Merge "lmkd: Add support for multiple lmkd client connections"
diff --git a/lmkd/lmkd.c b/lmkd/lmkd.c
index 838a5f4..988f9f2 100644
--- a/lmkd/lmkd.c
+++ b/lmkd/lmkd.c
@@ -122,13 +122,30 @@
static bool kill_heaviest_task;
static unsigned long kill_timeout_ms;
-/* control socket listen and data */
-static int ctrl_lfd;
-static int ctrl_dfd = -1;
-static int ctrl_dfd_reopened; /* did we reopen ctrl conn on this loop? */
+/* data required to handle events */
+struct event_handler_info {
+ int data;
+ void (*handler)(int data, uint32_t events);
+};
-/* 3 memory pressure levels, 1 ctrl listen socket, 1 ctrl data socket */
-#define MAX_EPOLL_EVENTS 5
+/* data required to handle socket events */
+struct sock_event_handler_info {
+ int sock;
+ struct event_handler_info handler_info;
+};
+
+/* max supported number of data connections */
+#define MAX_DATA_CONN 2
+
+/* socket event handler data */
+static struct sock_event_handler_info ctrl_sock;
+static struct sock_event_handler_info data_sock[MAX_DATA_CONN];
+
+/* vmpressure event handler data */
+static struct event_handler_info vmpressure_hinfo[VMPRESS_LEVEL_COUNT];
+
+/* 3 memory pressure levels, 1 ctrl listen socket, 2 ctrl data socket */
+#define MAX_EPOLL_EVENTS (1 + MAX_DATA_CONN + VMPRESS_LEVEL_COUNT)
static int epollfd;
static int maxevents;
@@ -398,17 +415,24 @@
}
}
-static void ctrl_data_close(void) {
- ALOGI("Closing Activity Manager data connection");
- close(ctrl_dfd);
- ctrl_dfd = -1;
+static void ctrl_data_close(int dsock_idx) {
+ struct epoll_event epev;
+
+ ALOGI("closing lmkd data connection");
+ if (epoll_ctl(epollfd, EPOLL_CTL_DEL, data_sock[dsock_idx].sock, &epev) == -1) {
+ // Log a warning and keep going
+ ALOGW("epoll_ctl for data connection socket failed; errno=%d", errno);
+ }
maxevents--;
+
+ close(data_sock[dsock_idx].sock);
+ data_sock[dsock_idx].sock = -1;
}
-static int ctrl_data_read(char *buf, size_t bufsz) {
+static int ctrl_data_read(int dsock_idx, char *buf, size_t bufsz) {
int ret = 0;
- ret = read(ctrl_dfd, buf, bufsz);
+ ret = read(data_sock[dsock_idx].sock, buf, bufsz);
if (ret == -1) {
ALOGE("control data socket read failed; errno=%d", errno);
@@ -420,14 +444,14 @@
return ret;
}
-static void ctrl_command_handler(void) {
+static void ctrl_command_handler(int dsock_idx) {
int ibuf[CTRL_PACKET_MAX / sizeof(int)];
int len;
int cmd = -1;
int nargs;
int targets;
- len = ctrl_data_read((char *)ibuf, CTRL_PACKET_MAX);
+ len = ctrl_data_read(dsock_idx, (char *)ibuf, CTRL_PACKET_MAX);
if (len <= 0)
return;
@@ -465,40 +489,57 @@
ALOGE("Wrong control socket read length cmd=%d len=%d", cmd, len);
}
-static void ctrl_data_handler(uint32_t events) {
- if (events & EPOLLHUP) {
- ALOGI("ActivityManager disconnected");
- if (!ctrl_dfd_reopened)
- ctrl_data_close();
- } else if (events & EPOLLIN) {
- ctrl_command_handler();
+static void ctrl_data_handler(int data, uint32_t events) {
+ if (events & EPOLLIN) {
+ ctrl_command_handler(data);
}
}
-static void ctrl_connect_handler(uint32_t events __unused) {
- struct epoll_event epev;
+static int get_free_dsock() {
+ for (int i = 0; i < MAX_DATA_CONN; i++) {
+ if (data_sock[i].sock < 0) {
+ return i;
+ }
+ }
+ return -1;
+}
- if (ctrl_dfd >= 0) {
- ctrl_data_close();
- ctrl_dfd_reopened = 1;
+static void ctrl_connect_handler(int data __unused, uint32_t events __unused) {
+ struct epoll_event epev;
+ int free_dscock_idx = get_free_dsock();
+
+ if (free_dscock_idx < 0) {
+ /*
+ * Number of data connections exceeded max supported. This should not
+ * happen but if it does we drop all existing connections and accept
+ * the new one. This prevents inactive connections from monopolizing
+ * data socket and if we drop ActivityManager connection it will
+ * immediately reconnect.
