Change ExecUtils to support callbacks.

artd needs the callbacks to get the pid in order to kill the subprocess.

Partially cherry-picked from
commit 659f49bdb1263ceb26f666052f3ef7e4732b4eb2

Bug: 244412198
Test: m test-art-host-gtest-art_runtime_tests
Merged-In: I8c40949b5ed88ff85ddedad9d86f0b9bbfddb98d
Change-Id: Ia28410bdf6314178756ee5e3a94000dc6f3ecc97

1 files changed, 12 insertions, 2 deletions

diff --git a/runtime/exec_utils.h b/runtime/exec_utils.h
index 751c64d9c8..aa0d0fc932 100644
--- a/runtime/exec_utils.h
+++ b/runtime/exec_utils.h
@@ -19,6 +19,7 @@
 
 #include <time.h>
 
+#include <functional>
 #include <string>
 #include <vector>
 
@@ -34,6 +35,14 @@ struct ProcessStat {
   int cpu_time_ms = 0;
 };
 
+struct ExecCallbacks {
+  // Called in the parent process as soon as the child process is forked.
+  std::function<void(pid_t pid)> on_start = [](pid_t) {};
+  // Called in the parent process after the child process exits while still in a waitable state, no
+  // matter the child process succeeds or not.
+  std::function<void(pid_t pid)> on_end = [](pid_t) {};
+};
+
 // Wrapper on fork/execv to run a command in a subprocess.
 // These spawn child processes using the environment as it was set when the single instance
 // of the runtime (Runtime::Current()) was started.  If no instance of the runtime was started, it
@@ -57,10 +66,11 @@ class ExecUtils {
                                 /*out*/ bool* timed_out,
                                 /*out*/ std::string* error_msg) const;
 
-  // Same as above, but also collects stat of the process. The stat is collected no matter the child
-  // process succeeds or not.
+  // Same as above, but also collects stat of the process and calls callbacks. The stat is collected
+  // no matter the child process succeeds or not.
   virtual int ExecAndReturnCode(const std::vector<std::string>& arg_vector,
                                 int timeout_sec,
+                                const ExecCallbacks& callbacks,
                                 /*out*/ bool* timed_out,
                                 /*out*/ ProcessStat* stat,
                                 /*out*/ std::string* error_msg) const;