apr_thread: Provide apr_threadattr_max_free_set().

When creating a thread, this allows to specify the "max_free" of its pool
allocator (i.e. apr_allocator_max_free_set), so that one can create thread
local subpools and have their memory usage regulated on cleanup/destroy.

One could achieve that already with:
    apr_allocator_max_free_set(apr_thread_pool_get(thread), max_free);
in the thread startup function, but it's more convenient, simpler and race
free to handle that in the thread attribute itself at creation time.



git-svn-id: https://svn.apache.org/repos/asf/apr/apr/trunk@1902715 13f79535-47bb-0310-9956-ffa450edef68

11 files changed, 74 insertions, 50 deletions

diff --git a/include/apr_thread_proc.h b/include/apr_thread_proc.h
index 952c76d2d..07571b6a1 100644
--- a/include/apr_thread_proc.h
+++ b/include/apr_thread_proc.h
@@ -278,6 +278,15 @@ APR_DECLARE(apr_status_t) apr_threadattr_guardsize_set(apr_threadattr_t *attr,
                                                        apr_size_t guardsize);
 
 /**
+ * Set the threshold at which the thread pool allocator should start
+ * giving blocks back to the system.
+ * @param attr The threadattr to affect 
+ * @param on Non-zero if detached threads should be created.
+ */
+APR_DECLARE(apr_status_t) apr_threadattr_max_free_set(apr_threadattr_t *attr, 
+                                                      apr_size_t size);
+
+/**
  * Create a new thread of execution
  * @param new_thread The newly created thread handle.
  * @param attr The threadattr to use to determine how to create the thread
diff --git a/include/arch/beos/apr_arch_threadproc.h b/include/arch/beos/apr_arch_threadproc.h
index 6754681c8..5c67c879e 100644
--- a/include/arch/beos/apr_arch_threadproc.h
+++ b/include/arch/beos/apr_arch_threadproc.h
@@ -53,6 +53,7 @@ struct apr_threadattr_t {
     int32 attr;
     int detached;
     int joinable;
+    apr_size_t max_free;
 };
 
 struct apr_threadkey_t {
diff --git a/include/arch/netware/apr_arch_threadproc.h b/include/arch/netware/apr_arch_threadproc.h
index ce217aaba..d726b34f7 100644
--- a/include/arch/netware/apr_arch_threadproc.h
+++ b/include/arch/netware/apr_arch_threadproc.h
@@ -44,6 +44,7 @@ struct apr_threadattr_t {
     apr_size_t  stack_size;
     apr_int32_t detach;
     char *thread_name;
+    apr_size_t max_free;
 };
 
 struct apr_threadkey_t {
diff --git a/include/arch/os2/apr_arch_threadproc.h b/include/arch/os2/apr_arch_threadproc.h
index c8017adbf..5e6b6a40d 100644
--- a/include/arch/os2/apr_arch_threadproc.h
+++ b/include/arch/os2/apr_arch_threadproc.h
@@ -29,6 +29,7 @@ struct apr_threadattr_t {
     apr_pool_t *pool;
     unsigned long attr;
     apr_size_t stacksize;
+    apr_size_t max_free;
 };
 
 struct apr_thread_t {
diff --git a/include/arch/unix/apr_arch_threadproc.h b/include/arch/unix/apr_arch_threadproc.h
index adeb51c8a..c39aeaa8f 100644
--- a/include/arch/unix/apr_arch_threadproc.h
+++ b/include/arch/unix/apr_arch_threadproc.h
@@ -65,6 +65,7 @@ struct apr_thread_t {
 struct apr_threadattr_t {
     apr_pool_t *pool;
     pthread_attr_t attr;
+    apr_size_t max_free;
 };
 
