2 files changed, 21 insertions, 0 deletions
diff --git a/test/util/cgroup_util.cc b/test/util/cgroup_util.cc
index 65d9c4986..d8d3fe471 100644
--- a/test/util/cgroup_util.cc
+++ b/test/util/cgroup_util.cc
@@ -17,6 +17,7 @@
 #include <sys/syscall.h>
 #include <unistd.h>
 
+#include "absl/strings/str_cat.h"
 #include "absl/strings/str_split.h"
 #include "test/util/fs_util.h"
 #include "test/util/mount_util.h"
@@ -50,6 +51,18 @@ PosixErrorOr<int64_t> Cgroup::ReadIntegerControlFile(
   return val;
 }
 
+PosixError Cgroup::WriteControlFile(absl::string_view name,
+                                    const std::string& value) const {
+  ASSIGN_OR_RETURN_ERRNO(FileDescriptor fd, Open(Relpath(name), O_WRONLY));
+  RETURN_ERROR_IF_SYSCALL_FAIL(WriteFd(fd.get(), value.c_str(), value.size()));
+  return NoError();
+}
+
+PosixError Cgroup::WriteIntegerControlFile(absl::string_view name,
+                                           int64_t value) const {
+  return WriteControlFile(name, absl::StrCat(value));
+}
+
 PosixErrorOr<absl::flat_hash_set<pid_t>> Cgroup::Procs() const {
   ASSIGN_OR_RETURN_ERRNO(std::string buf, ReadControlFile("cgroup.procs"));
   return ParsePIDList(buf);
diff --git a/test/util/cgroup_util.h b/test/util/cgroup_util.h
index b049559df..c6e4303e1 100644
--- a/test/util/cgroup_util.h
+++ b/test/util/cgroup_util.h
@@ -45,6 +45,14 @@ class Cgroup {
   // to parse it as an integer.
   PosixErrorOr<int64_t> ReadIntegerControlFile(absl::string_view name) const;
 
+  // Writes a string to a cgroup control file.
+  PosixError WriteControlFile(absl::string_view name,
+                              const std::string& value) const;
+
+  // Writes an integer value to a cgroup control file.
+  PosixError WriteIntegerControlFile(absl::string_view name,
+                                     int64_t value) const;
+
   // Returns the thread ids of the leaders of thread groups managed by this
   // cgroup.
   PosixErrorOr<absl::flat_hash_set<pid_t>> Procs() const;