imp linux get_max_process_size. addresses #1387

git-svn-id: file:///svn/toku/tokudb@8745 c7de825b-a66e-492c-adef-691d508d4ae1

linux/linux.c

@@ -169,3 +169,19 @@ toku_os_is_absolute_name(const char* path) {
     return path[0] == '/';
 }
 
+int
+toku_os_get_max_process_data_size(uint64_t *maxdata) {
+    int r;
+    struct rlimit rlimit;
+
+    r = getrlimit(RLIMIT_DATA, &rlimit);
+    if (r == 0) {
+        *maxdata = rlimit.rlim_max;
+        // for 32 bit processes, we assume that 1/2 of the address space is
+        // used for mapping the kernel.
+        if (sizeof (rlimit.rlim_max) == 4 && rlimit.rlim_max == 0xffffffff)
+            *maxdata /= 2;
+    } else
+        r = errno;
+    return r;
+}

linux/tests/Makefile

-CPPFLAGS = -I../../include -I..
+CPPFLAGS = -I../../toku_include -I..
 CFLAGS = -Wall -Werror -g -O0
 LDFLAGS = ../libtokuportability.a -lpthread
 SRCS = $(wildcard test-*.c)

linux/tests/test-max-data.c

+#define _GNU_SOURCE
+#include <stdio.h>
+#include <stdint.h>
+#include <inttypes.h>
+#include <unistd.h>
+#include <assert.h>
+#include "toku_os.h"
+
+int main(void) {
+    uint64_t maxdata;
+    int r = toku_os_get_max_process_data_size(&maxdata);
+    assert(r == 0);
+    printf("maxdata=%"PRIu64"\n", maxdata);
+    return 0;
+}

toku_include/toku_os.h

@@ -19,10 +19,10 @@ int toku_os_get_number_processors(void);
 // Returns: the number of active processors in the system
 int toku_os_get_number_active_processors(void);
 
-// Returns: the system page size
+// Returns: the system page size (in bytes)
 int toku_os_get_pagesize(void);
 
-// Returns: the total number of bytes of physical memory
+// Returns: the size of physical memory (in bytes)
 uint64_t toku_os_get_phys_memory_size(void);
 
 // Returns: 0 on success
@@ -51,6 +51,11 @@ int toku_os_get_rss(int64_t *rss);
 // Get the maximum in memory size (in bytes) of the current process
 int toku_os_get_max_rss(int64_t *maxrss);
 
+// Get the maximum size of the process data size (in bytes)
+// Success: returns 0 and sets *maxdata to the data size
+// Fail: returns an error number
+int toku_os_get_max_process_data_size(uint64_t *maxdata);
+
 int toku_os_initialize_settings(int verbosity)  __attribute__((__visibility__("default")));
 
 //