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-rw-r--r--runtime/exec_utils.cc124
1 files changed, 100 insertions, 24 deletions
diff --git a/runtime/exec_utils.cc b/runtime/exec_utils.cc
index db1baa76f9..463d4580cf 100644
--- a/runtime/exec_utils.cc
+++ b/runtime/exec_utils.cc
@@ -30,18 +30,22 @@ namespace art {
using android::base::StringPrintf;
-int ExecAndReturnCode(std::vector<std::string>& arg_vector, std::string* error_msg) {
- const std::string command_line(android::base::Join(arg_vector, ' '));
- CHECK_GE(arg_vector.size(), 1U) << command_line;
+namespace {
+
+std::string ToCommandLine(const std::vector<std::string>& args) {
+ return android::base::Join(args, ' ');
+}
+// Fork and execute a command specified in a subprocess.
+// If there is a runtime (Runtime::Current != nullptr) then the subprocess is created with the
+// same environment that existed when the runtime was started.
+// Returns the process id of the child process on success, -1 otherwise.
+pid_t ExecWithoutWait(std::vector<std::string>& arg_vector) {
// Convert the args to char pointers.
const char* program = arg_vector[0].c_str();
std::vector<char*> args;
- for (size_t i = 0; i < arg_vector.size(); ++i) {
- const std::string& arg = arg_vector[i];
- char* arg_str = const_cast<char*>(arg.c_str());
- CHECK(arg_str != nullptr) << i;
- args.push_back(arg_str);
+ for (const auto& arg : arg_vector) {
+ args.push_back(const_cast<char*>(arg.c_str()));
}
args.push_back(nullptr);
@@ -61,38 +65,110 @@ int ExecAndReturnCode(std::vector<std::string>& arg_vector, std::string* error_m
} else {
execve(program, &args[0], envp);
}
- PLOG(ERROR) << "Failed to execve(" << command_line << ")";
+ PLOG(ERROR) << "Failed to execve(" << ToCommandLine(arg_vector) << ")";
// _exit to avoid atexit handlers in child.
_exit(1);
} else {
- if (pid == -1) {
- *error_msg = StringPrintf("Failed to execv(%s) because fork failed: %s",
- command_line.c_str(), strerror(errno));
+ return pid;
+ }
+}
+
+} // namespace
+
+int ExecAndReturnCode(std::vector<std::string>& arg_vector, std::string* error_msg) {
+ pid_t pid = ExecWithoutWait(arg_vector);
+ if (pid == -1) {
+ *error_msg = StringPrintf("Failed to execv(%s) because fork failed: %s",
+ ToCommandLine(arg_vector).c_str(), strerror(errno));
+ return -1;
+ }
+
+ // wait for subprocess to finish
+ int status = -1;
+ pid_t got_pid = TEMP_FAILURE_RETRY(waitpid(pid, &status, 0));
+ if (got_pid != pid) {
+ *error_msg = StringPrintf("Failed after fork for execv(%s) because waitpid failed: "
+ "wanted %d, got %d: %s",
+ ToCommandLine(arg_vector).c_str(), pid, got_pid, strerror(errno));
+ return -1;
+ }
+ if (WIFEXITED(status)) {
+ return WEXITSTATUS(status);
+ }
+ return -1;
+}
+
+int ExecAndReturnCode(std::vector<std::string>& arg_vector,
+ time_t timeout_secs,
+ bool* timed_out,
+ std::string* error_msg) {
+ *timed_out = false;
+
+ // Start subprocess.
+ pid_t pid = ExecWithoutWait(arg_vector);
+ if (pid == -1) {
+ *error_msg = StringPrintf("Failed to execv(%s) because fork failed: %s",
+ ToCommandLine(arg_vector).c_str(), strerror(errno));
+ return -1;
+ }
+
+ // Add SIGCHLD to the signal set.
+ sigset_t child_mask, original_mask;
+ sigemptyset(&child_mask);
+ sigaddset(&child_mask, SIGCHLD);
+ if (sigprocmask(SIG_BLOCK, &child_mask, &original_mask) == -1) {
+ *error_msg = StringPrintf("Failed to set sigprocmask(): %s", strerror(errno));
+ return -1;
+ }
+
+ // Wait for a SIGCHLD notification.
+ errno = 0;
+ timespec ts = {timeout_secs, 0};
+ int wait_result = TEMP_FAILURE_RETRY(sigtimedwait(&child_mask, nullptr, &ts));
+ int wait_errno = errno;
+
+ // Restore the original signal set.
+ if (sigprocmask(SIG_SETMASK, &original_mask, nullptr) == -1) {
+ *error_msg = StringPrintf("Fail to restore sigprocmask(): %s", strerror(errno));
+ if (wait_result == 0) {
return -1;
}
+ }
- // wait for subprocess to finish
- int status = -1;
- pid_t got_pid = TEMP_FAILURE_RETRY(waitpid(pid, &status, 0));
- if (got_pid != pid) {
- *error_msg = StringPrintf("Failed after fork for execv(%s) because waitpid failed: "
- "wanted %d, got %d: %s",
- command_line.c_str(), pid, got_pid, strerror(errno));
- return -1;
+ // Having restored the signal set, see if we need to terminate the subprocess.
+ if (wait_result == -1) {
+ if (wait_errno == EAGAIN) {
+ *error_msg = "Timed out.";
+ *timed_out = true;
+ } else {
+ *error_msg = StringPrintf("Failed to sigtimedwait(): %s", strerror(errno));
}
- if (WIFEXITED(status)) {
- return WEXITSTATUS(status);
+ if (kill(pid, SIGKILL) != 0) {
+ PLOG(ERROR) << "Failed to kill() subprocess: ";
}
+ }
+
+ // Wait for subprocess to finish.
+ int status = -1;
+ pid_t got_pid = TEMP_FAILURE_RETRY(waitpid(pid, &status, 0));
+ if (got_pid != pid) {
+ *error_msg = StringPrintf("Failed after fork for execv(%s) because waitpid failed: "
+ "wanted %d, got %d: %s",
+ ToCommandLine(arg_vector).c_str(), pid, got_pid, strerror(errno));
return -1;
}
+ if (WIFEXITED(status)) {
+ return WEXITSTATUS(status);
+ }
+ return -1;
}
+
bool Exec(std::vector<std::string>& arg_vector, std::string* error_msg) {
int status = ExecAndReturnCode(arg_vector, error_msg);
if (status != 0) {
- const std::string command_line(android::base::Join(arg_vector, ' '));
*error_msg = StringPrintf("Failed execv(%s) because non-0 exit status",
- command_line.c_str());
+ ToCommandLine(arg_vector).c_str());
return false;
}
return true;