init: move reaping from ServiceManager to signal_handler.cpp

signal_handler.cpp itself needs to be cleaned up, but this is a step
to clean up ServiceManager.

Test: boot bullhead
Change-Id: I81f1e8ac4d09692cfb364bc702cbd3deb61aa55a
diff --git a/init/reboot.cpp b/init/reboot.cpp
index 6002040..b1cde93 100644
--- a/init/reboot.cpp
+++ b/init/reboot.cpp
@@ -53,6 +53,7 @@
 #include "init.h"
 #include "property_service.h"
 #include "service.h"
+#include "signal_handler.h"
 
 using android::base::StringPrintf;
 using android::base::Timer;
@@ -406,7 +407,7 @@
         // Only wait up to half of timeout here
         auto termination_wait_timeout = shutdown_timeout / 2;
         while (t.duration() < termination_wait_timeout) {
-            ServiceManager::GetInstance().ReapAnyOutstandingChildren();
+            ReapAnyOutstandingChildren();
 
             service_count = 0;
             ServiceManager::GetInstance().ForEachService([&service_count](Service* s) {
@@ -437,7 +438,7 @@
     ServiceManager::GetInstance().ForEachServiceShutdownOrder([](Service* s) {
         if (!s->IsShutdownCritical()) s->Stop();
     });
-    ServiceManager::GetInstance().ReapAnyOutstandingChildren();
+    ReapAnyOutstandingChildren();
 
     // 3. send volume shutdown to vold
     Service* voldService = ServiceManager::GetInstance().FindServiceByName("vold");
diff --git a/init/service.cpp b/init/service.cpp
index 7f79584..b5e2067 100644
--- a/init/service.cpp
+++ b/init/service.cpp
@@ -1091,69 +1091,6 @@
     }
 }
 
-bool ServiceManager::ReapOneProcess() {
-    siginfo_t siginfo = {};
-    // This returns a zombie pid or informs us that there are no zombies left to be reaped.
-    // It does NOT reap the pid; that is done below.
-    if (TEMP_FAILURE_RETRY(waitid(P_ALL, 0, &siginfo, WEXITED | WNOHANG | WNOWAIT)) != 0) {
-        PLOG(ERROR) << "waitid failed";
-        return false;
-    }
-
-    auto pid = siginfo.si_pid;
-    if (pid == 0) return false;
-
-    // At this point we know we have a zombie pid, so we use this scopeguard to reap the pid
-    // whenever the function returns from this point forward.
-    // We do NOT want to reap the zombie earlier as in Service::Reap(), we kill(-pid, ...) and we
-    // want the pid to remain valid throughout that (and potentially future) usages.
-    auto reaper = make_scope_guard([pid] { TEMP_FAILURE_RETRY(waitpid(pid, nullptr, WNOHANG)); });
-
-    if (PropertyChildReap(pid)) {
-        return true;
-    }
-
-    Service* svc = FindServiceByPid(pid);
-
-    std::string name;
-    std::string wait_string;
-    if (svc) {
-        name = StringPrintf("Service '%s' (pid %d)", svc->name().c_str(), pid);
-        if (svc->flags() & SVC_EXEC) {
-            auto exec_duration = boot_clock::now() - svc->time_started();
-            auto exec_duration_ms =
-                std::chrono::duration_cast<std::chrono::milliseconds>(exec_duration).count();
-            wait_string = StringPrintf(" waiting took %f seconds", exec_duration_ms / 1000.0f);
-        }
-    } else {
-        name = StringPrintf("Untracked pid %d", pid);
-    }
-
-    auto status = siginfo.si_status;
-    if (WIFEXITED(status)) {
-        LOG(INFO) << name << " exited with status " << WEXITSTATUS(status) << wait_string;
-    } else if (WIFSIGNALED(status)) {
-        LOG(INFO) << name << " killed by signal " << WTERMSIG(status) << wait_string;
-    }
-
-    if (!svc) {
-        return true;
-    }
-
-    svc->Reap();
-
-    if (svc->flags() & SVC_TEMPORARY) {
-        RemoveService(*svc);
-    }
-
-    return true;
-}
-
-void ServiceManager::ReapAnyOutstandingChildren() {
-    while (ReapOneProcess()) {
-    }
-}
-
 bool ServiceParser::ParseSection(std::vector<std::string>&& args, const std::string& filename,
                                  int line, std::string* err) {
     if (args.size() < 3) {
diff --git a/init/service.h b/init/service.h
index 4098005..a7c91ae 100644
--- a/init/service.h
+++ b/init/service.h
@@ -221,15 +221,10 @@
     void ForEachServiceShutdownOrder(const std::function<void(Service*)>& callback) const;
     void ForEachServiceInClass(const std::string& classname,
                                void (*func)(Service* svc)) const;
-    void ReapAnyOutstandingChildren();
     void RemoveService(const Service& svc);
     void DumpState() const;
 
   private:
-    // Cleans up a child process that exited.
-    // Returns true iff a children was cleaned up.
-    bool ReapOneProcess();
-
     std::vector<std::unique_ptr<Service>> services_;
 };
 
diff --git a/init/signal_handler.cpp b/init/signal_handler.cpp
index db1bfcf..d77a212 100644
--- a/init/signal_handler.cpp
+++ b/init/signal_handler.cpp
@@ -14,29 +14,94 @@
  * limitations under the License.
  */
 
