mpool: add new base module type "basic"

This commit adds a new mpool base module type: basic. This module can
be used with an opal_free_list_t to allocate space from a
pre-allocated block (such as a shared memory region). The new module
only supports allocation and is not meant for more dynamic use cases
at this time.

Signed-off-by: Nathan Hjelm <hjelmn@lanl.gov>

opal/mca/mpool/base/Makefile.am

@@ -28,7 +28,8 @@ libmca_mpool_la_SOURCES += \
         base/mpool_base_lookup.c \
         base/mpool_base_alloc.c \
 	base/mpool_base_tree.c \
-	base/mpool_base_default.c
+	base/mpool_base_default.c \
+	base/mpool_base_basic.c
 
 dist_opaldata_DATA += \
         base/help-mpool-base.txt

opal/mca/mpool/base/base.h

@@ -53,6 +53,8 @@ OPAL_DECLSPEC OBJ_CLASS_DECLARATION(mca_mpool_base_selected_module_t);
 OPAL_DECLSPEC mca_mpool_base_component_t* mca_mpool_base_component_lookup(const char* name);
 OPAL_DECLSPEC mca_mpool_base_module_t* mca_mpool_base_module_lookup(const char* name);
 
+OPAL_DECLSPEC mca_mpool_base_module_t *mca_mpool_basic_create (void *base, size_t size, unsigned min_align);
+
 /*
  * Globals
  */

opal/mca/mpool/base/mpool_base_basic.c

@@ -0,0 +1,109 @@
+/* -*- Mode: C; c-basic-offset:4 ; indent-tabs-mode:nil -*- */
+/*
+ * Copyright (c) 2015      Los Alamos National Security, LLC. All rights
+ *                         reserved.
+ * Copyright (c) 2016      Intel, Inc. All rights reserved.
+ * Copyrigth (c) 2018      Triad National Security, LLC. All rights
+ *                         reserved.
+ * $COPYRIGHT$
+ *
+ * Additional copyrights may follow
+ *
+ * $HEADER$
+ */
+
+#include "opal_config.h"
+#include "opal/align.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif  /* HAVE_UNISTD_H */
+
+#include "opal/mca/mca.h"
+#include "opal/mca/base/base.h"
+#include "opal/mca/mpool/base/base.h"
+#include "opal/constants.h"
+#include "opal/util/sys_limits.h"
+
+struct mca_mpool_base_basic_module_t {
+    mca_mpool_base_module_t super;
+    opal_mutex_t lock;
+    uintptr_t ptr;
+    size_t size;
+    size_t avail;
+    unsigned min_align;
+};
+typedef struct mca_mpool_base_basic_module_t mca_mpool_base_basic_module_t;
+
+static void *mca_mpool_base_basic_alloc (mca_mpool_base_module_t *mpool, size_t size,
+                                         size_t align, uint32_t flags)
+{
+    mca_mpool_base_basic_module_t *basic_module = (mca_mpool_base_basic_module_t *) mpool;
+    uintptr_t next_ptr;
+    void *ptr;
+
+    opal_mutex_lock (&basic_module->lock);
+
+    align = align > basic_module->min_align ? align : basic_module->min_align;
+
+    next_ptr = OPAL_ALIGN(basic_module->ptr, align, uintptr_t);
+
+    size = OPAL_ALIGN(size, 8, size_t) + next_ptr - basic_module->ptr;
+
+    if (size > basic_module->avail) {
+        opal_mutex_unlock (&basic_module->lock);
+        return NULL;
+    }
+
+    ptr = (void *) next_ptr;
+    basic_module->avail -= size;
+    basic_module->ptr += size;
+
+    opal_mutex_unlock (&basic_module->lock);
+    return ptr;
+}
+
+/**
+  * free function
+  */
+static void mca_mpool_base_basic_free (mca_mpool_base_module_t *mpool, void *addr)
+{
+    /* nothing to do for now */
+}
+
+static void mca_mpool_base_basic_finalize (struct mca_mpool_base_module_t *mpool)
+{
+    mca_mpool_base_basic_module_t *basic_module = (mca_mpool_base_basic_module_t *) mpool;
+
+    OBJ_DESTRUCT(&basic_module->lock);
+    free (mpool);
+}
+
+static mca_mpool_base_module_t mca_mpool_basic_template = {
+    .mpool_alloc = mca_mpool_base_basic_alloc,
+    .mpool_free = mca_mpool_base_basic_free,
+    .mpool_finalize = mca_mpool_base_basic_finalize,
+    .flags = MCA_MPOOL_FLAGS_MPI_ALLOC_MEM,
+};
+
+mca_mpool_base_module_t *mca_mpool_basic_create (void *base, size_t size, unsigned min_align)
+{
+    mca_mpool_base_basic_module_t *basic_module = calloc (1, sizeof (*basic_module));
+
+    if (OPAL_UNLIKELY(NULL == basic_module)) {
+        return NULL;
+    }
+
+    memcpy (&basic_module->super, &mca_mpool_basic_template, sizeof (mca_mpool_basic_template));
+
+    OBJ_CONSTRUCT(&basic_module->lock, opal_mutex_t);
+
+    basic_module->super.mpool_base = base;
+    basic_module->ptr = (uintptr_t) base;
+    basic_module->size = basic_module->avail = size;
+    basic_module->min_align = min_align;
+
+    return &basic_module->super;
+}