From c53db98517e19c7082ea99d75959e7fdde6bf6d9 Mon Sep 17 00:00:00 2001
From: Ben Vanik <ben.vanik@gmail.com>
Date: Wed, 16 Oct 2013 21:32:20 -0700
Subject: [PATCH] Locking around some JIT stuff. Excessive for now, but safer.

---
 src/xenia/cpu/processor.cc   | 10 ++++++++++
 src/xenia/cpu/processor.h    |  1 +
 src/xenia/cpu/x64/x64_jit.cc |  7 ++++++-
 src/xenia/cpu/x64/x64_jit.h  |  1 +
 4 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/src/xenia/cpu/processor.cc b/src/xenia/cpu/processor.cc
index 81722a2ca..c3c7fda97 100644
--- a/src/xenia/cpu/processor.cc
+++ b/src/xenia/cpu/processor.cc
@@ -50,6 +50,7 @@ Processor::Processor(xe_memory_ref memory, shared_ptr<Backend> backend) :
     interrupt_thread_lock_(NULL), interrupt_thread_state_(NULL) {
   memory_ = xe_memory_retain(memory);
   backend_ = backend;
+  sym_lock_ = xe_mutex_alloc(10000);
 
   InitializeIfNeeded();
 }
@@ -71,6 +72,7 @@ Processor::~Processor() {
 
   delete jit_;
   delete sym_table_;
+  xe_mutex_free(sym_lock_);
 
   graphics_system_.reset();
   export_resolver_.reset();
@@ -158,7 +160,9 @@ int Processor::LoadRawBinary(const xechar_t* path, uint32_t start_address) {
   // Initialize the module and prepare it for execution.
   XEEXPECTZERO(jit_->InitModule(exec_module));
 
+  xe_mutex_lock(sym_lock_);
   modules_.push_back(exec_module);
+  xe_mutex_unlock(sym_lock_);
 
   result_code = 0;
 XECLEANUP:
@@ -183,7 +187,9 @@ int Processor::LoadXexModule(const char* name, const char* path,
   // Initialize the module and prepare it for execution.
   XEEXPECTZERO(jit_->InitModule(exec_module));
 
+  xe_mutex_lock(sym_lock_);
   modules_.push_back(exec_module);
+  xe_mutex_unlock(sym_lock_);
 
   result_code = 0;
 XECLEANUP:
@@ -264,6 +270,7 @@ uint64_t Processor::ExecuteInterrupt(uint32_t address,
 
 FunctionSymbol* Processor::GetFunction(uint32_t address) {
   // Attempt to grab the function symbol from the global lookup table.
+  // The symbol table takes a lock so it should be safe.
   FunctionSymbol* fn_symbol = sym_table_->GetFunction(address);
   if (fn_symbol) {
     return fn_symbol;
@@ -274,13 +281,16 @@ FunctionSymbol* Processor::GetFunction(uint32_t address) {
   // symbol is not found (likely) it will do analysis on it.
   // TODO(benvanik): make this more efficient. Could use a binary search or
   //     something more clever.
+  xe_mutex_lock(sym_lock_);
   for (std::vector<ExecModule*>::iterator it = modules_.begin();
       it != modules_.end(); ++it) {
     fn_symbol = (*it)->FindFunctionSymbol(address);
     if (fn_symbol) {
+      xe_mutex_unlock(sym_lock_);
       return fn_symbol;
     }
   }
+  xe_mutex_unlock(sym_lock_);
 
   // Not found at all? That seems wrong...
   XEASSERTALWAYS();
diff --git a/src/xenia/cpu/processor.h b/src/xenia/cpu/processor.h
index 72f11eabb..53e49cb2d 100644
--- a/src/xenia/cpu/processor.h
+++ b/src/xenia/cpu/processor.h
@@ -76,6 +76,7 @@ private:
   sdb::SymbolTable*   sym_table_;
   JIT*                jit_;
   std::vector<ExecModule*> modules_;
+  xe_mutex_t*         sym_lock_;
 
   xe_mutex_t*         interrupt_thread_lock_;
   ThreadState*        interrupt_thread_state_;
diff --git a/src/xenia/cpu/x64/x64_jit.cc b/src/xenia/cpu/x64/x64_jit.cc
index 719ce04d9..4007dd7dd 100644
--- a/src/xenia/cpu/x64/x64_jit.cc
+++ b/src/xenia/cpu/x64/x64_jit.cc
@@ -27,10 +27,12 @@ using namespace AsmJit;
 X64JIT::X64JIT(xe_memory_ref memory, SymbolTable* sym_table) :
     JIT(memory, sym_table),
     emitter_(NULL) {
+  jit_lock_ = xe_mutex_alloc(10000);
 }
 
 X64JIT::~X64JIT() {
   delete emitter_;
+  xe_mutex_free(jit_lock_);
 }
 
 int X64JIT::Setup() {
@@ -160,17 +162,20 @@ int X64JIT::UninitModule(ExecModule* module) {
 
 void* X64JIT::GetFunctionPointer(sdb::FunctionSymbol* fn_symbol) {
   // Check function.
+  // TODO(benvanik): make this lock-free (or spin).
+  xe_mutex_lock(jit_lock_);
   x64_function_t fn_ptr = (x64_function_t)fn_symbol->impl_value;
   if (!fn_ptr) {
     // Function hasn't been prepped yet - make it now inline.
     // The emitter will lock and do other fancy things, if required.
     if (emitter_->PrepareFunction(fn_symbol)) {
+      xe_mutex_unlock(jit_lock_);
       return NULL;
     }
     fn_ptr = (x64_function_t)fn_symbol->impl_value;
     XEASSERTNOTNULL(fn_ptr);
   }
-
+  xe_mutex_unlock(jit_lock_);
   return fn_ptr;
 }
 
diff --git a/src/xenia/cpu/x64/x64_jit.h b/src/xenia/cpu/x64/x64_jit.h
index 09bede44b..739f36e20 100644
--- a/src/xenia/cpu/x64/x64_jit.h
+++ b/src/xenia/cpu/x64/x64_jit.h
@@ -43,6 +43,7 @@ protected:
   int CheckProcessor();
   void DumpCPUInfo();
 
+  xe_mutex_t*     jit_lock_;
   X64Emitter*     emitter_;
 };