write pid to ./objs/srs.pid.

 Simple-RTMP-Server
 Simple-RTMP-Server
 ==================
 ==================
 
 
-SRS(SIMPLE RTMP Server) over state-threads created in 2013.
+SRS(SIMPLE RTMP Server) over state-threads created in 2013.10.
 
 
 SRS is a simple, [RTMP](https://github.com/winlinvip/simple-rtmp-server/wiki/DeliveryRTMP)/[HLS](https://github.com/winlinvip/simple-rtmp-server/wiki/DeliveryHLS), 
 SRS is a simple, [RTMP](https://github.com/winlinvip/simple-rtmp-server/wiki/DeliveryRTMP)/[HLS](https://github.com/winlinvip/simple-rtmp-server/wiki/DeliveryHLS), 
 [high-performance](https://github.com/winlinvip/simple-rtmp-server/wiki/Performance), single/multiple(plan) processes, edge(plan)/origin live server, 
 [high-performance](https://github.com/winlinvip/simple-rtmp-server/wiki/Performance), single/multiple(plan) processes, edge(plan)/origin live server, 
@@ -169,6 +169,7 @@ See also: [Performance Test Guide](https://github.com/winlinvip/simple-rtmp-serv
 * nginx v1.5.0: 139524 lines <br/>
 * nginx v1.5.0: 139524 lines <br/>
 
 
 ### History
 ### History
+* v1.0, 2014-03-21, write pid to ./objs/srs.pid.
 * v1.0, 2014-03-20, refine hls code, support pure audio HLS.
 * v1.0, 2014-03-20, refine hls code, support pure audio HLS.
 * v1.0, 2014-03-19, add vn/an for FFMPEG to drop video/audio for radio stream.
 * v1.0, 2014-03-19, add vn/an for FFMPEG to drop video/audio for radio stream.
 * v1.0, 2014-03-19, refine handshake, client support coplex handshake, add utest.
 * v1.0, 2014-03-19, refine handshake, client support coplex handshake, add utest.
@@ -429,7 +430,7 @@ Bandwidth Test Workflow:
 @See: class SrsBandwidth comments.
 @See: class SrsBandwidth comments.
 </pre>
 </pre>
 
 
-Beijing, 2013<br/>
+Beijing, 2013.10<br/>
 Winlin
 Winlin
 
 
 
 

@@ -2,6 +2,12 @@
 
 
 # the listen ports, split by space.
 # the listen ports, split by space.
 listen              1935;
 listen              1935;
+# the pid file
+# to ensure only one process can use a pid file
+# and provides the current running process id, for script, 
+# for example, init.d script to manage the server.
+# default: ./objs/srs.pid
+pid                 ./objs/srs.pid;
 # the default chunk size is 128, max is 65536,
 # the default chunk size is 128, max is 65536,
 # some client does not support chunk size change,
 # some client does not support chunk size change,
 # however, most clients supports it and it can improve 
 # however, most clients supports it and it can improve 

@@ -682,6 +682,7 @@ int SrsConfig::parse_file(const char* filename)
     // TODO: check forward.
     // TODO: check forward.
     // TODO: check ffmpeg.
     // TODO: check ffmpeg.
     // TODO: check http.
     // TODO: check http.
+    // TODO: check pid.
     
     
     return ret;
     return ret;
 }
 }
@@ -1440,6 +1441,17 @@ SrsConfDirective* SrsConfig::get_listen()
     return root->get("listen");
     return root->get("listen");
 }
 }
 
 
+string SrsConfig::get_pid_file()
+{
+    SrsConfDirective* conf = root->get("pid");
+    
+    if (!conf) {
+        return SRS_CONF_DEFAULT_PID_FILE;
+    }
+    
+    return conf->arg0();
+}
+
 int SrsConfig::get_chunk_size(const std::string &vhost)
 int SrsConfig::get_chunk_size(const std::string &vhost)
 {
 {
     SrsConfDirective* conf = get_vhost(vhost);
     SrsConfDirective* conf = get_vhost(vhost);

@@ -38,6 +38,7 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #define RTMP_VHOST_DEFAULT "__defaultVhost__"
 #define RTMP_VHOST_DEFAULT "__defaultVhost__"
 
 
 #define SRS_LOCALHOST "127.0.0.1"
 #define SRS_LOCALHOST "127.0.0.1"
+#define SRS_CONF_DEFAULT_PID_FILE "./objs/srs.pid"
 
 
 #define SRS_CONF_DEFAULT_HLS_PATH "./objs/nginx/html"
 #define SRS_CONF_DEFAULT_HLS_PATH "./objs/nginx/html"
 #define SRS_CONF_DEFAULT_HLS_FRAGMENT 10
 #define SRS_CONF_DEFAULT_HLS_FRAGMENT 10
@@ -162,6 +163,7 @@ public:
     virtual SrsConfDirective*   get_refer_play(std::string vhost);
     virtual SrsConfDirective*   get_refer_play(std::string vhost);
     virtual SrsConfDirective*   get_refer_publish(std::string vhost);
     virtual SrsConfDirective*   get_refer_publish(std::string vhost);
     virtual SrsConfDirective*   get_listen();
     virtual SrsConfDirective*   get_listen();
+    virtual std::string         get_pid_file();
     virtual int                 get_chunk_size(const std::string& vhost);
     virtual int                 get_chunk_size(const std::string& vhost);
     virtual int                 get_pithy_print_publish();
     virtual int                 get_pithy_print_publish();
     virtual int                 get_pithy_print_forwarder();
     virtual int                 get_pithy_print_forwarder();

