");
accept_nbd_client(params, client_fd, &client_address);

16
src/util.c
View File

@@ -17,7 +17,7 @@ void error_init()
main_thread = pthread_self();
}
void error(int consult_errno, int close_socket, pthread_mutex_t* unlock, const char* format, ...)
void error(int consult_errno, int fatal, int close_socket, pthread_mutex_t* unlock, const char* format, ...)
{
va_list argptr;
@@ -31,19 +31,19 @@ void error(int consult_errno, int close_socket, pthread_mutex_t* unlock, const c
fprintf(stderr, " (errno=%d, %s)", errno, strerror(errno));
}
if (close_socket)
close(close_socket);
if (unlock)
pthread_mutex_unlock(unlock);
if (close_socket) { close(close_socket); }
if (unlock) { pthread_mutex_unlock(unlock); }
fprintf(stderr, "\n");
if (pthread_equal(pthread_self(), main_thread))
if (fatal || pthread_equal(pthread_self(), main_thread)) {
exit(1);
else
}
else {
fprintf(stderr, "Killing Thread\n");
pthread_exit((void*) 1);
}
}
void* xrealloc(void* ptr, size_t size)
{

10
src/util.h
View File

@@ -6,7 +6,7 @@
void error_init();
void error(int consult_errno, int close_socket, pthread_mutex_t* unlock, const char* format, ...);
void error(int consult_errno, int fatal, int close_socket, pthread_mutex_t* unlock, const char* format, ...);
void* xrealloc(void* ptr, size_t size);
@@ -21,14 +21,14 @@ void debug(const char*msg, ...);
#endif
#define CLIENT_ERROR(msg, ...) \
error(0, client->socket, &client->serve->l_io, msg, ##__VA_ARGS__)
error(0, 0, client->socket, &client->serve->l_io, msg, ##__VA_ARGS__)
#define CLIENT_ERROR_ON_FAILURE(test, msg, ...) \
if (test < 0) { error(1, client->socket, &client->serve->l_io, msg, ##__VA_ARGS__); }
if (test < 0) { error(1, 0, client->socket, &client->serve->l_io, msg, ##__VA_ARGS__); }
#define SERVER_ERROR(msg, ...) \
error(0, 0, NULL, msg, ##__VA_ARGS__)
error(0, 1, 0, NULL, msg, ##__VA_ARGS__)
#define SERVER_ERROR_ON_FAILURE(test, msg, ...) \
if (test < 0) { error(1, 0, NULL, msg, ##__VA_ARGS__); }
if (test < 0) { error(1, 1, 0, NULL, msg, ##__VA_ARGS__); }
#define NULLCHECK(x); if ( NULL == (x) ) { SERVER_ERROR( "Null " #x "." ); }

34
tests/check_client.c
View File

@@ -1,15 +1,18 @@
#include <check.h>
#include "self_pipe.h"
#include "nbdtypes.h"
#include "client.h"
#define FAKE_SERVER ((struct server *)23)
#define FAKE_SOCKET (42)
START_TEST( test_assigns_socket )
{
struct client * c;
c = client_create( NULL, 42 );
c = client_create( FAKE_SERVER, FAKE_SOCKET );
fail_unless( 42 == c->socket, "Socket wasn't assigned." );
}
@@ -22,11 +25,9 @@ START_TEST( test_assigns_server )
/* can't predict the storage size so we can't allocate one on
* the stack
*/
struct server * s = (struct server *)42;
c = client_create( FAKE_SERVER, FAKE_SOCKET );
c = client_create( (struct server *)s, 0 );
fail_unless( s == c->serve, "Serve wasn't assigned." );
fail_unless( FAKE_SERVER == c->serve, "Serve wasn't assigned." );
}
END_TEST
@@ -34,7 +35,7 @@ END_TEST
START_TEST( test_opens_stop_signal )
{
struct client *c = client_create( NULL, 0 );
struct client *c = client_create( FAKE_SERVER, FAKE_SOCKET );
client_signal_stop( c );
@@ -47,7 +48,7 @@ END_TEST
START_TEST( test_closes_stop_signal )
{
struct client *c = client_create( NULL, 0 );
struct client *c = client_create( FAKE_SERVER, FAKE_SOCKET );
int read_fd = c->stop_signal->read_fd;
int write_fd = c->stop_signal->write_fd;
@@ -59,6 +60,24 @@ START_TEST( test_closes_stop_signal )
END_TEST
START_TEST( test_read_request_quits_on_stop_signal )
{
int fds[2];
struct nbd_request nbdr;
pipe( fds );
struct client *c = client_create( FAKE_SERVER, fds[0] );
client_signal_stop( c );
int client_read_request( struct client *, struct nbd_request *);
fail_unless( 0 == client_read_request( c, &nbdr ), "Didn't quit on stop." );
close( fds[0] );
close( fds[1] );
}
END_TEST
Suite *client_suite()
{
Suite *s = suite_create("client");
@@ -71,6 +90,7 @@ Suite *client_suite()
tcase_add_test(tc_create, test_assigns_server);
tcase_add_test(tc_signal, test_opens_stop_signal);
tcase_add_test(tc_signal, test_read_request_quits_on_stop_signal);
tcase_add_test( tc_destroy, test_closes_stop_signal );