Tidy up the sync dir, remove dead or mis-designed code in favour of OS primitives, switch rust_kernel to use a lock/signal pair and wait rather than spin.

1 files changed, 97 insertions, 0 deletions

diff --git a/src/rt/sync/lock_and_signal.cpp b/src/rt/sync/lock_and_signal.cpp
new file mode 100755
index 00000000..c010086e
--- /dev/null
+++ b/src/rt/sync/lock_and_signal.cpp
@@ -0,0 +1,97 @@
+#include "../globals.h"
+
+/*
+ * A "lock-and-signal" pair. These are necessarily coupled on pthreads
+ * systems, and artificially coupled (by this file) on win32. Put
+ * together here to minimize ifdefs elsewhere; you must use them as
+ * if you're using a pthreads cvar+mutex pair.
+ */
+
+#include "lock_and_signal.h"
+
+#if defined(__WIN32__)
+lock_and_signal::lock_and_signal() {
+    _event = CreateEvent(NULL, FALSE, FALSE, NULL);
+    InitializeCriticalSection(&_cs);
+}
+
+#else
+lock_and_signal::lock_and_signal() {
+    pthread_cond_init(&_cond, NULL);
+    pthread_mutex_init(&_mutex, NULL);
+}
+#endif
+
+lock_and_signal::~lock_and_signal() {
+#if defined(__WIN32__)
+    CloseHandle(_event);
+#else
+    pthread_cond_destroy(&_cond);
+    pthread_mutex_destroy(&_mutex);
+#endif
+}
+
+void lock_and_signal::lock() {
+#if defined(__WIN32__)
+  EnterCriticalSection(&_cs);
+#else
+  pthread_mutex_lock(&_mutex);
+#endif
+}
+
+void lock_and_signal::unlock() {
+#if defined(__WIN32__)
+  LeaveCriticalSection(&_cs);
+#else
+  pthread_mutex_unlock(&_mutex);
+#endif
+}
+
+
+/**
+ * Wait indefinitely until condition is signaled.
+ */
+void lock_and_signal::wait() {
+    timed_wait(0);
+}
+
+void lock_and_signal::timed_wait(size_t timeout_in_ns) {
+#if defined(__WIN32__)
+  LeaveCriticalSection(&_cs);
+  WaitForSingleObject(_event, INFINITE);
+  EnterCriticalSection(&_cs);
+#else
+    if (timeout_in_ns == 0) {
+        pthread_cond_wait(&_cond, &_mutex);
+    } else {
+        timeval time_val;
+        gettimeofday(&time_val, NULL);
+        timespec time_spec;
+        time_spec.tv_sec = time_val.tv_sec + 0;
+        time_spec.tv_nsec = time_val.tv_usec * 1000 + timeout_in_ns;
+        pthread_cond_timedwait(&_cond, &_mutex, &time_spec);
+    }
+#endif
+}
+
+/**
+ * Signal condition, and resume the waiting thread.
+ */
+void lock_and_signal::signal() {
+#if defined(__WIN32__)
+    SetEvent(_event);
+#else
+    pthread_cond_signal(&_cond);
+#endif
+}
+
+
+//
+// Local Variables:
+// mode: C++
+// fill-column: 78;
+// indent-tabs-mode: nil
+// c-basic-offset: 4
+// buffer-file-coding-system: utf-8-unix
+// compile-command: "make -k -C .. 2>&1 | sed -e 's/\\/x\\//x:\\//g'";
+// End: