rewrote libc_cxa

src/Emulator/HLE/Libraries/LibC/libc_cxa.cpp

@@ -0,0 +1,147 @@
+#include "libc_cxa.h"
+#include "debug.h"
+#include "Util/log.h"
+
+// adapted from https://opensource.apple.com/source/libcppabi/libcppabi-14/src/cxa_guard.cxx.auto.html
+
+namespace Emulator::HLE::Libraries::LibC::Cxa {
+constexpr bool log_file_cxa = true;  // disable it to disable logging
+
+// This file implements the __cxa_guard_* functions as defined at:
+//     http://www.codesourcery.com/public/cxx-abi/abi.html
+//
+// The goal of these functions is to support thread-safe, one-time
+// initialization of function scope variables.  The compiler will generate
+// code like the following:
+//
+//  if ( obj_guard.first_byte == 0 ) {
+//      if ( __cxa_guard_acquire(&obj_guard) ) {
+//        try {
+//          ... initialize the object ...;
+//        }
+//        catch (...) {
+//          __cxa_guard_abort(&obj_guard);
+//          throw;
+//        }
+//        ... queue object destructor with __cxa_atexit() ...;
+//        __cxa_guard_release(&obj_guard);
+//      }
+//   }
+//
+// Notes:
+//   ojb_guard is a 64-bytes in size and statically initialized to zero.
+//
+//   Section 6.7 of the C++ Spec says "If control re-enters the declaration
+//   recursively while the object is being initialized, the behavior is
+//   undefined".  This implementation calls abort().
+//
+
+// Note don't use function local statics to avoid use of cxa functions...
+static pthread_mutex_t __guard_mutex;
+static pthread_once_t __once_control = PTHREAD_ONCE_INIT;
+
+static void makeRecusiveMutex() {
+    pthread_mutexattr_t recursiveMutexAttr;
+    pthread_mutexattr_init(&recursiveMutexAttr);
+    pthread_mutexattr_settype(&recursiveMutexAttr, PTHREAD_MUTEX_RECURSIVE);
+    pthread_mutex_init(&__guard_mutex, &recursiveMutexAttr);
+}
+
+__attribute__((noinline)) static pthread_mutex_t* guard_mutex() {
+    pthread_once(&__once_control, &makeRecusiveMutex);
+    return &__guard_mutex;
+}
+
+// helper functions for getting/setting flags in guard_object
+static bool initializerHasRun(u64* guard_object) { return (*((u08*)guard_object) != 0); }
+
+static void setInitializerHasRun(u64* guard_object) { *((u08*)guard_object) = 1; }
+
+static bool inUse(u64* guard_object) { return (((u08*)guard_object)[1] != 0); }
+
+static void setInUse(u64* guard_object) { ((u08*)guard_object)[1] = 1; }
+
+static void setNotInUse(u64* guard_object) { ((u08*)guard_object)[1] = 0; }
+
+//
+// Returns 1 if the caller needs to run the initializer and then either
+// call __cxa_guard_release() or __cxa_guard_abort().  If zero is returned,
+// then the initializer has already been run.  This function blocks
+// if another thread is currently running the initializer.  This function
+// aborts if called again on the same guard object without an intervening
+// call to __cxa_guard_release() or __cxa_guard_abort().
+//
+int PS4_SYSV_ABI __cxa_guard_acquire(u64* guard_object) {
+    // Double check that the initializer has not already been run
+    if (initializerHasRun(guard_object)) return 0;
+
+    // We now need to acquire a lock that allows only one thread
+    // to run the initializer.  If a different thread calls
+    // __cxa_guard_acquire() with the same guard object, we want
+    // that thread to block until this thread is done running the
+    // initializer and calls __cxa_guard_release().  But if the same
+    // thread calls __cxa_guard_acquire() with the same guard object,
+    // we want to abort.
+    // To implement this we have one global pthread recursive mutex
+    // shared by all guard objects, but only one at a time.
+
+    int result = ::pthread_mutex_lock(guard_mutex());
+    if (result != 0) {
+        LOG_TRACE_IF(log_file_cxa, "__cxa_guard_acquire(): pthread_mutex_lock failed with {}\n",result);
+    }
+    // At this point all other threads will block in __cxa_guard_acquire()
+
+    // Check if another thread has completed initializer run
+    if (initializerHasRun(guard_object)) {
+        int result = ::pthread_mutex_unlock(guard_mutex());
+        if (result != 0) {
+            LOG_TRACE_IF(log_file_cxa,"__cxa_guard_acquire(): pthread_mutex_unlock failed with {}\n",result);
+        }
+        return 0;
+    }
+
+    // The pthread mutex is recursive to allow other lazy initialized
+    // function locals to be evaluated during evaluation of this one.
+    // But if the same thread can call __cxa_guard_acquire() on the
+    // *same* guard object again, we call abort();
+    if (inUse(guard_object)) {
+        LOG_TRACE_IF(log_file_cxa,"__cxa_guard_acquire(): initializer for function local static variable called enclosing function\n");
+    }
+
+    // mark this guard object as being in use
+    setInUse(guard_object);
+
+    // return non-zero to tell caller to run initializer
+    return 1;
+}
+
+//
+// Sets the first byte of the guard_object to a non-zero value.
+// Releases any locks acquired by __cxa_guard_acquire().
+//
+void PS4_SYSV_ABI __cxa_guard_release(u64* guard_object) {
+    // first mark initalizer as having been run, so
+    // other threads won't try to re-run it.
+    setInitializerHasRun(guard_object);
+
+    // release global mutex
+    int result = ::pthread_mutex_unlock(guard_mutex());
+    if (result != 0) {
+        LOG_TRACE_IF(log_file_cxa,"__cxa_guard_acquire(): pthread_mutex_unlock failed with {}\n",result);
+    }
+}
+
+//
+// Releases any locks acquired by __cxa_guard_acquire().
+//
+void PS4_SYSV_ABI __cxa_guard_abort(u64* guard_object) {
+    int result = ::pthread_mutex_unlock(guard_mutex());
+    if (result != 0) {
+        LOG_TRACE_IF(log_file_cxa,"__cxa_guard_abort(): pthread_mutex_unlock failed with {}\n",result);
+    }
+
+    // now reset state, so possible to try to initialize again
+    setNotInUse(guard_object);
+}
+
+}  // namespace Emulator::HLE::Libraries::LibC::Cxa

src/Emulator/HLE/Libraries/LibC/libc_cxa.h

@@ -0,0 +1,11 @@
+#pragma once
+#define _TIMESPEC_DEFINED
+
+#include <pthread.h>
+#include <types.h>
+
+namespace Emulator::HLE::Libraries::LibC::Cxa {
+int PS4_SYSV_ABI __cxa_guard_acquire(u64* guard_object);
+void PS4_SYSV_ABI __cxa_guard_release(u64* guard_object);
+void PS4_SYSV_ABI __cxa_guard_abort(u64* guard_object);
+}  // namespace Emulator::HLE::Libraries::LibC::Cxa