simMutex

runtime/vm/simulator_arm64.h

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 // Declares a Simulator for ARM64 instructions if we are not generating a native
 // ARM64 binary. This Simulator allows us to run and debug ARM64 code generation
 // on regular desktop machines.
 // Dart calls into generated code by "calling" the InvokeDartCode stub,
 // which will start execution in the Simulator or forwards to the real entry
 // on a ARM64 HW platform.
 
 #ifndef VM_SIMULATOR_ARM64_H_
 #define VM_SIMULATOR_ARM64_H_
 
 #ifndef VM_SIMULATOR_H_
 #error Do not include simulator_arm64.h directly; use simulator.h.
 #endif
 
 #include "vm/constants_arm64.h"
 
 namespace dart {
 
 class Isolate;
 class Mutex;
 class RawObject;
 class SimulatorSetjmpBuffer;
+class Thread;
 
 typedef struct {
   union {
     int64_t i64[2];
     int32_t i32[4];
   } bits;
 } simd_value_t;
 
 class Simulator {
  public:
@@ skipping 141 matching lines @@
   inline int16_t ReadH(uword addr, Instr* instr);
   inline void WriteH(uword addr, uint16_t value, Instr* instr);
 
   inline uint32_t ReadWU(uword addr, Instr* instr);
   inline int32_t ReadW(uword addr, Instr* instr);
   inline void WriteW(uword addr, uint32_t value, Instr* instr);
 
   inline intptr_t ReadX(uword addr, Instr* instr);
   inline void WriteX(uword addr, intptr_t value, Instr* instr);
 
-  // In Dart, there is at most one thread per isolate.
-  // We keep track of 16 exclusive access address tags across all isolates.
+  // We keep track of 16 exclusive access address tags across all threads.
   // Since we cannot simulate a native context switch, which clears
   // the exclusive access state of the local monitor (using the CLREX
-  // instruction), we associate the isolate requesting exclusive access to the
-  // address tag. Multiple isolates requesting exclusive access (using the LDREX
+  // instruction), we associate the thread requesting exclusive access to the
+  // address tag. Multiple threads requesting exclusive access (using the LDREX
   // instruction) to the same address will result in multiple address tags being
-  // created for the same address, one per isolate.
-  // At any given time, each isolate is associated to at most one address tag.
+  // created for the same address, one per thread.
+  // At any given time, each thread is associated to at most one address tag.
   static Mutex* exclusive_access_lock_;
   static const int kNumAddressTags = 16;
   static struct AddressTag {
-    Isolate* isolate;
+    Thread* thread;
     uword addr;
   } exclusive_access_state_[kNumAddressTags];
   static int next_address_tag_;
 
   // Synchronization primitives support.
   void ClearExclusive();
   intptr_t ReadExclusiveW(uword addr, Instr* instr);
   intptr_t WriteExclusiveW(uword addr, intptr_t value, Instr* instr);
 
-  // Set access to given address to 'exclusive state' for current isolate.
+  // Set access to given address to 'exclusive state' for current thread.
   static void SetExclusiveAccess(uword addr);
 
-  // Returns true if the current isolate has exclusive access to given address,
+  // Returns true if the current thread has exclusive access to given address,
   // returns false otherwise. In either case, set access to given address to
-  // 'open state' for all isolates.
+  // 'open state' for all threads.
   // If given addr is NULL, set access to 'open state' for current
-  // isolate (CLREX).
+  // thread (CLREX).
   static bool HasExclusiveAccessAndOpen(uword addr);
 
   // Helper functions to set the conditional flags in the architecture state.
   void SetNZFlagsW(int32_t val);
   bool CarryFromW(int32_t left, int32_t right, int32_t carry);
   bool OverflowFromW(int32_t left, int32_t right, int32_t carry);
 
   void SetNZFlagsX(int64_t val);
   bool CarryFromX(int64_t alu_out, int64_t left, int64_t right, bool addition);
   bool OverflowFromX(
@@ skipping 40 matching lines @@
   }
 
   friend class SimulatorDebugger;
   friend class SimulatorSetjmpBuffer;
   DISALLOW_COPY_AND_ASSIGN(Simulator);
 };
 
 }  // namespace dart
 
 #endif  // VM_SIMULATOR_ARM64_H_