 struct apr_threadkey_t {
diff --git a/include/arch/win32/apr_arch_threadproc.h b/include/arch/win32/apr_arch_threadproc.h
index 13568256e..23b0172ec 100644
--- a/include/arch/win32/apr_arch_threadproc.h
+++ b/include/arch/win32/apr_arch_threadproc.h
@@ -38,6 +38,7 @@ struct apr_threadattr_t {
     apr_pool_t *pool;
     apr_int32_t detach;
     apr_size_t stacksize;
+    apr_size_t max_free;
 };
 
 struct apr_threadkey_t {
diff --git a/threadproc/beos/thread.c b/threadproc/beos/thread.c
index f14ef076e..0d59a58f7 100644
--- a/threadproc/beos/thread.c
+++ b/threadproc/beos/thread.c
@@ -62,6 +62,13 @@ APR_DECLARE(apr_status_t) apr_threadattr_guardsize_set(apr_threadattr_t *attr,
     return APR_ENOTIMPL;
 }
 
+APR_DECLARE(apr_status_t) apr_threadattr_max_free_set(apr_threadattr_t *attr, 
+                                                      apr_size_t size)
+{
+    attr->max_free = size;
+    return APR_SUCCESS;
+}
+
 #if APR_HAS_THREAD_LOCAL
 static APR_THREAD_LOCAL apr_thread_t *current_thread = NULL;
 #endif
@@ -91,27 +98,22 @@ static apr_status_t alloc_thread(apr_thread_t **new,
 {
     apr_status_t stat;
     apr_abortfunc_t abort_fn = apr_pool_abort_get(pool);
-    apr_allocator_t *allocator;
     apr_pool_t *p;
 
     /* The thread can be detached anytime (from the creation or later with
      * apr_thread_detach), so it needs its own pool and allocator to not
      * depend on a parent pool which could be destroyed before the thread
      * exits. The allocator needs no mutex obviously since the pool should
-     * not be used nor create children pools outside the thread.
+     * not be used nor create children pools outside the thread. Passing
+     * NULL allocator will create one like that.
      */
-    stat = apr_allocator_create(&allocator);
+    stat = apr_pool_create_unmanaged_ex(&p, abort_fn, NULL);
     if (stat != APR_SUCCESS) {
-        if (abort_fn)
-            abort_fn(stat);
         return stat;
     }
-    stat = apr_pool_create_unmanaged_ex(&p, abort_fn, allocator);
-    if (stat != APR_SUCCESS) {
-        apr_allocator_destroy(allocator);
-        return stat;
+    if (attr && attr->max_free) {
+        apr_allocator_max_free_set(apr_pool_allocator_get(p), attr->max_free);
     }
-    apr_allocator_owner_set(allocator, p);
 
     (*new) = (apr_thread_t *)apr_pcalloc(p, sizeof(apr_thread_t));
     if ((*new) == NULL) {
diff --git a/threadproc/netware/thread.c b/threadproc/netware/thread.c
index 24122119a..f91957b2f 100644
--- a/threadproc/netware/thread.c
+++ b/threadproc/netware/thread.c
@@ -64,6 +64,13 @@ APR_DECLARE(apr_status_t) apr_threadattr_guardsize_set(apr_threadattr_t *attr,
     return APR_ENOTIMPL;
 }
 
+APR_DECLARE(apr_status_t) apr_threadattr_max_free_set(apr_threadattr_t *attr, 
+                                                      apr_size_t size)
+{
+    attr->max_free = size;
+    return APR_SUCCESS;
+}
+
 #if APR_HAS_THREAD_LOCAL
 static APR_THREAD_LOCAL apr_thread_t *current_thread = NULL;
 #endif
@@ -93,27 +100,22 @@ static apr_status_t alloc_thread(apr_thread_t **new,
 {
     apr_status_t stat;
     apr_abortfunc_t abort_fn = apr_pool_abort_get(pool);
-    apr_allocator_t *allocator;
     apr_pool_t *p;
 
