Mac: stop zombie ps processes from being created.

This fixes two bugs:
- the output buffer for the ps command being run could be too small (fix: buffer
  enlargened); and
- if the output buffer was too small, waitpid() wouldn't be called (fix: always
  call waitpid(), obviously).

BUG=31378
TEST=On a big, long-running Chrome/Chromium (with many processes, e.g., renderers), check that there are no zombie ps processes (with PPID the browser process); looking at about:memory may help speed up the creation of such zombies. Also, run the new test, ProcessUtilTest.GetAppOutputRestrictedNoZombies.

Review URL: http://codereview.chromium.org/523033

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@35456 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 22 insertions, 0 deletions

diff --git a/base/process_util_unittest.cc b/base/process_util_unittest.cc
index 8bbd784..4b313a3 100644
--- a/base/process_util_unittest.cc
+++ b/base/process_util_unittest.cc
@@ -337,6 +337,28 @@ TEST_F(ProcessUtilTest, GetAppOutputRestricted) {
   EXPECT_STREQ("", output.c_str());
 }
 
+TEST_F(ProcessUtilTest, GetAppOutputRestrictedNoZombies) {
+  std::vector<std::string> argv;
+  argv.push_back("/bin/sh");  // argv[0]
+  argv.push_back("-c");       // argv[1]
+  argv.push_back("echo 123456789012345678901234567890");  // argv[2]
+
+  // Run |GetAppOutputRestricted()| 300 (> default per-user processes on Mac OS
+  // 10.5) times with an output buffer big enough to capture all output.
+  for (int i = 0; i < 300; i++) {
+    std::string output;
+    EXPECT_TRUE(GetAppOutputRestricted(CommandLine(argv), &output, 100));
+    EXPECT_STREQ("123456789012345678901234567890\n", output.c_str());
+  }
+
+  // Ditto, but with an output buffer too small to capture all output.
+  for (int i = 0; i < 300; i++) {
+    std::string output;
+    EXPECT_TRUE(GetAppOutputRestricted(CommandLine(argv), &output, 10));
+    EXPECT_STREQ("1234567890", output.c_str());
+  }
+}
+
 #if defined(OS_LINUX)
 TEST_F(ProcessUtilTest, GetParentProcessId) {
   base::ProcessId ppid = GetParentProcessId(GetCurrentProcId());