ANRdaemon: fix a bug in handling dump request when trace is running.

Change-Id: I16e2be8b90841eef251c83eda9f71c8e70f519ad

1 files changed, 104 insertions, 93 deletions

diff --git a/ANRdaemon/ANRdaemon.cpp b/ANRdaemon/ANRdaemon.cpp
index d611bf62..35f2ecbb 100644
--- a/ANRdaemon/ANRdaemon.cpp
+++ b/ANRdaemon/ANRdaemon.cpp
@@ -84,6 +84,7 @@ static int idle_threshold = 10;
 
 static bool quit = false;
 static bool suspend= false;
+static bool dump_requested = false;
 static bool err = false;
 static char err_msg[100];
 static bool tracing = false;
@@ -246,107 +247,20 @@ static void dfs_set_property(uint64_t mtag, const char* mapp, bool enable) {
 }
 
 /*
- * Start logging when cpu usage is high. Meanwhile, moniter the cpu usage and
- * stop logging when it drops down.
- */
-static void start_tracing(void) {
-    ALOGD("High cpu usage, start logging.");
-
-    if (dfs_enable(true, dfs_control_path) != 0) {
-        ALOGE("Failed to start tracing.");
-        return;
-    }
-    tracing = true;
-
-    /* Stop logging when cpu usage drops or the daemon is suspended.*/
-    do {
-        usleep(tracing_check_period);
-    } while (!suspend && is_heavy_load());
-
-    if (dfs_enable(false, dfs_control_path) != 0) {
-        ALOGE("Failed to stop tracing.");
-    }
-
-    ALOGD("Usage back to low, stop logging.");
-    tracing = false;
-}
-
-/*
- * Set the tracing log buffer size.
- * Note the actual buffer size will be buf_size_kb * number of cores.
- * E.g. for dory, the total buffer size is buf_size_kb * 4.
- */
-static int set_tracing_buffer_size(void) {
-    int fd = open(dfs_buffer_size_path, O_WRONLY);
-    if (fd == -1) {
-        err = true;
-        sprintf(err_msg, "Can't open atrace buffer size file under /d/tracing.");
-        return -1;
-    }
-    ssize_t len = strlen(buf_size_kb);
-    if (write(fd, buf_size_kb, len) != len) {
-        err = true;
-        sprintf(err_msg, "Error in writing to atrace buffer size file.");
-    }
-    close(fd);
-    return (err?-1:0);
-
-}
-
-/*
- * Main loop to moniter the cpu usage and decided whether to start logging.
- */
-static void start(void) {
-    if ((set_tracing_buffer_size()) != 0)
-        return;
-
-    dfs_set_property(tag, apps, true);
-    dfs_poke_binder();
-
-    get_cpu_stat(&old_cpu);
-    sleep(check_period);
-
-    while (!quit && !err) {
-        if (!suspend && is_heavy_load()) {
-            /*
-             * Increase process priority to make sure we can stop logging when
-             * necessary and do not overwrite the buffer
-             */
-            setpriority(PRIO_PROCESS, 0, -20);
-            start_tracing();
-            setpriority(PRIO_PROCESS, 0, 0);
-        }
-        sleep(check_period);
-    }
-    return;
-}
-
-/*
  * Dump the log in a compressed format for systrace to visualize.
+ * Create a dump file "dump_of_anrdaemon.<current_time>" under /data/misc/anrd
  */
 static void dump_trace()
 {
-    int remain_attempts = 5;
-    suspend = true;
-    while (tracing) {
-        ALOGI("Waiting logging to stop.");
-        usleep(tracing_check_period);
-        remain_attempts--;
-        if (remain_attempts == 0) {
-            ALOGE("Can't stop logging after 5 attempts. Dump aborted.");
-            return;
-        }
-    }
-
-    /*
-     * Create a dump file "dump_of_anrdaemon.<current_time>" under /data/misc/anrd
-     */
     time_t now = time(0);
     struct tm  tstruct;
     char time_buf[time_buf_size];
     char path_buf[path_buf_size];
     const char* header = " done\nTRACE:\n";
     ssize_t header_len = strlen(header);
+
+    ALOGI("Started to dump ANRdaemon trace.");
+
     tstruct = *localtime(&now);
     strftime(time_buf, time_buf_size, "%Y-%m-%d.%X", &tstruct);
     snprintf(path_buf, path_buf_size, "/data/misc/anrd/dump_of_anrdaemon.%s", time_buf);
@@ -442,10 +356,107 @@ static void dump_trace()
     close(trace_fd);
     close(output_fd);
 