@@ -27,6 +27,9 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #include <sys/socket.h>
 #include <sys/socket.h>
 #include <arpa/inet.h>
 #include <arpa/inet.h>
 #include <signal.h>
 #include <signal.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
 
 
 #include <algorithm>
 #include <algorithm>
 
 
@@ -198,6 +201,81 @@ int SrsServer::initialize()
     return ret;
     return ret;
 }
 }
 
 
+int SrsServer::acquire_pid_file()
+{
+    int ret = ERROR_SUCCESS;
+    
+    std::string pid_file = _srs_config->get_pid_file();
+    
+    // -rw-r--r-- 
+    // 644
+    int mode = S_IRUSR | S_IWUSR |  S_IRGRP | S_IROTH;
+    
+    int fd;
+    // open pid file
+    if ((fd = ::open(pid_file.c_str(), O_WRONLY | O_CREAT, mode)) < 0) {
+        ret = ERROR_SYSTEM_PID_ACQUIRE;
+        srs_error("open pid file %s error, ret=%#x", pid_file.c_str(), ret);
+        return ret;
+    }
+    
+    // require write lock
+    flock lock;
+
+    lock.l_type = F_WRLCK; // F_RDLCK, F_WRLCK, F_UNLCK
+    lock.l_start = 0; // type offset, relative to l_whence
+    lock.l_whence = SEEK_SET;  // SEEK_SET, SEEK_CUR, SEEK_END
+    lock.l_len = 0;
+    
+    if (fcntl(fd, F_SETLK, &lock) < 0) {
+        if(errno == EACCES || errno == EAGAIN) {
+            ret = ERROR_SYSTEM_PID_ALREADY_RUNNING;
+            srs_error("srs is already running! ret=%#x", ret);
+            return ret;
+        }
+        
+        ret = ERROR_SYSTEM_PID_LOCK;
+        srs_error("require lock for file %s error! ret=%#x", pid_file.c_str(), ret);
+        return ret;
+    }
+
+    // truncate file
+    if (ftruncate(fd, 0) < 0) {
+        ret = ERROR_SYSTEM_PID_TRUNCATE_FILE;
+        srs_error("truncate pid file %s error! ret=%#x", pid_file.c_str(), ret);
+        return ret;
+    }
+
+    int pid = (int)getpid();
+    
+    // write the pid
+    char buf[512];
+    snprintf(buf, sizeof(buf), "%d", pid);
+    if (write(fd, buf, strlen(buf)) != (int)strlen(buf)) {
+        ret = ERROR_SYSTEM_PID_WRITE_FILE;
+        srs_error("write our pid error! pid=%d file=%s ret=%#x", pid, pid_file.c_str(), ret);
+        return ret;
+    }
+
+    // auto close when fork child process.
+    int val;
+    if ((val = fcntl(fd, F_GETFD, 0)) < 0) {
+        ret = ERROR_SYSTEM_PID_GET_FILE_INFO;
+        srs_error("fnctl F_GETFD error! file=%s ret=%#x", pid_file.c_str(), ret);
+        return ret;
+    }
+    val |= FD_CLOEXEC;
+    if (fcntl(fd, F_SETFD, val) < 0) {
+        ret = ERROR_SYSTEM_PID_SET_FILE_INFO;
+        srs_error("fcntl F_SETFD error! file=%s ret=%#x", pid_file.c_str(), ret);
+        return ret;
+    }
+    
+    srs_trace("write pid=%d to %s success!", pid, pid_file.c_str());
+    
+    return ret;
+}
+
 int SrsServer::listen()
 int SrsServer::listen()
 {
 {
     int ret = ERROR_SUCCESS;
     int ret = ERROR_SUCCESS;

@@ -79,6 +79,7 @@ public:
     virtual ~SrsServer();
     virtual ~SrsServer();
 public:
 public:
     virtual int initialize();
     virtual int initialize();
+    virtual int acquire_pid_file();
     virtual int listen();
     virtual int listen();
     virtual int cycle();
     virtual int cycle();
     virtual void remove(SrsConnection* conn);
     virtual void remove(SrsConnection* conn);

@@ -92,6 +92,13 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #define ERROR_SYSTEM_WAITPID                413
 #define ERROR_SYSTEM_WAITPID                413
 #define ERROR_SYSTEM_BANDWIDTH_KEY          414
 #define ERROR_SYSTEM_BANDWIDTH_KEY          414
 #define ERROR_SYSTEM_BANDWIDTH_DENIED       415
 #define ERROR_SYSTEM_BANDWIDTH_DENIED       415
+#define ERROR_SYSTEM_PID_ACQUIRE            416
+#define ERROR_SYSTEM_PID_ALREADY_RUNNING    417
+#define ERROR_SYSTEM_PID_LOCK               418
+#define ERROR_SYSTEM_PID_TRUNCATE_FILE      419
+#define ERROR_SYSTEM_PID_WRITE_FILE         420
+#define ERROR_SYSTEM_PID_GET_FILE_INFO      421
+#define ERROR_SYSTEM_PID_SET_FILE_INFO      422
 
 
 // see librtmp.
 // see librtmp.
 // failed when open ssl create the dh
 // failed when open ssl create the dh

@@ -91,6 +91,10 @@ int main(int argc, char** argv)
     
     
     // TODO: create log dir in _srs_config->get_log_dir()
     // TODO: create log dir in _srs_config->get_log_dir()
     
     
+    if ((ret = _srs_server->acquire_pid_file()) != ERROR_SUCCESS) {
+        return ret;
+    }
+    
     if ((ret = _srs_server->listen()) != ERROR_SUCCESS) {
     if ((ret = _srs_server->listen()) != ERROR_SUCCESS) {
         return ret;
         return ret;
     }
     }