diff options
Diffstat (limited to 'absl/base/internal/sysinfo.cc')
| -rw-r--r-- | absl/base/internal/sysinfo.cc | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/absl/base/internal/sysinfo.cc b/absl/base/internal/sysinfo.cc index 6c69683f..349d9268 100644 --- a/absl/base/internal/sysinfo.cc +++ b/absl/base/internal/sysinfo.cc @@ -39,6 +39,7 @@ #endif #include <string.h> + #include <cassert> #include <cstdint> #include <cstdio> @@ -50,6 +51,7 @@ #include <vector> #include "absl/base/call_once.h" +#include "absl/base/config.h" #include "absl/base/internal/raw_logging.h" #include "absl/base/internal/spinlock.h" #include "absl/base/internal/unscaledcycleclock.h" @@ -420,6 +422,18 @@ pid_t GetTID() { #endif +// GetCachedTID() caches the thread ID in thread-local storage (which is a +// userspace construct) to avoid unnecessary system calls. Without this caching, +// it can take roughly 98ns, while it takes roughly 1ns with this caching. +pid_t GetCachedTID() { +#if ABSL_HAVE_THREAD_LOCAL + static thread_local pid_t thread_id = GetTID(); + return thread_id; +#else + return GetTID(); +#endif // ABSL_HAVE_THREAD_LOCAL +} + } // namespace base_internal ABSL_NAMESPACE_END } // namespace absl |