made it so that zemaphore is used on mac, semaphore on linux, and other clean up

threads-sema/Makefile

@@ -1,5 +1,11 @@
 CC     := gcc
-CFLAGS := -Wall -Werror -I../include 
+CFLAGS := -Wall -Werror -I../include -pthread
+
+OS     := $(shell uname -s)
+LIBS   := 
+ifeq ($(OS),Linux)
+	LIBS += -pthread
+endif
 
 SRCS   := dining_philosophers_deadlock.c \
 	dining_philosophers_deadlock_print.c \
@@ -9,7 +15,8 @@ SRCS   := dining_philosophers_deadlock.c \
 	binary.c \
 	producer_consumer_works.c \
 	rwlock.c \
-	zemaphore.c
+	zemaphore.c \
+	throttle.c 
 
 OBJS   := ${SRCS:c=o}
 PROGS  := ${SRCS:.c=}
@@ -18,7 +25,7 @@ PROGS  := ${SRCS:.c=}
 all: ${PROGS}
 
 ${PROGS} : % : %.o Makefile
-	${CC} $< -o $@ -pthread
+	${CC} $< -o $@ ${LIBS}
 
 clean:
 	rm -f ${PROGS} ${OBJS}

threads-sema/binary.c

@@ -6,6 +6,12 @@
 #include "common.h"
 #include "common_threads.h"
 
+#ifdef linux
+#include <semaphore.h>
+#elif __APPLE__
+#include "zemaphore.h"
+#endif
+
 sem_t mutex;
 volatile int counter = 0;
 
@@ -26,7 +32,7 @@ int main(int argc, char *argv[]) {
     Pthread_create(&c2, NULL, child, NULL);
     Pthread_join(c1, NULL);
     Pthread_join(c2, NULL);
-    printf("result: %d\n", counter);
+    printf("result: %d (should be 20000000)\n", counter);
     return 0;
 }
     

threads-sema/dining_philosophers_deadlock.c

@@ -5,6 +5,12 @@
 #include "common.h"
 #include "common_threads.h"
 
+#ifdef linux
+#include <semaphore.h>
+#elif __APPLE__
+#include "zemaphore.h"
+#endif
+
 typedef struct {
     int num_loops;
     int thread_id;

threads-sema/dining_philosophers_deadlock_print.c

@@ -5,6 +5,12 @@
 #include "common.h"
 #include "common_threads.h"
 
+#ifdef linux
+#include <semaphore.h>
+#elif __APPLE__
+#include "zemaphore.h"
+#endif
+
 typedef struct {
     int num_loops;
     int thread_id;

threads-sema/dining_philosophers_no_deadlock.c

@@ -5,6 +5,12 @@
 #include "common.h"
 #include "common_threads.h"
 
+#ifdef linux
+#include <semaphore.h>
+#elif __APPLE__
+#include "zemaphore.h"
+#endif
+
 typedef struct {
     int num_loops;
     int thread_id;

threads-sema/dining_philosophers_no_deadlock_print.c

@@ -5,6 +5,12 @@
 #include "common.h"
 #include "common_threads.h"
 
+#ifdef linux
+#include <semaphore.h>
+#elif __APPLE__
+#include "zemaphore.h"
+#endif
+
 typedef struct {
     int num_loops;
     int thread_id;

threads-sema/join.c

@@ -6,10 +6,16 @@
 #include "common.h"
 #include "common_threads.h"
 
+#ifdef linux
+#include <semaphore.h>
+#elif __APPLE__
+#include "zemaphore.h"
+#endif
+
 sem_t s;
 
 void *child(void *arg) {
-    sleep(4);
+    sleep(2);
     printf("child\n");
     Sem_post(&s); // signal here: child is done
     return NULL;

threads-sema/producer_consumer_works.c

@@ -3,11 +3,16 @@
 #include <assert.h>
 #include <pthread.h>
 #include <stdlib.h>
-#include <semaphore.h>
 
 #include "common.h"
 #include "common_threads.h"
 