-    suspend = false;
     ALOGI("Finished dump. Output file stored at: %s", path_buf);
 }
 
+/*
+ * Start logging when cpu usage is high. Meanwhile, moniter the cpu usage and
+ * stop logging when it drops down.
+ */
+static void start_tracing(void) {
+    ALOGD("High cpu usage, start logging.");
+
+    if (dfs_enable(true, dfs_control_path) != 0) {
+        ALOGE("Failed to start tracing.");
+        return;
+    }
+    tracing = true;
+
+    /* Stop logging when cpu usage drops or the daemon is suspended.*/
+    do {
+        usleep(tracing_check_period);
+    } while (!suspend && !dump_requested && is_heavy_load());
+
+    if (dfs_enable(false, dfs_control_path) != 0) {
+        ALOGE("Failed to stop tracing.");
+        err = true;
+        return;
+    }
+    tracing = false;
+
+    if (suspend) {
+        ALOGI("trace stopped due to suspend. Send SIGCONT to resume.");
+    } else if (dump_requested) {
+        ALOGI("trace stopped due to dump request.");
+        dump_trace();
+        dump_requested = false;
+    } else {
+        ALOGD("Usage back to low, stop logging.");
+    }
+}
+
+/*
+ * Set the tracing log buffer size.
+ * Note the actual buffer size will be buf_size_kb * number of cores.
+ */
+static int set_tracing_buffer_size(void) {
+    int fd = open(dfs_buffer_size_path, O_WRONLY);
+    if (fd == -1) {
+        err = true;
+        sprintf(err_msg, "Can't open atrace buffer size file under /d/tracing.");
+        return -1;
+    }
+    ssize_t len = strlen(buf_size_kb);
+    if (write(fd, buf_size_kb, len) != len) {
+        err = true;
+        sprintf(err_msg, "Error in writing to atrace buffer size file.");
+    }
+    close(fd);
+    return (err?-1:0);
+
+}
+
+/*
+ * Main loop to moniter the cpu usage and decided whether to start logging.
+ */
+static void start(void) {
+    if ((set_tracing_buffer_size()) != 0)
+        return;
+
+    dfs_set_property(tag, apps, true);
+    dfs_poke_binder();
+
+    get_cpu_stat(&old_cpu);
+    sleep(check_period);
+
+    while (!quit && !err) {
+        if (!suspend && is_heavy_load()) {
+            /*
+             * Increase process priority to make sure we can stop logging when
+             * necessary and do not overwrite the buffer
+             */
+            setpriority(PRIO_PROCESS, 0, -20);
+            start_tracing();
+            setpriority(PRIO_PROCESS, 0, 0);
+        }
+        sleep(check_period);
+    }
+    return;
+}
+
+/*
+ * If trace is not running, dump trace right away.
+ * If trace is running, request to dump trace.
+ */
+static void request_dump_trace()
+{
+    if (!tracing) {
+        dump_trace();
+    } else if (!dump_requested) {
+        dump_requested = true;
+    }
+}
+
 static void handle_signal(int signo)
 {
     switch (signo) {
@@ -460,7 +471,7 @@ static void handle_signal(int signo)
             suspend = false;
             break;
         case SIGUSR1:
-            dump_trace();
+            request_dump_trace();
     }
 }