am 2899c94b: Merge "Switch init to epoll."

* commit '2899c94b9d962c308ef71ee10809c61ac39e0ce5':
  Switch init to epoll.

init/init.cpp

@@ -25,8 +25,8 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sys/epoll.h>
 #include <sys/mount.h>
-#include <sys/poll.h>
 #include <sys/socket.h>
 #include <sys/stat.h>
 #include <sys/types.h>
@@ -82,6 +82,17 @@ static const char *ENV[32];
 
 bool waiting_for_exec = false;
 
+static int epoll_fd = -1;
+
+void register_epoll_handler(int fd, void (*fn)()) {
+    epoll_event ev;
+    ev.events = EPOLLIN;
+    ev.data.ptr = reinterpret_cast<void*>(fn);
+    if (epoll_ctl(epoll_fd, EPOLL_CTL_ADD, fd, &ev) == -1) {
+        ERROR("epoll_ctl failed: %s\n", strerror(errno));
+    }
+}
+
 void service::NotifyStateChange(const char* new_state) {
     if (!properties_initialized()) {
         // If properties aren't available yet, we can't set them.
@@ -1037,7 +1048,13 @@ int main(int argc, char** argv) {
     restorecon("/dev/__properties__");
     restorecon_recursive("/sys");
 
-    signal_init();
+    epoll_fd = epoll_create1(EPOLL_CLOEXEC);
+    if (epoll_fd == -1) {
+        ERROR("epoll_create1 failed: %s\n", strerror(errno));
+        exit(1);
+    }
+
+    signal_handler_init();
 
     property_load_boot_defaults();
     start_property_service();
@@ -1071,27 +1088,12 @@ int main(int argc, char** argv) {
     // Run all property triggers based on current state of the properties.
     queue_builtin_action(queue_property_triggers_action, "queue_property_triggers");
 
-    size_t fd_count = 0;
-    struct pollfd ufds[3];
-    ufds[fd_count++] = { .fd = get_signal_fd(), .events = POLLIN, .revents = 0 };
-    ufds[fd_count++] = { .fd = get_property_set_fd(), .events = POLLIN, .revents = 0 };
-    // TODO: can we work out when /dev/keychord is first accessible and open this fd then?
-    bool keychord_fd_init = false;
-
     while (true) {
         if (!waiting_for_exec) {
             execute_one_command();
             restart_processes();
         }
 
-        if (!keychord_fd_init && get_keychord_fd() > 0) {
-            ufds[fd_count].fd = get_keychord_fd();
-            ufds[fd_count].events = POLLIN;
-            ufds[fd_count].revents = 0;
-            fd_count++;
-            keychord_fd_init = true;
-        }
-
         int timeout = -1;
         if (process_needs_restart) {
             timeout = (process_needs_restart - gettime()) * 1000;
@@ -1105,24 +1107,12 @@ int main(int argc, char** argv) {
 
         bootchart_sample(&timeout);
 
-        int nr = TEMP_FAILURE_RETRY(poll(ufds, fd_count, timeout));
+        epoll_event ev;
-        if (nr <= 0) {
+        int nr = TEMP_FAILURE_RETRY(epoll_wait(epoll_fd, &ev, 1, timeout));
-            if (nr == -1) {
+        if (nr == -1) {
-                ERROR("poll failed: %s\n", strerror(errno));
+            ERROR("epoll_wait failed: %s\n", strerror(errno));
-            }
+        } else if (nr == 1) {
-            continue;
+            ((void (*)()) ev.data.ptr)();
-        }
-
-        for (size_t i = 0; i < fd_count; i++) {
-            if (ufds[i].revents & POLLIN) {
-                if (ufds[i].fd == get_property_set_fd()) {
-                    handle_property_set_fd();
-                } else if (ufds[i].fd == get_keychord_fd()) {
-                    handle_keychord();
-                } else if (ufds[i].fd == get_signal_fd()) {
-                    handle_signal();
-                }
-            }
         }
     }
 

init/init.h

@@ -155,4 +155,6 @@ int selinux_reload_policy(void);
 
 void zap_stdio(void);
 