     /* The thread can be detached anytime (from the creation or later with
      * apr_thread_detach), so it needs its own pool and allocator to not
      * depend on a parent pool which could be destroyed before the thread
      * exits. The allocator needs no mutex obviously since the pool should
-     * not be used nor create children pools outside the thread.
+     * not be used nor create children pools outside the thread. Passing
+     * NULL allocator will create one like that.
      */
-    stat = apr_allocator_create(&allocator);
+    stat = apr_pool_create_unmanaged_ex(&p, abort_fn, NULL);
     if (stat != APR_SUCCESS) {
-        if (abort_fn)
-            abort_fn(stat);
         return stat;
     }
-    stat = apr_pool_create_unmanaged_ex(&p, abort_fn, allocator);
-    if (stat != APR_SUCCESS) {
-        apr_allocator_destroy(allocator);
-        return stat;
+    if (attr && attr->max_free) {
+        apr_allocator_max_free_set(apr_pool_allocator_get(p), attr->max_free);
     }
-    apr_allocator_owner_set(allocator, p);
 
     (*new) = (apr_thread_t *)apr_pcalloc(p, sizeof(apr_thread_t));
     if ((*new) == NULL) {
diff --git a/threadproc/os2/thread.c b/threadproc/os2/thread.c
index e0540188d..2756baf28 100644
--- a/threadproc/os2/thread.c
+++ b/threadproc/os2/thread.c
@@ -68,6 +68,13 @@ APR_DECLARE(apr_status_t) apr_threadattr_guardsize_set(apr_threadattr_t *attr,
     return APR_ENOTIMPL;
 }
 
+APR_DECLARE(apr_status_t) apr_threadattr_max_free_set(apr_threadattr_t *attr, 
+                                                      apr_size_t size)
+{
+    attr->max_free = size;
+    return APR_SUCCESS;
+}
+
 #if APR_HAS_THREAD_LOCAL
 static APR_THREAD_LOCAL apr_thread_t *current_thread = NULL;
 #endif
@@ -95,27 +102,22 @@ static apr_status_t alloc_thread(apr_thread_t **new,
 {
     apr_status_t stat;
     apr_abortfunc_t abort_fn = apr_pool_abort_get(pool);
-    apr_allocator_t *allocator;
     apr_pool_t *p;
 
     /* The thread can be detached anytime (from the creation or later with
      * apr_thread_detach), so it needs its own pool and allocator to not
      * depend on a parent pool which could be destroyed before the thread
      * exits. The allocator needs no mutex obviously since the pool should
-     * not be used nor create children pools outside the thread.
+     * not be used nor create children pools outside the thread. Passing
+     * NULL allocator will create one like that.
      */
-    stat = apr_allocator_create(&allocator);
+    stat = apr_pool_create_unmanaged_ex(&p, abort_fn, NULL);
     if (stat != APR_SUCCESS) {
-        if (abort_fn)
-            abort_fn(stat);
         return stat;
     }
-    stat = apr_pool_create_unmanaged_ex(&p, abort_fn, allocator);
-    if (stat != APR_SUCCESS) {
-        apr_allocator_destroy(allocator);
-        return stat;
+    if (attr && attr->max_free) {
+        apr_allocator_max_free_set(apr_pool_allocator_get(p), attr->max_free);
     }
-    apr_allocator_owner_set(allocator, p);
 
     (*new) = (apr_thread_t *)apr_pcalloc(p, sizeof(apr_thread_t));
     if ((*new) == NULL) {
diff --git a/threadproc/unix/thread.c b/threadproc/unix/thread.c
index 209fe7c86..68b14db3c 100644
--- a/threadproc/unix/thread.c
+++ b/threadproc/unix/thread.c
@@ -136,6 +136,13 @@ APR_DECLARE(apr_status_t) apr_threadattr_guardsize_set(apr_threadattr_t *attr,
 #endif
 }
 
