add memusage

1 files changed, 191 insertions, 0 deletions

diff --git a/memusage.c b/memusage.c
new file mode 100644
index 0000000..16c166a
--- /dev/null
+++ b/memusage.c
@@ -0,0 +1,191 @@
+/* Utility to print running total of VmPeak and VmSize of a program */
+#define _GNU_SOURCE
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <signal.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define PATH_MAX 2048
+
+int child_pid;
+
+static int main_loop(char *pidstatus)
+{
+	char *line;
+	char *vmsize;
+	char *vmpeak;
+	char *vmrss;
+	char *vmhwm;
+
+	size_t len;
+
+	FILE *f;
+
+	vmsize = NULL;
+	vmpeak = NULL;
+	vmrss = NULL;
+	vmhwm = NULL;
+	line = malloc(128);
+	len = 128;
+
+	f = fopen(pidstatus, "r");
+	if (!f) return 1;
+
+	/* Read memory size data from /proc/pid/status */
+	while (!vmsize || !vmpeak || !vmrss || !vmhwm)
+	{
+		if (getline(&line, &len, f) == -1)
+		{
+			/* Some of the information isn't there, die.
+			   Hopefully we have at least one measure.  */
+			return 1;
+		}
+
+		/* Find VmPeak */
+		if (!strncmp(line, "VmPeak:", 7))
+		{
+			vmpeak = strdup(&line[7]);
+		}
+
+		/* Find VmSize */
+		else if (!strncmp(line, "VmSize:", 7))
+		{
+			vmsize = strdup(&line[7]);
+		}
+
+		/* Find VmRSS */
+		else if (!strncmp(line, "VmRSS:", 6))
+		{
+			vmrss = strdup(&line[7]);
+		}
+
+		/* Find VmHWM */
+		else if (!strncmp(line, "VmHWM:", 6))
+		{
+			vmhwm = strdup(&line[7]);
+		}
+	}
+	free(line);
+
+	fclose(f);
+
+	/* Get rid of " kB\n"*/
+	len = strlen(vmsize);
+	vmsize[len - 4] = 0;
+	len = strlen(vmpeak);
+	vmpeak[len - 4] = 0;
+	len = strlen(vmrss);
+	vmrss[len - 4] = 0;
+	len = strlen(vmhwm);
+	vmhwm[len - 4] = 0;
+
+	/* Output results to stderr */
+	fprintf(stderr, "%s;%s;%s;%s\n", vmsize, vmpeak, vmrss, vmhwm);
+
+	free(vmpeak);
+	free(vmsize);
+	free(vmrss);
+	free(vmhwm);
+
+	/* Success */
+	return 0;
+}
+
+static int usage(char *me)
+{
+	fprintf(stderr, "%s: filename args\n", me);
+	fprintf(stderr, "Run program, and print VmSize, VmPeak, VmRSS and VmHWM (in KiB) to stderr\n");
+
+	return 1;
+}
+
+static int child(int argc, char **argv)
+{
+	char **newargs = malloc(sizeof(char *) * argc);
+	int i;
+
+	/* We can't be certain that argv is NULL-terminated, so do that now */
+	for (i = 0; i < argc - 1; i++)
+	{
+		newargs[i] = argv[i+1];
+	}
+	newargs[argc - 1] = NULL;
+
+	/* Launch the child */
+	execvp(argv[1], newargs);
+
+	return 0;
+}
+
+static void sig_chld(int dummy)
+{
+	int status, child_val;
+	int pid;
+
+	(void) dummy;
+
+	pid = waitpid(-1, &status, WNOHANG);
+	if (pid < 0)
+	{
+		fprintf(stderr, "waitpid failed\n");
+		return;
+	}
+
+	/* Only worry about direct child */
+	if (pid != child_pid) return;
+
+	/* Get child status value */
+	if (WIFEXITED(status))
+	{
+		fprintf(stderr, "# End memusage\n");
+		child_val = WEXITSTATUS(status);
+		exit(child_val);
+	}
+	else if (WIFSIGNALED(status))
+	{
+		fprintf(stderr, "Child terminated by signal %d\n", WTERMSIG(status));
+		exit(1);
+	}
+}
+
+int main(int argc, char **argv)
+{
+	char buf[PATH_MAX];
+
+	struct sigaction act;
+
+	if (argc < 2) return usage(argv[0]);
+
+	act.sa_handler = sig_chld;
+
+	/* We don't want to block any other signals */
+	sigemptyset(&act.sa_mask);
+
+	act.sa_flags = SA_NOCLDSTOP;
+
+	if (sigaction(SIGCHLD, &act, NULL) < 0)
+	{
+		perror("sigaction");
+		return 1;
+	}
+
+	child_pid = fork();
+
+	if (!child_pid) return child(argc, argv);
+
+	snprintf(buf, PATH_MAX, "/proc/%d/status", child_pid);
+
+	fprintf(stderr, "VmSize;VmPeak;VmRSS;VmHWM\n");
+	/* Continual scan of proc */
+	while (!main_loop(buf))
+	{
+		/* Wait for 0.1 sec */
+		usleep(100000);
+	}
+
+	/* This should never be reached we exit when our child exits */
+	return 1;
+}