static int event_on_accept (struct event_data *self, struct kevent *event) {
struct sockaddr client;
socklen_t client_len = sizeof(client);
int client_fd = accept(server_fd, &client, &client_len);
int flags;
int err;
if (client_fd < 0) {
if (errno == EWOULDBLOCK || errno == EAGAIN) return 0;
on_error("Accept failed (should this be fatal?): %s\n", strerror(errno));
}
flags = fcntl(client_fd, F_GETFL, 0);
if (flags < 0) on_error("Could not get client socket flags: %s\n", strerror(errno));
err = fcntl(client_fd, F_SETFL, flags | O_NONBLOCK);
if (err < 0) on_error("Could not set client socket to be non blocking: %s\n", strerror(errno));
struct event_data *client_data = (struct event_data *) malloc(sizeof(struct event_data));
client_data->on_read = event_on_read;
client_data->on_write = event_on_write;
event_change(client_fd, EVFILT_READ, EV_ADD | EV_ENABLE, client_data);
event_change(client_fd, EVFILT_WRITE, EV_ADD | EV_ENABLE, client_data);
return 1;
}
static int event_on_read (struct event_data *self, struct kevent *event) {
if (self->buffer_read == BUFFER_SIZE) {
event_change(event->ident, EVFILT_READ, EV_DISABLE, self);
return 0;
}
int n = read(event->ident, self->buffer + self->buffer_read, BUFFER_SIZE - self->buffer_read);
if (n < 0) {
if (errno == EWOULDBLOCK || errno == EAGAIN) return 0;
on_error("Read failed (should this be fatal?): %s\n", strerror(errno));
}
if (n == 0) {
free(self);
close(event->ident);
return 0;
}
if (self->buffer_read == 0) {
event_change(event->ident, EVFILT_WRITE, EV_ENABLE, self);
}
self->buffer_read += n;
return event_flush_write(self, event);
}
JNIEXPORT jint JNICALL
Agent_OnLoad(JavaVM *jvm, char *options, void *reserved)
{
jvmtiEventCallbacks *evCbs;
jvmtiCapabilities caps;
jvmtiEnv *jvmti;
jint rc;
jint jvmtiVer;
agent_options = options ? strdup(options) : "";
evCbs = get_jvmti_callbacks();
memset(evCbs, 0, sizeof(*evCbs));
memset(&caps, 0, sizeof(caps));
evCbs->VMInit = cbVMInit;
evCbs->VMDeath = cbVMDeath;
caps.can_generate_breakpoint_events = 1;
caps.can_generate_method_entry_events = 1;
caps.can_generate_method_exit_events = 1;
caps.can_generate_exception_events = 1;
caps.can_tag_objects = 1;
caps.can_get_source_file_name = 1;
caps.can_get_line_numbers = 1;
caps.can_access_local_variables = 1;
caps.can_generate_single_step_events = 1; /* Used for line-oriented stepping */
/* caps.can_generate_frame_pop_events = 1; */
caps.can_force_early_return = 1;
rc = (*jvm)->GetEnv(jvm, (void **)&jvmti, JVMTI_VERSION_1_0);
if(rc < 0)
{
fprintf(stderr, "Failed to get JVMTI env\n");
return JNI_ERR;
}
Gagent.jvm = jvm;
Gagent.jvmti = jvmti;
Gagent.jerr = (*Gagent.jvmti)->GetVersionNumber(Gagent.jvmti, &jvmtiVer);
check_jvmti_error(Gagent.jvmti, Gagent.jerr);
printf("JVMTI version %d.%d.%d\n",
(jvmtiVer & JVMTI_VERSION_MASK_MAJOR) >> JVMTI_VERSION_SHIFT_MAJOR,
(jvmtiVer & JVMTI_VERSION_MASK_MINOR) >> JVMTI_VERSION_SHIFT_MINOR,
(jvmtiVer & JVMTI_VERSION_MASK_MICRO) >> JVMTI_VERSION_SHIFT_MICRO);
Gagent.jerr = (*Gagent.jvmti)->AddCapabilities(Gagent.jvmti, &caps);
check_jvmti_error(Gagent.jvmti, Gagent.jerr);
Gagent.jerr = (*Gagent.jvmti)->SetEventCallbacks(Gagent.jvmti,
evCbs, sizeof(jvmtiEventCallbacks));
check_jvmti_error(Gagent.jvmti, Gagent.jerr);
/* Check that any calls to SetEventNotificationMode are valid in the
OnLoad phase before calling here. */
Gagent.jerr = event_change(Gagent.jvmti, JVMTI_ENABLE, JVMTI_EVENT_VM_INIT, NULL);
check_jvmti_error(Gagent.jvmti, Gagent.jerr);
Gagent.jerr = event_change(Gagent.jvmti, JVMTI_ENABLE, JVMTI_EVENT_VM_DEATH, NULL);
check_jvmti_error(Gagent.jvmti, Gagent.jerr);
return JNI_OK;
}
static int event_on_write (struct event_data *self, struct kevent *event) {
if (self->buffer_read == self->buffer_write) {
event_change(event->ident, EVFILT_WRITE, EV_DISABLE, self);
return 0;
}
return event_flush_write(self, event);
}
int main (int argc, char *argv[]) {
if (argc < 2) {
printf("Usage: %s [socket-path]\n", argv[0]);
exit(1);
}
struct event_data server = {
.on_read = event_on_accept,
.on_write = NULL
};
event_server_listen(argv[1]);
event_change(server_fd, EVFILT_READ, EV_ADD | EV_ENABLE, &server);
event_loop();
return 0;
}