Refactor CPU mutex code

src/cpu/exception.c

@@ -42,7 +42,7 @@ void exception_trigger(rv32_cpu_t* cpu, uint32_t scause, uint32_t tval)
 	cpu->pc = cpu->csr[CSR_STVEC] & 0xFFFFFFFC;
 
     // Unlock cpu mutex, cpu_loop will lock it just after
-	pthread_mutex_unlock(&cpu0_mutex);
+	pthread_mutex_unlock(&cpu->mutex);
 
     // cpu loop (attribute noreturn should erase previous stack)
 	cpu_loop(cpu);

src/cpu/interrupt.c

@@ -33,7 +33,7 @@ void interrupt_trigger(rv32_cpu_t* cpu, uint32_t scause)
 	// but we know it is not in the middle of an instruction
 	// (we got the mutex) ; this way we can just change
 	// registers to set interrupt handler execution
-	pthread_mutex_lock(&cpu0_mutex);
+	pthread_mutex_lock(&cpu->mutex);
 
 	// Set xCAUSE with interrupt bit set
 	cpu->csr[CSR_SCAUSE] = 0x80000000 | scause;
@@ -67,7 +67,7 @@ void interrupt_trigger(rv32_cpu_t* cpu, uint32_t scause)
 			break;
 	}
 
-	pthread_mutex_unlock(&cpu0_mutex);
+	pthread_mutex_unlock(&cpu->mutex);
 }
 
 void interrupt_timer_thread()

src/cpu/rv32cpu.c

@@ -11,7 +11,6 @@
 #include <stdio.h>
 
 rv32_cpu_t* cpu0;
-pthread_mutex_t cpu0_mutex;
 
 typedef union RAW_INSTRUCTION
 {
@@ -43,7 +42,7 @@ static void cpu_print_instruction(instruction_t* instruction);
 void cpu_init()
 {
 	cpu0 = calloc(1, sizeof(rv32_cpu_t));
-	pthread_mutex_init(&cpu0_mutex, 0);
+	pthread_mutex_init(&cpu0->mutex, 0);
 	pthread_cond_init(&cpu0->sim_condition, 0);
 	cpu0->regs.zero = 0;
 	cpu0->privilege_mode = MACHINE;
@@ -716,14 +715,14 @@ __attribute__((noreturn)) void cpu_loop(rv32_cpu_t* cpu)
 	while(1)
 	{
 		// Aquire CPU mutex
-		pthread_mutex_lock(&cpu0_mutex);
+		pthread_mutex_lock(&cpu->mutex);
 
 		// No simulation ticks left : wakeup people waiting on sim end
 		if(!cpu->sim_ticks_left)
-			pthread_cond_signal(&cpu0->sim_condition);
+			pthread_cond_signal(&cpu->sim_condition);
 		// Then, wait for simulation state to change until we get more ticks to simulate
 		while(!cpu->sim_ticks_left)
-			pthread_cond_wait(&cpu0->sim_condition, &cpu0_mutex);
+			pthread_cond_wait(&cpu->sim_condition, &cpu->mutex);
 
 		// Fetch
 		raw_instruction_t raw_instruction;
@@ -758,7 +757,7 @@ __attribute__((noreturn)) void cpu_loop(rv32_cpu_t* cpu)
 			cpu->sim_ticks_left--;
 
 		// Let go of cpu mutex
-		pthread_mutex_unlock(&cpu0_mutex);
+		pthread_mutex_unlock(&cpu->mutex);
 	}
 }
 

src/cpu/rv32cpu.h

@@ -205,13 +205,14 @@ typedef struct RV32_CPU
 	ssize_t sim_ticks_left; // -1 : simulate forever
 	size_t sim_ticks_done;
 	pthread_cond_t sim_condition;
+
+	pthread_mutex_t mutex;
 } rv32_cpu_t;
 
 uint32_t csr_read(struct RV32_CPU* cpu, uint32_t csr);
 void csr_write(struct RV32_CPU* cpu, uint32_t csr, uint32_t value);
 
 extern rv32_cpu_t* cpu0;
-extern pthread_mutex_t cpu0_mutex;
 void cpu_init();
 __attribute__((noreturn)) void cpu_loop(rv32_cpu_t* cpu);
 

src/gdbstub/gdbstub.c

@@ -203,7 +203,7 @@ void gdbstub_thread_gdb()
 			char resp[32 * 8 + 8 + 1] = {0};
 
