jit: Use std::mutex instead of pthread_mutex_t

This allows JIT to be built with a different thread model from posix
where pthread isn't available

By renaming the acquire_mutex () and release_mutex () member functions
to lock() and unlock() we make the playback::context type meet the C++
Lockable requirements. This allows it to be used with a scoped lock
(i.e. RAII) type as std::lock_guard. This automatically releases the
mutex when leaving the scope.

Co-authored-by: LIU Hao <lh_mouse@126.com>

gcc/jit/ChangeLog:

	* jit-playback.cc (playback::context::scoped_lock): Define RAII
	lock type.
	(playback::context::compile): Use scoped_lock to acquire mutex
	for the active playback context.
	(jit_mutex): Change to std::mutex.
	(playback::context::acquire_mutex): Rename to ...
	(playback::context::lock): ... this.
	(playback::context::release_mutex): Rename to ...
	(playback::context::unlock): ... this.
	* jit-playback.h (playback::context): Rename members and declare
	scoped_lock.
	* jit-recording.cc (INCLUDE_PTHREAD_H): Remove unused define.
	* libgccjit.cc (version_mutex): Change to std::mutex.
	(struct jit_version_info): Use std::lock_guard to acquire and
	release mutex.

gcc/ChangeLog:

	* system.h [INCLUDE_MUTEX]: Include header for std::mutex.

1 files changed, 3 insertions, 4 deletions

diff --git a/gcc/jit/libgccjit.cc b/gcc/jit/libgccjit.cc
index ca86266..8884128 100644
--- a/gcc/jit/libgccjit.cc
+++ b/gcc/jit/libgccjit.cc
@@ -19,7 +19,7 @@ along with GCC; see the file COPYING3.  If not see
 <http://www.gnu.org/licenses/>.  */
 
 #include "config.h"
-#define INCLUDE_PTHREAD_H
+#define INCLUDE_MUTEX
 #include "system.h"
 #include "coretypes.h"
 #include "timevar.h"
@@ -4060,7 +4060,7 @@ gcc_jit_context_new_rvalue_from_vector (gcc_jit_context *ctxt,
    Ideally this would be within parse_basever, but the mutex is only needed
    by libgccjit.  */
 
-static pthread_mutex_t version_mutex = PTHREAD_MUTEX_INITIALIZER;
+static std::mutex version_mutex;
 
 struct jit_version_info
 {
@@ -4068,9 +4068,8 @@ struct jit_version_info
      guarded by version_mutex.  */
   jit_version_info ()
   {
-    pthread_mutex_lock (&version_mutex);
+    std::lock_guard<std::mutex> g (version_mutex);
     parse_basever (&major, &minor, &patchlevel);
-    pthread_mutex_unlock (&version_mutex);
   }
 
   int major;