+#include "signal_handler.h"
+
 #include <signal.h>
 #include <string.h>
 #include <sys/socket.h>
 #include <sys/types.h>
+#include <sys/wait.h>
 #include <unistd.h>
 
+#include <android-base/chrono_utils.h>
 #include <android-base/logging.h>
+#include <android-base/scopeguard.h>
+#include <android-base/stringprintf.h>
 
 #include "init.h"
+#include "property_service.h"
 #include "service.h"
 
+using android::base::StringPrintf;
+using android::base::boot_clock;
+using android::base::make_scope_guard;
+
 namespace android {
 namespace init {
 
 static int signal_write_fd = -1;
 static int signal_read_fd = -1;
 
+static bool ReapOneProcess() {
+    siginfo_t siginfo = {};
+    // This returns a zombie pid or informs us that there are no zombies left to be reaped.
+    // It does NOT reap the pid; that is done below.
+    if (TEMP_FAILURE_RETRY(waitid(P_ALL, 0, &siginfo, WEXITED | WNOHANG | WNOWAIT)) != 0) {
+        PLOG(ERROR) << "waitid failed";
+        return false;
+    }
+
+    auto pid = siginfo.si_pid;
+    if (pid == 0) return false;
+
+    // At this point we know we have a zombie pid, so we use this scopeguard to reap the pid
+    // whenever the function returns from this point forward.
+    // We do NOT want to reap the zombie earlier as in Service::Reap(), we kill(-pid, ...) and we
+    // want the pid to remain valid throughout that (and potentially future) usages.
+    auto reaper = make_scope_guard([pid] { TEMP_FAILURE_RETRY(waitpid(pid, nullptr, WNOHANG)); });
+
+    if (PropertyChildReap(pid)) return true;
+
+    Service* service = ServiceManager::GetInstance().FindServiceByPid(pid);
+
+    std::string name;
+    std::string wait_string;
+    if (service) {
+        name = StringPrintf("Service '%s' (pid %d)", service->name().c_str(), pid);
+        if (service->flags() & SVC_EXEC) {
+            auto exec_duration = boot_clock::now() - service->time_started();
+            auto exec_duration_ms =
+                std::chrono::duration_cast<std::chrono::milliseconds>(exec_duration).count();
+            wait_string = StringPrintf(" waiting took %f seconds", exec_duration_ms / 1000.0f);
+        }
+    } else {
+        name = StringPrintf("Untracked pid %d", pid);
+    }
+
+    auto status = siginfo.si_status;
+    if (WIFEXITED(status)) {
+        LOG(INFO) << name << " exited with status " << WEXITSTATUS(status) << wait_string;
+    } else if (WIFSIGNALED(status)) {
+        LOG(INFO) << name << " killed by signal " << WTERMSIG(status) << wait_string;
+    }
+
+    if (!service) return true;
+
+    service->Reap();
+
+    if (service->flags() & SVC_TEMPORARY) {
+        ServiceManager::GetInstance().RemoveService(*service);
+    }
+
+    return true;
+}
+
 static void handle_signal() {
     // Clear outstanding requests.
     char buf[32];
     read(signal_read_fd, buf, sizeof(buf));
 
-    ServiceManager::GetInstance().ReapAnyOutstandingChildren();
+    ReapAnyOutstandingChildren();
 }
 
 static void SIGCHLD_handler(int) {
@@ -45,6 +110,11 @@
     }
 }
 
+void ReapAnyOutstandingChildren() {
+    while (ReapOneProcess()) {
+    }
+}
+
 void signal_handler_init() {
     // Create a signalling mechanism for SIGCHLD.
     int s[2];
@@ -63,7 +133,7 @@
     act.sa_flags = SA_NOCLDSTOP;
     sigaction(SIGCHLD, &act, 0);
 
-    ServiceManager::GetInstance().ReapAnyOutstandingChildren();
+    ReapAnyOutstandingChildren();
 
     register_epoll_handler(signal_read_fd, handle_signal);
 }
diff --git a/init/signal_handler.h b/init/signal_handler.h
index f7881ab..9362be5 100644
--- a/init/signal_handler.h
+++ b/init/signal_handler.h
@@ -20,6 +20,8 @@
 namespace android {
 namespace init {
 
+void ReapAnyOutstandingChildren();
+
 void signal_handler_init(void);
 
 }  // namespace init