+APR_DECLARE(apr_status_t) apr_threadattr_max_free_set(apr_threadattr_t *attr, 
+                                                      apr_size_t size)
+{
+    attr->max_free = size;
+    return APR_SUCCESS;
+}
+
 #if APR_HAS_THREAD_LOCAL
 static APR_THREAD_LOCAL apr_thread_t *current_thread = NULL;
 #endif
@@ -165,27 +172,22 @@ static apr_status_t alloc_thread(apr_thread_t **new,
 {
     apr_status_t stat;
     apr_abortfunc_t abort_fn = apr_pool_abort_get(pool);
-    apr_allocator_t *allocator;
     apr_pool_t *p;
 
     /* The thread can be detached anytime (from the creation or later with
      * apr_thread_detach), so it needs its own pool and allocator to not
      * depend on a parent pool which could be destroyed before the thread
      * exits. The allocator needs no mutex obviously since the pool should
-     * not be used nor create children pools outside the thread.
+     * not be used nor create children pools outside the thread. Passing
+     * NULL allocator will create one like that.
      */
-    stat = apr_allocator_create(&allocator);
+    stat = apr_pool_create_unmanaged_ex(&p, abort_fn, NULL);
     if (stat != APR_SUCCESS) {
-        if (abort_fn)
-            abort_fn(stat);
         return stat;
     }
-    stat = apr_pool_create_unmanaged_ex(&p, abort_fn, allocator);
-    if (stat != APR_SUCCESS) {
-        apr_allocator_destroy(allocator);
-        return stat;
+    if (attr && attr->max_free) {
+        apr_allocator_max_free_set(apr_pool_allocator_get(p), attr->max_free);
     }
-    apr_allocator_owner_set(allocator, p);
 
     (*new) = (apr_thread_t *)apr_pcalloc(p, sizeof(apr_thread_t));
     if ((*new) == NULL) {
diff --git a/threadproc/win32/thread.c b/threadproc/win32/thread.c
index 0b672e698..7ae7ca062 100644
--- a/threadproc/win32/thread.c
+++ b/threadproc/win32/thread.c
@@ -72,6 +72,13 @@ APR_DECLARE(apr_status_t) apr_threadattr_guardsize_set(apr_threadattr_t *attr,
     return APR_ENOTIMPL;
 }
 
+APR_DECLARE(apr_status_t) apr_threadattr_max_free_set(apr_threadattr_t *attr, 
+                                                      apr_size_t size)
+{
+    attr->max_free = size;
+    return APR_SUCCESS;
+}
+
 #if APR_HAS_THREAD_LOCAL
 static APR_THREAD_LOCAL apr_thread_t *current_thread = NULL;
 #endif
@@ -102,27 +109,22 @@ static apr_status_t alloc_thread(apr_thread_t **new,
 {
     apr_status_t stat;
     apr_abortfunc_t abort_fn = apr_pool_abort_get(pool);
-    apr_allocator_t *allocator;
     apr_pool_t *p;
 
     /* The thread can be detached anytime (from the creation or later with
      * apr_thread_detach), so it needs its own pool and allocator to not
      * depend on a parent pool which could be destroyed before the thread
      * exits. The allocator needs no mutex obviously since the pool should
-     * not be used nor create children pools outside the thread.
+     * not be used nor create children pools outside the thread. Passing
+     * NULL allocator will create one like that.
      */
-    stat = apr_allocator_create(&allocator);
+    stat = apr_pool_create_unmanaged_ex(&p, abort_fn, NULL);
     if (stat != APR_SUCCESS) {
-        if (abort_fn)
-            abort_fn(stat);
         return stat;
     }
-    stat = apr_pool_create_unmanaged_ex(&p, abort_fn, allocator);
-    if (stat != APR_SUCCESS) {
-        apr_allocator_destroy(allocator);
-        return stat;
+    if (attr && attr->max_free) {
+        apr_allocator_max_free_set(apr_pool_allocator_get(p), attr->max_free);
     }
-    apr_allocator_owner_set(allocator, p);
 
     (*new) = (apr_thread_t *)apr_pcalloc(p, sizeof(apr_thread_t));
     if ((*new) == NULL) {