+ */
+ for (int i = 0; i < MAX_DATA_CONN; i++) {
+ ctrl_data_close(i);
+ }
+ free_dscock_idx = 0;
}
- ctrl_dfd = accept(ctrl_lfd, NULL, NULL);
-
- if (ctrl_dfd < 0) {
+ data_sock[free_dscock_idx].sock = accept(ctrl_sock.sock, NULL, NULL);
+ if (data_sock[free_dscock_idx].sock < 0) {
ALOGE("lmkd control socket accept failed; errno=%d", errno);
return;
}
- ALOGI("ActivityManager connected");
- maxevents++;
+ ALOGI("lmkd data connection established");
+ /* use data to store data connection idx */
+ data_sock[free_dscock_idx].handler_info.data = free_dscock_idx;
+ data_sock[free_dscock_idx].handler_info.handler = ctrl_data_handler;
epev.events = EPOLLIN;
- epev.data.ptr = (void *)ctrl_data_handler;
- if (epoll_ctl(epollfd, EPOLL_CTL_ADD, ctrl_dfd, &epev) == -1) {
+ epev.data.ptr = (void *)&(data_sock[free_dscock_idx].handler_info);
+ if (epoll_ctl(epollfd, EPOLL_CTL_ADD, data_sock[free_dscock_idx].sock, &epev) == -1) {
ALOGE("epoll_ctl for data connection socket failed; errno=%d", errno);
- ctrl_data_close();
+ ctrl_data_close(free_dscock_idx);
return;
}
+ maxevents++;
}
static int zoneinfo_parse_protection(char *cp) {
@@ -802,7 +843,7 @@
(to->tv_usec - from->tv_usec) / 1000;
}
-static void mp_event_common(enum vmpressure_level level) {
+static void mp_event_common(int data, uint32_t events __unused) {
int ret;
unsigned long long evcount;
int64_t mem_usage, memsw_usage;
@@ -811,6 +852,7 @@
struct mem_size free_mem;
static struct timeval last_report_tm;
static unsigned long skip_count = 0;
+ enum vmpressure_level level = (enum vmpressure_level)data;
/*
* Check all event counters from low to critical
@@ -927,26 +969,15 @@
}
}
-static void mp_event_low(uint32_t events __unused) {
- mp_event_common(VMPRESS_LEVEL_LOW);
-}
-
-static void mp_event_medium(uint32_t events __unused) {
- mp_event_common(VMPRESS_LEVEL_MEDIUM);
-}
-
-static void mp_event_critical(uint32_t events __unused) {
- mp_event_common(VMPRESS_LEVEL_CRITICAL);
-}
-
-static bool init_mp_common(void *event_handler, enum vmpressure_level level) {
+static bool init_mp_common(enum vmpressure_level level) {
int mpfd;
int evfd;
int evctlfd;
char buf[256];
struct epoll_event epev;
int ret;
- const char *levelstr = level_name[level];
+ int level_idx = (int)level;
+ const char *levelstr = level_name[level_idx];
mpfd = open(MEMCG_SYSFS_PATH "memory.pressure_level", O_RDONLY | O_CLOEXEC);
if (mpfd < 0) {
@@ -972,7 +1003,7 @@
goto err;
}
- ret = write(evctlfd, buf, strlen(buf) + 1);
+ ret = TEMP_FAILURE_RETRY(write(evctlfd, buf, strlen(buf) + 1));
if (ret == -1) {
ALOGE("cgroup.event_control write failed for level %s; errno=%d",
levelstr, errno);
@@ -980,7 +1011,10 @@
}
epev.events = EPOLLIN;
- epev.data.ptr = event_handler;
+ /* use data to store event level */
+ vmpressure_hinfo[level_idx].data = level_idx;
+ vmpressure_hinfo[level_idx].handler = mp_event_common;
+ epev.data.ptr = (void *)&vmpressure_hinfo[level_idx];
ret = epoll_ctl(epollfd, EPOLL_CTL_ADD, evfd, &epev);
if (ret == -1) {
ALOGE("epoll_ctl for level %s failed; errno=%d", levelstr, errno);
