logcat: Add -T flag (-t w/o assumption of -d)
(cherry picked from commit de02546e3d7c9c307e3d87e0a7fe8bb39b363a72)
Change-Id: I49763e2db83755e0b7b12dfa3f83a3957c54d389
diff --git a/logcat/logcat.cpp b/logcat/logcat.cpp
index a54167e..3c33938 100644
--- a/logcat/logcat.cpp
+++ b/logcat/logcat.cpp
@@ -223,6 +223,7 @@
" -c clear (flush) the entire log and exit\n"
" -d dump the log and then exit (don't block)\n"
" -t <count> print only the most recent <count> lines (implies -d)\n"
+ " -T <count> print only the most recent <count> lines (does not imply -d)\n"
" -g get the size of the log's ring buffer and exit\n"
" -b <buffer> Request alternate ring buffer, 'main', 'system', 'radio'\n"
" or 'events'. Multiple -b parameters are allowed and the\n"
@@ -302,7 +303,7 @@
for (;;) {
int ret;
- ret = getopt(argc, argv, "cdt:gsQf:r::n:v:b:B");
+ ret = getopt(argc, argv, "cdt:T:gsQf:r::n:v:b:B");
if (ret < 0) {
break;
@@ -325,6 +326,8 @@
case 't':
mode = O_RDONLY | O_NDELAY;
+ /* FALLTHRU */
+ case 'T':
tail_lines = atoi(optarg);
break;
diff --git a/logcat/tests/logcat_test.cpp b/logcat/tests/logcat_test.cpp
index a4b796b..f963a3a 100644
--- a/logcat/tests/logcat_test.cpp
+++ b/logcat/tests/logcat_test.cpp
@@ -373,3 +373,71 @@
ASSERT_EQ(1, signals);
}
+
+static void caught_blocking_tail(int signum)
+{
+ unsigned long long v = 0xA55ADEADBEEF0000ULL;
+
+ v += getpid() & 0xFFFF;
+
+ LOG_FAILURE_RETRY(__android_log_btwrite(0, EVENT_TYPE_LONG, &v, sizeof(v)));
+}
+
+TEST(logcat, blocking_tail) {
+ FILE *fp;
+ unsigned long long v = 0xA55ADEADBEEF0000ULL;
+
+ pid_t pid = getpid();
+
+ v += pid & 0xFFFF;
+
+ ASSERT_EQ(0, NULL == (fp = popen(
+ "( trap exit HUP QUIT INT PIPE KILL ; sleep 6; echo DONE )&"
+ " logcat -b events -T 5 2>&1",
+ "r")));
+
+ char buffer[5120];
+
+ int count = 0;
+
+ int signals = 0;
+
+ signal(SIGALRM, caught_blocking_tail);
+ alarm(2);
+ while (fgets(buffer, sizeof(buffer), fp)) {
+ alarm(2);
+
+ ++count;
+
+ if (!strncmp(buffer, "DONE", 4)) {
+ break;
+ }
+
+ int p;
+ unsigned long long l;
+
+ if ((2 != sscanf(buffer, "I/[0] ( %u): %lld", &p, &l))
+ || (p != pid)) {
+ continue;
+ }
+
+ if (l == v) {
+ if (count >= 5) {
+ ++signals;
+ }
+ break;
+ }
+ }
+ alarm(0);
+ signal(SIGALRM, SIG_DFL);
+
+ /* Generate SIGPIPE */
+ fclose(fp);
+ caught_blocking_tail(0);
+
+ pclose(fp);
+
+ ASSERT_LT(5, count);
+
+ ASSERT_EQ(1, signals);
+}