Abseil LTS branch, Aug 2023, Patch 1 (#1534)

* Add StdcppWaiter to the end of the list of waiter implementations

Since ABSL_INTERNAL_HAVE_STDCPP_WAITER is defined on all systems
it is effectively a fallback. I left the condition there in case
we have to disable it on some platform in the future.

PiperOrigin-RevId: 555629066
Change-Id: I76ca78c7f36d1d02dc4950a44c66903a2aaf2a52

* Use native methods to implement absl::base_internal::GetPID() on
FreeBSD, NetBSD, and OpenBSD

https://man.freebsd.org/cgi/man.cgi?query=pthread_getthreadid_np
https://man.netbsd.org/_lwp_self.2
https://man.openbsd.org/getthrid.2

* Abseil LTS branch, Aug 2023, Patch 1
Bump ABSL_LTS_RELEASE_PATCH_LEVEL to 1

Author: derekmauro

absl/base/config.h

@@ -112,7 +112,7 @@
 // LTS releases can be obtained from
 // https://github.com/abseil/abseil-cpp/releases.
 #define ABSL_LTS_RELEASE_VERSION 20230802
-#define ABSL_LTS_RELEASE_PATCH_LEVEL 0
+#define ABSL_LTS_RELEASE_PATCH_LEVEL 1
 
 // Helper macro to convert a CPP variable to a string literal.
 #define ABSL_INTERNAL_DO_TOKEN_STR(x) #x

absl/base/internal/sysinfo.cc

@@ -34,6 +34,14 @@
 #include <sys/sysctl.h>
 #endif
 
+#ifdef __FreeBSD__
+#include <pthread_np.h>
+#endif
+
+#ifdef __NetBSD__
+#include <lwp.h>
+#endif
+
 #if defined(__myriad2__)
 #include <rtems.h>
 #endif
@@ -432,6 +440,18 @@ pid_t GetTID() {
   return static_cast<pid_t>(tid);
 }
 
+#elif defined(__FreeBSD__)
+
+pid_t GetTID() { return static_cast<pid_t>(pthread_getthreadid_np()); }
+
+#elif defined(__OpenBSD__)
+
+pid_t GetTID() { return getthrid(); }
+
+#elif defined(__NetBSD__)
+
+pid_t GetTID() { return static_cast<pid_t>(_lwp_self()); }
+
 #elif defined(__native_client__)
 
 pid_t GetTID() {

absl/synchronization/internal/waiter.h

@@ -40,6 +40,8 @@
 #define ABSL_WAITER_MODE ABSL_WAITER_MODE_SEM
 #elif defined(ABSL_INTERNAL_HAVE_PTHREAD_WAITER)
 #define ABSL_WAITER_MODE ABSL_WAITER_MODE_CONDVAR
+#elif defined(ABSL_INTERNAL_HAVE_STDCPP_WAITER)
+#define ABSL_WAITER_MODE ABSL_WAITER_MODE_STDCPP
 #else
 #error ABSL_WAITER_MODE is undefined
 #endif