From 0e8b57b8673614742947ca9501e5d916734594ad Mon Sep 17 00:00:00 2001
From: Rishitha Minol <rishithaminol@gmail.com>
Date: Wed, 21 Mar 2018 14:00:32 +0530
Subject: [PATCH] added a way of remembering number of cliens

---
 cmarketcap.c |  3 +++
 httpd.c      | 46 +++++++++++++++++++++++++++++++++++++++++++++-
 httpd.h      |  3 +++
 timer.c      |  5 ++++-
 4 files changed, 55 insertions(+), 2 deletions(-)

diff --git a/cmarketcap.c b/cmarketcap.c
index 97a3070..9500992 100644
--- a/cmarketcap.c
+++ b/cmarketcap.c
@@ -12,6 +12,7 @@
 #include "timer.h"
 
 pthread_mutex_t shift_column_locker = PTHREAD_MUTEX_INITIALIZER;
+
 struct global_data_handle global_data_handle;
 
 /* @brief coin_history column map */
@@ -106,6 +107,8 @@ int main(int argc, char *argv[])
 
 	pthread_mutex_init(&mysql_db_access, NULL);
 	pthread_mutex_init(&shift_column_locker, NULL);
+	init_httpd_mutexes();
+
 	global_data_handle.httpd_sockfd = 0;
 
 	prog_name = *argv;
diff --git a/httpd.c b/httpd.c
index 890d3bd..14d1289 100644
--- a/httpd.c
+++ b/httpd.c
@@ -19,11 +19,20 @@
 #define CLIENT_MAX  10
 #define MAX_URI_SIZE 2048
 
+pthread_mutex_t number_of_clients_var_locker = PTHREAD_MUTEX_INITIALIZER;
+size_t number_of_clients = 0;
+#define LOCK_NUM_OF_CLIENTS_LOCKER pthread_mutex_lock( \
+	&number_of_clients_var_locker)
+#define UNLOCK_NUM_OF_CLIENTS_LOCKER pthread_mutex_unlock( \
+	&number_of_clients_var_locker)
+
 static void parse_http_header(char *buff, struct myhttp_header *header);
 static void *__cb_read_from_client(void *cb_arg);
 static int check_http_header(struct myhttp_header *header);
 static void send_header(int sockfd, char *code, char *type);
 static void send_json_response(int sockfd, struct myhttp_header *header, MYSQL *db);
+static void inc_number_of_clients(); /*! Increment number of clients */
+static void dec_number_of_clients(); /*! Decrement number of clients */
 
 /** @brief Parse http headers into a data structure.
  *
@@ -354,6 +363,7 @@ static void *__cb_read_from_client(void *cb_arg)
 	pthread_detach(pthread_self());
 
 	DEBUG_MSG("waiting for client to write...\n");
+	inc_number_of_clients();
 	while ((nbytes = read(sockfd, buffer, RD_BUFF_MAX))) {
 		DEBUG_MSG("client wrote %d bytes\n", nbytes);
 		if (nbytes < 0) {
@@ -375,6 +385,7 @@ static void *__cb_read_from_client(void *cb_arg)
 		}
 	}
 
+	dec_number_of_clients();
 	close(sockfd);
 	free(_cb_arg);
 	DEBUG_MSG("Connection closed\n");
@@ -382,6 +393,33 @@ static void *__cb_read_from_client(void *cb_arg)
 	pthread_exit(NULL);
 }
 
+/* @brief returns number of clients at the moment */
+size_t num_of_clients()
+{
+	size_t num;
+	LOCK_NUM_OF_CLIENTS_LOCKER;
+	num = number_of_clients;
+	UNLOCK_NUM_OF_CLIENTS_LOCKER;
+
+	return num;
+}
+
+/* @brief Increas number of clients at the moment */
+static void inc_number_of_clients()
+{
+	LOCK_NUM_OF_CLIENTS_LOCKER;
+	number_of_clients++;
+	UNLOCK_NUM_OF_CLIENTS_LOCKER;
+}
+
+/* @brief Decrease number of clients at the moment */
+static void dec_number_of_clients()
+{
+	LOCK_NUM_OF_CLIENTS_LOCKER;
+	number_of_clients--;
+	UNLOCK_NUM_OF_CLIENTS_LOCKER;
+}
+
 /* @brief needs openned database */
 int __cb_main_thread(MYSQL *db)
 {
@@ -453,4 +491,10 @@ int __cb_main_thread(MYSQL *db)
 
 	//pthread_exit(NULL);
 	return 0;
-} /* main */
+} /* __cb_main_thread */
+
+/* @brief Initialize mutex functionalities of 'httpd.c' section */
+void init_httpd_mutexes()
+{
+	pthread_mutex_init(&number_of_clients_var_locker, NULL);
+}
diff --git a/httpd.h b/httpd.h
index e18059f..e7e21f9 100644
--- a/httpd.h
+++ b/httpd.h
@@ -41,4 +41,7 @@ extern void print_uri_base(struct uri_base *ub);
 extern void free_uri_base(struct uri_base *ub);
 /*! @} */ /* uri_tokenization */
 
+extern size_t num_of_clients();
+extern void init_httpd_mutexes();
+
 #endif
\ No newline at end of file
diff --git a/timer.c b/timer.c
index c931730..e828a78 100644
--- a/timer.c
+++ b/timer.c
@@ -2,6 +2,8 @@
 #include <time.h>
 #include <unistd.h>
 
+#include "httpd.h"
+
 /* @brief Count down timer display
  *
  * @param[in] sec number of seconds to wait
@@ -14,7 +16,8 @@ void wait_countdown_timer(const char *wait_str, int sec)
 	i = sec;
 
 	do {
-		printf("%s%3d(s)", wait_str, i);
+		printf("%s%3d(s) number_of_clients = %lu", wait_str, i,
+			num_of_clients());
 		fflush(stdout);
 		i--;
 		sleep(1);