优化多线程: 线程优先级、线程分离、线程先到先得（实时调度）算法

Makefile

@@ -2,7 +2,7 @@ CROSS_COMPILE ?=
 CC := $(CROSS_COMPILE)gcc
 STRIP := $(CROSS_COMPILE)strip
 CFLAGS = -Wall -g -O3
-LIB = -lssh2 -pthread
+LIB = -lssh2 -pthread -static
 OBJ = tunnel
 
 SSH2_LIB := $(shell pkg-config --static --libs --cflags libssh2)
@@ -12,7 +12,7 @@ all:forward-tunnel reverse-tunnel
 
 forward-tunnel: forward-tunnel.o
 	$(CC) $(CFLAGS) -o forward-tunnel $^ $(SSH2_LIB) $(LIB)
-	$(STRIP) forward-tunnel
+	: $(STRIP) forward-tunnel
 
 reverse-tunnel: reverse-tunnel.o
 	$(CC) $(CFLAGS) -o reverse-tunnel $^ $(SSH2_LIB) $(LIB)

forward-tunnel.c

@@ -218,6 +218,13 @@ shutdown:
 
 }
 
+int nice( int increment)
+{
+    int oldprio = getpriority(PRIO_PROCESS, getpid());
+    printf("%d\n", oldprio);
+    return setpriority(PRIO_PROCESS, getpid(), oldprio + increment);
+}
+
 static char help_info(void)
 {
     static const char name[] = "STunnel";
@@ -346,14 +353,7 @@ int main(int argc, char *argv[], char **env)
     
     fprintf(stderr, "Waiting for TCP connection on %s:%d...\n", inet_ntoa(sin.sin_addr), ntohs(sin.sin_port));
 
-    pthread_t thread_id = 0;
+
-    sigset_t signal_mask;
-    sigemptyset(&signal_mask);
-    sigaddset(&signal_mask, SIGPIPE); // 忽略PIPE信号
-    if (pthread_sigmask(SIG_BLOCK, &signal_mask, NULL) != 0) {
-        printf("block sigpipe error\n");
-    }
-    
     if (daemon_is == 1) {
         if (daemon(1, 1)) {
             perror("daemon");
@@ -361,6 +361,30 @@ int main(int argc, char *argv[], char **env)
         }
     }
 
+    
+    if (-1 == (nice(-20)))          // 进程优先级
+        perror("nice");
+
+    
+    pthread_t thread_id = 0;
+    pthread_attr_t attr;
+    pthread_attr_init(&attr);
+    struct sched_param sched_param;
+    sigset_t signal_mask;
+    
+    sigemptyset(&signal_mask);
+    sigaddset(&signal_mask, SIGPIPE);                               // 忽略PIPE信号
+    if (pthread_sigmask(SIG_BLOCK, &signal_mask, NULL) != 0) {
+        printf("block sigpipe error\n");
+    }
+    pthread_attr_setschedpolicy(&attr, SCHED_FIFO);                 // 先到先得（实时调度）算法.
+    //pthread_attr_getschedparam(&attr, &sched_param);
+    sched_param.sched_priority = 99;
+    pthread_attr_setschedparam(&attr, &sched_param);                // SCHED_FIFO 和 SCHED_RR 策略的静态优先级范围为 1 到 99 ，其余的优先级为 0 政策。 
+    pthread_attr_setscope(&attr, PTHREAD_SCOPE_SYSTEM);             // 系统所有线程之间争夺 CPU 资源.
+    pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);    // 线程执行完函数后，会自行终止并释放占用的资源.
+
+    
     while (1) {
         server_addr_len = sizeof(server_addr);
         forwardsock = accept(listensock, (struct sockaddr *)&sin, &server_addr_len);
@@ -369,11 +393,10 @@ int main(int argc, char *argv[], char **env)
             goto shutdown;
         }
 
-        pthread_create(&thread_id, NULL, &forward_tunnel, (void *)&forwardsock);
+        pthread_create(&thread_id, &attr, &forward_tunnel, (void *)&forwardsock);
 
     }
 
-    pthread_join(thread_id, NULL);
     pthread_exit(NULL);
 
 

forward-tunnel.h

@@ -16,7 +16,11 @@
 #include <signal.h>
 #include <pthread.h>
 
+#include <sys/time.h>
+#include <sys/resource.h>
+
 #define BUILD(fmt...)  do { fprintf(stderr,"%s %s ",__DATE__,__TIME__); fprintf(stderr, ##fmt); } while(0)
+
 #ifndef INADDR_NONE
 #define INADDR_NONE (in_addr_t)-1
 #endif