 			// Obtain CPU0 mutex
-			pthread_mutex_lock(&cpu0_mutex);
+			pthread_mutex_lock(&cpu0->mutex);
 
 			// All general purpose registers in host byte order as chars
 			for(size_t i = 0; i < 32; i++)
@@ -217,7 +217,7 @@ void gdbstub_thread_gdb()
 			snprintf(resp + 32 * 8, 9, "%08x", pc);
 
 			// Let go of CPU0 mutex
-			pthread_mutex_unlock(&cpu0_mutex);
+			pthread_mutex_unlock(&cpu0->mutex);
 
 			// Final packet size, send packet
 			size_t size = 32 * 8 + 8;
@@ -228,7 +228,7 @@ void gdbstub_thread_gdb()
 			// G : write all registers -> read and set all registers
 
 			// Obtain CPU0 mutex
-			pthread_mutex_lock(&cpu0_mutex);
+			pthread_mutex_lock(&cpu0->mutex);
 
 			// All general purpose registers in host byte order as chars
 			for(size_t i = 1; i < 32; i++)
@@ -247,7 +247,7 @@ void gdbstub_thread_gdb()
 			cpu0->pc = pc;
 
 			// Let go of CPU0 Mutex
-			pthread_mutex_unlock(&cpu0_mutex);
+			pthread_mutex_unlock(&cpu0->mutex);
 
 			gdbstub_send_packet("OK", 2);
 		}
@@ -296,9 +296,9 @@ void gdbstub_thread_gdb()
 			send(gdb_socket, "+", 1, 0);
 
 			// Continue simulation, for 1 tick
-			pthread_mutex_lock(&cpu0_mutex);
+			pthread_mutex_lock(&cpu0->mutex);
 			cpu0->sim_ticks_left = 1;
-			pthread_mutex_unlock(&cpu0_mutex);
+			pthread_mutex_unlock(&cpu0->mutex);
 			pthread_cond_signal(&cpu0->sim_condition);
 		}
 		else if(packet[0] == 'c')
@@ -309,9 +309,9 @@ void gdbstub_thread_gdb()
 			send(gdb_socket, "+", 1, 0);
 
 			// Continue simulation
-			pthread_mutex_lock(&cpu0_mutex);
+			pthread_mutex_lock(&cpu0->mutex);
 			cpu0->sim_ticks_left = -1;
-			pthread_mutex_unlock(&cpu0_mutex);
+			pthread_mutex_unlock(&cpu0->mutex);
 			pthread_cond_signal(&cpu0->sim_condition);
 		}
 		else gdbstub_send_unsupported();
@@ -322,8 +322,8 @@ void gdbstub_cpu_watcher_thread()
 {
 	while(1)
 	{
-		pthread_mutex_lock(&cpu0_mutex);
-		pthread_cond_wait(&cpu0->sim_condition, &cpu0_mutex);
+		pthread_mutex_lock(&cpu0->mutex);
+		pthread_cond_wait(&cpu0->sim_condition, &cpu0->mutex);
 		if(!cpu0->sim_ticks_left && cpu0->sim_ticks_done > 0)
 		{
 			// Send back halt reason
@@ -331,7 +331,7 @@ void gdbstub_cpu_watcher_thread()
 			char* resp = "S05";
 			gdbstub_send_packet(resp, 3);
 		}
-		pthread_mutex_unlock(&cpu0_mutex);
+		pthread_mutex_unlock(&cpu0->mutex);
 	}
 }
 
@@ -342,7 +342,7 @@ void gdbstub_cpu_watcher_thread()
 static void gdbstub_handle_ctrlc()
 {
 	// Halt the simulation
-	pthread_mutex_lock(&cpu0_mutex);
+	pthread_mutex_lock(&cpu0->mutex);
 	cpu0->sim_ticks_left = 0;
-	pthread_mutex_unlock(&cpu0_mutex);
+	pthread_mutex_unlock(&cpu0->mutex);
 }