+void register_epoll_handler(int fd, void (*fn)());
+
 #endif	/* _INIT_INIT_H */

init/keychords.cpp

@@ -62,37 +62,7 @@ void add_service_keycodes(struct service *svc)
     }
 }
 
-void keychord_init()
+static void handle_keychord() {
-{
-    int fd, ret;
-
-    service_for_each(add_service_keycodes);
-
-    /* nothing to do if no services require keychords */
-    if (!keychords)
-        return;
-
-    fd = open("/dev/keychord", O_RDWR | O_CLOEXEC);
-    if (fd < 0) {
-        ERROR("could not open /dev/keychord\n");
-        return;
-    }
-
-    ret = write(fd, keychords, keychords_length);
-    if (ret != keychords_length) {
-        ERROR("could not configure /dev/keychord %d: %s\n", ret, strerror(errno));
-        close(fd);
-        fd = -1;
-    }
-
-    free(keychords);
-    keychords = 0;
-
-    keychord_fd = fd;
-}
-
-void handle_keychord()
-{
     struct service *svc;
     char adb_enabled[PROP_VALUE_MAX];
     int ret;
@@ -117,7 +87,28 @@ void handle_keychord()
     }
 }
 
-int get_keychord_fd()
+void keychord_init() {
-{
+    service_for_each(add_service_keycodes);
-    return keychord_fd;
+
+    // Nothing to do if no services require keychords.
+    if (!keychords) {
+        return;
+    }
+
+    keychord_fd = TEMP_FAILURE_RETRY(open("/dev/keychord", O_RDWR | O_CLOEXEC));
+    if (keychord_fd == -1) {
+        ERROR("could not open /dev/keychord: %s\n", strerror(errno));
+        return;
+    }
+
+    int ret = write(keychord_fd, keychords, keychords_length);
+    if (ret != keychords_length) {
+        ERROR("could not configure /dev/keychord %d: %s\n", ret, strerror(errno));
+        close(keychord_fd);
+    }
+
+    free(keychords);
+    keychords = nullptr;
+
+    register_epoll_handler(keychord_fd, handle_keychord);
 }

init/keychords.h

@@ -19,9 +19,7 @@
 
 struct service;
 
-void add_service_keycodes(struct service *svc);
+void add_service_keycodes(service*);
-void keychord_init(void);
+void keychord_init();
-void handle_keychord(void);
-int get_keychord_fd(void);
 
 #endif

init/property_service.cpp

@@ -246,7 +246,7 @@ int property_set(const char* name, const char* value) {
     return rc;
 }
 
-void handle_property_set_fd()
+static void handle_property_set_fd()
 {
     prop_msg msg;
     int s;
@@ -527,8 +527,6 @@ void start_property_service() {
     }
 
     listen(property_set_fd, 8);
-}
 
-int get_property_set_fd() {
+    register_epoll_handler(property_set_fd, handle_property_set_fd);
-    return property_set_fd;
 }

init/property_service.h

@@ -20,7 +20,6 @@
 #include <stddef.h>
 #include <sys/system_properties.h>
 
-extern void handle_property_set_fd(void);
 extern void property_init(void);
 extern void property_load_boot_defaults(void);
 extern void load_persist_props(void);
@@ -30,7 +29,6 @@ void get_property_workspace(int *fd, int *sz);
 extern int __property_get(const char *name, char *value);
 extern int property_set(const char *name, const char *value);
 extern bool properties_initialized();
-int get_property_set_fd(void);
 
 #ifndef __clang__
 extern void __property_get_size_error()

init/signal_handler.cpp

@@ -147,7 +147,7 @@ static void reap_any_outstanding_children() {
     }
 }
 
-void handle_signal() {
+static void handle_signal() {
     // Clear outstanding requests.
     char buf[32];
     read(signal_read_fd, buf, sizeof(buf));
@@ -161,7 +161,7 @@ static void SIGCHLD_handler(int) {
     }
 }
 
-void signal_init() {
+void signal_handler_init() {
     // Create a signalling mechanism for SIGCHLD.
     int s[2];
     if (socketpair(AF_UNIX, SOCK_STREAM | SOCK_NONBLOCK | SOCK_CLOEXEC, 0, s) == -1) {
@@ -180,8 +180,6 @@ void signal_init() {
     sigaction(SIGCHLD, &act, 0);
 
     reap_any_outstanding_children();
-}
 
-int get_signal_fd() {
+    register_epoll_handler(signal_read_fd, handle_signal);
-    return signal_read_fd;
 }

init/signal_handler.h

@@ -17,8 +17,6 @@
 #ifndef _INIT_SIGNAL_HANDLER_H_
 #define _INIT_SIGNAL_HANDLER_H_
 
-void signal_init(void);
+void signal_handler_init(void);
-void handle_signal(void);
-int get_signal_fd(void);
 
 #endif