@@ -1017,21 +1051,27 @@
return -1;
}
- ctrl_lfd = android_get_control_socket("lmkd");
- if (ctrl_lfd < 0) {
+ // mark data connections as not connected
+ for (int i = 0; i < MAX_DATA_CONN; i++) {
+ data_sock[i].sock = -1;
+ }
+
+ ctrl_sock.sock = android_get_control_socket("lmkd");
+ if (ctrl_sock.sock < 0) {
ALOGE("get lmkd control socket failed");
return -1;
}
- ret = listen(ctrl_lfd, 1);
+ ret = listen(ctrl_sock.sock, MAX_DATA_CONN);
if (ret < 0) {
ALOGE("lmkd control socket listen failed (errno=%d)", errno);
return -1;
}
epev.events = EPOLLIN;
- epev.data.ptr = (void *)ctrl_connect_handler;
- if (epoll_ctl(epollfd, EPOLL_CTL_ADD, ctrl_lfd, &epev) == -1) {
+ ctrl_sock.handler_info.handler = ctrl_connect_handler;
+ epev.data.ptr = (void *)&(ctrl_sock.handler_info);
+ if (epoll_ctl(epollfd, EPOLL_CTL_ADD, ctrl_sock.sock, &epev) == -1) {
ALOGE("epoll_ctl for lmkd control socket failed (errno=%d)", errno);
return -1;
}
@@ -1043,10 +1083,9 @@
if (use_inkernel_interface) {
ALOGI("Using in-kernel low memory killer interface");
} else {
- if (!init_mp_common((void *)&mp_event_low, VMPRESS_LEVEL_LOW) ||
- !init_mp_common((void *)&mp_event_medium, VMPRESS_LEVEL_MEDIUM) ||
- !init_mp_common((void *)&mp_event_critical,
- VMPRESS_LEVEL_CRITICAL)) {
+ if (!init_mp_common(VMPRESS_LEVEL_LOW) ||
+ !init_mp_common(VMPRESS_LEVEL_MEDIUM) ||
+ !init_mp_common(VMPRESS_LEVEL_CRITICAL)) {
ALOGE("Kernel does not support memory pressure events or in-kernel low memory killer");
return -1;
}
@@ -1061,12 +1100,14 @@
}
static void mainloop(void) {
+ struct event_handler_info* handler_info;
+ struct epoll_event *evt;
+
while (1) {
struct epoll_event events[maxevents];
int nevents;
int i;
- ctrl_dfd_reopened = 0;
nevents = epoll_wait(epollfd, events, maxevents, -1);
if (nevents == -1) {
@@ -1076,11 +1117,33 @@
continue;
}
- for (i = 0; i < nevents; ++i) {
- if (events[i].events & EPOLLERR)
+ /*
+ * First pass to see if any data socket connections were dropped.
+ * Dropped connection should be handled before any other events
+ * to deallocate data connection and correctly handle cases when
+ * connection gets dropped and reestablished in the same epoll cycle.
+ * In such cases it's essential to handle connection closures first.
+ */
+ for (i = 0, evt = &events[0]; i < nevents; ++i, evt++) {
+ if ((evt->events & EPOLLHUP) && evt->data.ptr) {
+ ALOGI("lmkd data connection dropped");
+ handler_info = (struct event_handler_info*)evt->data.ptr;
+ ctrl_data_close(handler_info->data);
+ }
+ }
+
+ /* Second pass to handle all other events */
+ for (i = 0, evt = &events[0]; i < nevents; ++i, evt++) {
+ if (evt->events & EPOLLERR)
ALOGD("EPOLLERR on event #%d", i);
- if (events[i].data.ptr)
- (*(void (*)(uint32_t))events[i].data.ptr)(events[i].events);
+ if (evt->events & EPOLLHUP) {
+ /* This case was handled in the first pass */
+ continue;
+ }
+ if (evt->data.ptr) {
+ handler_info = (struct event_handler_info*)evt->data.ptr;
+ handler_info->handler(handler_info->data, evt->events);
+ }
}
}
}