Customize the stack size of the threads used by pupnp through the new THREAD_STACK_SIZE variable

This patch allows a user to customize the stack size of the threads used by
pupnp through the new THREAD_STACK_SIZE variable. This is especially useful
on embedded systems with limited memory where the user can set THREAD_STACK_SIZE
to ITHREAD_STACK_MIN.

However, as this modification can have side effects, I set 0 as the default
value, so threads will continue to use the default stack size of the system
(which varies greatly as stated in
https://computing.llnl.gov/tutorials/pthreads/).

ChangeLog

@@ -2,6 +2,20 @@
 Version 1.6.7
 *******************************************************************************
 
+2010-09-18 Fabrice Fontaine <fabrice.fontaine(at)orange-ftgroup.com>
+
+	Customize the stack size of the threads used by pupnp through the new THREAD_STACK_SIZE variable
+
+	This patch allows a user to customize the stack size of the threads used by
+	pupnp through the new THREAD_STACK_SIZE variable. This is especially useful
+	on embedded systems with limited memory where the user can set THREAD_STACK_SIZE
+	to ITHREAD_STACK_MIN.
+
+	However, as this modification can have side effects, I set 0 as the default
+	value, so threads will continue to use the default stack size of the system
+	(which varies greatly as stated in
+	https://computing.llnl.gov/tutorials/pthreads/).
+
 2010-09-16 Fabrice Fontaine <fabrice.fontaine(at)orange-ftgroup.com>
 
 	Broken IPv6.

build/inc/config.h

@@ -111,6 +111,24 @@
 /* @} */
 
 
+/*!
+ * \name THREAD_STACK_SIZE
+ *
+ * The {\tt THREAD_STACK_SIZE} constant defines the minimum stack size (in
+ * bytes) allocated for the stack of each thread the thread pool inside the
+ * SDK will create.  These threads are used for both callbacks into
+ * applications built on top of the library and also for making connections
+ * to other control points and devices.  This value will not be used if it
+ * is lower than ITHREAD_STACK_MIN or greater than a system-imposed limit.
+ * This value can be used to lower memory overhead in embedded systems.
+ * The default value is 0 (so it is not used by default).
+ *
+ * @{
+ */
+#define THREAD_STACK_SIZE 0
+/* @} */
+
+
 /*! \name MAX_JOBS_TOTAL
  *
  *  The {\tt MAX_JOBS_TOTAL} constant determines the maximum number of jobs

threadutil/inc/ThreadPool.h

@@ -115,6 +115,10 @@ typedef enum priority {
 #define DEFAULT_MAX_THREADS 10
 
 
+/*! default stack size used by TPAttrInit */
+#define DEFAULT_STACK_SIZE 0
+
+
 /*! default jobs per thread used by TPAttrInit */
 #define DEFAULT_JOBS_PER_THREAD 10
 
@@ -182,6 +186,10 @@ typedef struct THREADPOOLATTR
 	/* maxThreads, ThreadPool will never have more than this number of threads */
 	int maxThreads;
 
+	/* stackSize (in bytes), this is the minimum stack size allocated for each
+	 * thread */
+	size_t stackSize;
+
 	/* maxIdleTime (in milliseconds) this is the maximum time a thread will
 	 * remain idle before dying */
 	int maxIdleTime;
@@ -522,6 +530,20 @@ int TPAttrSetMaxThreads(ThreadPoolAttr *attr, int maxThreads);
 int TPAttrSetMinThreads(ThreadPoolAttr *attr, int minThreads);
 
 
+/****************************************************************************
+ * Function: TPAttrSetStackSize
+ *
+ *  Description:
+ *      Sets the stack size for the thread pool attributes.
+ *  Parameters:
+ *      attr - must be valid thread pool attributes.
+ *      stackSize - value to set
+ *  Returns:
+ *      Always returns 0.
+ *****************************************************************************/
+int TPAttrSetStackSize(ThreadPoolAttr *attr, size_t stackSize);
+
+
 /****************************************************************************
  * Function: TPAttrSetIdleTime
  *

threadutil/inc/ithread.h

@@ -85,7 +85,10 @@ extern "C" {
 
 #define ITHREAD_CANCELED PTHREAD_CANCELED
 
-  
+
+#define ITHREAD_STACK_MIN PTHREAD_STACK_MIN
+
+
 /***************************************************************************
  * Name: ithread_t
  *
@@ -726,6 +729,49 @@ static UPNP_INLINE int ithread_cleanup_thread(void) {
    ***************************************************************************/
 #define ithread_cond_destroy pthread_cond_destroy
 