+#ifdef linux
+#include <semaphore.h>
+#elif __APPLE__
+#include "zemaphore.h"
+#endif
+
 int max;
 int loops;
 int *buffer;

threads-sema/rwlock.c

@@ -1,12 +1,17 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <pthread.h>
-#include <semaphore.h>
 #include <unistd.h>
 
 #include "common.h"
 #include "common_threads.h"
 
+#ifdef linux
+#include <semaphore.h>
+#elif __APPLE__
+#include "zemaphore.h"
+#endif
+
 typedef struct _rwlock_t {
     sem_t writelock;
     sem_t lock;

threads-sema/throttle.c

@@ -0,0 +1,48 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <pthread.h>
+#include <unistd.h>
+
+#include "common.h"
+#include "common_threads.h"
+
+#ifdef linux
+#include <semaphore.h>
+#elif __APPLE__
+#include "zemaphore.h"
+#endif
+
+sem_t s;
+
+void *child(void *arg) {
+    Sem_wait(&s); 
+    printf("child %lld\n", (long long int) arg);
+    sleep(1);
+    Sem_post(&s); 
+    return NULL;
+}
+
+int main(int argc, char *argv[]) {
+    if (argc != 3) {
+	fprintf(stderr, "usage: throttle <num_threads> <sem_value>\n");
+	exit(1);
+    }
+    int num_threads = atoi(argv[1]);
+    int sem_value = atoi(argv[2]);
+    
+    Sem_init(&s, sem_value); 
+
+    printf("parent: begin\n");
+    pthread_t c[num_threads];
+
+    int i;
+    for (i = 0; i < num_threads; i++) 
+	Pthread_create(&c[i], NULL, child, (void *) (long long int)i);
+
+    for (i = 0; i < num_threads; i++) 
+	Pthread_join(c[i], NULL);
+
+    printf("parent: end\n");
+    return 0;
+}
+    

threads-sema/zemaphore.c

@@ -5,34 +5,7 @@
 
 #include "common.h"
 #include "common_threads.h"
-
-typedef struct __Zem_t {
-    int value;
-    pthread_cond_t  cond;
-    pthread_mutex_t lock;
-} Zem_t;
-
-void Zem_init(Zem_t *z, int value) {
-    z->value = value;
-    Cond_init(&z->cond);
-    Mutex_init(&z->lock);
-}
-
-void Zem_wait(Zem_t *z) {
-    Mutex_lock(&z->lock);
-    while (z->value <= 0)
-	Cond_wait(&z->cond, &z->lock);
-    z->value--;
-    Mutex_unlock(&z->lock);
-}
-
-void Zem_post(Zem_t *z) {
-    Mutex_lock(&z->lock);
-    z->value++;
-    Cond_signal(&z->cond);
-    Mutex_unlock(&z->lock);
-}
-
+#include "zemaphore.h"
 
 Zem_t s;
 

threads-sema/zemaphore.h

@@ -0,0 +1,37 @@
+#ifndef __zemaphore_h__
+#define __zemaphore_h__
+
+typedef struct __Zem_t {
+    int value;
+    pthread_cond_t  cond;
+    pthread_mutex_t lock;
+} Zem_t;
+
+void Zem_init(Zem_t *z, int value) {
+    z->value = value;
+    Cond_init(&z->cond);
+    Mutex_init(&z->lock);
+}
+
+void Zem_wait(Zem_t *z) {
+    Mutex_lock(&z->lock);
+    while (z->value <= 0)
+	Cond_wait(&z->cond, &z->lock);
+    z->value--;
+    Mutex_unlock(&z->lock);
+}
+
+void Zem_post(Zem_t *z) {
+    Mutex_lock(&z->lock);
+    z->value++;
+    Cond_signal(&z->cond);
+    Mutex_unlock(&z->lock);
+}
+
+typedef Zem_t sem_t;
+
+#define Sem_wait(s)    Zem_wait(s)
+#define Sem_post(s)    Zem_post(s)
+#define Sem_init(s, v) Zem_init(s, v)
+
+#endif // __zemaphore_h__