+  /****************************************************************************
+   * Function: ithread_attr_init
+   *
+   *  Description:
+   *      Initialises thread attribute object.
+   *  Parameters:
+   *      ithread_attr_t *attr (must be valid non NULL pointer to
+   *      ithread_attr_t)
+   *  Returns:
+   *      0 on success. Nonzero on failure.
+   *      See man page for pthread_attr_init
+   ***************************************************************************/
+#define ithread_attr_init pthread_attr_init
+
+  /****************************************************************************
+   * Function: ithread_attr_destroy
+   *
+   *  Description:
+   *      Destroys thread attribute object.
+   *  Parameters:
+   *      ithread_attr_t *attr (must be valid non NULL pointer to
+   *      ithread_attr_t)
+   *  Returns:
+   *      0 on success. Nonzero on failure.
+   *      See man page for pthread_attr_destroy
+   ***************************************************************************/
+#define ithread_attr_destroy pthread_attr_destroy
+
+  /****************************************************************************
+   * Function: ithread_attr_setstacksize
+   *
+   *  Description:
+   *      Sets stack size of a thread attribute object.
+   *  Parameters:
+   *      ithread_attr_t *attr (must be valid non NULL pointer to
+   *      ithread_attr_t)
+   *      size_t stacksize (value of stacksize must be greater than
+   *      ITHREAD_STACK_MIN and lower than system-imposed limits
+   *  Returns:
+   *      0 on success. Nonzero on failure.
+   *      See man page for pthread_attr_setstacksize
+   ***************************************************************************/
+#define ithread_attr_setstacksize pthread_attr_setstacksize
 
   /****************************************************************************
    * Function: ithread_create
@@ -735,7 +781,7 @@ static UPNP_INLINE int ithread_cleanup_thread(void) {
    *      and argument.
    *  Parameters:
    *      ithread_t * thread (must be valid non NULL pointer to pthread_t)
-   *      ithread_attr_t *attr, IGNORED
+   *      ithread_attr_t *attr
    *      void * (start_routine) (void *arg) (start routine)
    *      void * arg - argument.
    *  Returns:

threadutil/src/ThreadPool.c

@@ -609,12 +609,16 @@ static int CreateWorker(ThreadPool *tp)
 	ithread_t temp;
 	int rc = 0;
 	int currentThreads = tp->totalThreads + 1;
+	ithread_attr_t attr;
 
 	if (tp->attr.maxThreads != INFINITE_THREADS &&
 	    currentThreads > tp->attr.maxThreads) {
 		return EMAXTHREADS;
 	}
-	rc = ithread_create(&temp, NULL, WorkerThread, tp);
+	ithread_attr_init(&attr);
+	ithread_attr_setstacksize(&attr, tp->attr.stackSize);
+	rc = ithread_create(&temp, &attr, WorkerThread, tp);
+	ithread_attr_destroy(&attr);
 	if (rc == 0) {
 		rc = ithread_detach(temp);
 		while (tp->totalThreads < currentThreads) {
@@ -1174,6 +1178,7 @@ int TPAttrInit(ThreadPoolAttr *attr)
 	attr->maxIdleTime    = DEFAULT_IDLE_TIME;
 	attr->maxThreads     = DEFAULT_MAX_THREADS;
 	attr->minThreads     = DEFAULT_MIN_THREADS;
+	attr->stackSize      = DEFAULT_STACK_SIZE;
 	attr->schedPolicy    = DEFAULT_POLICY;
 	attr->starvationTime = DEFAULT_STARVATION_TIME;
 	attr->maxJobsTotal   = DEFAULT_MAX_JOBS_TOTAL;
@@ -1298,6 +1303,28 @@ int TPAttrSetMinThreads(ThreadPoolAttr *attr, int minThreads)
 	return 0;
 }
 
+/****************************************************************************
+ * Function: TPAttrSetStackSize
+ *
+ *  Description:
+ *      Sets the stack size for the thread pool attributes.
+ *  Parameters:
+ *      attr - must be valid thread pool attributes.
+ *      stackSize - value to set
+ *  Returns:
+ *      Always returns 0.
+ *****************************************************************************/
+int TPAttrSetStackSize(ThreadPoolAttr *attr, size_t stackSize)
+{
+        if (!attr) {
+                return EINVAL;
+        }
+        attr->stackSize = stackSize;
+
+        return 0;
+}
+
+
 /****************************************************************************
  * Function: TPAttrSetIdleTime
  *

upnp/src/api/upnpapi.c

@@ -282,6 +282,7 @@ static int UpnpInitThreadPools(void)
 	TPAttrInit(&attr);
 	TPAttrSetMaxThreads(&attr, MAX_THREADS);
 	TPAttrSetMinThreads(&attr, MIN_THREADS);
+	TPAttrSetStackSize(&attr, THREAD_STACK_SIZE);
 	TPAttrSetJobsPerThread(&attr, JOBS_PER_THREAD);
 	TPAttrSetIdleTime(&attr, THREAD_IDLE_TIME);
 	TPAttrSetMaxJobsTotal(&attr, MAX_JOBS_TOTAL);

upnp/src/inc/config.h

@@ -111,6 +111,24 @@
 /* @} */
 
 
+/*!
+ * \name THREAD_STACK_SIZE
+ *
+ * The {\tt THREAD_STACK_SIZE} constant defines the minimum stack size (in
+ * bytes) allocated for the stack of each thread the thread pool inside the
+ * SDK will create.  These threads are used for both callbacks into
+ * applications built on top of the library and also for making connections
+ * to other control points and devices.  This value will not be used if it
+ * is lower than ITHREAD_STACK_MIN or greater than a system-imposed limit.
+ * This value can be used to lower memory overhead in embedded systems.
+ * The default value is 0 (so it is not used by default).
+ *
+ * @{
+ */
+#define THREAD_STACK_SIZE 0
+/* @} */
+
+
 /*! \name MAX_JOBS_TOTAL
  *
  *  The {\tt MAX_JOBS_TOTAL} constant determines the maximum number of jobs